add idl4k kernel firmware version 1.13.0.105

kernel/drivers/spi/Kconfig

@@ -0,0 +1,292 @@
+#
+# SPI driver configuration
+#
+# NOTE:  the reason this doesn't show SPI slave support is mostly that
+# nobody's needed a slave side API yet.  The master-role API is not
+# fully appropriate there, so it'd need some thought to do well.
+#
+menuconfig SPI
+	bool "SPI support"
+	depends on HAS_IOMEM
+	help
+	  The "Serial Peripheral Interface" is a low level synchronous
+	  protocol.  Chips that support SPI can have data transfer rates
+	  up to several tens of Mbit/sec.  Chips are addressed with a
+	  controller and a chipselect.  Most SPI slaves don't support
+	  dynamic device discovery; some are even write-only or read-only.
+
+	  SPI is widely used by microcontrollers to talk with sensors,
+	  eeprom and flash memory, codecs and various other controller
+	  chips, analog to digital (and d-to-a) converters, and more.
+	  MMC and SD cards can be accessed using SPI protocol; and for
+	  DataFlash cards used in MMC sockets, SPI must always be used.
+
+	  SPI is one of a family of similar protocols using a four wire
+	  interface (select, clock, data in, data out) including Microwire
+	  (half duplex), SSP, SSI, and PSP.  This driver framework should
+	  work with most such devices and controllers.
+
+if SPI
+
+config SPI_DEBUG
+	boolean "Debug support for SPI drivers"
+	depends on DEBUG_KERNEL
+	help
+	  Say "yes" to enable debug messaging (like dev_dbg and pr_debug),
+	  sysfs, and debugfs support in SPI controller and protocol drivers.
+
+#
+# MASTER side ... talking to discrete SPI slave chips including microcontrollers
+#
+
+config SPI_MASTER
+#	boolean "SPI Master Support"
+	boolean
+	default SPI
+	help
+	  If your system has an master-capable SPI controller (which
+	  provides the clock and chipselect), you can enable that
+	  controller and the protocol drivers for the SPI slave chips
+	  that are connected.
+
+if SPI_MASTER
+
+comment "SPI Master Controller Drivers"
+
+config SPI_ATMEL
+	tristate "Atmel SPI Controller"
+	depends on (ARCH_AT91 || AVR32)
+	help
+	  This selects a driver for the Atmel SPI Controller, present on
+	  many AT32 (AVR32) and AT91 (ARM) chips.
+
+config SPI_BFIN
+	tristate "SPI controller driver for ADI Blackfin5xx"
+	depends on BLACKFIN
+	help
+	  This is the SPI controller master driver for Blackfin 5xx processor.
+
+config SPI_AU1550
+	tristate "Au1550/Au12x0 SPI Controller"
+	depends on (SOC_AU1550 || SOC_AU1200) && EXPERIMENTAL
+	select SPI_BITBANG
+	help
+	  If you say yes to this option, support will be included for the
+	  Au1550 SPI controller (may also work with Au1200,Au1210,Au1250).
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called au1550_spi.
+
+config SPI_BITBANG
+	tristate "Utilities for Bitbanging SPI masters"
+	help
+	  With a few GPIO pins, your system can bitbang the SPI protocol.
+	  Select this to get SPI support through I/O pins (GPIO, parallel
+	  port, etc).  Or, some systems' SPI master controller drivers use
+	  this code to manage the per-word or per-transfer accesses to the
+	  hardware shift registers.
+
+	  This is library code, and is automatically selected by drivers that
+	  need it.  You only need to select this explicitly to support driver
+	  modules that aren't part of this kernel tree.
+
+config SPI_BUTTERFLY
+	tristate "Parallel port adapter for AVR Butterfly (DEVELOPMENT)"
+	depends on PARPORT
+	select SPI_BITBANG
+	help
+	  This uses a custom parallel port cable to connect to an AVR
+	  Butterfly <http://www.atmel.com/products/avr/butterfly>, an
+	  inexpensive battery powered microcontroller evaluation board.
+	  This same cable can be used to flash new firmware.
+
+config SPI_GPIO
+	tristate "GPIO-based bitbanging SPI Master"
+	depends on GENERIC_GPIO
+	select SPI_BITBANG
+	help
+	  This simple GPIO bitbanging SPI master uses the arch-neutral GPIO
+	  interface to manage MOSI, MISO, SCK, and chipselect signals.  SPI
+	  slaves connected to a bus using this driver are configured as usual,
+	  except that the spi_board_info.controller_data holds the GPIO number
+	  for the chipselect used by this controller driver.
+
+	  Note that this driver often won't achieve even 1 Mbit/sec speeds,
+	  making it unusually slow for SPI.  If your platform can inline
+	  GPIO operations, you should be able to leverage that for better
+	  speed with a custom version of this driver; see the source code.
+
+config SPI_IMX
+	tristate "Freescale i.MX SPI controllers"
+	depends on ARCH_MXC
+	select SPI_BITBANG
+	help
+	  This enables using the Freescale i.MX SPI controllers in master
+	  mode.
+
+config SPI_LM70_LLP
+	tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)"
+	depends on PARPORT && EXPERIMENTAL
+	select SPI_BITBANG
+	help
+	  This driver supports the NS LM70 LLP Evaluation Board,
+	  which interfaces to an LM70 temperature sensor using
+	  a parallel port.
+
+config SPI_MPC52xx_PSC
+	tristate "Freescale MPC52xx PSC SPI controller"
+	depends on PPC_MPC52xx && EXPERIMENTAL
+	help
+	  This enables using the Freescale MPC52xx Programmable Serial
+	  Controller in master SPI mode.
+
+config SPI_MPC8xxx
+	tristate "Freescale MPC8xxx SPI controller"
+	depends on FSL_SOC
+	help
+	  This enables using the Freescale MPC8xxx SPI controllers in master
+	  mode.
+
+	  This driver uses a simple set of shift registers for data (opposed
+	  to the CPM based descriptor model).
+
+config SPI_OMAP_UWIRE
+	tristate "OMAP1 MicroWire"
+	depends on ARCH_OMAP1
+	select SPI_BITBANG
+	help
+	  This hooks up to the MicroWire controller on OMAP1 chips.
+
+config SPI_OMAP24XX
+	tristate "McSPI driver for OMAP24xx/OMAP34xx"
+	depends on ARCH_OMAP24XX || ARCH_OMAP34XX
+	help
+	  SPI master controller for OMAP24xx/OMAP34xx Multichannel SPI
+	  (McSPI) modules.
+
+config SPI_ORION
+	tristate "Orion SPI master (EXPERIMENTAL)"
+	depends on PLAT_ORION && EXPERIMENTAL
+	help
+	  This enables using the SPI master controller on the Orion chips.
+
+config SPI_PL022
+	tristate "ARM AMBA PL022 SSP controller (EXPERIMENTAL)"
+	depends on ARM_AMBA && EXPERIMENTAL
+	default y if MACH_U300
+	default y if ARCH_REALVIEW
+	default y if INTEGRATOR_IMPD1
+	default y if ARCH_VERSATILE
+	help
+	  This selects the ARM(R) AMBA(R) PrimeCell PL022 SSP
+	  controller. If you have an embedded system with an AMBA(R)
+	  bus and a PL022 controller, say Y or M here.
+
+config SPI_PPC4xx
+	tristate "PPC4xx SPI Controller"
+	depends on PPC32 && 4xx && SPI_MASTER
+	select SPI_BITBANG
+	help
+	  This selects a driver for the PPC4xx SPI Controller.
+
+config SPI_PXA2XX
+	tristate "PXA2xx SSP SPI master"
+	depends on ARCH_PXA && EXPERIMENTAL
+	select PXA_SSP
+	help
+	  This enables using a PXA2xx SSP port as a SPI master controller.
+	  The driver can be configured to use any SSP port and additional
+	  documentation can be found a Documentation/spi/pxa2xx.
+
+config SPI_S3C24XX
+	tristate "Samsung S3C24XX series SPI"
+	depends on ARCH_S3C2410 && EXPERIMENTAL
+	select SPI_BITBANG
+	help
+	  SPI driver for Samsung S3C24XX series ARM SoCs
+
+config SPI_S3C24XX_GPIO
+	tristate "Samsung S3C24XX series SPI by GPIO"
+	depends on ARCH_S3C2410 && EXPERIMENTAL
+	select SPI_BITBANG
+	help
+	  SPI driver for Samsung S3C24XX series ARM SoCs using
+	  GPIO lines to provide the SPI bus. This can be used where
+	  the inbuilt hardware cannot provide the transfer mode, or
+	  where the board is using non hardware connected pins.
+
+config SPI_SH_SCI
+	tristate "SuperH SCI SPI controller"
+	depends on SUPERH
+	select SPI_BITBANG
+	help
+	  SPI driver for SuperH SCI blocks.
+
+config SPI_STMP3XXX
+	tristate "Freescale STMP37xx/378x SPI/SSP controller"
+	depends on ARCH_STMP3XXX && SPI_MASTER
+	help
+	  SPI driver for Freescale STMP37xx/378x SoC SSP interface
+
+config SPI_STM
+	tristate "STMicroelectronics SPI SSC-based driver"
+	depends on CPU_SUBTYPE_ST40
+	select SPI_BITBANG
+	help
+	  STMicroelectronics SoCs support for SPI.
+	  If you say yes to this option, support will be included for the
+	  SSC driven SPI.
+
+config SPI_TXX9
+	tristate "Toshiba TXx9 SPI controller"
+	depends on GENERIC_GPIO && CPU_TX49XX
+	help
+	  SPI driver for Toshiba TXx9 MIPS SoCs
+
+config SPI_XILINX
+	tristate "Xilinx SPI controller"
+	depends on (XILINX_VIRTEX || MICROBLAZE) && EXPERIMENTAL
+	select SPI_BITBANG
+	help
+	  This exposes the SPI controller IP from the Xilinx EDK.
+
+	  See the "OPB Serial Peripheral Interface (SPI) (v1.00e)"
+	  Product Specification document (DS464) for hardware details.
+
+#
+# Add new SPI master controllers in alphabetical order above this line
+#
+
+#
+# There are lots of SPI device types, with sensors and memory
+# being probably the most widely used ones.
+#
+comment "SPI Protocol Masters"
+
+config SPI_SPIDEV
+	tristate "User mode SPI device driver support"
+	depends on EXPERIMENTAL
+	help
+	  This supports user mode SPI protocol drivers.
+
+	  Note that this application programming interface is EXPERIMENTAL
+	  and hence SUBJECT TO CHANGE WITHOUT NOTICE while it stabilizes.
+
+config SPI_TLE62X0
+	tristate "Infineon TLE62X0 (for power switching)"
+	depends on SYSFS
+	help
+	  SPI driver for Infineon TLE62X0 series line driver chips,
+	  such as the TLE6220, TLE6230 and TLE6240.  This provides a
+	  sysfs interface, with each line presented as a kind of GPIO
+	  exposing both switch control and diagnostic feedback.
+
+#
+# Add new SPI protocol masters in alphabetical order above this line
+#
+
+endif # SPI_MASTER
+
+# (slave support would go here)
+
+endif # SPI

kernel/drivers/spi/Makefile

@@ -0,0 +1,48 @@
+#
+# Makefile for kernel SPI drivers.
+#
+
+ifeq ($(CONFIG_SPI_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
+
+# small core, mostly translating board-specific
+# config declarations into driver model code
+obj-$(CONFIG_SPI_MASTER)		+= spi.o
+
+# SPI master controller drivers (bus)
+obj-$(CONFIG_SPI_ATMEL)			+= atmel_spi.o
+obj-$(CONFIG_SPI_BFIN)			+= spi_bfin5xx.o
+obj-$(CONFIG_SPI_BITBANG)		+= spi_bitbang.o
+obj-$(CONFIG_SPI_AU1550)		+= au1550_spi.o
+obj-$(CONFIG_SPI_BUTTERFLY)		+= spi_butterfly.o
+obj-$(CONFIG_SPI_GPIO)			+= spi_gpio.o
+obj-$(CONFIG_SPI_IMX)			+= spi_imx.o
+obj-$(CONFIG_SPI_LM70_LLP)		+= spi_lm70llp.o
+obj-$(CONFIG_SPI_PXA2XX)		+= pxa2xx_spi.o
+obj-$(CONFIG_SPI_OMAP_UWIRE)		+= omap_uwire.o
+obj-$(CONFIG_SPI_OMAP24XX)		+= omap2_mcspi.o
+obj-$(CONFIG_SPI_ORION)			+= orion_spi.o
+obj-$(CONFIG_SPI_PL022)			+= amba-pl022.o
+obj-$(CONFIG_SPI_MPC52xx_PSC)		+= mpc52xx_psc_spi.o
+obj-$(CONFIG_SPI_MPC8xxx)		+= spi_mpc8xxx.o
+obj-$(CONFIG_SPI_PPC4xx)		+= spi_ppc4xx.o
+obj-$(CONFIG_SPI_S3C24XX_GPIO)		+= spi_s3c24xx_gpio.o
+obj-$(CONFIG_SPI_S3C24XX)		+= spi_s3c24xx.o
+obj-$(CONFIG_SPI_STM)			+= spi_stm.o
+obj-$(CONFIG_SPI_TXX9)			+= spi_txx9.o
+obj-$(CONFIG_SPI_XILINX)		+= xilinx_spi.o
+obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.o
+obj-$(CONFIG_SPI_STMP3XXX)		+= spi_stmp.o
+# 	... add above this line ...
+
+# SPI protocol drivers (device/link on bus)
+obj-$(CONFIG_SPI_SPIDEV)	+= spidev.o
+obj-$(CONFIG_SPI_TLE62X0)	+= tle62x0.o
+# 	... add above this line ...
+
+# SPI slave controller drivers (upstream link)
+# 	... add above this line ...
+
+# SPI slave drivers (protocol for that link)
+# 	... add above this line ...

kernel/drivers/spi/atmel_spi.c

@@ -0,0 +1,923 @@
+/*
+ * Driver for Atmel AT32 and AT91 SPI Controllers
+ *
+ * Copyright (C) 2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+
+#include <asm/io.h>
+#include <mach/board.h>
+#include <mach/gpio.h>
+#include <mach/cpu.h>
+
+#include "atmel_spi.h"
+
+/*
+ * The core SPI transfer engine just talks to a register bank to set up
+ * DMA transfers; transfer queue progress is driven by IRQs.  The clock
+ * framework provides the base clock, subdivided for each spi_device.
+ */
+struct atmel_spi {
+	spinlock_t		lock;
+
+	void __iomem		*regs;
+	int			irq;
+	struct clk		*clk;
+	struct platform_device	*pdev;
+	struct spi_device	*stay;
+
+	u8			stopping;
+	struct list_head	queue;
+	struct spi_transfer	*current_transfer;
+	unsigned long		current_remaining_bytes;
+	struct spi_transfer	*next_transfer;
+	unsigned long		next_remaining_bytes;
+
+	void			*buffer;
+	dma_addr_t		buffer_dma;
+};
+
+/* Controller-specific per-slave state */
+struct atmel_spi_device {
+	unsigned int		npcs_pin;
+	u32			csr;
+};
+
+#define BUFFER_SIZE		PAGE_SIZE
+#define INVALID_DMA_ADDRESS	0xffffffff
+
+/*
+ * Version 2 of the SPI controller has
+ *  - CR.LASTXFER
+ *  - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero)
+ *  - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
+ *  - SPI_CSRx.CSAAT
+ *  - SPI_CSRx.SBCR allows faster clocking
+ *
+ * We can determine the controller version by reading the VERSION
+ * register, but I haven't checked that it exists on all chips, and
+ * this is cheaper anyway.
+ */
+static bool atmel_spi_is_v2(void)
+{
+	return !cpu_is_at91rm9200();
+}
+
+/*
+ * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby
+ * they assume that spi slave device state will not change on deselect, so
+ * that automagic deselection is OK.  ("NPCSx rises if no data is to be
+ * transmitted")  Not so!  Workaround uses nCSx pins as GPIOs; or newer
+ * controllers have CSAAT and friends.
+ *
+ * Since the CSAAT functionality is a bit weird on newer controllers as
+ * well, we use GPIO to control nCSx pins on all controllers, updating
+ * MR.PCS to avoid confusing the controller.  Using GPIOs also lets us
+ * support active-high chipselects despite the controller's belief that
+ * only active-low devices/systems exists.
+ *
+ * However, at91rm9200 has a second erratum whereby nCS0 doesn't work
+ * right when driven with GPIO.  ("Mode Fault does not allow more than one
+ * Master on Chip Select 0.")  No workaround exists for that ... so for
+ * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH,
+ * and (c) will trigger that first erratum in some cases.
+ *
+ * TODO: Test if the atmel_spi_is_v2() branch below works on
+ * AT91RM9200 if we use some other register than CSR0. However, don't
+ * do this unconditionally since AP7000 has an errata where the BITS
+ * field in CSR0 overrides all other CSRs.
+ */
+
+static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
+{
+	struct atmel_spi_device *asd = spi->controller_state;
+	unsigned active = spi->mode & SPI_CS_HIGH;
+	u32 mr;
+
+	if (atmel_spi_is_v2()) {
+		/*
+		 * Always use CSR0. This ensures that the clock
+		 * switches to the correct idle polarity before we
+		 * toggle the CS.
+		 */
+		spi_writel(as, CSR0, asd->csr);
+		spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
+				| SPI_BIT(MSTR));
+		mr = spi_readl(as, MR);
+		gpio_set_value(asd->npcs_pin, active);
+	} else {
+		u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
+		int i;
+		u32 csr;
+
+		/* Make sure clock polarity is correct */
+		for (i = 0; i < spi->master->num_chipselect; i++) {
+			csr = spi_readl(as, CSR0 + 4 * i);
+			if ((csr ^ cpol) & SPI_BIT(CPOL))
+				spi_writel(as, CSR0 + 4 * i,
+						csr ^ SPI_BIT(CPOL));
+		}
+
+		mr = spi_readl(as, MR);
+		mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
+		if (spi->chip_select != 0)
+			gpio_set_value(asd->npcs_pin, active);
+		spi_writel(as, MR, mr);
+	}
+
+	dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
+			asd->npcs_pin, active ? " (high)" : "",
+			mr);
+}
+
+static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
+{
+	struct atmel_spi_device *asd = spi->controller_state;
+	unsigned active = spi->mode & SPI_CS_HIGH;
+	u32 mr;
+
+	/* only deactivate *this* device; sometimes transfers to
+	 * another device may be active when this routine is called.
+	 */
+	mr = spi_readl(as, MR);
+	if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
+		mr = SPI_BFINS(PCS, 0xf, mr);
+		spi_writel(as, MR, mr);
+	}
+
+	dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
+			asd->npcs_pin, active ? " (low)" : "",
+			mr);
+
+	if (atmel_spi_is_v2() || spi->chip_select != 0)
+		gpio_set_value(asd->npcs_pin, !active);
+}
+
+static inline int atmel_spi_xfer_is_last(struct spi_message *msg,
+					struct spi_transfer *xfer)
+{
+	return msg->transfers.prev == &xfer->transfer_list;
+}
+
+static inline int atmel_spi_xfer_can_be_chained(struct spi_transfer *xfer)
+{
+	return xfer->delay_usecs == 0 && !xfer->cs_change;
+}
+
+static void atmel_spi_next_xfer_data(struct spi_master *master,
+				struct spi_transfer *xfer,
+				dma_addr_t *tx_dma,
+				dma_addr_t *rx_dma,
+				u32 *plen)
+{
+	struct atmel_spi	*as = spi_master_get_devdata(master);
+	u32			len = *plen;
+
+	/* use scratch buffer only when rx or tx data is unspecified */
+	if (xfer->rx_buf)
+		*rx_dma = xfer->rx_dma + xfer->len - len;
+	else {
+		*rx_dma = as->buffer_dma;
+		if (len > BUFFER_SIZE)
+			len = BUFFER_SIZE;
+	}
+	if (xfer->tx_buf)
+		*tx_dma = xfer->tx_dma + xfer->len - len;
+	else {
+		*tx_dma = as->buffer_dma;
+		if (len > BUFFER_SIZE)
+			len = BUFFER_SIZE;
+		memset(as->buffer, 0, len);
+		dma_sync_single_for_device(&as->pdev->dev,
+				as->buffer_dma, len, DMA_TO_DEVICE);
+	}
+
+	*plen = len;
+}
+
+/*
+ * Submit next transfer for DMA.
+ * lock is held, spi irq is blocked
+ */
+static void atmel_spi_next_xfer(struct spi_master *master,
+				struct spi_message *msg)
+{
+	struct atmel_spi	*as = spi_master_get_devdata(master);
+	struct spi_transfer	*xfer;
+	u32			len, remaining;
+	u32			ieval;
+	dma_addr_t		tx_dma, rx_dma;
+
+	if (!as->current_transfer)
+		xfer = list_entry(msg->transfers.next,
+				struct spi_transfer, transfer_list);
+	else if (!as->next_transfer)
+		xfer = list_entry(as->current_transfer->transfer_list.next,
+				struct spi_transfer, transfer_list);
+	else
+		xfer = NULL;
+
+	if (xfer) {
+		spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
+
+		len = xfer->len;
+		atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
+		remaining = xfer->len - len;
+
+		spi_writel(as, RPR, rx_dma);
+		spi_writel(as, TPR, tx_dma);
+
+		if (msg->spi->bits_per_word > 8)
+			len >>= 1;
+		spi_writel(as, RCR, len);
+		spi_writel(as, TCR, len);
+
+		dev_dbg(&msg->spi->dev,
+			"  start xfer %p: len %u tx %p/%08x rx %p/%08x\n",
+			xfer, xfer->len, xfer->tx_buf, xfer->tx_dma,
+			xfer->rx_buf, xfer->rx_dma);
+	} else {
+		xfer = as->next_transfer;
+		remaining = as->next_remaining_bytes;
+	}
+
+	as->current_transfer = xfer;
+	as->current_remaining_bytes = remaining;
+
+	if (remaining > 0)
+		len = remaining;
+	else if (!atmel_spi_xfer_is_last(msg, xfer)
+			&& atmel_spi_xfer_can_be_chained(xfer)) {
+		xfer = list_entry(xfer->transfer_list.next,
+				struct spi_transfer, transfer_list);
+		len = xfer->len;
+	} else
+		xfer = NULL;
+
+	as->next_transfer = xfer;
+
+	if (xfer) {
+		u32	total;
+
+		total = len;
+		atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
+		as->next_remaining_bytes = total - len;
+
+		spi_writel(as, RNPR, rx_dma);
+		spi_writel(as, TNPR, tx_dma);
+
+		if (msg->spi->bits_per_word > 8)
+			len >>= 1;
+		spi_writel(as, RNCR, len);
+		spi_writel(as, TNCR, len);
+
+		dev_dbg(&msg->spi->dev,
+			"  next xfer %p: len %u tx %p/%08x rx %p/%08x\n",
+			xfer, xfer->len, xfer->tx_buf, xfer->tx_dma,
+			xfer->rx_buf, xfer->rx_dma);
+		ieval = SPI_BIT(ENDRX) | SPI_BIT(OVRES);
+	} else {
+		spi_writel(as, RNCR, 0);
+		spi_writel(as, TNCR, 0);
+		ieval = SPI_BIT(RXBUFF) | SPI_BIT(ENDRX) | SPI_BIT(OVRES);
+	}
+
+	/* REVISIT: We're waiting for ENDRX before we start the next
+	 * transfer because we need to handle some difficult timing
+	 * issues otherwise. If we wait for ENDTX in one transfer and
+	 * then starts waiting for ENDRX in the next, it's difficult
+	 * to tell the difference between the ENDRX interrupt we're
+	 * actually waiting for and the ENDRX interrupt of the
+	 * previous transfer.
+	 *
+	 * It should be doable, though. Just not now...
+	 */
+	spi_writel(as, IER, ieval);
+	spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN));
+}
+
+static void atmel_spi_next_message(struct spi_master *master)
+{
+	struct atmel_spi	*as = spi_master_get_devdata(master);
+	struct spi_message	*msg;
+	struct spi_device	*spi;
+
+	BUG_ON(as->current_transfer);
+
+	msg = list_entry(as->queue.next, struct spi_message, queue);
+	spi = msg->spi;
+
+	dev_dbg(master->dev.parent, "start message %p for %s\n",
+			msg, dev_name(&spi->dev));
+
+	/* select chip if it's not still active */
+	if (as->stay) {
+		if (as->stay != spi) {
+			cs_deactivate(as, as->stay);
+			cs_activate(as, spi);
+		}
+		as->stay = NULL;
+	} else
+		cs_activate(as, spi);
+
+	atmel_spi_next_xfer(master, msg);
+}
+
+/*
+ * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma:
+ *  - The buffer is either valid for CPU access, else NULL
+ *  - If the buffer is valid, so is its DMA addresss
+ *
+ * This driver manages the dma addresss unless message->is_dma_mapped.
+ */
+static int
+atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer)
+{
+	struct device	*dev = &as->pdev->dev;
+
+	xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS;
+	if (xfer->tx_buf) {
+		xfer->tx_dma = dma_map_single(dev,
+				(void *) xfer->tx_buf, xfer->len,
+				DMA_TO_DEVICE);
+		if (dma_mapping_error(dev, xfer->tx_dma))
+			return -ENOMEM;
+	}
+	if (xfer->rx_buf) {
+		xfer->rx_dma = dma_map_single(dev,
+				xfer->rx_buf, xfer->len,
+				DMA_FROM_DEVICE);
+		if (dma_mapping_error(dev, xfer->rx_dma)) {
+			if (xfer->tx_buf)
+				dma_unmap_single(dev,
+						xfer->tx_dma, xfer->len,
+						DMA_TO_DEVICE);
+			return -ENOMEM;
+		}
+	}
+	return 0;
+}
+
+static void atmel_spi_dma_unmap_xfer(struct spi_master *master,
+				     struct spi_transfer *xfer)
+{
+	if (xfer->tx_dma != INVALID_DMA_ADDRESS)
+		dma_unmap_single(master->dev.parent, xfer->tx_dma,
+				 xfer->len, DMA_TO_DEVICE);
+	if (xfer->rx_dma != INVALID_DMA_ADDRESS)
+		dma_unmap_single(master->dev.parent, xfer->rx_dma,
+				 xfer->len, DMA_FROM_DEVICE);
+}
+
+static void
+atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as,
+		struct spi_message *msg, int status, int stay)
+{
+	if (!stay || status < 0)
+		cs_deactivate(as, msg->spi);
+	else
+		as->stay = msg->spi;
+
+	list_del(&msg->queue);
+	msg->status = status;
+
+	dev_dbg(master->dev.parent,
+		"xfer complete: %u bytes transferred\n",
+		msg->actual_length);
+
+	spin_unlock(&as->lock);
+	msg->complete(msg->context);
+	spin_lock(&as->lock);
+
+	as->current_transfer = NULL;
+	as->next_transfer = NULL;
+
+	/* continue if needed */
+	if (list_empty(&as->queue) || as->stopping)
+		spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
+	else
+		atmel_spi_next_message(master);
+}
+
+static irqreturn_t
+atmel_spi_interrupt(int irq, void *dev_id)
+{
+	struct spi_master	*master = dev_id;
+	struct atmel_spi	*as = spi_master_get_devdata(master);
+	struct spi_message	*msg;
+	struct spi_transfer	*xfer;
+	u32			status, pending, imr;
+	int			ret = IRQ_NONE;
+
+	spin_lock(&as->lock);
+
+	xfer = as->current_transfer;
+	msg = list_entry(as->queue.next, struct spi_message, queue);
+
+	imr = spi_readl(as, IMR);
+	status = spi_readl(as, SR);
+	pending = status & imr;
+
+	if (pending & SPI_BIT(OVRES)) {
+		int timeout;
+
+		ret = IRQ_HANDLED;
+
+		spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX)
+				     | SPI_BIT(OVRES)));
+
+		/*
+		 * When we get an overrun, we disregard the current
+		 * transfer. Data will not be copied back from any
+		 * bounce buffer and msg->actual_len will not be
+		 * updated with the last xfer.
+		 *
+		 * We will also not process any remaning transfers in
+		 * the message.
+		 *
+		 * First, stop the transfer and unmap the DMA buffers.
+		 */
+		spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
+		if (!msg->is_dma_mapped)
+			atmel_spi_dma_unmap_xfer(master, xfer);
+
+		/* REVISIT: udelay in irq is unfriendly */
+		if (xfer->delay_usecs)
+			udelay(xfer->delay_usecs);
+
+		dev_warn(master->dev.parent, "overrun (%u/%u remaining)\n",
+			 spi_readl(as, TCR), spi_readl(as, RCR));
+
+		/*
+		 * Clean up DMA registers and make sure the data
+		 * registers are empty.
+		 */
+		spi_writel(as, RNCR, 0);
+		spi_writel(as, TNCR, 0);
+		spi_writel(as, RCR, 0);
+		spi_writel(as, TCR, 0);
+		for (timeout = 1000; timeout; timeout--)
+			if (spi_readl(as, SR) & SPI_BIT(TXEMPTY))
+				break;
+		if (!timeout)
+			dev_warn(master->dev.parent,
+				 "timeout waiting for TXEMPTY");
+		while (spi_readl(as, SR) & SPI_BIT(RDRF))
+			spi_readl(as, RDR);
+
+		/* Clear any overrun happening while cleaning up */
+		spi_readl(as, SR);
+
+		atmel_spi_msg_done(master, as, msg, -EIO, 0);
+	} else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) {
+		ret = IRQ_HANDLED;
+
+		spi_writel(as, IDR, pending);
+
+		if (as->current_remaining_bytes == 0) {
+			msg->actual_length += xfer->len;
+
+			if (!msg->is_dma_mapped)
+				atmel_spi_dma_unmap_xfer(master, xfer);
+
+			/* REVISIT: udelay in irq is unfriendly */
+			if (xfer->delay_usecs)
+				udelay(xfer->delay_usecs);
+
+			if (atmel_spi_xfer_is_last(msg, xfer)) {
+				/* report completed message */
+				atmel_spi_msg_done(master, as, msg, 0,
+						xfer->cs_change);
+			} else {
+				if (xfer->cs_change) {
+					cs_deactivate(as, msg->spi);
+					udelay(1);
+					cs_activate(as, msg->spi);
+				}
+
+				/*
+				 * Not done yet. Submit the next transfer.
+				 *
+				 * FIXME handle protocol options for xfer
+				 */
+				atmel_spi_next_xfer(master, msg);
+			}
+		} else {
+			/*
+			 * Keep going, we still have data to send in
+			 * the current transfer.
+			 */
+			atmel_spi_next_xfer(master, msg);
+		}
+	}
+
+	spin_unlock(&as->lock);
+
+	return ret;
+}
+
+static int atmel_spi_setup(struct spi_device *spi)
+{
+	struct atmel_spi	*as;
+	struct atmel_spi_device	*asd;
+	u32			scbr, csr;
+	unsigned int		bits = spi->bits_per_word;
+	unsigned long		bus_hz;
+	unsigned int		npcs_pin;
+	int			ret;
+
+	as = spi_master_get_devdata(spi->master);
+
+	if (as->stopping)
+		return -ESHUTDOWN;
+
+	if (spi->chip_select > spi->master->num_chipselect) {
+		dev_dbg(&spi->dev,
+				"setup: invalid chipselect %u (%u defined)\n",
+				spi->chip_select, spi->master->num_chipselect);
+		return -EINVAL;
+	}
+
+	if (bits < 8 || bits > 16) {
+		dev_dbg(&spi->dev,
+				"setup: invalid bits_per_word %u (8 to 16)\n",
+				bits);
+		return -EINVAL;
+	}
+
+	/* see notes above re chipselect */
+	if (!atmel_spi_is_v2()
+			&& spi->chip_select == 0
+			&& (spi->mode & SPI_CS_HIGH)) {
+		dev_dbg(&spi->dev, "setup: can't be active-high\n");
+		return -EINVAL;
+	}
+
+	/* v1 chips start out at half the peripheral bus speed. */
+	bus_hz = clk_get_rate(as->clk);
+	if (!atmel_spi_is_v2())
+		bus_hz /= 2;
+
+	if (spi->max_speed_hz) {
+		/*
+		 * Calculate the lowest divider that satisfies the
+		 * constraint, assuming div32/fdiv/mbz == 0.
+		 */
+		scbr = DIV_ROUND_UP(bus_hz, spi->max_speed_hz);
+
+		/*
+		 * If the resulting divider doesn't fit into the
+		 * register bitfield, we can't satisfy the constraint.
+		 */
+		if (scbr >= (1 << SPI_SCBR_SIZE)) {
+			dev_dbg(&spi->dev,
+				"setup: %d Hz too slow, scbr %u; min %ld Hz\n",
+				spi->max_speed_hz, scbr, bus_hz/255);
+			return -EINVAL;
+		}
+	} else
+		/* speed zero means "as slow as possible" */
+		scbr = 0xff;
+
+	csr = SPI_BF(SCBR, scbr) | SPI_BF(BITS, bits - 8);
+	if (spi->mode & SPI_CPOL)
+		csr |= SPI_BIT(CPOL);
+	if (!(spi->mode & SPI_CPHA))
+		csr |= SPI_BIT(NCPHA);
+
+	/* DLYBS is mostly irrelevant since we manage chipselect using GPIOs.
+	 *
+	 * DLYBCT would add delays between words, slowing down transfers.
+	 * It could potentially be useful to cope with DMA bottlenecks, but
+	 * in those cases it's probably best to just use a lower bitrate.
+	 */
+	csr |= SPI_BF(DLYBS, 0);
+	csr |= SPI_BF(DLYBCT, 0);
+
+	/* chipselect must have been muxed as GPIO (e.g. in board setup) */
+	npcs_pin = (unsigned int)spi->controller_data;
+	asd = spi->controller_state;
+	if (!asd) {
+		asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL);
+		if (!asd)
+			return -ENOMEM;
+
+		ret = gpio_request(npcs_pin, dev_name(&spi->dev));
+		if (ret) {
+			kfree(asd);
+			return ret;
+		}
+
+		asd->npcs_pin = npcs_pin;
+		spi->controller_state = asd;
+		gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH));
+	} else {
+		unsigned long		flags;
+
+		spin_lock_irqsave(&as->lock, flags);
+		if (as->stay == spi)
+			as->stay = NULL;
+		cs_deactivate(as, spi);
+		spin_unlock_irqrestore(&as->lock, flags);
+	}
+
+	asd->csr = csr;
+
+	dev_dbg(&spi->dev,
+		"setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
+		bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
+
+	if (!atmel_spi_is_v2())
+		spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
+
+	return 0;
+}
+
+static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+	struct atmel_spi	*as;
+	struct spi_transfer	*xfer;
+	unsigned long		flags;
+	struct device		*controller = spi->master->dev.parent;
+
+	as = spi_master_get_devdata(spi->master);
+
+	dev_dbg(controller, "new message %p submitted for %s\n",
+			msg, dev_name(&spi->dev));
+
+	if (unlikely(list_empty(&msg->transfers)))
+		return -EINVAL;
+
+	if (as->stopping)
+		return -ESHUTDOWN;
+
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
+			dev_dbg(&spi->dev, "missing rx or tx buf\n");
+			return -EINVAL;
+		}
+
+		/* FIXME implement these protocol options!! */
+		if (xfer->bits_per_word || xfer->speed_hz) {
+			dev_dbg(&spi->dev, "no protocol options yet\n");
+			return -ENOPROTOOPT;
+		}
+
+		/*
+		 * DMA map early, for performance (empties dcache ASAP) and
+		 * better fault reporting.  This is a DMA-only driver.
+		 *
+		 * NOTE that if dma_unmap_single() ever starts to do work on
+		 * platforms supported by this driver, we would need to clean
+		 * up mappings for previously-mapped transfers.
+		 */
+		if (!msg->is_dma_mapped) {
+			if (atmel_spi_dma_map_xfer(as, xfer) < 0)
+				return -ENOMEM;
+		}
+	}
+
+#ifdef VERBOSE
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		dev_dbg(controller,
+			"  xfer %p: len %u tx %p/%08x rx %p/%08x\n",
+			xfer, xfer->len,
+			xfer->tx_buf, xfer->tx_dma,
+			xfer->rx_buf, xfer->rx_dma);
+	}
+#endif
+
+	msg->status = -EINPROGRESS;
+	msg->actual_length = 0;
+
+	spin_lock_irqsave(&as->lock, flags);
+	list_add_tail(&msg->queue, &as->queue);
+	if (!as->current_transfer)
+		atmel_spi_next_message(spi->master);
+	spin_unlock_irqrestore(&as->lock, flags);
+
+	return 0;
+}
+
+static void atmel_spi_cleanup(struct spi_device *spi)
+{
+	struct atmel_spi	*as = spi_master_get_devdata(spi->master);
+	struct atmel_spi_device	*asd = spi->controller_state;
+	unsigned		gpio = (unsigned) spi->controller_data;
+	unsigned long		flags;
+
+	if (!asd)
+		return;
+
+	spin_lock_irqsave(&as->lock, flags);
+	if (as->stay == spi) {
+		as->stay = NULL;
+		cs_deactivate(as, spi);
+	}
+	spin_unlock_irqrestore(&as->lock, flags);
+
+	spi->controller_state = NULL;
+	gpio_free(gpio);
+	kfree(asd);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int __init atmel_spi_probe(struct platform_device *pdev)
+{
+	struct resource		*regs;
+	int			irq;
+	struct clk		*clk;
+	int			ret;
+	struct spi_master	*master;
+	struct atmel_spi	*as;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs)
+		return -ENXIO;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	clk = clk_get(&pdev->dev, "spi_clk");
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	/* setup spi core then atmel-specific driver state */
+	ret = -ENOMEM;
+	master = spi_alloc_master(&pdev->dev, sizeof *as);
+	if (!master)
+		goto out_free;
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
+	master->bus_num = pdev->id;
+	master->num_chipselect = 4;
+	master->setup = atmel_spi_setup;
+	master->transfer = atmel_spi_transfer;
+	master->cleanup = atmel_spi_cleanup;
+	platform_set_drvdata(pdev, master);
+
+	as = spi_master_get_devdata(master);
+
+	/*
+	 * Scratch buffer is used for throwaway rx and tx data.
+	 * It's coherent to minimize dcache pollution.
+	 */
+	as->buffer = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE,
+					&as->buffer_dma, GFP_KERNEL);
+	if (!as->buffer)
+		goto out_free;
+
+	spin_lock_init(&as->lock);
+	INIT_LIST_HEAD(&as->queue);
+	as->pdev = pdev;
+	as->regs = ioremap(regs->start, (regs->end - regs->start) + 1);
+	if (!as->regs)
+		goto out_free_buffer;
+	as->irq = irq;
+	as->clk = clk;
+
+	ret = request_irq(irq, atmel_spi_interrupt, 0,
+			dev_name(&pdev->dev), master);
+	if (ret)
+		goto out_unmap_regs;
+
+	/* Initialize the hardware */
+	clk_enable(clk);
+	spi_writel(as, CR, SPI_BIT(SWRST));
+	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
+	spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
+	spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
+	spi_writel(as, CR, SPI_BIT(SPIEN));
+
+	/* go! */
+	dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n",
+			(unsigned long)regs->start, irq);
+
+	ret = spi_register_master(master);
+	if (ret)
+		goto out_reset_hw;
+
+	return 0;
+
+out_reset_hw:
+	spi_writel(as, CR, SPI_BIT(SWRST));
+	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
+	clk_disable(clk);
+	free_irq(irq, master);
+out_unmap_regs:
+	iounmap(as->regs);
+out_free_buffer:
+	dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
+			as->buffer_dma);
+out_free:
+	clk_put(clk);
+	spi_master_put(master);
+	return ret;
+}
+
+static int __exit atmel_spi_remove(struct platform_device *pdev)
+{
+	struct spi_master	*master = platform_get_drvdata(pdev);
+	struct atmel_spi	*as = spi_master_get_devdata(master);
+	struct spi_message	*msg;
+
+	/* reset the hardware and block queue progress */
+	spin_lock_irq(&as->lock);
+	as->stopping = 1;
+	spi_writel(as, CR, SPI_BIT(SWRST));
+	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
+	spi_readl(as, SR);
+	spin_unlock_irq(&as->lock);
+
+	/* Terminate remaining queued transfers */
+	list_for_each_entry(msg, &as->queue, queue) {
+		/* REVISIT unmapping the dma is a NOP on ARM and AVR32
+		 * but we shouldn't depend on that...
+		 */
+		msg->status = -ESHUTDOWN;
+		msg->complete(msg->context);
+	}
+
+	dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
+			as->buffer_dma);
+
+	clk_disable(as->clk);
+	clk_put(as->clk);
+	free_irq(as->irq, master);
+	iounmap(as->regs);
+
+	spi_unregister_master(master);
+
+	return 0;
+}
+
+#ifdef	CONFIG_PM
+
+static int atmel_spi_suspend(struct platform_device *pdev, pm_message_t mesg)
+{
+	struct spi_master	*master = platform_get_drvdata(pdev);
+	struct atmel_spi	*as = spi_master_get_devdata(master);
+
+	clk_disable(as->clk);
+	return 0;
+}
+
+static int atmel_spi_resume(struct platform_device *pdev)
+{
+	struct spi_master	*master = platform_get_drvdata(pdev);
+	struct atmel_spi	*as = spi_master_get_devdata(master);
+
+	clk_enable(as->clk);
+	return 0;
+}
+
+#else
+#define	atmel_spi_suspend	NULL
+#define	atmel_spi_resume	NULL
+#endif
+
+
+static struct platform_driver atmel_spi_driver = {
+	.driver		= {
+		.name	= "atmel_spi",
+		.owner	= THIS_MODULE,
+	},
+	.suspend	= atmel_spi_suspend,
+	.resume		= atmel_spi_resume,
+	.remove		= __exit_p(atmel_spi_remove),
+};
+
+static int __init atmel_spi_init(void)
+{
+	return platform_driver_probe(&atmel_spi_driver, atmel_spi_probe);
+}
+module_init(atmel_spi_init);
+
+static void __exit atmel_spi_exit(void)
+{
+	platform_driver_unregister(&atmel_spi_driver);
+}
+module_exit(atmel_spi_exit);
+
+MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver");
+MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:atmel_spi");

kernel/drivers/spi/atmel_spi.h

@@ -0,0 +1,167 @@
+/*
+ * Register definitions for Atmel Serial Peripheral Interface (SPI)
+ *
+ * Copyright (C) 2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __ATMEL_SPI_H__
+#define __ATMEL_SPI_H__
+
+/* SPI register offsets */
+#define SPI_CR					0x0000
+#define SPI_MR					0x0004
+#define SPI_RDR					0x0008
+#define SPI_TDR					0x000c
+#define SPI_SR					0x0010
+#define SPI_IER					0x0014
+#define SPI_IDR					0x0018
+#define SPI_IMR					0x001c
+#define SPI_CSR0				0x0030
+#define SPI_CSR1				0x0034
+#define SPI_CSR2				0x0038
+#define SPI_CSR3				0x003c
+#define SPI_RPR					0x0100
+#define SPI_RCR					0x0104
+#define SPI_TPR					0x0108
+#define SPI_TCR					0x010c
+#define SPI_RNPR				0x0110
+#define SPI_RNCR				0x0114
+#define SPI_TNPR				0x0118
+#define SPI_TNCR				0x011c
+#define SPI_PTCR				0x0120
+#define SPI_PTSR				0x0124
+
+/* Bitfields in CR */
+#define SPI_SPIEN_OFFSET			0
+#define SPI_SPIEN_SIZE				1
+#define SPI_SPIDIS_OFFSET			1
+#define SPI_SPIDIS_SIZE				1
+#define SPI_SWRST_OFFSET			7
+#define SPI_SWRST_SIZE				1
+#define SPI_LASTXFER_OFFSET			24
+#define SPI_LASTXFER_SIZE			1
+
+/* Bitfields in MR */
+#define SPI_MSTR_OFFSET				0
+#define SPI_MSTR_SIZE				1
+#define SPI_PS_OFFSET				1
+#define SPI_PS_SIZE				1
+#define SPI_PCSDEC_OFFSET			2
+#define SPI_PCSDEC_SIZE				1
+#define SPI_FDIV_OFFSET				3
+#define SPI_FDIV_SIZE				1
+#define SPI_MODFDIS_OFFSET			4
+#define SPI_MODFDIS_SIZE			1
+#define SPI_LLB_OFFSET				7
+#define SPI_LLB_SIZE				1
+#define SPI_PCS_OFFSET				16
+#define SPI_PCS_SIZE				4
+#define SPI_DLYBCS_OFFSET			24
+#define SPI_DLYBCS_SIZE				8
+
+/* Bitfields in RDR */
+#define SPI_RD_OFFSET				0
+#define SPI_RD_SIZE				16
+
+/* Bitfields in TDR */
+#define SPI_TD_OFFSET				0
+#define SPI_TD_SIZE				16
+
+/* Bitfields in SR */
+#define SPI_RDRF_OFFSET				0
+#define SPI_RDRF_SIZE				1
+#define SPI_TDRE_OFFSET				1
+#define SPI_TDRE_SIZE				1
+#define SPI_MODF_OFFSET				2
+#define SPI_MODF_SIZE				1
+#define SPI_OVRES_OFFSET			3
+#define SPI_OVRES_SIZE				1
+#define SPI_ENDRX_OFFSET			4
+#define SPI_ENDRX_SIZE				1
+#define SPI_ENDTX_OFFSET			5
+#define SPI_ENDTX_SIZE				1
+#define SPI_RXBUFF_OFFSET			6
+#define SPI_RXBUFF_SIZE				1
+#define SPI_TXBUFE_OFFSET			7
+#define SPI_TXBUFE_SIZE				1
+#define SPI_NSSR_OFFSET				8
+#define SPI_NSSR_SIZE				1
+#define SPI_TXEMPTY_OFFSET			9
+#define SPI_TXEMPTY_SIZE			1
+#define SPI_SPIENS_OFFSET			16
+#define SPI_SPIENS_SIZE				1
+
+/* Bitfields in CSR0 */
+#define SPI_CPOL_OFFSET				0
+#define SPI_CPOL_SIZE				1
+#define SPI_NCPHA_OFFSET			1
+#define SPI_NCPHA_SIZE				1
+#define SPI_CSAAT_OFFSET			3
+#define SPI_CSAAT_SIZE				1
+#define SPI_BITS_OFFSET				4
+#define SPI_BITS_SIZE				4
+#define SPI_SCBR_OFFSET				8
+#define SPI_SCBR_SIZE				8
+#define SPI_DLYBS_OFFSET			16
+#define SPI_DLYBS_SIZE				8
+#define SPI_DLYBCT_OFFSET			24
+#define SPI_DLYBCT_SIZE				8
+
+/* Bitfields in RCR */
+#define SPI_RXCTR_OFFSET			0
+#define SPI_RXCTR_SIZE				16
+
+/* Bitfields in TCR */
+#define SPI_TXCTR_OFFSET			0
+#define SPI_TXCTR_SIZE				16
+
+/* Bitfields in RNCR */
+#define SPI_RXNCR_OFFSET			0
+#define SPI_RXNCR_SIZE				16
+
+/* Bitfields in TNCR */
+#define SPI_TXNCR_OFFSET			0
+#define SPI_TXNCR_SIZE				16
+
+/* Bitfields in PTCR */
+#define SPI_RXTEN_OFFSET			0
+#define SPI_RXTEN_SIZE				1
+#define SPI_RXTDIS_OFFSET			1
+#define SPI_RXTDIS_SIZE				1
+#define SPI_TXTEN_OFFSET			8
+#define SPI_TXTEN_SIZE				1
+#define SPI_TXTDIS_OFFSET			9
+#define SPI_TXTDIS_SIZE				1
+
+/* Constants for BITS */
+#define SPI_BITS_8_BPT				0
+#define SPI_BITS_9_BPT				1
+#define SPI_BITS_10_BPT				2
+#define SPI_BITS_11_BPT				3
+#define SPI_BITS_12_BPT				4
+#define SPI_BITS_13_BPT				5
+#define SPI_BITS_14_BPT				6
+#define SPI_BITS_15_BPT				7
+#define SPI_BITS_16_BPT				8
+
+/* Bit manipulation macros */
+#define SPI_BIT(name) \
+	(1 << SPI_##name##_OFFSET)
+#define SPI_BF(name,value) \
+	(((value) & ((1 << SPI_##name##_SIZE) - 1)) << SPI_##name##_OFFSET)
+#define SPI_BFEXT(name,value) \
+	(((value) >> SPI_##name##_OFFSET) & ((1 << SPI_##name##_SIZE) - 1))
+#define SPI_BFINS(name,value,old) \
+	( ((old) & ~(((1 << SPI_##name##_SIZE) - 1) << SPI_##name##_OFFSET)) \
+	  | SPI_BF(name,value))
+
+/* Register access macros */
+#define spi_readl(port,reg) \
+	__raw_readl((port)->regs + SPI_##reg)
+#define spi_writel(port,reg,value) \
+	__raw_writel((value), (port)->regs + SPI_##reg)
+
+#endif /* __ATMEL_SPI_H__ */

kernel/drivers/spi/mpc52xx_psc_spi.c

@@ -0,0 +1,531 @@
+/*
+ * MPC52xx PSC in SPI mode driver.
+ *
+ * Maintainer: Dragos Carp
+ *
+ * Copyright (C) 2006 TOPTICA Photonics AG.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/of_platform.h>
+#include <linux/workqueue.h>
+#include <linux/completion.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+#include <linux/fsl_devices.h>
+
+#include <asm/mpc52xx.h>
+#include <asm/mpc52xx_psc.h>
+
+#define MCLK 20000000 /* PSC port MClk in hz */
+
+struct mpc52xx_psc_spi {
+	/* fsl_spi_platform data */
+	void (*cs_control)(struct spi_device *spi, bool on);
+	u32 sysclk;
+
+	/* driver internal data */
+	struct mpc52xx_psc __iomem *psc;
+	struct mpc52xx_psc_fifo __iomem *fifo;
+	unsigned int irq;
+	u8 bits_per_word;
+	u8 busy;
+
+	struct workqueue_struct *workqueue;
+	struct work_struct work;
+
+	struct list_head queue;
+	spinlock_t lock;
+
+	struct completion done;
+};
+
+/* controller state */
+struct mpc52xx_psc_spi_cs {
+	int bits_per_word;
+	int speed_hz;
+};
+
+/* set clock freq, clock ramp, bits per work
+ * if t is NULL then reset the values to the default values
+ */
+static int mpc52xx_psc_spi_transfer_setup(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
+
+	cs->speed_hz = (t && t->speed_hz)
+			? t->speed_hz : spi->max_speed_hz;
+	cs->bits_per_word = (t && t->bits_per_word)
+			? t->bits_per_word : spi->bits_per_word;
+	cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8;
+	return 0;
+}
+
+static void mpc52xx_psc_spi_activate_cs(struct spi_device *spi)
+{
+	struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
+	struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+	struct mpc52xx_psc __iomem *psc = mps->psc;
+	u32 sicr;
+	u16 ccr;
+
+	sicr = in_be32(&psc->sicr);
+
+	/* Set clock phase and polarity */
+	if (spi->mode & SPI_CPHA)
+		sicr |= 0x00001000;
+	else
+		sicr &= ~0x00001000;
+	if (spi->mode & SPI_CPOL)
+		sicr |= 0x00002000;
+	else
+		sicr &= ~0x00002000;
+
+	if (spi->mode & SPI_LSB_FIRST)
+		sicr |= 0x10000000;
+	else
+		sicr &= ~0x10000000;
+	out_be32(&psc->sicr, sicr);
+
+	/* Set clock frequency and bits per word
+	 * Because psc->ccr is defined as 16bit register instead of 32bit
+	 * just set the lower byte of BitClkDiv
+	 */
+	ccr = in_be16((u16 __iomem *)&psc->ccr);
+	ccr &= 0xFF00;
+	if (cs->speed_hz)
+		ccr |= (MCLK / cs->speed_hz - 1) & 0xFF;
+	else /* by default SPI Clk 1MHz */
+		ccr |= (MCLK / 1000000 - 1) & 0xFF;
+	out_be16((u16 __iomem *)&psc->ccr, ccr);
+	mps->bits_per_word = cs->bits_per_word;
+
+	if (mps->cs_control)
+		mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
+}
+
+static void mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi)
+{
+	struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+
+	if (mps->cs_control)
+		mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
+}
+
+#define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1)
+/* wake up when 80% fifo full */
+#define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100)
+
+static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi,
+						struct spi_transfer *t)
+{
+	struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+	struct mpc52xx_psc __iomem *psc = mps->psc;
+	struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
+	unsigned rb = 0;	/* number of bytes receieved */
+	unsigned sb = 0;	/* number of bytes sent */
+	unsigned char *rx_buf = (unsigned char *)t->rx_buf;
+	unsigned char *tx_buf = (unsigned char *)t->tx_buf;
+	unsigned rfalarm;
+	unsigned send_at_once = MPC52xx_PSC_BUFSIZE;
+	unsigned recv_at_once;
+	int last_block = 0;
+
+	if (!t->tx_buf && !t->rx_buf && t->len)
+		return -EINVAL;
+
+	/* enable transmiter/receiver */
+	out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
+	while (rb < t->len) {
+		if (t->len - rb > MPC52xx_PSC_BUFSIZE) {
+			rfalarm = MPC52xx_PSC_RFALARM;
+			last_block = 0;
+		} else {
+			send_at_once = t->len - sb;
+			rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb);
+			last_block = 1;
+		}
+
+		dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once);
+		for (; send_at_once; sb++, send_at_once--) {
+			/* set EOF flag before the last word is sent */
+			if (send_at_once == 1 && last_block)
+				out_8(&psc->ircr2, 0x01);
+
+			if (tx_buf)
+				out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]);
+			else
+				out_8(&psc->mpc52xx_psc_buffer_8, 0);
+		}
+
+
+		/* enable interrupts and wait for wake up
+		 * if just one byte is expected the Rx FIFO genererates no
+		 * FFULL interrupt, so activate the RxRDY interrupt
+		 */
+		out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
+		if (t->len - rb == 1) {
+			out_8(&psc->mode, 0);
+		} else {
+			out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
+			out_be16(&fifo->rfalarm, rfalarm);
+		}
+		out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
+		wait_for_completion(&mps->done);
+		recv_at_once = in_be16(&fifo->rfnum);
+		dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once);
+
+		send_at_once = recv_at_once;
+		if (rx_buf) {
+			for (; recv_at_once; rb++, recv_at_once--)
+				rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8);
+		} else {
+			for (; recv_at_once; rb++, recv_at_once--)
+				in_8(&psc->mpc52xx_psc_buffer_8);
+		}
+	}
+	/* disable transmiter/receiver */
+	out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
+
+	return 0;
+}
+
+static void mpc52xx_psc_spi_work(struct work_struct *work)
+{
+	struct mpc52xx_psc_spi *mps =
+		container_of(work, struct mpc52xx_psc_spi, work);
+
+	spin_lock_irq(&mps->lock);
+	mps->busy = 1;
+	while (!list_empty(&mps->queue)) {
+		struct spi_message *m;
+		struct spi_device *spi;
+		struct spi_transfer *t = NULL;
+		unsigned cs_change;
+		int status;
+
+		m = container_of(mps->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irq(&mps->lock);
+
+		spi = m->spi;
+		cs_change = 1;
+		status = 0;
+		list_for_each_entry (t, &m->transfers, transfer_list) {
+			if (t->bits_per_word || t->speed_hz) {
+				status = mpc52xx_psc_spi_transfer_setup(spi, t);
+				if (status < 0)
+					break;
+			}
+
+			if (cs_change)
+				mpc52xx_psc_spi_activate_cs(spi);
+			cs_change = t->cs_change;
+
+			status = mpc52xx_psc_spi_transfer_rxtx(spi, t);
+			if (status)
+				break;
+			m->actual_length += t->len;
+
+			if (t->delay_usecs)
+				udelay(t->delay_usecs);
+
+			if (cs_change)
+				mpc52xx_psc_spi_deactivate_cs(spi);
+		}
+
+		m->status = status;
+		m->complete(m->context);
+
+		if (status || !cs_change)
+			mpc52xx_psc_spi_deactivate_cs(spi);
+
+		mpc52xx_psc_spi_transfer_setup(spi, NULL);
+
+		spin_lock_irq(&mps->lock);
+	}
+	mps->busy = 0;
+	spin_unlock_irq(&mps->lock);
+}
+
+static int mpc52xx_psc_spi_setup(struct spi_device *spi)
+{
+	struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+	struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
+	unsigned long flags;
+
+	if (spi->bits_per_word%8)
+		return -EINVAL;
+
+	if (!cs) {
+		cs = kzalloc(sizeof *cs, GFP_KERNEL);
+		if (!cs)
+			return -ENOMEM;
+		spi->controller_state = cs;
+	}
+
+	cs->bits_per_word = spi->bits_per_word;
+	cs->speed_hz = spi->max_speed_hz;
+
+	spin_lock_irqsave(&mps->lock, flags);
+	if (!mps->busy)
+		mpc52xx_psc_spi_deactivate_cs(spi);
+	spin_unlock_irqrestore(&mps->lock, flags);
+
+	return 0;
+}
+
+static int mpc52xx_psc_spi_transfer(struct spi_device *spi,
+		struct spi_message *m)
+{
+	struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	m->actual_length = 0;
+	m->status = -EINPROGRESS;
+
+	spin_lock_irqsave(&mps->lock, flags);
+	list_add_tail(&m->queue, &mps->queue);
+	queue_work(mps->workqueue, &mps->work);
+	spin_unlock_irqrestore(&mps->lock, flags);
+
+	return 0;
+}
+
+static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
+{
+	kfree(spi->controller_state);
+}
+
+static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
+{
+	struct mpc52xx_psc __iomem *psc = mps->psc;
+	struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
+	u32 mclken_div;
+	int ret = 0;
+
+	/* default sysclk is 512MHz */
+	mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
+	mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
+
+	/* Reset the PSC into a known state */
+	out_8(&psc->command, MPC52xx_PSC_RST_RX);
+	out_8(&psc->command, MPC52xx_PSC_RST_TX);
+	out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
+
+	/* Disable interrupts, interrupts are based on alarm level */
+	out_be16(&psc->mpc52xx_psc_imr, 0);
+	out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
+	out_8(&fifo->rfcntl, 0);
+	out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
+
+	/* Configure 8bit codec mode as a SPI master and use EOF flags */
+	/* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */
+	out_be32(&psc->sicr, 0x0180C800);
+	out_be16((u16 __iomem *)&psc->ccr, 0x070F); /* default SPI Clk 1MHz */
+
+	/* Set 2ms DTL delay */
+	out_8(&psc->ctur, 0x00);
+	out_8(&psc->ctlr, 0x84);
+
+	mps->bits_per_word = 8;
+
+	return ret;
+}
+
+static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)
+{
+	struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id;
+	struct mpc52xx_psc __iomem *psc = mps->psc;
+
+	/* disable interrupt and wake up the work queue */
+	if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
+		out_be16(&psc->mpc52xx_psc_imr, 0);
+		complete(&mps->done);
+		return IRQ_HANDLED;
+	}
+	return IRQ_NONE;
+}
+
+/* bus_num is used only for the case dev->platform_data == NULL */
+static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
+				u32 size, unsigned int irq, s16 bus_num)
+{
+	struct fsl_spi_platform_data *pdata = dev->platform_data;
+	struct mpc52xx_psc_spi *mps;
+	struct spi_master *master;
+	int ret;
+
+	master = spi_alloc_master(dev, sizeof *mps);
+	if (master == NULL)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, master);
+	mps = spi_master_get_devdata(master);
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+
+	mps->irq = irq;
+	if (pdata == NULL) {
+		dev_warn(dev, "probe called without platform data, no "
+				"cs_control function will be called\n");
+		mps->cs_control = NULL;
+		mps->sysclk = 0;
+		master->bus_num = bus_num;
+		master->num_chipselect = 255;
+	} else {
+		mps->cs_control = pdata->cs_control;
+		mps->sysclk = pdata->sysclk;
+		master->bus_num = pdata->bus_num;
+		master->num_chipselect = pdata->max_chipselect;
+	}
+	master->setup = mpc52xx_psc_spi_setup;
+	master->transfer = mpc52xx_psc_spi_transfer;
+	master->cleanup = mpc52xx_psc_spi_cleanup;
+
+	mps->psc = ioremap(regaddr, size);
+	if (!mps->psc) {
+		dev_err(dev, "could not ioremap I/O port range\n");
+		ret = -EFAULT;
+		goto free_master;
+	}
+	/* On the 5200, fifo regs are immediately ajacent to the psc regs */
+	mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);
+
+	ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi",
+				mps);
+	if (ret)
+		goto free_master;
+
+	ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
+	if (ret < 0)
+		goto free_irq;
+
+	spin_lock_init(&mps->lock);
+	init_completion(&mps->done);
+	INIT_WORK(&mps->work, mpc52xx_psc_spi_work);
+	INIT_LIST_HEAD(&mps->queue);
+
+	mps->workqueue = create_singlethread_workqueue(
+		dev_name(master->dev.parent));
+	if (mps->workqueue == NULL) {
+		ret = -EBUSY;
+		goto free_irq;
+	}
+
+	ret = spi_register_master(master);
+	if (ret < 0)
+		goto unreg_master;
+
+	return ret;
+
+unreg_master:
+	destroy_workqueue(mps->workqueue);
+free_irq:
+	free_irq(mps->irq, mps);
+free_master:
+	if (mps->psc)
+		iounmap(mps->psc);
+	spi_master_put(master);
+
+	return ret;
+}
+
+static int __exit mpc52xx_psc_spi_do_remove(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct mpc52xx_psc_spi *mps = spi_master_get_devdata(master);
+
+	flush_workqueue(mps->workqueue);
+	destroy_workqueue(mps->workqueue);
+	spi_unregister_master(master);
+	free_irq(mps->irq, mps);
+	if (mps->psc)
+		iounmap(mps->psc);
+
+	return 0;
+}
+
+static int __init mpc52xx_psc_spi_of_probe(struct of_device *op,
+	const struct of_device_id *match)
+{
+	const u32 *regaddr_p;
+	u64 regaddr64, size64;
+	s16 id = -1;
+
+	regaddr_p = of_get_address(op->node, 0, &size64, NULL);
+	if (!regaddr_p) {
+		printk(KERN_ERR "Invalid PSC address\n");
+		return -EINVAL;
+	}
+	regaddr64 = of_translate_address(op->node, regaddr_p);
+
+	/* get PSC id (1..6, used by port_config) */
+	if (op->dev.platform_data == NULL) {
+		const u32 *psc_nump;
+
+		psc_nump = of_get_property(op->node, "cell-index", NULL);
+		if (!psc_nump || *psc_nump > 5) {
+			printk(KERN_ERR "mpc52xx_psc_spi: Device node %s has invalid "
+					"cell-index property\n", op->node->full_name);
+			return -EINVAL;
+		}
+		id = *psc_nump + 1;
+	}
+
+	return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
+					irq_of_parse_and_map(op->node, 0), id);
+}
+
+static int __exit mpc52xx_psc_spi_of_remove(struct of_device *op)
+{
+	return mpc52xx_psc_spi_do_remove(&op->dev);
+}
+
+static struct of_device_id mpc52xx_psc_spi_of_match[] = {
+	{ .compatible = "fsl,mpc5200-psc-spi", },
+	{ .compatible = "mpc5200-psc-spi", }, /* old */
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match);
+
+static struct of_platform_driver mpc52xx_psc_spi_of_driver = {
+	.owner = THIS_MODULE,
+	.name = "mpc52xx-psc-spi",
+	.match_table = mpc52xx_psc_spi_of_match,
+	.probe = mpc52xx_psc_spi_of_probe,
+	.remove = __exit_p(mpc52xx_psc_spi_of_remove),
+	.driver = {
+		.name = "mpc52xx-psc-spi",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init mpc52xx_psc_spi_init(void)
+{
+	return of_register_platform_driver(&mpc52xx_psc_spi_of_driver);
+}
+module_init(mpc52xx_psc_spi_init);
+
+static void __exit mpc52xx_psc_spi_exit(void)
+{
+	of_unregister_platform_driver(&mpc52xx_psc_spi_of_driver);
+}
+module_exit(mpc52xx_psc_spi_exit);
+
+MODULE_AUTHOR("Dragos Carp");
+MODULE_DESCRIPTION("MPC52xx PSC SPI Driver");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/omap_uwire.c

@@ -0,0 +1,592 @@
+/*
+ * omap_uwire.c -- MicroWire interface driver for OMAP
+ *
+ * Copyright 2003 MontaVista Software Inc. <source@mvista.com>
+ *
+ * Ported to 2.6 OMAP uwire interface.
+ * Copyright (C) 2004 Texas Instruments.
+ *
+ * Generalization patches by Juha Yrjola <juha.yrjola@nokia.com>
+ *
+ * Copyright (C) 2005 David Brownell (ported to 2.6 SPI interface)
+ * Copyright (C) 2006 Nokia
+ *
+ * Many updates by Imre Deak <imre.deak@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <mach/hardware.h>
+#include <asm/io.h>
+#include <asm/mach-types.h>
+
+#include <mach/mux.h>
+#include <mach/omap730.h>	/* OMAP730_IO_CONF registers */
+
+
+/* FIXME address is now a platform device resource,
+ * and irqs should show there too...
+ */
+#define UWIRE_BASE_PHYS		0xFFFB3000
+
+/* uWire Registers: */
+#define UWIRE_IO_SIZE 0x20
+#define UWIRE_TDR     0x00
+#define UWIRE_RDR     0x00
+#define UWIRE_CSR     0x01
+#define UWIRE_SR1     0x02
+#define UWIRE_SR2     0x03
+#define UWIRE_SR3     0x04
+#define UWIRE_SR4     0x05
+#define UWIRE_SR5     0x06
+
+/* CSR bits */
+#define	RDRB	(1 << 15)
+#define	CSRB	(1 << 14)
+#define	START	(1 << 13)
+#define	CS_CMD	(1 << 12)
+
+/* SR1 or SR2 bits */
+#define UWIRE_READ_FALLING_EDGE		0x0001
+#define UWIRE_READ_RISING_EDGE		0x0000
+#define UWIRE_WRITE_FALLING_EDGE	0x0000
+#define UWIRE_WRITE_RISING_EDGE		0x0002
+#define UWIRE_CS_ACTIVE_LOW		0x0000
+#define UWIRE_CS_ACTIVE_HIGH		0x0004
+#define UWIRE_FREQ_DIV_2		0x0000
+#define UWIRE_FREQ_DIV_4		0x0008
+#define UWIRE_FREQ_DIV_8		0x0010
+#define UWIRE_CHK_READY			0x0020
+#define UWIRE_CLK_INVERTED		0x0040
+
+
+struct uwire_spi {
+	struct spi_bitbang	bitbang;
+	struct clk		*ck;
+};
+
+struct uwire_state {
+	unsigned	bits_per_word;
+	unsigned	div1_idx;
+};
+
+/* REVISIT compile time constant for idx_shift? */
+/*
+ * Or, put it in a structure which is used throughout the driver;
+ * that avoids having to issue two loads for each bit of static data.
+ */
+static unsigned int uwire_idx_shift;
+static void __iomem *uwire_base;
+
+static inline void uwire_write_reg(int idx, u16 val)
+{
+	__raw_writew(val, uwire_base + (idx << uwire_idx_shift));
+}
+
+static inline u16 uwire_read_reg(int idx)
+{
+	return __raw_readw(uwire_base + (idx << uwire_idx_shift));
+}
+
+static inline void omap_uwire_configure_mode(u8 cs, unsigned long flags)
+{
+	u16	w, val = 0;
+	int	shift, reg;
+
+	if (flags & UWIRE_CLK_INVERTED)
+		val ^= 0x03;
+	val = flags & 0x3f;
+	if (cs & 1)
+		shift = 6;
+	else
+		shift = 0;
+	if (cs <= 1)
+		reg = UWIRE_SR1;
+	else
+		reg = UWIRE_SR2;
+
+	w = uwire_read_reg(reg);
+	w &= ~(0x3f << shift);
+	w |= val << shift;
+	uwire_write_reg(reg, w);
+}
+
+static int wait_uwire_csr_flag(u16 mask, u16 val, int might_not_catch)
+{
+	u16 w;
+	int c = 0;
+	unsigned long max_jiffies = jiffies + HZ;
+
+	for (;;) {
+		w = uwire_read_reg(UWIRE_CSR);
+		if ((w & mask) == val)
+			break;
+		if (time_after(jiffies, max_jiffies)) {
+			printk(KERN_ERR "%s: timeout. reg=%#06x "
+					"mask=%#06x val=%#06x\n",
+			       __func__, w, mask, val);
+			return -1;
+		}
+		c++;
+		if (might_not_catch && c > 64)
+			break;
+	}
+	return 0;
+}
+
+static void uwire_set_clk1_div(int div1_idx)
+{
+	u16 w;
+
+	w = uwire_read_reg(UWIRE_SR3);
+	w &= ~(0x03 << 1);
+	w |= div1_idx << 1;
+	uwire_write_reg(UWIRE_SR3, w);
+}
+
+static void uwire_chipselect(struct spi_device *spi, int value)
+{
+	struct	uwire_state *ust = spi->controller_state;
+	u16	w;
+	int	old_cs;
+
+
+	BUG_ON(wait_uwire_csr_flag(CSRB, 0, 0));
+
+	w = uwire_read_reg(UWIRE_CSR);
+	old_cs = (w >> 10) & 0x03;
+	if (value == BITBANG_CS_INACTIVE || old_cs != spi->chip_select) {
+		/* Deselect this CS, or the previous CS */
+		w &= ~CS_CMD;
+		uwire_write_reg(UWIRE_CSR, w);
+	}
+	/* activate specfied chipselect */
+	if (value == BITBANG_CS_ACTIVE) {
+		uwire_set_clk1_div(ust->div1_idx);
+		/* invert clock? */
+		if (spi->mode & SPI_CPOL)
+			uwire_write_reg(UWIRE_SR4, 1);
+		else
+			uwire_write_reg(UWIRE_SR4, 0);
+
+		w = spi->chip_select << 10;
+		w |= CS_CMD;
+		uwire_write_reg(UWIRE_CSR, w);
+	}
+}
+
+static int uwire_txrx(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct uwire_state *ust = spi->controller_state;
+	unsigned	len = t->len;
+	unsigned	bits = ust->bits_per_word;
+	unsigned	bytes;
+	u16		val, w;
+	int		status = 0;
+
+	if (!t->tx_buf && !t->rx_buf)
+		return 0;
+
+	/* Microwire doesn't read and write concurrently */
+	if (t->tx_buf && t->rx_buf)
+		return -EPERM;
+
+	w = spi->chip_select << 10;
+	w |= CS_CMD;
+
+	if (t->tx_buf) {
+		const u8	*buf = t->tx_buf;
+
+		/* NOTE:  DMA could be used for TX transfers */
+
+		/* write one or two bytes at a time */
+		while (len >= 1) {
+			/* tx bit 15 is first sent; we byteswap multibyte words
+			 * (msb-first) on the way out from memory.
+			 */
+			val = *buf++;
+			if (bits > 8) {
+				bytes = 2;
+				val |= *buf++ << 8;
+			} else
+				bytes = 1;
+			val <<= 16 - bits;
+
+#ifdef	VERBOSE
+			pr_debug("%s: write-%d =%04x\n",
+					dev_name(&spi->dev), bits, val);
+#endif
+			if (wait_uwire_csr_flag(CSRB, 0, 0))
+				goto eio;
+
+			uwire_write_reg(UWIRE_TDR, val);
+
+			/* start write */
+			val = START | w | (bits << 5);
+
+			uwire_write_reg(UWIRE_CSR, val);
+			len -= bytes;
+
+			/* Wait till write actually starts.
+			 * This is needed with MPU clock 60+ MHz.
+			 * REVISIT: we may not have time to catch it...
+			 */
+			if (wait_uwire_csr_flag(CSRB, CSRB, 1))
+				goto eio;
+
+			status += bytes;
+		}
+
+		/* REVISIT:  save this for later to get more i/o overlap */
+		if (wait_uwire_csr_flag(CSRB, 0, 0))
+			goto eio;
+
+	} else if (t->rx_buf) {
+		u8		*buf = t->rx_buf;
+
+		/* read one or two bytes at a time */
+		while (len) {
+			if (bits > 8) {
+				bytes = 2;
+			} else
+				bytes = 1;
+
+			/* start read */
+			val = START | w | (bits << 0);
+			uwire_write_reg(UWIRE_CSR, val);
+			len -= bytes;
+
+			/* Wait till read actually starts */
+			(void) wait_uwire_csr_flag(CSRB, CSRB, 1);
+
+			if (wait_uwire_csr_flag(RDRB | CSRB,
+						RDRB, 0))
+				goto eio;
+
+			/* rx bit 0 is last received; multibyte words will
+			 * be properly byteswapped on the way to memory.
+			 */
+			val = uwire_read_reg(UWIRE_RDR);
+			val &= (1 << bits) - 1;
+			*buf++ = (u8) val;
+			if (bytes == 2)
+				*buf++ = val >> 8;
+			status += bytes;
+#ifdef	VERBOSE
+			pr_debug("%s: read-%d =%04x\n",
+					dev_name(&spi->dev), bits, val);
+#endif
+
+		}
+	}
+	return status;
+eio:
+	return -EIO;
+}
+
+static int uwire_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct uwire_state	*ust = spi->controller_state;
+	struct uwire_spi	*uwire;
+	unsigned		flags = 0;
+	unsigned		bits;
+	unsigned		hz;
+	unsigned long		rate;
+	int			div1_idx;
+	int			div1;
+	int			div2;
+	int			status;
+
+	uwire = spi_master_get_devdata(spi->master);
+
+	if (spi->chip_select > 3) {
+		pr_debug("%s: cs%d?\n", dev_name(&spi->dev), spi->chip_select);
+		status = -ENODEV;
+		goto done;
+	}
+
+	bits = spi->bits_per_word;
+	if (t != NULL && t->bits_per_word)
+		bits = t->bits_per_word;
+
+	if (bits > 16) {
+		pr_debug("%s: wordsize %d?\n", dev_name(&spi->dev), bits);
+		status = -ENODEV;
+		goto done;
+	}
+	ust->bits_per_word = bits;
+
+	/* mode 0..3, clock inverted separately;
+	 * standard nCS signaling;
+	 * don't treat DI=high as "not ready"
+	 */
+	if (spi->mode & SPI_CS_HIGH)
+		flags |= UWIRE_CS_ACTIVE_HIGH;
+
+	if (spi->mode & SPI_CPOL)
+		flags |= UWIRE_CLK_INVERTED;
+
+	switch (spi->mode & (SPI_CPOL | SPI_CPHA)) {
+	case SPI_MODE_0:
+	case SPI_MODE_3:
+		flags |= UWIRE_WRITE_FALLING_EDGE | UWIRE_READ_RISING_EDGE;
+		break;
+	case SPI_MODE_1:
+	case SPI_MODE_2:
+		flags |= UWIRE_WRITE_RISING_EDGE | UWIRE_READ_FALLING_EDGE;
+		break;
+	}
+
+	/* assume it's already enabled */
+	rate = clk_get_rate(uwire->ck);
+
+	hz = spi->max_speed_hz;
+	if (t != NULL && t->speed_hz)
+		hz = t->speed_hz;
+
+	if (!hz) {
+		pr_debug("%s: zero speed?\n", dev_name(&spi->dev));
+		status = -EINVAL;
+		goto done;
+	}
+
+	/* F_INT = mpu_xor_clk / DIV1 */
+	for (div1_idx = 0; div1_idx < 4; div1_idx++) {
+		switch (div1_idx) {
+		case 0:
+			div1 = 2;
+			break;
+		case 1:
+			div1 = 4;
+			break;
+		case 2:
+			div1 = 7;
+			break;
+		default:
+		case 3:
+			div1 = 10;
+			break;
+		}
+		div2 = (rate / div1 + hz - 1) / hz;
+		if (div2 <= 8)
+			break;
+	}
+	if (div1_idx == 4) {
+		pr_debug("%s: lowest clock %ld, need %d\n",
+			dev_name(&spi->dev), rate / 10 / 8, hz);
+		status = -EDOM;
+		goto done;
+	}
+
+	/* we have to cache this and reset in uwire_chipselect as this is a
+	 * global parameter and another uwire device can change it under
+	 * us */
+	ust->div1_idx = div1_idx;
+	uwire_set_clk1_div(div1_idx);
+
+	rate /= div1;
+
+	switch (div2) {
+	case 0:
+	case 1:
+	case 2:
+		flags |= UWIRE_FREQ_DIV_2;
+		rate /= 2;
+		break;
+	case 3:
+	case 4:
+		flags |= UWIRE_FREQ_DIV_4;
+		rate /= 4;
+		break;
+	case 5:
+	case 6:
+	case 7:
+	case 8:
+		flags |= UWIRE_FREQ_DIV_8;
+		rate /= 8;
+		break;
+	}
+	omap_uwire_configure_mode(spi->chip_select, flags);
+	pr_debug("%s: uwire flags %02x, armxor %lu KHz, SCK %lu KHz\n",
+			__func__, flags,
+			clk_get_rate(uwire->ck) / 1000,
+			rate / 1000);
+	status = 0;
+done:
+	return status;
+}
+
+static int uwire_setup(struct spi_device *spi)
+{
+	struct uwire_state *ust = spi->controller_state;
+
+	if (ust == NULL) {
+		ust = kzalloc(sizeof(*ust), GFP_KERNEL);
+		if (ust == NULL)
+			return -ENOMEM;
+		spi->controller_state = ust;
+	}
+
+	return uwire_setup_transfer(spi, NULL);
+}
+
+static void uwire_cleanup(struct spi_device *spi)
+{
+	kfree(spi->controller_state);
+}
+
+static void uwire_off(struct uwire_spi *uwire)
+{
+	uwire_write_reg(UWIRE_SR3, 0);
+	clk_disable(uwire->ck);
+	clk_put(uwire->ck);
+	spi_master_put(uwire->bitbang.master);
+}
+
+static int __init uwire_probe(struct platform_device *pdev)
+{
+	struct spi_master	*master;
+	struct uwire_spi	*uwire;
+	int			status;
+
+	master = spi_alloc_master(&pdev->dev, sizeof *uwire);
+	if (!master)
+		return -ENODEV;
+
+	uwire = spi_master_get_devdata(master);
+
+	uwire_base = ioremap(UWIRE_BASE_PHYS, UWIRE_IO_SIZE);
+	if (!uwire_base) {
+		dev_dbg(&pdev->dev, "can't ioremap UWIRE\n");
+		spi_master_put(master);
+		return -ENOMEM;
+	}
+
+	dev_set_drvdata(&pdev->dev, uwire);
+
+	uwire->ck = clk_get(&pdev->dev, "fck");
+	if (IS_ERR(uwire->ck)) {
+		status = PTR_ERR(uwire->ck);
+		dev_dbg(&pdev->dev, "no functional clock?\n");
+		spi_master_put(master);
+		return status;
+	}
+	clk_enable(uwire->ck);
+
+	if (cpu_is_omap730())
+		uwire_idx_shift = 1;
+	else
+		uwire_idx_shift = 2;
+
+	uwire_write_reg(UWIRE_SR3, 1);
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
+	master->flags = SPI_MASTER_HALF_DUPLEX;
+
+	master->bus_num = 2;	/* "official" */
+	master->num_chipselect = 4;
+	master->setup = uwire_setup;
+	master->cleanup = uwire_cleanup;
+
+	uwire->bitbang.master = master;
+	uwire->bitbang.chipselect = uwire_chipselect;
+	uwire->bitbang.setup_transfer = uwire_setup_transfer;
+	uwire->bitbang.txrx_bufs = uwire_txrx;
+
+	status = spi_bitbang_start(&uwire->bitbang);
+	if (status < 0) {
+		uwire_off(uwire);
+		iounmap(uwire_base);
+	}
+	return status;
+}
+
+static int __exit uwire_remove(struct platform_device *pdev)
+{
+	struct uwire_spi	*uwire = dev_get_drvdata(&pdev->dev);
+	int			status;
+
+	// FIXME remove all child devices, somewhere ...
+
+	status = spi_bitbang_stop(&uwire->bitbang);
+	uwire_off(uwire);
+	iounmap(uwire_base);
+	return status;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:omap_uwire");
+
+static struct platform_driver uwire_driver = {
+	.driver = {
+		.name		= "omap_uwire",
+		.owner		= THIS_MODULE,
+	},
+	.remove		= __exit_p(uwire_remove),
+	// suspend ... unuse ck
+	// resume ... use ck
+};
+
+static int __init omap_uwire_init(void)
+{
+	/* FIXME move these into the relevant board init code. also, include
+	 * H3 support; it uses tsc2101 like H2 (on a different chipselect).
+	 */
+
+	if (machine_is_omap_h2()) {
+		/* defaults: W21 SDO, U18 SDI, V19 SCL */
+		omap_cfg_reg(N14_1610_UWIRE_CS0);
+		omap_cfg_reg(N15_1610_UWIRE_CS1);
+	}
+	if (machine_is_omap_perseus2()) {
+		/* configure pins: MPU_UW_nSCS1, MPU_UW_SDO, MPU_UW_SCLK */
+		int val = omap_readl(OMAP730_IO_CONF_9) & ~0x00EEE000;
+		omap_writel(val | 0x00AAA000, OMAP730_IO_CONF_9);
+	}
+
+	return platform_driver_probe(&uwire_driver, uwire_probe);
+}
+
+static void __exit omap_uwire_exit(void)
+{
+	platform_driver_unregister(&uwire_driver);
+}
+
+subsys_initcall(omap_uwire_init);
+module_exit(omap_uwire_exit);
+
+MODULE_LICENSE("GPL");
+

kernel/drivers/spi/orion_spi.c

@@ -0,0 +1,573 @@
+/*
+ * orion_spi.c -- Marvell Orion SPI controller driver
+ *
+ * Author: Shadi Ammouri <shadi@marvell.com>
+ * Copyright (C) 2007-2008 Marvell Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/orion_spi.h>
+#include <asm/unaligned.h>
+
+#define DRIVER_NAME			"orion_spi"
+
+#define ORION_NUM_CHIPSELECTS		1 /* only one slave is supported*/
+#define ORION_SPI_WAIT_RDY_MAX_LOOP	2000 /* in usec */
+
+#define ORION_SPI_IF_CTRL_REG		0x00
+#define ORION_SPI_IF_CONFIG_REG		0x04
+#define ORION_SPI_DATA_OUT_REG		0x08
+#define ORION_SPI_DATA_IN_REG		0x0c
+#define ORION_SPI_INT_CAUSE_REG		0x10
+
+#define ORION_SPI_IF_8_16_BIT_MODE	(1 << 5)
+#define ORION_SPI_CLK_PRESCALE_MASK	0x1F
+
+struct orion_spi {
+	struct work_struct	work;
+
+	/* Lock access to transfer list.	*/
+	spinlock_t		lock;
+
+	struct list_head	msg_queue;
+	struct spi_master	*master;
+	void __iomem		*base;
+	unsigned int		max_speed;
+	unsigned int		min_speed;
+	struct orion_spi_info	*spi_info;
+};
+
+static struct workqueue_struct *orion_spi_wq;
+
+static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
+{
+	return orion_spi->base + reg;
+}
+
+static inline void
+orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
+{
+	void __iomem *reg_addr = spi_reg(orion_spi, reg);
+	u32 val;
+
+	val = readl(reg_addr);
+	val |= mask;
+	writel(val, reg_addr);
+}
+
+static inline void
+orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
+{
+	void __iomem *reg_addr = spi_reg(orion_spi, reg);
+	u32 val;
+
+	val = readl(reg_addr);
+	val &= ~mask;
+	writel(val, reg_addr);
+}
+
+static int orion_spi_set_transfer_size(struct orion_spi *orion_spi, int size)
+{
+	if (size == 16) {
+		orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
+				  ORION_SPI_IF_8_16_BIT_MODE);
+	} else if (size == 8) {
+		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
+				  ORION_SPI_IF_8_16_BIT_MODE);
+	} else {
+		pr_debug("Bad bits per word value %d (only 8 or 16 are "
+			 "allowed).\n", size);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
+{
+	u32 tclk_hz;
+	u32 rate;
+	u32 prescale;
+	u32 reg;
+	struct orion_spi *orion_spi;
+
+	orion_spi = spi_master_get_devdata(spi->master);
+
+	tclk_hz = orion_spi->spi_info->tclk;
+
+	/*
+	 * the supported rates are: 4,6,8...30
+	 * round up as we look for equal or less speed
+	 */
+	rate = DIV_ROUND_UP(tclk_hz, speed);
+	rate = roundup(rate, 2);
+
+	/* check if requested speed is too small */
+	if (rate > 30)
+		return -EINVAL;
+
+	if (rate < 4)
+		rate = 4;
+
+	/* Convert the rate to SPI clock divisor value.	*/
+	prescale = 0x10 + rate/2;
+
+	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
+	reg = ((reg & ~ORION_SPI_CLK_PRESCALE_MASK) | prescale);
+	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
+
+	return 0;
+}
+
+/*
+ * called only when no transfer is active on the bus
+ */
+static int
+orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct orion_spi *orion_spi;
+	unsigned int speed = spi->max_speed_hz;
+	unsigned int bits_per_word = spi->bits_per_word;
+	int	rc;
+
+	orion_spi = spi_master_get_devdata(spi->master);
+
+	if ((t != NULL) && t->speed_hz)
+		speed = t->speed_hz;
+
+	if ((t != NULL) && t->bits_per_word)
+		bits_per_word = t->bits_per_word;
+
+	rc = orion_spi_baudrate_set(spi, speed);
+	if (rc)
+		return rc;
+
+	return orion_spi_set_transfer_size(orion_spi, bits_per_word);
+}
+
+static void orion_spi_set_cs(struct orion_spi *orion_spi, int enable)
+{
+	if (enable)
+		orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
+	else
+		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
+}
+
+static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
+{
+	int i;
+
+	for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
+		if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
+			return 1;
+		else
+			udelay(1);
+	}
+
+	return -1;
+}
+
+static inline int
+orion_spi_write_read_8bit(struct spi_device *spi,
+			  const u8 **tx_buf, u8 **rx_buf)
+{
+	void __iomem *tx_reg, *rx_reg, *int_reg;
+	struct orion_spi *orion_spi;
+
+	orion_spi = spi_master_get_devdata(spi->master);
+	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
+	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
+	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
+
+	/* clear the interrupt cause register */
+	writel(0x0, int_reg);
+
+	if (tx_buf && *tx_buf)
+		writel(*(*tx_buf)++, tx_reg);
+	else
+		writel(0, tx_reg);
+
+	if (orion_spi_wait_till_ready(orion_spi) < 0) {
+		dev_err(&spi->dev, "TXS timed out\n");
+		return -1;
+	}
+
+	if (rx_buf && *rx_buf)
+		*(*rx_buf)++ = readl(rx_reg);
+
+	return 1;
+}
+
+static inline int
+orion_spi_write_read_16bit(struct spi_device *spi,
+			   const u16 **tx_buf, u16 **rx_buf)
+{
+	void __iomem *tx_reg, *rx_reg, *int_reg;
+	struct orion_spi *orion_spi;
+
+	orion_spi = spi_master_get_devdata(spi->master);
+	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
+	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
+	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
+
+	/* clear the interrupt cause register */
+	writel(0x0, int_reg);
+
+	if (tx_buf && *tx_buf)
+		writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
+	else
+		writel(0, tx_reg);
+
+	if (orion_spi_wait_till_ready(orion_spi) < 0) {
+		dev_err(&spi->dev, "TXS timed out\n");
+		return -1;
+	}
+
+	if (rx_buf && *rx_buf)
+		put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
+
+	return 1;
+}
+
+static unsigned int
+orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct orion_spi *orion_spi;
+	unsigned int count;
+	int word_len;
+
+	orion_spi = spi_master_get_devdata(spi->master);
+	word_len = spi->bits_per_word;
+	count = xfer->len;
+
+	if (word_len == 8) {
+		const u8 *tx = xfer->tx_buf;
+		u8 *rx = xfer->rx_buf;
+
+		do {
+			if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
+				goto out;
+			count--;
+		} while (count);
+	} else if (word_len == 16) {
+		const u16 *tx = xfer->tx_buf;
+		u16 *rx = xfer->rx_buf;
+
+		do {
+			if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
+				goto out;
+			count -= 2;
+		} while (count);
+	}
+
+out:
+	return xfer->len - count;
+}
+
+
+static void orion_spi_work(struct work_struct *work)
+{
+	struct orion_spi *orion_spi =
+		container_of(work, struct orion_spi, work);
+
+	spin_lock_irq(&orion_spi->lock);
+	while (!list_empty(&orion_spi->msg_queue)) {
+		struct spi_message *m;
+		struct spi_device *spi;
+		struct spi_transfer *t = NULL;
+		int par_override = 0;
+		int status = 0;
+		int cs_active = 0;
+
+		m = container_of(orion_spi->msg_queue.next, struct spi_message,
+				 queue);
+
+		list_del_init(&m->queue);
+		spin_unlock_irq(&orion_spi->lock);
+
+		spi = m->spi;
+
+		/* Load defaults */
+		status = orion_spi_setup_transfer(spi, NULL);
+
+		if (status < 0)
+			goto msg_done;
+
+		list_for_each_entry(t, &m->transfers, transfer_list) {
+			if (par_override || t->speed_hz || t->bits_per_word) {
+				par_override = 1;
+				status = orion_spi_setup_transfer(spi, t);
+				if (status < 0)
+					break;
+				if (!t->speed_hz && !t->bits_per_word)
+					par_override = 0;
+			}
+
+			if (!cs_active) {
+				orion_spi_set_cs(orion_spi, 1);
+				cs_active = 1;
+			}
+
+			if (t->len)
+				m->actual_length +=
+					orion_spi_write_read(spi, t);
+
+			if (t->delay_usecs)
+				udelay(t->delay_usecs);
+
+			if (t->cs_change) {
+				orion_spi_set_cs(orion_spi, 0);
+				cs_active = 0;
+			}
+		}
+
+msg_done:
+		if (cs_active)
+			orion_spi_set_cs(orion_spi, 0);
+
+		m->status = status;
+		m->complete(m->context);
+
+		spin_lock_irq(&orion_spi->lock);
+	}
+
+	spin_unlock_irq(&orion_spi->lock);
+}
+
+static int __init orion_spi_reset(struct orion_spi *orion_spi)
+{
+	/* Verify that the CS is deasserted */
+	orion_spi_set_cs(orion_spi, 0);
+
+	return 0;
+}
+
+static int orion_spi_setup(struct spi_device *spi)
+{
+	struct orion_spi *orion_spi;
+
+	orion_spi = spi_master_get_devdata(spi->master);
+
+	/* Fix ac timing if required.   */
+	if (orion_spi->spi_info->enable_clock_fix)
+		orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
+				  (1 << 14));
+
+	if ((spi->max_speed_hz == 0)
+			|| (spi->max_speed_hz > orion_spi->max_speed))
+		spi->max_speed_hz = orion_spi->max_speed;
+
+	if (spi->max_speed_hz < orion_spi->min_speed) {
+		dev_err(&spi->dev, "setup: requested speed too low %d Hz\n",
+			spi->max_speed_hz);
+		return -EINVAL;
+	}
+
+	/*
+	 * baudrate & width will be set orion_spi_setup_transfer
+	 */
+	return 0;
+}
+
+static int orion_spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct orion_spi *orion_spi;
+	struct spi_transfer *t = NULL;
+	unsigned long flags;
+
+	m->actual_length = 0;
+	m->status = 0;
+
+	/* reject invalid messages and transfers */
+	if (list_empty(&m->transfers) || !m->complete)
+		return -EINVAL;
+
+	orion_spi = spi_master_get_devdata(spi->master);
+
+	list_for_each_entry(t, &m->transfers, transfer_list) {
+		unsigned int bits_per_word = spi->bits_per_word;
+
+		if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
+			dev_err(&spi->dev,
+				"message rejected : "
+				"invalid transfer data buffers\n");
+			goto msg_rejected;
+		}
+
+		if ((t != NULL) && t->bits_per_word)
+			bits_per_word = t->bits_per_word;
+
+		if ((bits_per_word != 8) && (bits_per_word != 16)) {
+			dev_err(&spi->dev,
+				"message rejected : "
+				"invalid transfer bits_per_word (%d bits)\n",
+				bits_per_word);
+			goto msg_rejected;
+		}
+		/*make sure buffer length is even when working in 16 bit mode*/
+		if ((t != NULL) && (t->bits_per_word == 16) && (t->len & 1)) {
+			dev_err(&spi->dev,
+				"message rejected : "
+				"odd data length (%d) while in 16 bit mode\n",
+				t->len);
+			goto msg_rejected;
+		}
+
+		if (t->speed_hz && t->speed_hz < orion_spi->min_speed) {
+			dev_err(&spi->dev,
+				"message rejected : "
+				"device min speed (%d Hz) exceeds "
+				"required transfer speed (%d Hz)\n",
+				orion_spi->min_speed, t->speed_hz);
+			goto msg_rejected;
+		}
+	}
+
+
+	spin_lock_irqsave(&orion_spi->lock, flags);
+	list_add_tail(&m->queue, &orion_spi->msg_queue);
+	queue_work(orion_spi_wq, &orion_spi->work);
+	spin_unlock_irqrestore(&orion_spi->lock, flags);
+
+	return 0;
+msg_rejected:
+	/* Message rejected and not queued */
+	m->status = -EINVAL;
+	if (m->complete)
+		m->complete(m->context);
+	return -EINVAL;
+}
+
+static int __init orion_spi_probe(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct orion_spi *spi;
+	struct resource *r;
+	struct orion_spi_info *spi_info;
+	int status = 0;
+
+	spi_info = pdev->dev.platform_data;
+
+	master = spi_alloc_master(&pdev->dev, sizeof *spi);
+	if (master == NULL) {
+		dev_dbg(&pdev->dev, "master allocation failed\n");
+		return -ENOMEM;
+	}
+
+	if (pdev->id != -1)
+		master->bus_num = pdev->id;
+
+	/* we support only mode 0, and no options */
+	master->mode_bits = 0;
+
+	master->setup = orion_spi_setup;
+	master->transfer = orion_spi_transfer;
+	master->num_chipselect = ORION_NUM_CHIPSELECTS;
+
+	dev_set_drvdata(&pdev->dev, master);
+
+	spi = spi_master_get_devdata(master);
+	spi->master = master;
+	spi->spi_info = spi_info;
+
+	spi->max_speed = DIV_ROUND_UP(spi_info->tclk, 4);
+	spi->min_speed = DIV_ROUND_UP(spi_info->tclk, 30);
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		status = -ENODEV;
+		goto out;
+	}
+
+	if (!request_mem_region(r->start, (r->end - r->start) + 1,
+				dev_name(&pdev->dev))) {
+		status = -EBUSY;
+		goto out;
+	}
+	spi->base = ioremap(r->start, SZ_1K);
+
+	INIT_WORK(&spi->work, orion_spi_work);
+
+	spin_lock_init(&spi->lock);
+	INIT_LIST_HEAD(&spi->msg_queue);
+
+	if (orion_spi_reset(spi) < 0)
+		goto out_rel_mem;
+
+	status = spi_register_master(master);
+	if (status < 0)
+		goto out_rel_mem;
+
+	return status;
+
+out_rel_mem:
+	release_mem_region(r->start, (r->end - r->start) + 1);
+
+out:
+	spi_master_put(master);
+	return status;
+}
+
+
+static int __exit orion_spi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct orion_spi *spi;
+	struct resource *r;
+
+	master = dev_get_drvdata(&pdev->dev);
+	spi = spi_master_get_devdata(master);
+
+	cancel_work_sync(&spi->work);
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(r->start, (r->end - r->start) + 1);
+
+	spi_unregister_master(master);
+
+	return 0;
+}
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+
+static struct platform_driver orion_spi_driver = {
+	.driver = {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.remove		= __exit_p(orion_spi_remove),
+};
+
+static int __init orion_spi_init(void)
+{
+	orion_spi_wq = create_singlethread_workqueue(
+				orion_spi_driver.driver.name);
+	if (orion_spi_wq == NULL)
+		return -ENOMEM;
+
+	return platform_driver_probe(&orion_spi_driver, orion_spi_probe);
+}
+module_init(orion_spi_init);
+
+static void __exit orion_spi_exit(void)
+{
+	flush_workqueue(orion_spi_wq);
+	platform_driver_unregister(&orion_spi_driver);
+
+	destroy_workqueue(orion_spi_wq);
+}
+module_exit(orion_spi_exit);
+
+MODULE_DESCRIPTION("Orion SPI driver");
+MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi.c

@@ -0,0 +1,893 @@
+/*
+ * spi.c - SPI init/core code
+ *
+ * Copyright (C) 2005 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/cache.h>
+#include <linux/mutex.h>
+#include <linux/mod_devicetable.h>
+#include <linux/spi/spi.h>
+
+
+/* SPI bustype and spi_master class are registered after board init code
+ * provides the SPI device tables, ensuring that both are present by the
+ * time controller driver registration causes spi_devices to "enumerate".
+ */
+static void spidev_release(struct device *dev)
+{
+	struct spi_device	*spi = to_spi_device(dev);
+
+	/* spi masters may cleanup for released devices */
+	if (spi->master->cleanup)
+		spi->master->cleanup(spi);
+
+	spi_master_put(spi->master);
+	kfree(dev);
+}
+
+static ssize_t
+modalias_show(struct device *dev, struct device_attribute *a, char *buf)
+{
+	const struct spi_device	*spi = to_spi_device(dev);
+
+	return sprintf(buf, "%s\n", spi->modalias);
+}
+
+static struct device_attribute spi_dev_attrs[] = {
+	__ATTR_RO(modalias),
+	__ATTR_NULL,
+};
+
+/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
+ * and the sysfs version makes coldplug work too.
+ */
+
+static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
+						const struct spi_device *sdev)
+{
+	while (id->name[0]) {
+		if (!strcmp(sdev->modalias, id->name))
+			return id;
+		id++;
+	}
+	return NULL;
+}
+
+const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
+{
+	const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
+
+	return spi_match_id(sdrv->id_table, sdev);
+}
+EXPORT_SYMBOL_GPL(spi_get_device_id);
+
+static int spi_match_device(struct device *dev, struct device_driver *drv)
+{
+	const struct spi_device	*spi = to_spi_device(dev);
+	const struct spi_driver	*sdrv = to_spi_driver(drv);
+
+	if (sdrv->id_table)
+		return !!spi_match_id(sdrv->id_table, spi);
+
+	return strcmp(spi->modalias, drv->name) == 0;
+}
+
+static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct spi_device		*spi = to_spi_device(dev);
+
+	add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
+	return 0;
+}
+
+#ifdef	CONFIG_PM
+
+static int spi_suspend(struct device *dev, pm_message_t message)
+{
+	int			value = 0;
+	struct spi_driver	*drv = to_spi_driver(dev->driver);
+
+	/* suspend will stop irqs and dma; no more i/o */
+	if (drv) {
+		if (drv->suspend)
+			value = drv->suspend(to_spi_device(dev), message);
+		else
+			dev_dbg(dev, "... can't suspend\n");
+	}
+	return value;
+}
+
+static int spi_resume(struct device *dev)
+{
+	int			value = 0;
+	struct spi_driver	*drv = to_spi_driver(dev->driver);
+
+	/* resume may restart the i/o queue */
+	if (drv) {
+		if (drv->resume)
+			value = drv->resume(to_spi_device(dev));
+		else
+			dev_dbg(dev, "... can't resume\n");
+	}
+	return value;
+}
+
+#else
+#define spi_suspend	NULL
+#define spi_resume	NULL
+#endif
+
+struct bus_type spi_bus_type = {
+	.name		= "spi",
+	.dev_attrs	= spi_dev_attrs,
+	.match		= spi_match_device,
+	.uevent		= spi_uevent,
+	.suspend	= spi_suspend,
+	.resume		= spi_resume,
+};
+EXPORT_SYMBOL_GPL(spi_bus_type);
+
+
+static int spi_drv_probe(struct device *dev)
+{
+	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
+
+	return sdrv->probe(to_spi_device(dev));
+}
+
+static int spi_drv_remove(struct device *dev)
+{
+	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
+
+	return sdrv->remove(to_spi_device(dev));
+}
+
+static void spi_drv_shutdown(struct device *dev)
+{
+	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
+
+	sdrv->shutdown(to_spi_device(dev));
+}
+
+/**
+ * spi_register_driver - register a SPI driver
+ * @sdrv: the driver to register
+ * Context: can sleep
+ */
+int spi_register_driver(struct spi_driver *sdrv)
+{
+	sdrv->driver.bus = &spi_bus_type;
+	if (sdrv->probe)
+		sdrv->driver.probe = spi_drv_probe;
+	if (sdrv->remove)
+		sdrv->driver.remove = spi_drv_remove;
+	if (sdrv->shutdown)
+		sdrv->driver.shutdown = spi_drv_shutdown;
+	return driver_register(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(spi_register_driver);
+
+/*-------------------------------------------------------------------------*/
+
+/* SPI devices should normally not be created by SPI device drivers; that
+ * would make them board-specific.  Similarly with SPI master drivers.
+ * Device registration normally goes into like arch/.../mach.../board-YYY.c
+ * with other readonly (flashable) information about mainboard devices.
+ */
+
+struct boardinfo {
+	struct list_head	list;
+	unsigned		n_board_info;
+	struct spi_board_info	board_info[0];
+};
+
+static LIST_HEAD(board_list);
+static DEFINE_MUTEX(board_lock);
+
+/**
+ * spi_alloc_device - Allocate a new SPI device
+ * @master: Controller to which device is connected
+ * Context: can sleep
+ *
+ * Allows a driver to allocate and initialize a spi_device without
+ * registering it immediately.  This allows a driver to directly
+ * fill the spi_device with device parameters before calling
+ * spi_add_device() on it.
+ *
+ * Caller is responsible to call spi_add_device() on the returned
+ * spi_device structure to add it to the SPI master.  If the caller
+ * needs to discard the spi_device without adding it, then it should
+ * call spi_dev_put() on it.
+ *
+ * Returns a pointer to the new device, or NULL.
+ */
+struct spi_device *spi_alloc_device(struct spi_master *master)
+{
+	struct spi_device	*spi;
+	struct device		*dev = master->dev.parent;
+
+	if (!spi_master_get(master))
+		return NULL;
+
+	spi = kzalloc(sizeof *spi, GFP_KERNEL);
+	if (!spi) {
+		dev_err(dev, "cannot alloc spi_device\n");
+		spi_master_put(master);
+		return NULL;
+	}
+
+	spi->master = master;
+	spi->dev.parent = dev;
+	spi->dev.bus = &spi_bus_type;
+	spi->dev.release = spidev_release;
+	device_initialize(&spi->dev);
+	return spi;
+}
+EXPORT_SYMBOL_GPL(spi_alloc_device);
+
+/**
+ * spi_add_device - Add spi_device allocated with spi_alloc_device
+ * @spi: spi_device to register
+ *
+ * Companion function to spi_alloc_device.  Devices allocated with
+ * spi_alloc_device can be added onto the spi bus with this function.
+ *
+ * Returns 0 on success; negative errno on failure
+ */
+int spi_add_device(struct spi_device *spi)
+{
+	static DEFINE_MUTEX(spi_add_lock);
+	struct device *dev = spi->master->dev.parent;
+	int status;
+
+	/* Chipselects are numbered 0..max; validate. */
+	if (spi->chip_select >= spi->master->num_chipselect) {
+		dev_err(dev, "cs%d >= max %d\n",
+			spi->chip_select,
+			spi->master->num_chipselect);
+		return -EINVAL;
+	}
+
+	/* Set the bus ID string */
+	dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
+			spi->chip_select);
+
+
+	/* We need to make sure there's no other device with this
+	 * chipselect **BEFORE** we call setup(), else we'll trash
+	 * its configuration.  Lock against concurrent add() calls.
+	 */
+	mutex_lock(&spi_add_lock);
+
+	if (bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev))
+			!= NULL) {
+		dev_err(dev, "chipselect %d already in use\n",
+				spi->chip_select);
+		status = -EBUSY;
+		goto done;
+	}
+
+	/* Drivers may modify this initial i/o setup, but will
+	 * normally rely on the device being setup.  Devices
+	 * using SPI_CS_HIGH can't coexist well otherwise...
+	 */
+	status = spi_setup(spi);
+	if (status < 0) {
+		dev_err(dev, "can't %s %s, status %d\n",
+				"setup", dev_name(&spi->dev), status);
+		goto done;
+	}
+
+	/* Device may be bound to an active driver when this returns */
+	status = device_add(&spi->dev);
+	if (status < 0)
+		dev_err(dev, "can't %s %s, status %d\n",
+				"add", dev_name(&spi->dev), status);
+	else
+		dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
+
+done:
+	mutex_unlock(&spi_add_lock);
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_add_device);
+
+/**
+ * spi_new_device - instantiate one new SPI device
+ * @master: Controller to which device is connected
+ * @chip: Describes the SPI device
+ * Context: can sleep
+ *
+ * On typical mainboards, this is purely internal; and it's not needed
+ * after board init creates the hard-wired devices.  Some development
+ * platforms may not be able to use spi_register_board_info though, and
+ * this is exported so that for example a USB or parport based adapter
+ * driver could add devices (which it would learn about out-of-band).
+ *
+ * Returns the new device, or NULL.
+ */
+struct spi_device *spi_new_device(struct spi_master *master,
+				  struct spi_board_info *chip)
+{
+	struct spi_device	*proxy;
+	int			status;
+
+	/* NOTE:  caller did any chip->bus_num checks necessary.
+	 *
+	 * Also, unless we change the return value convention to use
+	 * error-or-pointer (not NULL-or-pointer), troubleshootability
+	 * suggests syslogged diagnostics are best here (ugh).
+	 */
+
+	proxy = spi_alloc_device(master);
+	if (!proxy)
+		return NULL;
+
+	WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
+
+	proxy->chip_select = chip->chip_select;
+	proxy->max_speed_hz = chip->max_speed_hz;
+	proxy->mode = chip->mode;
+	proxy->irq = chip->irq;
+	strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
+	proxy->dev.platform_data = (void *) chip->platform_data;
+	proxy->controller_data = chip->controller_data;
+	proxy->controller_state = NULL;
+
+	status = spi_add_device(proxy);
+	if (status < 0) {
+		spi_dev_put(proxy);
+		return NULL;
+	}
+
+	return proxy;
+}
+EXPORT_SYMBOL_GPL(spi_new_device);
+
+/**
+ * spi_register_board_info - register SPI devices for a given board
+ * @info: array of chip descriptors
+ * @n: how many descriptors are provided
+ * Context: can sleep
+ *
+ * Board-specific early init code calls this (probably during arch_initcall)
+ * with segments of the SPI device table.  Any device nodes are created later,
+ * after the relevant parent SPI controller (bus_num) is defined.  We keep
+ * this table of devices forever, so that reloading a controller driver will
+ * not make Linux forget about these hard-wired devices.
+ *
+ * Other code can also call this, e.g. a particular add-on board might provide
+ * SPI devices through its expansion connector, so code initializing that board
+ * would naturally declare its SPI devices.
+ *
+ * The board info passed can safely be __initdata ... but be careful of
+ * any embedded pointers (platform_data, etc), they're copied as-is.
+ */
+int __init
+spi_register_board_info(struct spi_board_info const *info, unsigned n)
+{
+	struct boardinfo	*bi;
+
+	bi = kmalloc(sizeof(*bi) + n * sizeof *info, GFP_KERNEL);
+	if (!bi)
+		return -ENOMEM;
+	bi->n_board_info = n;
+	memcpy(bi->board_info, info, n * sizeof *info);
+
+	mutex_lock(&board_lock);
+	list_add_tail(&bi->list, &board_list);
+	mutex_unlock(&board_lock);
+	return 0;
+}
+
+/* FIXME someone should add support for a __setup("spi", ...) that
+ * creates board info from kernel command lines
+ */
+
+static void scan_boardinfo(struct spi_master *master)
+{
+	struct boardinfo	*bi;
+
+	mutex_lock(&board_lock);
+	list_for_each_entry(bi, &board_list, list) {
+		struct spi_board_info	*chip = bi->board_info;
+		unsigned		n;
+
+		for (n = bi->n_board_info; n > 0; n--, chip++) {
+			if (chip->bus_num != master->bus_num)
+				continue;
+			/* NOTE: this relies on spi_new_device to
+			 * issue diagnostics when given bogus inputs
+			 */
+			(void) spi_new_device(master, chip);
+		}
+	}
+	mutex_unlock(&board_lock);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void spi_master_release(struct device *dev)
+{
+	struct spi_master *master;
+
+	master = container_of(dev, struct spi_master, dev);
+	kfree(master);
+}
+
+static struct class spi_master_class = {
+	.name		= "spi_master",
+	.owner		= THIS_MODULE,
+	.dev_release	= spi_master_release,
+};
+
+
+/**
+ * spi_alloc_master - allocate SPI master controller
+ * @dev: the controller, possibly using the platform_bus
+ * @size: how much zeroed driver-private data to allocate; the pointer to this
+ *	memory is in the driver_data field of the returned device,
+ *	accessible with spi_master_get_devdata().
+ * Context: can sleep
+ *
+ * This call is used only by SPI master controller drivers, which are the
+ * only ones directly touching chip registers.  It's how they allocate
+ * an spi_master structure, prior to calling spi_register_master().
+ *
+ * This must be called from context that can sleep.  It returns the SPI
+ * master structure on success, else NULL.
+ *
+ * The caller is responsible for assigning the bus number and initializing
+ * the master's methods before calling spi_register_master(); and (after errors
+ * adding the device) calling spi_master_put() to prevent a memory leak.
+ */
+struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
+{
+	struct spi_master	*master;
+
+	if (!dev)
+		return NULL;
+
+	master = kzalloc(size + sizeof *master, GFP_KERNEL);
+	if (!master)
+		return NULL;
+
+	device_initialize(&master->dev);
+	master->dev.class = &spi_master_class;
+	master->dev.parent = get_device(dev);
+	spi_master_set_devdata(master, &master[1]);
+
+	return master;
+}
+EXPORT_SYMBOL_GPL(spi_alloc_master);
+
+/**
+ * spi_register_master - register SPI master controller
+ * @master: initialized master, originally from spi_alloc_master()
+ * Context: can sleep
+ *
+ * SPI master controllers connect to their drivers using some non-SPI bus,
+ * such as the platform bus.  The final stage of probe() in that code
+ * includes calling spi_register_master() to hook up to this SPI bus glue.
+ *
+ * SPI controllers use board specific (often SOC specific) bus numbers,
+ * and board-specific addressing for SPI devices combines those numbers
+ * with chip select numbers.  Since SPI does not directly support dynamic
+ * device identification, boards need configuration tables telling which
+ * chip is at which address.
+ *
+ * This must be called from context that can sleep.  It returns zero on
+ * success, else a negative error code (dropping the master's refcount).
+ * After a successful return, the caller is responsible for calling
+ * spi_unregister_master().
+ */
+int spi_register_master(struct spi_master *master)
+{
+	static atomic_t		dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
+	struct device		*dev = master->dev.parent;
+	int			status = -ENODEV;
+	int			dynamic = 0;
+
+	if (!dev)
+		return -ENODEV;
+
+	/* even if it's just one always-selected device, there must
+	 * be at least one chipselect
+	 */
+	if (master->num_chipselect == 0)
+		return -EINVAL;
+
+	/* convention:  dynamically assigned bus IDs count down from the max */
+	if (master->bus_num < 0) {
+		/* FIXME switch to an IDR based scheme, something like
+		 * I2C now uses, so we can't run out of "dynamic" IDs
+		 */
+		master->bus_num = atomic_dec_return(&dyn_bus_id);
+		dynamic = 1;
+	}
+
+	/* register the device, then userspace will see it.
+	 * registration fails if the bus ID is in use.
+	 */
+	dev_set_name(&master->dev, "spi%u", master->bus_num);
+	status = device_add(&master->dev);
+	if (status < 0)
+		goto done;
+	dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
+			dynamic ? " (dynamic)" : "");
+
+	/* populate children from any spi device tables */
+	scan_boardinfo(master);
+	status = 0;
+done:
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_register_master);
+
+
+static int __unregister(struct device *dev, void *master_dev)
+{
+	/* note: before about 2.6.14-rc1 this would corrupt memory: */
+	if (dev != master_dev)
+		spi_unregister_device(to_spi_device(dev));
+	return 0;
+}
+
+/**
+ * spi_unregister_master - unregister SPI master controller
+ * @master: the master being unregistered
+ * Context: can sleep
+ *
+ * This call is used only by SPI master controller drivers, which are the
+ * only ones directly touching chip registers.
+ *
+ * This must be called from context that can sleep.
+ */
+void spi_unregister_master(struct spi_master *master)
+{
+	int dummy;
+
+	dummy = device_for_each_child(master->dev.parent, &master->dev,
+					__unregister);
+	device_unregister(&master->dev);
+}
+EXPORT_SYMBOL_GPL(spi_unregister_master);
+
+static int __spi_master_match(struct device *dev, void *data)
+{
+	struct spi_master *m;
+	u16 *bus_num = data;
+
+	m = container_of(dev, struct spi_master, dev);
+	return m->bus_num == *bus_num;
+}
+
+/**
+ * spi_busnum_to_master - look up master associated with bus_num
+ * @bus_num: the master's bus number
+ * Context: can sleep
+ *
+ * This call may be used with devices that are registered after
+ * arch init time.  It returns a refcounted pointer to the relevant
+ * spi_master (which the caller must release), or NULL if there is
+ * no such master registered.
+ */
+struct spi_master *spi_busnum_to_master(u16 bus_num)
+{
+	struct device		*dev;
+	struct spi_master	*master = NULL;
+
+	dev = class_find_device(&spi_master_class, NULL, &bus_num,
+				__spi_master_match);
+	if (dev)
+		master = container_of(dev, struct spi_master, dev);
+	/* reference got in class_find_device */
+	return master;
+}
+EXPORT_SYMBOL_GPL(spi_busnum_to_master);
+
+
+/*-------------------------------------------------------------------------*/
+
+/* Core methods for SPI master protocol drivers.  Some of the
+ * other core methods are currently defined as inline functions.
+ */
+
+/**
+ * spi_setup - setup SPI mode and clock rate
+ * @spi: the device whose settings are being modified
+ * Context: can sleep, and no requests are queued to the device
+ *
+ * SPI protocol drivers may need to update the transfer mode if the
+ * device doesn't work with its default.  They may likewise need
+ * to update clock rates or word sizes from initial values.  This function
+ * changes those settings, and must be called from a context that can sleep.
+ * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
+ * effect the next time the device is selected and data is transferred to
+ * or from it.  When this function returns, the spi device is deselected.
+ *
+ * Note that this call will fail if the protocol driver specifies an option
+ * that the underlying controller or its driver does not support.  For
+ * example, not all hardware supports wire transfers using nine bit words,
+ * LSB-first wire encoding, or active-high chipselects.
+ */
+int spi_setup(struct spi_device *spi)
+{
+	unsigned	bad_bits;
+	int		status;
+
+	/* help drivers fail *cleanly* when they need options
+	 * that aren't supported with their current master
+	 */
+	bad_bits = spi->mode & ~spi->master->mode_bits;
+	if (bad_bits) {
+		dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+			bad_bits);
+		return -EINVAL;
+	}
+
+	if (!spi->bits_per_word)
+		spi->bits_per_word = 8;
+
+	status = spi->master->setup(spi);
+
+	dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s"
+				"%u bits/w, %u Hz max --> %d\n",
+			(int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
+			(spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
+			(spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
+			(spi->mode & SPI_3WIRE) ? "3wire, " : "",
+			(spi->mode & SPI_LOOP) ? "loopback, " : "",
+			spi->bits_per_word, spi->max_speed_hz,
+			status);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_setup);
+
+/**
+ * spi_async - asynchronous SPI transfer
+ * @spi: device with which data will be exchanged
+ * @message: describes the data transfers, including completion callback
+ * Context: any (irqs may be blocked, etc)
+ *
+ * This call may be used in_irq and other contexts which can't sleep,
+ * as well as from task contexts which can sleep.
+ *
+ * The completion callback is invoked in a context which can't sleep.
+ * Before that invocation, the value of message->status is undefined.
+ * When the callback is issued, message->status holds either zero (to
+ * indicate complete success) or a negative error code.  After that
+ * callback returns, the driver which issued the transfer request may
+ * deallocate the associated memory; it's no longer in use by any SPI
+ * core or controller driver code.
+ *
+ * Note that although all messages to a spi_device are handled in
+ * FIFO order, messages may go to different devices in other orders.
+ * Some device might be higher priority, or have various "hard" access
+ * time requirements, for example.
+ *
+ * On detection of any fault during the transfer, processing of
+ * the entire message is aborted, and the device is deselected.
+ * Until returning from the associated message completion callback,
+ * no other spi_message queued to that device will be processed.
+ * (This rule applies equally to all the synchronous transfer calls,
+ * which are wrappers around this core asynchronous primitive.)
+ */
+int spi_async(struct spi_device *spi, struct spi_message *message)
+{
+	struct spi_master *master = spi->master;
+
+	/* Half-duplex links include original MicroWire, and ones with
+	 * only one data pin like SPI_3WIRE (switches direction) or where
+	 * either MOSI or MISO is missing.  They can also be caused by
+	 * software limitations.
+	 */
+	if ((master->flags & SPI_MASTER_HALF_DUPLEX)
+			|| (spi->mode & SPI_3WIRE)) {
+		struct spi_transfer *xfer;
+		unsigned flags = master->flags;
+
+		list_for_each_entry(xfer, &message->transfers, transfer_list) {
+			if (xfer->rx_buf && xfer->tx_buf)
+				return -EINVAL;
+			if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
+				return -EINVAL;
+			if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
+				return -EINVAL;
+		}
+	}
+
+	message->spi = spi;
+	message->status = -EINPROGRESS;
+	return master->transfer(spi, message);
+}
+EXPORT_SYMBOL_GPL(spi_async);
+
+
+/*-------------------------------------------------------------------------*/
+
+/* Utility methods for SPI master protocol drivers, layered on
+ * top of the core.  Some other utility methods are defined as
+ * inline functions.
+ */
+
+static void spi_complete(void *arg)
+{
+	complete(arg);
+}
+
+/**
+ * spi_sync - blocking/synchronous SPI data transfers
+ * @spi: device with which data will be exchanged
+ * @message: describes the data transfers
+ * Context: can sleep
+ *
+ * This call may only be used from a context that may sleep.  The sleep
+ * is non-interruptible, and has no timeout.  Low-overhead controller
+ * drivers may DMA directly into and out of the message buffers.
+ *
+ * Note that the SPI device's chip select is active during the message,
+ * and then is normally disabled between messages.  Drivers for some
+ * frequently-used devices may want to minimize costs of selecting a chip,
+ * by leaving it selected in anticipation that the next message will go
+ * to the same chip.  (That may increase power usage.)
+ *
+ * Also, the caller is guaranteeing that the memory associated with the
+ * message will not be freed before this call returns.
+ *
+ * It returns zero on success, else a negative error code.
+ */
+int spi_sync(struct spi_device *spi, struct spi_message *message)
+{
+	DECLARE_COMPLETION_ONSTACK(done);
+	int status;
+
+	message->complete = spi_complete;
+	message->context = &done;
+	status = spi_async(spi, message);
+	if (status == 0) {
+		wait_for_completion(&done);
+		status = message->status;
+	}
+	message->context = NULL;
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_sync);
+
+/* portable code must never pass more than 32 bytes */
+#define	SPI_BUFSIZ	max(32,SMP_CACHE_BYTES)
+
+static u8	*buf;
+
+/**
+ * spi_write_then_read - SPI synchronous write followed by read
+ * @spi: device with which data will be exchanged
+ * @txbuf: data to be written (need not be dma-safe)
+ * @n_tx: size of txbuf, in bytes
+ * @rxbuf: buffer into which data will be read (need not be dma-safe)
+ * @n_rx: size of rxbuf, in bytes
+ * Context: can sleep
+ *
+ * This performs a half duplex MicroWire style transaction with the
+ * device, sending txbuf and then reading rxbuf.  The return value
+ * is zero for success, else a negative errno status code.
+ * This call may only be used from a context that may sleep.
+ *
+ * Parameters to this routine are always copied using a small buffer;
+ * portable code should never use this for more than 32 bytes.
+ * Performance-sensitive or bulk transfer code should instead use
+ * spi_{async,sync}() calls with dma-safe buffers.
+ */
+int spi_write_then_read(struct spi_device *spi,
+		const u8 *txbuf, unsigned n_tx,
+		u8 *rxbuf, unsigned n_rx)
+{
+	static DEFINE_MUTEX(lock);
+
+	int			status;
+	struct spi_message	message;
+	struct spi_transfer	x[2];
+	u8			*local_buf;
+
+	/* Use preallocated DMA-safe buffer.  We can't avoid copying here,
+	 * (as a pure convenience thing), but we can keep heap costs
+	 * out of the hot path ...
+	 */
+	if ((n_tx + n_rx) > SPI_BUFSIZ)
+		return -EINVAL;
+
+	spi_message_init(&message);
+	memset(x, 0, sizeof x);
+	if (n_tx) {
+		x[0].len = n_tx;
+		spi_message_add_tail(&x[0], &message);
+	}
+	if (n_rx) {
+		x[1].len = n_rx;
+		spi_message_add_tail(&x[1], &message);
+	}
+
+	/* ... unless someone else is using the pre-allocated buffer */
+	if (!mutex_trylock(&lock)) {
+		local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
+		if (!local_buf)
+			return -ENOMEM;
+	} else
+		local_buf = buf;
+
+	memcpy(local_buf, txbuf, n_tx);
+	x[0].tx_buf = local_buf;
+	x[1].rx_buf = local_buf + n_tx;
+
+	/* do the i/o */
+	status = spi_sync(spi, &message);
+	if (status == 0)
+		memcpy(rxbuf, x[1].rx_buf, n_rx);
+
+	if (x[0].tx_buf == buf)
+		mutex_unlock(&lock);
+	else
+		kfree(local_buf);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_write_then_read);
+
+/*-------------------------------------------------------------------------*/
+
+static int __init spi_init(void)
+{
+	int	status;
+
+	buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
+	if (!buf) {
+		status = -ENOMEM;
+		goto err0;
+	}
+
+	status = bus_register(&spi_bus_type);
+	if (status < 0)
+		goto err1;
+
+	status = class_register(&spi_master_class);
+	if (status < 0)
+		goto err2;
+	return 0;
+
+err2:
+	bus_unregister(&spi_bus_type);
+err1:
+	kfree(buf);
+	buf = NULL;
+err0:
+	return status;
+}
+
+/* board_info is normally registered in arch_initcall(),
+ * but even essential drivers wait till later
+ *
+ * REVISIT only boardinfo really needs static linking. the rest (device and
+ * driver registration) _could_ be dynamically linked (modular) ... costs
+ * include needing to have boardinfo data structures be much more public.
+ */
+postcore_initcall(spi_init);
+

kernel/drivers/spi/spi_bitbang.c

@@ -0,0 +1,512 @@
+/*
+ * spi_bitbang.c - polling/bitbanging SPI master controller driver utilities
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * FIRST PART (OPTIONAL):  word-at-a-time spi_transfer support.
+ * Use this for GPIO or shift-register level hardware APIs.
+ *
+ * spi_bitbang_cs is in spi_device->controller_state, which is unavailable
+ * to glue code.  These bitbang setup() and cleanup() routines are always
+ * used, though maybe they're called from controller-aware code.
+ *
+ * chipselect() and friends may use use spi_device->controller_data and
+ * controller registers as appropriate.
+ *
+ *
+ * NOTE:  SPI controller pins can often be used as GPIO pins instead,
+ * which means you could use a bitbang driver either to get hardware
+ * working quickly, or testing for differences that aren't speed related.
+ */
+
+struct spi_bitbang_cs {
+	unsigned	nsecs;	/* (clock cycle time)/2 */
+	u32		(*txrx_word)(struct spi_device *spi, unsigned nsecs,
+					u32 word, u8 bits);
+	unsigned	(*txrx_bufs)(struct spi_device *,
+					u32 (*txrx_word)(
+						struct spi_device *spi,
+						unsigned nsecs,
+						u32 word, u8 bits),
+					unsigned, struct spi_transfer *);
+};
+
+static unsigned bitbang_txrx_8(
+	struct spi_device	*spi,
+	u32			(*txrx_word)(struct spi_device *spi,
+					unsigned nsecs,
+					u32 word, u8 bits),
+	unsigned		ns,
+	struct spi_transfer	*t
+) {
+	unsigned		bits = spi->bits_per_word;
+	unsigned		count = t->len;
+	const u8		*tx = t->tx_buf;
+	u8			*rx = t->rx_buf;
+
+	while (likely(count > 0)) {
+		u8		word = 0;
+
+		if (tx)
+			word = *tx++;
+		word = txrx_word(spi, ns, word, bits);
+		if (rx)
+			*rx++ = word;
+		count -= 1;
+	}
+	return t->len - count;
+}
+
+static unsigned bitbang_txrx_16(
+	struct spi_device	*spi,
+	u32			(*txrx_word)(struct spi_device *spi,
+					unsigned nsecs,
+					u32 word, u8 bits),
+	unsigned		ns,
+	struct spi_transfer	*t
+) {
+	unsigned		bits = spi->bits_per_word;
+	unsigned		count = t->len;
+	const u16		*tx = t->tx_buf;
+	u16			*rx = t->rx_buf;
+
+	while (likely(count > 1)) {
+		u16		word = 0;
+
+		if (tx)
+			word = *tx++;
+		word = txrx_word(spi, ns, word, bits);
+		if (rx)
+			*rx++ = word;
+		count -= 2;
+	}
+	return t->len - count;
+}
+
+static unsigned bitbang_txrx_32(
+	struct spi_device	*spi,
+	u32			(*txrx_word)(struct spi_device *spi,
+					unsigned nsecs,
+					u32 word, u8 bits),
+	unsigned		ns,
+	struct spi_transfer	*t
+) {
+	unsigned		bits = spi->bits_per_word;
+	unsigned		count = t->len;
+	const u32		*tx = t->tx_buf;
+	u32			*rx = t->rx_buf;
+
+	while (likely(count > 3)) {
+		u32		word = 0;
+
+		if (tx)
+			word = *tx++;
+		word = txrx_word(spi, ns, word, bits);
+		if (rx)
+			*rx++ = word;
+		count -= 4;
+	}
+	return t->len - count;
+}
+
+int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct spi_bitbang_cs	*cs = spi->controller_state;
+	u8			bits_per_word;
+	u32			hz;
+
+	if (t) {
+		bits_per_word = t->bits_per_word;
+		hz = t->speed_hz;
+	} else {
+		bits_per_word = 0;
+		hz = 0;
+	}
+
+	/* spi_transfer level calls that work per-word */
+	if (!bits_per_word)
+		bits_per_word = spi->bits_per_word;
+	if (bits_per_word <= 8)
+		cs->txrx_bufs = bitbang_txrx_8;
+	else if (bits_per_word <= 16)
+		cs->txrx_bufs = bitbang_txrx_16;
+	else if (bits_per_word <= 32)
+		cs->txrx_bufs = bitbang_txrx_32;
+	else
+		return -EINVAL;
+
+	/* nsecs = (clock period)/2 */
+	if (!hz)
+		hz = spi->max_speed_hz;
+	if (hz) {
+		cs->nsecs = (1000000000/2) / hz;
+		if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000))
+			return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_setup_transfer);
+
+/**
+ * spi_bitbang_setup - default setup for per-word I/O loops
+ */
+int spi_bitbang_setup(struct spi_device *spi)
+{
+	struct spi_bitbang_cs	*cs = spi->controller_state;
+	struct spi_bitbang	*bitbang;
+	int			retval;
+	unsigned long		flags;
+
+	bitbang = spi_master_get_devdata(spi->master);
+
+	if (!cs) {
+		cs = kzalloc(sizeof *cs, GFP_KERNEL);
+		if (!cs)
+			return -ENOMEM;
+		spi->controller_state = cs;
+	}
+
+	/* per-word shift register access, in hardware or bitbanging */
+	cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
+	if (!cs->txrx_word)
+		return -EINVAL;
+
+	retval = bitbang->setup_transfer(spi, NULL);
+	if (retval < 0)
+		return retval;
+
+	dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs);
+
+	/* NOTE we _need_ to call chipselect() early, ideally with adapter
+	 * setup, unless the hardware defaults cooperate to avoid confusion
+	 * between normal (active low) and inverted chipselects.
+	 */
+
+	/* deselect chip (low or high) */
+	spin_lock_irqsave(&bitbang->lock, flags);
+	if (!bitbang->busy) {
+		bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
+		ndelay(cs->nsecs);
+	}
+	spin_unlock_irqrestore(&bitbang->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_setup);
+
+/**
+ * spi_bitbang_cleanup - default cleanup for per-word I/O loops
+ */
+void spi_bitbang_cleanup(struct spi_device *spi)
+{
+	kfree(spi->controller_state);
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_cleanup);
+
+static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct spi_bitbang_cs	*cs = spi->controller_state;
+	unsigned		nsecs = cs->nsecs;
+
+	return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * SECOND PART ... simple transfer queue runner.
+ *
+ * This costs a task context per controller, running the queue by
+ * performing each transfer in sequence.  Smarter hardware can queue
+ * several DMA transfers at once, and process several controller queues
+ * in parallel; this driver doesn't match such hardware very well.
+ *
+ * Drivers can provide word-at-a-time i/o primitives, or provide
+ * transfer-at-a-time ones to leverage dma or fifo hardware.
+ */
+static void bitbang_work(struct work_struct *work)
+{
+	struct spi_bitbang	*bitbang =
+		container_of(work, struct spi_bitbang, work);
+	unsigned long		flags;
+	int			do_setup = -1;
+	int			(*setup_transfer)(struct spi_device *,
+					struct spi_transfer *);
+
+	setup_transfer = bitbang->setup_transfer;
+
+	spin_lock_irqsave(&bitbang->lock, flags);
+	bitbang->busy = 1;
+	while (!list_empty(&bitbang->queue)) {
+		struct spi_message	*m;
+		struct spi_device	*spi;
+		unsigned		nsecs;
+		struct spi_transfer	*t = NULL;
+		unsigned		tmp;
+		unsigned		cs_change;
+		int			status;
+
+		m = container_of(bitbang->queue.next, struct spi_message,
+				queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&bitbang->lock, flags);
+
+		/* FIXME this is made-up ... the correct value is known to
+		 * word-at-a-time bitbang code, and presumably chipselect()
+		 * should enforce these requirements too?
+		 */
+		nsecs = 100;
+
+		spi = m->spi;
+		tmp = 0;
+		cs_change = 1;
+		status = 0;
+
+		list_for_each_entry (t, &m->transfers, transfer_list) {
+
+			/* override speed or wordsize? */
+			if (t->speed_hz || t->bits_per_word)
+				do_setup = 1;
+
+			/* init (-1) or override (1) transfer params */
+			if (do_setup != 0) {
+				if (!setup_transfer) {
+					status = -ENOPROTOOPT;
+					break;
+				}
+				status = setup_transfer(spi, t);
+				if (status < 0)
+					break;
+			}
+
+			/* set up default clock polarity, and activate chip;
+			 * this implicitly updates clock and spi modes as
+			 * previously recorded for this device via setup().
+			 * (and also deselects any other chip that might be
+			 * selected ...)
+			 */
+			if (cs_change) {
+				bitbang->chipselect(spi, BITBANG_CS_ACTIVE);
+				ndelay(nsecs);
+			}
+			cs_change = t->cs_change;
+			if (!t->tx_buf && !t->rx_buf && t->len) {
+				status = -EINVAL;
+				break;
+			}
+
+			/* transfer data.  the lower level code handles any
+			 * new dma mappings it needs. our caller always gave
+			 * us dma-safe buffers.
+			 */
+			if (t->len) {
+				/* REVISIT dma API still needs a designated
+				 * DMA_ADDR_INVALID; ~0 might be better.
+				 */
+				if (!m->is_dma_mapped)
+					t->rx_dma = t->tx_dma = 0;
+				status = bitbang->txrx_bufs(spi, t);
+			}
+			if (status > 0)
+				m->actual_length += status;
+			if (status != t->len) {
+				/* always report some kind of error */
+				if (status >= 0)
+					status = -EREMOTEIO;
+				break;
+			}
+			status = 0;
+
+			/* protocol tweaks before next transfer */
+			if (t->delay_usecs)
+				udelay(t->delay_usecs);
+
+			if (!cs_change)
+				continue;
+			if (t->transfer_list.next == &m->transfers)
+				break;
+
+			/* sometimes a short mid-message deselect of the chip
+			 * may be needed to terminate a mode or command
+			 */
+			ndelay(nsecs);
+			bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
+			ndelay(nsecs);
+		}
+
+		m->status = status;
+		m->complete(m->context);
+
+		/* restore speed and wordsize if it was overridden */
+		if (do_setup == 1)
+			setup_transfer(spi, NULL);
+		do_setup = 0;
+
+		/* normally deactivate chipselect ... unless no error and
+		 * cs_change has hinted that the next message will probably
+		 * be for this chip too.
+		 */
+		if (!(status == 0 && cs_change)) {
+			ndelay(nsecs);
+			bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
+			ndelay(nsecs);
+		}
+
+		spin_lock_irqsave(&bitbang->lock, flags);
+	}
+	bitbang->busy = 0;
+	spin_unlock_irqrestore(&bitbang->lock, flags);
+}
+
+/**
+ * spi_bitbang_transfer - default submit to transfer queue
+ */
+int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct spi_bitbang	*bitbang;
+	unsigned long		flags;
+	int			status = 0;
+
+	m->actual_length = 0;
+	m->status = -EINPROGRESS;
+
+	bitbang = spi_master_get_devdata(spi->master);
+
+	spin_lock_irqsave(&bitbang->lock, flags);
+	if (!spi->max_speed_hz)
+		status = -ENETDOWN;
+	else {
+		list_add_tail(&m->queue, &bitbang->queue);
+		queue_work(bitbang->workqueue, &bitbang->work);
+	}
+	spin_unlock_irqrestore(&bitbang->lock, flags);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
+
+/*----------------------------------------------------------------------*/
+
+/**
+ * spi_bitbang_start - start up a polled/bitbanging SPI master driver
+ * @bitbang: driver handle
+ *
+ * Caller should have zero-initialized all parts of the structure, and then
+ * provided callbacks for chip selection and I/O loops.  If the master has
+ * a transfer method, its final step should call spi_bitbang_transfer; or,
+ * that's the default if the transfer routine is not initialized.  It should
+ * also set up the bus number and number of chipselects.
+ *
+ * For i/o loops, provide callbacks either per-word (for bitbanging, or for
+ * hardware that basically exposes a shift register) or per-spi_transfer
+ * (which takes better advantage of hardware like fifos or DMA engines).
+ *
+ * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup,
+ * spi_bitbang_cleanup and spi_bitbang_setup_transfer to handle those spi
+ * master methods.  Those methods are the defaults if the bitbang->txrx_bufs
+ * routine isn't initialized.
+ *
+ * This routine registers the spi_master, which will process requests in a
+ * dedicated task, keeping IRQs unblocked most of the time.  To stop
+ * processing those requests, call spi_bitbang_stop().
+ */
+int spi_bitbang_start(struct spi_bitbang *bitbang)
+{
+	int	status;
+
+	if (!bitbang->master || !bitbang->chipselect)
+		return -EINVAL;
+
+	INIT_WORK(&bitbang->work, bitbang_work);
+	spin_lock_init(&bitbang->lock);
+	INIT_LIST_HEAD(&bitbang->queue);
+
+	if (!bitbang->master->mode_bits)
+		bitbang->master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags;
+
+	if (!bitbang->master->transfer)
+		bitbang->master->transfer = spi_bitbang_transfer;
+	if (!bitbang->txrx_bufs) {
+		bitbang->use_dma = 0;
+		bitbang->txrx_bufs = spi_bitbang_bufs;
+		if (!bitbang->master->setup) {
+			if (!bitbang->setup_transfer)
+				bitbang->setup_transfer =
+					 spi_bitbang_setup_transfer;
+			bitbang->master->setup = spi_bitbang_setup;
+			bitbang->master->cleanup = spi_bitbang_cleanup;
+		}
+	} else if (!bitbang->master->setup)
+		return -EINVAL;
+
+	/* this task is the only thing to touch the SPI bits */
+	bitbang->busy = 0;
+	bitbang->workqueue = create_singlethread_workqueue(
+			dev_name(bitbang->master->dev.parent));
+	if (bitbang->workqueue == NULL) {
+		status = -EBUSY;
+		goto err1;
+	}
+
+	/* driver may get busy before register() returns, especially
+	 * if someone registered boardinfo for devices
+	 */
+	status = spi_register_master(bitbang->master);
+	if (status < 0)
+		goto err2;
+
+	return status;
+
+err2:
+	destroy_workqueue(bitbang->workqueue);
+err1:
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_start);
+
+/**
+ * spi_bitbang_stop - stops the task providing spi communication
+ */
+int spi_bitbang_stop(struct spi_bitbang *bitbang)
+{
+	spi_unregister_master(bitbang->master);
+
+	WARN_ON(!list_empty(&bitbang->queue));
+
+	destroy_workqueue(bitbang->workqueue);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_stop);
+
+MODULE_LICENSE("GPL");
+

kernel/drivers/spi/spi_butterfly.c

@@ -0,0 +1,357 @@
+/*
+ * spi_butterfly.c - parport-to-butterfly adapter
+ *
+ * Copyright (C) 2005 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/parport.h>
+
+#include <linux/sched.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/flash.h>
+
+#include <linux/mtd/partitions.h>
+
+
+/*
+ * This uses SPI to talk with an "AVR Butterfly", which is a $US20 card
+ * with a battery powered AVR microcontroller and lots of goodies.  You
+ * can use GCC to develop firmware for this.
+ *
+ * See Documentation/spi/butterfly for information about how to build
+ * and use this custom parallel port cable.
+ */
+
+
+/* DATA output bits (pins 2..9 == D0..D7) */
+#define	butterfly_nreset (1 << 1)		/* pin 3 */
+
+#define	spi_sck_bit	(1 << 0)		/* pin 2 */
+#define	spi_mosi_bit	(1 << 7)		/* pin 9 */
+
+#define	vcc_bits	((1 << 6) | (1 << 5))	/* pins 7, 8 */
+
+/* STATUS input bits */
+#define	spi_miso_bit	PARPORT_STATUS_BUSY	/* pin 11 */
+
+/* CONTROL output bits */
+#define	spi_cs_bit	PARPORT_CONTROL_SELECT	/* pin 17 */
+
+
+
+static inline struct butterfly *spidev_to_pp(struct spi_device *spi)
+{
+	return spi->controller_data;
+}
+
+
+struct butterfly {
+	/* REVISIT ... for now, this must be first */
+	struct spi_bitbang	bitbang;
+
+	struct parport		*port;
+	struct pardevice	*pd;
+
+	u8			lastbyte;
+
+	struct spi_device	*dataflash;
+	struct spi_device	*butterfly;
+	struct spi_board_info	info[2];
+
+};
+
+/*----------------------------------------------------------------------*/
+
+static inline void
+setsck(struct spi_device *spi, int is_on)
+{
+	struct butterfly	*pp = spidev_to_pp(spi);
+	u8			bit, byte = pp->lastbyte;
+
+	bit = spi_sck_bit;
+
+	if (is_on)
+		byte |= bit;
+	else
+		byte &= ~bit;
+	parport_write_data(pp->port, byte);
+	pp->lastbyte = byte;
+}
+
+static inline void
+setmosi(struct spi_device *spi, int is_on)
+{
+	struct butterfly	*pp = spidev_to_pp(spi);
+	u8			bit, byte = pp->lastbyte;
+
+	bit = spi_mosi_bit;
+
+	if (is_on)
+		byte |= bit;
+	else
+		byte &= ~bit;
+	parport_write_data(pp->port, byte);
+	pp->lastbyte = byte;
+}
+
+static inline int getmiso(struct spi_device *spi)
+{
+	struct butterfly	*pp = spidev_to_pp(spi);
+	int			value;
+	u8			bit;
+
+	bit = spi_miso_bit;
+
+	/* only STATUS_BUSY is NOT negated */
+	value = !(parport_read_status(pp->port) & bit);
+	return (bit == PARPORT_STATUS_BUSY) ? value : !value;
+}
+
+static void butterfly_chipselect(struct spi_device *spi, int value)
+{
+	struct butterfly	*pp = spidev_to_pp(spi);
+
+	/* set default clock polarity */
+	if (value != BITBANG_CS_INACTIVE)
+		setsck(spi, spi->mode & SPI_CPOL);
+
+	/* here, value == "activate or not";
+	 * most PARPORT_CONTROL_* bits are negated, so we must
+	 * morph it to value == "bit value to write in control register"
+	 */
+	if (spi_cs_bit == PARPORT_CONTROL_INIT)
+		value = !value;
+
+	parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0);
+}
+
+
+/* we only needed to implement one mode here, and choose SPI_MODE_0 */
+
+#define	spidelay(X)	do{}while(0)
+//#define	spidelay	ndelay
+
+#define	EXPAND_BITBANG_TXRX
+#include <linux/spi/spi_bitbang.h>
+
+static u32
+butterfly_txrx_word_mode0(struct spi_device *spi,
+		unsigned nsecs,
+		u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+/*----------------------------------------------------------------------*/
+
+/* override default partitioning with cmdlinepart */
+static struct mtd_partition partitions[] = { {
+	/* JFFS2 wants partitions of 4*N blocks for this device,
+	 * so sectors 0 and 1 can't be partitions by themselves.
+	 */
+
+	/* sector 0 = 8 pages * 264 bytes/page (1 block)
+	 * sector 1 = 248 pages * 264 bytes/page
+	 */
+	.name		= "bookkeeping",	// 66 KB
+	.offset		= 0,
+	.size		= (8 + 248) * 264,
+//	.mask_flags	= MTD_WRITEABLE,
+}, {
+	/* sector 2 = 256 pages * 264 bytes/page
+	 * sectors 3-5 = 512 pages * 264 bytes/page
+	 */
+	.name		= "filesystem",		// 462 KB
+	.offset		= MTDPART_OFS_APPEND,
+	.size		= MTDPART_SIZ_FULL,
+} };
+
+static struct flash_platform_data flash = {
+	.name		= "butterflash",
+	.parts		= partitions,
+	.nr_parts	= ARRAY_SIZE(partitions),
+};
+
+
+/* REVISIT remove this ugly global and its "only one" limitation */
+static struct butterfly *butterfly;
+
+static void butterfly_attach(struct parport *p)
+{
+	struct pardevice	*pd;
+	int			status;
+	struct butterfly	*pp;
+	struct spi_master	*master;
+	struct device		*dev = p->physport->dev;
+
+	if (butterfly || !dev)
+		return;
+
+	/* REVISIT:  this just _assumes_ a butterfly is there ... no probe,
+	 * and no way to be selective about what it binds to.
+	 */
+
+	master = spi_alloc_master(dev, sizeof *pp);
+	if (!master) {
+		status = -ENOMEM;
+		goto done;
+	}
+	pp = spi_master_get_devdata(master);
+
+	/*
+	 * SPI and bitbang hookup
+	 *
+	 * use default setup(), cleanup(), and transfer() methods; and
+	 * only bother implementing mode 0.  Start it later.
+	 */
+	master->bus_num = 42;
+	master->num_chipselect = 2;
+
+	pp->bitbang.master = spi_master_get(master);
+	pp->bitbang.chipselect = butterfly_chipselect;
+	pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0;
+
+	/*
+	 * parport hookup
+	 */
+	pp->port = p;
+	pd = parport_register_device(p, "spi_butterfly",
+			NULL, NULL, NULL,
+			0 /* FLAGS */, pp);
+	if (!pd) {
+		status = -ENOMEM;
+		goto clean0;
+	}
+	pp->pd = pd;
+
+	status = parport_claim(pd);
+	if (status < 0)
+		goto clean1;
+
+	/*
+	 * Butterfly reset, powerup, run firmware
+	 */
+	pr_debug("%s: powerup/reset Butterfly\n", p->name);
+
+	/* nCS for dataflash (this bit is inverted on output) */
+	parport_frob_control(pp->port, spi_cs_bit, 0);
+
+	/* stabilize power with chip in reset (nRESET), and
+	 * spi_sck_bit clear (CPOL=0)
+	 */
+	pp->lastbyte |= vcc_bits;
+	parport_write_data(pp->port, pp->lastbyte);
+	msleep(5);
+
+	/* take it out of reset; assume long reset delay */
+	pp->lastbyte |= butterfly_nreset;
+	parport_write_data(pp->port, pp->lastbyte);
+	msleep(100);
+
+
+	/*
+	 * Start SPI ... for now, hide that we're two physical busses.
+	 */
+	status = spi_bitbang_start(&pp->bitbang);
+	if (status < 0)
+		goto clean2;
+
+	/* Bus 1 lets us talk to at45db041b (firmware disables AVR SPI), AVR
+	 * (firmware resets at45, acts as spi slave) or neither (we ignore
+	 * both, AVR uses AT45).  Here we expect firmware for the first option.
+	 */
+
+	pp->info[0].max_speed_hz = 15 * 1000 * 1000;
+	strcpy(pp->info[0].modalias, "mtd_dataflash");
+	pp->info[0].platform_data = &flash;
+	pp->info[0].chip_select = 1;
+	pp->info[0].controller_data = pp;
+	pp->dataflash = spi_new_device(pp->bitbang.master, &pp->info[0]);
+	if (pp->dataflash)
+		pr_debug("%s: dataflash at %s\n", p->name,
+				dev_name(&pp->dataflash->dev));
+
+	// dev_info(_what?_, ...)
+	pr_info("%s: AVR Butterfly\n", p->name);
+	butterfly = pp;
+	return;
+
+clean2:
+	/* turn off VCC */
+	parport_write_data(pp->port, 0);
+
+	parport_release(pp->pd);
+clean1:
+	parport_unregister_device(pd);
+clean0:
+	(void) spi_master_put(pp->bitbang.master);
+done:
+	pr_debug("%s: butterfly probe, fail %d\n", p->name, status);
+}
+
+static void butterfly_detach(struct parport *p)
+{
+	struct butterfly	*pp;
+	int			status;
+
+	/* FIXME this global is ugly ... but, how to quickly get from
+	 * the parport to the "struct butterfly" associated with it?
+	 * "old school" driver-internal device lists?
+	 */
+	if (!butterfly || butterfly->port != p)
+		return;
+	pp = butterfly;
+	butterfly = NULL;
+
+	/* stop() unregisters child devices too */
+	status = spi_bitbang_stop(&pp->bitbang);
+
+	/* turn off VCC */
+	parport_write_data(pp->port, 0);
+	msleep(10);
+
+	parport_release(pp->pd);
+	parport_unregister_device(pp->pd);
+
+	(void) spi_master_put(pp->bitbang.master);
+}
+
+static struct parport_driver butterfly_driver = {
+	.name =		"spi_butterfly",
+	.attach =	butterfly_attach,
+	.detach =	butterfly_detach,
+};
+
+
+static int __init butterfly_init(void)
+{
+	return parport_register_driver(&butterfly_driver);
+}
+device_initcall(butterfly_init);
+
+static void __exit butterfly_exit(void)
+{
+	parport_unregister_driver(&butterfly_driver);
+}
+module_exit(butterfly_exit);
+
+MODULE_DESCRIPTION("Parport Adapter driver for AVR Butterfly");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_gpio.c

@@ -0,0 +1,365 @@
+/*
+ * spi_gpio.c - SPI master driver using generic bitbanged GPIO
+ *
+ * Copyright (C) 2006,2008 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/spi_gpio.h>
+
+
+/*
+ * This bitbanging SPI master driver should help make systems usable
+ * when a native hardware SPI engine is not available, perhaps because
+ * its driver isn't yet working or because the I/O pins it requires
+ * are used for other purposes.
+ *
+ * platform_device->driver_data ... points to spi_gpio
+ *
+ * spi->controller_state ... reserved for bitbang framework code
+ * spi->controller_data ... holds chipselect GPIO
+ *
+ * spi->master->dev.driver_data ... points to spi_gpio->bitbang
+ */
+
+struct spi_gpio {
+	struct spi_bitbang		bitbang;
+	struct spi_gpio_platform_data	pdata;
+	struct platform_device		*pdev;
+};
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Because the overhead of going through four GPIO procedure calls
+ * per transferred bit can make performance a problem, this code
+ * is set up so that you can use it in either of two ways:
+ *
+ *   - The slow generic way:  set up platform_data to hold the GPIO
+ *     numbers used for MISO/MOSI/SCK, and issue procedure calls for
+ *     each of them.  This driver can handle several such busses.
+ *
+ *   - The quicker inlined way:  only helps with platform GPIO code
+ *     that inlines operations for constant GPIOs.  This can give
+ *     you tight (fast!) inner loops, but each such bus needs a
+ *     new driver.  You'll define a new C file, with Makefile and
+ *     Kconfig support; the C code can be a total of six lines:
+ *
+ *		#define DRIVER_NAME	"myboard_spi2"
+ *		#define	SPI_MISO_GPIO	119
+ *		#define	SPI_MOSI_GPIO	120
+ *		#define	SPI_SCK_GPIO	121
+ *		#define	SPI_N_CHIPSEL	4
+ *		#include "spi_gpio.c"
+ */
+
+#ifndef DRIVER_NAME
+#define DRIVER_NAME	"spi_gpio"
+
+#define GENERIC_BITBANG	/* vs tight inlines */
+
+/* all functions referencing these symbols must define pdata */
+#define SPI_MISO_GPIO	((pdata)->miso)
+#define SPI_MOSI_GPIO	((pdata)->mosi)
+#define SPI_SCK_GPIO	((pdata)->sck)
+
+#define SPI_N_CHIPSEL	((pdata)->num_chipselect)
+
+#endif
+
+/*----------------------------------------------------------------------*/
+
+static inline const struct spi_gpio_platform_data * __pure
+spi_to_pdata(const struct spi_device *spi)
+{
+	const struct spi_bitbang	*bang;
+	const struct spi_gpio		*spi_gpio;
+
+	bang = spi_master_get_devdata(spi->master);
+	spi_gpio = container_of(bang, struct spi_gpio, bitbang);
+	return &spi_gpio->pdata;
+}
+
+/* this is #defined to avoid unused-variable warnings when inlining */
+#define pdata		spi_to_pdata(spi)
+
+static inline void setsck(const struct spi_device *spi, int is_on)
+{
+	gpio_set_value(SPI_SCK_GPIO, is_on);
+}
+
+static inline void setmosi(const struct spi_device *spi, int is_on)
+{
+	gpio_set_value(SPI_MOSI_GPIO, is_on);
+}
+
+static inline int getmiso(const struct spi_device *spi)
+{
+	return !!gpio_get_value(SPI_MISO_GPIO);
+}
+
+#undef pdata
+
+/*
+ * NOTE:  this clocks "as fast as we can".  It "should" be a function of the
+ * requested device clock.  Software overhead means we usually have trouble
+ * reaching even one Mbit/sec (except when we can inline bitops), so for now
+ * we'll just assume we never need additional per-bit slowdowns.
+ */
+#define spidelay(nsecs)	do {} while (0)
+
+#define	EXPAND_BITBANG_TXRX
+#include <linux/spi/spi_bitbang.h>
+
+/*
+ * These functions can leverage inline expansion of GPIO calls to shrink
+ * costs for a txrx bit, often by factors of around ten (by instruction
+ * count).  That is particularly visible for larger word sizes, but helps
+ * even with default 8-bit words.
+ *
+ * REVISIT overheads calling these functions for each word also have
+ * significant performance costs.  Having txrx_bufs() calls that inline
+ * the txrx_word() logic would help performance, e.g. on larger blocks
+ * used with flash storage or MMC/SD.  There should also be ways to make
+ * GCC be less stupid about reloading registers inside the I/O loops,
+ * even without inlined GPIO calls; __attribute__((hot)) on GCC 4.3?
+ */
+
+static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi,
+		unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi,
+		unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
+}
+
+static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi,
+		unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
+}
+
+static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi,
+		unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
+}
+
+/*----------------------------------------------------------------------*/
+
+static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
+{
+	unsigned long cs = (unsigned long) spi->controller_data;
+
+	/* set initial clock polarity */
+	if (is_active)
+		setsck(spi, spi->mode & SPI_CPOL);
+
+	if (cs != SPI_GPIO_NO_CHIPSELECT) {
+		/* SPI is normally active-low */
+		gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
+	}
+}
+
+static int spi_gpio_setup(struct spi_device *spi)
+{
+	unsigned long	cs = (unsigned long) spi->controller_data;
+	int		status = 0;
+
+	if (spi->bits_per_word > 32)
+		return -EINVAL;
+
+	if (!spi->controller_state) {
+		if (cs != SPI_GPIO_NO_CHIPSELECT) {
+			status = gpio_request(cs, dev_name(&spi->dev));
+			if (status)
+				return status;
+			status = gpio_direction_output(cs, spi->mode & SPI_CS_HIGH);
+		}
+	}
+	if (!status)
+		status = spi_bitbang_setup(spi);
+	if (status) {
+		if (!spi->controller_state && cs != SPI_GPIO_NO_CHIPSELECT)
+			gpio_free(cs);
+	}
+	return status;
+}
+
+static void spi_gpio_cleanup(struct spi_device *spi)
+{
+	unsigned long	cs = (unsigned long) spi->controller_data;
+
+	if (cs != SPI_GPIO_NO_CHIPSELECT)
+		gpio_free(cs);
+	spi_bitbang_cleanup(spi);
+}
+
+static int __init spi_gpio_alloc(unsigned pin, const char *label, bool is_in)
+{
+	int value;
+
+	value = gpio_request(pin, label);
+	if (value == 0) {
+		if (is_in)
+			value = gpio_direction_input(pin);
+		else
+			value = gpio_direction_output(pin, 0);
+	}
+	return value;
+}
+
+static int __init
+spi_gpio_request(struct spi_gpio_platform_data *pdata, const char *label)
+{
+	int value;
+
+	/* NOTE:  SPI_*_GPIO symbols may reference "pdata" */
+
+	value = spi_gpio_alloc(SPI_MOSI_GPIO, label, false);
+	if (value)
+		goto done;
+
+	value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
+	if (value)
+		goto free_mosi;
+
+	value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
+	if (value)
+		goto free_miso;
+
+	goto done;
+
+free_miso:
+	gpio_free(SPI_MISO_GPIO);
+free_mosi:
+	gpio_free(SPI_MOSI_GPIO);
+done:
+	return value;
+}
+
+static int __init spi_gpio_probe(struct platform_device *pdev)
+{
+	int				status;
+	struct spi_master		*master;
+	struct spi_gpio			*spi_gpio;
+	struct spi_gpio_platform_data	*pdata;
+
+	pdata = pdev->dev.platform_data;
+#ifdef GENERIC_BITBANG
+	if (!pdata || !pdata->num_chipselect)
+		return -ENODEV;
+#endif
+
+	status = spi_gpio_request(pdata, dev_name(&pdev->dev));
+	if (status < 0)
+		return status;
+
+	master = spi_alloc_master(&pdev->dev, sizeof *spi_gpio);
+	if (!master) {
+		status = -ENOMEM;
+		goto gpio_free;
+	}
+	spi_gpio = spi_master_get_devdata(master);
+	platform_set_drvdata(pdev, spi_gpio);
+
+	spi_gpio->pdev = pdev;
+	if (pdata)
+		spi_gpio->pdata = *pdata;
+
+	master->bus_num = pdev->id;
+	master->num_chipselect = SPI_N_CHIPSEL;
+	master->setup = spi_gpio_setup;
+	master->cleanup = spi_gpio_cleanup;
+
+	spi_gpio->bitbang.master = spi_master_get(master);
+	spi_gpio->bitbang.chipselect = spi_gpio_chipselect;
+	spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0;
+	spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1;
+	spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
+	spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
+	spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
+	spi_gpio->bitbang.flags = SPI_CS_HIGH;
+
+	status = spi_bitbang_start(&spi_gpio->bitbang);
+	if (status < 0) {
+		spi_master_put(spi_gpio->bitbang.master);
+gpio_free:
+		gpio_free(SPI_MISO_GPIO);
+		gpio_free(SPI_MOSI_GPIO);
+		gpio_free(SPI_SCK_GPIO);
+		spi_master_put(master);
+	}
+
+	return status;
+}
+
+static int __exit spi_gpio_remove(struct platform_device *pdev)
+{
+	struct spi_gpio			*spi_gpio;
+	struct spi_gpio_platform_data	*pdata;
+	int				status;
+
+	spi_gpio = platform_get_drvdata(pdev);
+	pdata = pdev->dev.platform_data;
+
+	/* stop() unregisters child devices too */
+	status = spi_bitbang_stop(&spi_gpio->bitbang);
+	spi_master_put(spi_gpio->bitbang.master);
+
+	platform_set_drvdata(pdev, NULL);
+
+	gpio_free(SPI_MISO_GPIO);
+	gpio_free(SPI_MOSI_GPIO);
+	gpio_free(SPI_SCK_GPIO);
+
+	return status;
+}
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+
+static struct platform_driver spi_gpio_driver = {
+	.driver.name	= DRIVER_NAME,
+	.driver.owner	= THIS_MODULE,
+	.remove		= __exit_p(spi_gpio_remove),
+};
+
+static int __init spi_gpio_init(void)
+{
+	return platform_driver_probe(&spi_gpio_driver, spi_gpio_probe);
+}
+module_init(spi_gpio_init);
+
+static void __exit spi_gpio_exit(void)
+{
+	platform_driver_unregister(&spi_gpio_driver);
+}
+module_exit(spi_gpio_exit);
+
+
+MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO ");
+MODULE_AUTHOR("David Brownell");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_imx.c

@@ -0,0 +1,680 @@
+/*
+ * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright (C) 2008 Juergen Beisert
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/types.h>
+
+#include <mach/spi.h>
+
+#define DRIVER_NAME "spi_imx"
+
+#define MXC_CSPIRXDATA		0x00
+#define MXC_CSPITXDATA		0x04
+#define MXC_CSPICTRL		0x08
+#define MXC_CSPIINT		0x0c
+#define MXC_RESET		0x1c
+
+/* generic defines to abstract from the different register layouts */
+#define MXC_INT_RR	(1 << 0) /* Receive data ready interrupt */
+#define MXC_INT_TE	(1 << 1) /* Transmit FIFO empty interrupt */
+
+struct spi_imx_config {
+	unsigned int speed_hz;
+	unsigned int bpw;
+	unsigned int mode;
+	int cs;
+};
+
+struct spi_imx_data {
+	struct spi_bitbang bitbang;
+
+	struct completion xfer_done;
+	void *base;
+	int irq;
+	struct clk *clk;
+	unsigned long spi_clk;
+	int *chipselect;
+
+	unsigned int count;
+	void (*tx)(struct spi_imx_data *);
+	void (*rx)(struct spi_imx_data *);
+	void *rx_buf;
+	const void *tx_buf;
+	unsigned int txfifo; /* number of words pushed in tx FIFO */
+
+	/* SoC specific functions */
+	void (*intctrl)(struct spi_imx_data *, int);
+	int (*config)(struct spi_imx_data *, struct spi_imx_config *);
+	void (*trigger)(struct spi_imx_data *);
+	int (*rx_available)(struct spi_imx_data *);
+};
+
+#define MXC_SPI_BUF_RX(type)						\
+static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)		\
+{									\
+	unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA);	\
+									\
+	if (spi_imx->rx_buf) {						\
+		*(type *)spi_imx->rx_buf = val;				\
+		spi_imx->rx_buf += sizeof(type);			\
+	}								\
+}
+
+#define MXC_SPI_BUF_TX(type)						\
+static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx)		\
+{									\
+	type val = 0;							\
+									\
+	if (spi_imx->tx_buf) {						\
+		val = *(type *)spi_imx->tx_buf;				\
+		spi_imx->tx_buf += sizeof(type);			\
+	}								\
+									\
+	spi_imx->count -= sizeof(type);					\
+									\
+	writel(val, spi_imx->base + MXC_CSPITXDATA);			\
+}
+
+MXC_SPI_BUF_RX(u8)
+MXC_SPI_BUF_TX(u8)
+MXC_SPI_BUF_RX(u16)
+MXC_SPI_BUF_TX(u16)
+MXC_SPI_BUF_RX(u32)
+MXC_SPI_BUF_TX(u32)
+
+/* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
+ * (which is currently not the case in this driver)
+ */
+static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
+	256, 384, 512, 768, 1024};
+
+/* MX21, MX27 */
+static unsigned int spi_imx_clkdiv_1(unsigned int fin,
+		unsigned int fspi)
+{
+	int i, max;
+
+	if (cpu_is_mx21())
+		max = 18;
+	else
+		max = 16;
+
+	for (i = 2; i < max; i++)
+		if (fspi * mxc_clkdivs[i] >= fin)
+			return i;
+
+	return max;
+}
+
+/* MX1, MX31, MX35 */
+static unsigned int spi_imx_clkdiv_2(unsigned int fin,
+		unsigned int fspi)
+{
+	int i, div = 4;
+
+	for (i = 0; i < 7; i++) {
+		if (fspi * div >= fin)
+			return i;
+		div <<= 1;
+	}
+
+	return 7;
+}
+
+#define MX31_INTREG_TEEN	(1 << 0)
+#define MX31_INTREG_RREN	(1 << 3)
+
+#define MX31_CSPICTRL_ENABLE	(1 << 0)
+#define MX31_CSPICTRL_MASTER	(1 << 1)
+#define MX31_CSPICTRL_XCH	(1 << 2)
+#define MX31_CSPICTRL_POL	(1 << 4)
+#define MX31_CSPICTRL_PHA	(1 << 5)
+#define MX31_CSPICTRL_SSCTL	(1 << 6)
+#define MX31_CSPICTRL_SSPOL	(1 << 7)
+#define MX31_CSPICTRL_BC_SHIFT	8
+#define MX35_CSPICTRL_BL_SHIFT	20
+#define MX31_CSPICTRL_CS_SHIFT	24
+#define MX35_CSPICTRL_CS_SHIFT	12
+#define MX31_CSPICTRL_DR_SHIFT	16
+
+#define MX31_CSPISTATUS		0x14
+#define MX31_STATUS_RR		(1 << 3)
+
+/* These functions also work for the i.MX35, but be aware that
+ * the i.MX35 has a slightly different register layout for bits
+ * we do not use here.
+ */
+static void mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
+{
+	unsigned int val = 0;
+
+	if (enable & MXC_INT_TE)
+		val |= MX31_INTREG_TEEN;
+	if (enable & MXC_INT_RR)
+		val |= MX31_INTREG_RREN;
+
+	writel(val, spi_imx->base + MXC_CSPIINT);
+}
+
+static void mx31_trigger(struct spi_imx_data *spi_imx)
+{
+	unsigned int reg;
+
+	reg = readl(spi_imx->base + MXC_CSPICTRL);
+	reg |= MX31_CSPICTRL_XCH;
+	writel(reg, spi_imx->base + MXC_CSPICTRL);
+}
+
+static int mx31_config(struct spi_imx_data *spi_imx,
+		struct spi_imx_config *config)
+{
+	unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
+
+	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
+		MX31_CSPICTRL_DR_SHIFT;
+
+	if (cpu_is_mx31())
+		reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT;
+	else if (cpu_is_mx35()) {
+		reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
+		reg |= MX31_CSPICTRL_SSCTL;
+	}
+
+	if (config->mode & SPI_CPHA)
+		reg |= MX31_CSPICTRL_PHA;
+	if (config->mode & SPI_CPOL)
+		reg |= MX31_CSPICTRL_POL;
+	if (config->mode & SPI_CS_HIGH)
+		reg |= MX31_CSPICTRL_SSPOL;
+	if (config->cs < 0) {
+		if (cpu_is_mx31())
+			reg |= (config->cs + 32) << MX31_CSPICTRL_CS_SHIFT;
+		else if (cpu_is_mx35())
+			reg |= (config->cs + 32) << MX35_CSPICTRL_CS_SHIFT;
+	}
+
+	writel(reg, spi_imx->base + MXC_CSPICTRL);
+
+	return 0;
+}
+
+static int mx31_rx_available(struct spi_imx_data *spi_imx)
+{
+	return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
+}
+
+#define MX27_INTREG_RR		(1 << 4)
+#define MX27_INTREG_TEEN	(1 << 9)
+#define MX27_INTREG_RREN	(1 << 13)
+
+#define MX27_CSPICTRL_POL	(1 << 5)
+#define MX27_CSPICTRL_PHA	(1 << 6)
+#define MX27_CSPICTRL_SSPOL	(1 << 8)
+#define MX27_CSPICTRL_XCH	(1 << 9)
+#define MX27_CSPICTRL_ENABLE	(1 << 10)
+#define MX27_CSPICTRL_MASTER	(1 << 11)
+#define MX27_CSPICTRL_DR_SHIFT	14
+#define MX27_CSPICTRL_CS_SHIFT	19
+
+static void mx27_intctrl(struct spi_imx_data *spi_imx, int enable)
+{
+	unsigned int val = 0;
+
+	if (enable & MXC_INT_TE)
+		val |= MX27_INTREG_TEEN;
+	if (enable & MXC_INT_RR)
+		val |= MX27_INTREG_RREN;
+
+	writel(val, spi_imx->base + MXC_CSPIINT);
+}
+
+static void mx27_trigger(struct spi_imx_data *spi_imx)
+{
+	unsigned int reg;
+
+	reg = readl(spi_imx->base + MXC_CSPICTRL);
+	reg |= MX27_CSPICTRL_XCH;
+	writel(reg, spi_imx->base + MXC_CSPICTRL);
+}
+
+static int mx27_config(struct spi_imx_data *spi_imx,
+		struct spi_imx_config *config)
+{
+	unsigned int reg = MX27_CSPICTRL_ENABLE | MX27_CSPICTRL_MASTER;
+
+	reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz) <<
+		MX27_CSPICTRL_DR_SHIFT;
+	reg |= config->bpw - 1;
+
+	if (config->mode & SPI_CPHA)
+		reg |= MX27_CSPICTRL_PHA;
+	if (config->mode & SPI_CPOL)
+		reg |= MX27_CSPICTRL_POL;
+	if (config->mode & SPI_CS_HIGH)
+		reg |= MX27_CSPICTRL_SSPOL;
+	if (config->cs < 0)
+		reg |= (config->cs + 32) << MX27_CSPICTRL_CS_SHIFT;
+
+	writel(reg, spi_imx->base + MXC_CSPICTRL);
+
+	return 0;
+}
+
+static int mx27_rx_available(struct spi_imx_data *spi_imx)
+{
+	return readl(spi_imx->base + MXC_CSPIINT) & MX27_INTREG_RR;
+}
+
+#define MX1_INTREG_RR		(1 << 3)
+#define MX1_INTREG_TEEN		(1 << 8)
+#define MX1_INTREG_RREN		(1 << 11)
+
+#define MX1_CSPICTRL_POL	(1 << 4)
+#define MX1_CSPICTRL_PHA	(1 << 5)
+#define MX1_CSPICTRL_XCH	(1 << 8)
+#define MX1_CSPICTRL_ENABLE	(1 << 9)
+#define MX1_CSPICTRL_MASTER	(1 << 10)
+#define MX1_CSPICTRL_DR_SHIFT	13
+
+static void mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
+{
+	unsigned int val = 0;
+
+	if (enable & MXC_INT_TE)
+		val |= MX1_INTREG_TEEN;
+	if (enable & MXC_INT_RR)
+		val |= MX1_INTREG_RREN;
+
+	writel(val, spi_imx->base + MXC_CSPIINT);
+}
+
+static void mx1_trigger(struct spi_imx_data *spi_imx)
+{
+	unsigned int reg;
+
+	reg = readl(spi_imx->base + MXC_CSPICTRL);
+	reg |= MX1_CSPICTRL_XCH;
+	writel(reg, spi_imx->base + MXC_CSPICTRL);
+}
+
+static int mx1_config(struct spi_imx_data *spi_imx,
+		struct spi_imx_config *config)
+{
+	unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
+
+	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
+		MX1_CSPICTRL_DR_SHIFT;
+	reg |= config->bpw - 1;
+
+	if (config->mode & SPI_CPHA)
+		reg |= MX1_CSPICTRL_PHA;
+	if (config->mode & SPI_CPOL)
+		reg |= MX1_CSPICTRL_POL;
+
+	writel(reg, spi_imx->base + MXC_CSPICTRL);
+
+	return 0;
+}
+
+static int mx1_rx_available(struct spi_imx_data *spi_imx)
+{
+	return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
+}
+
+static void spi_imx_chipselect(struct spi_device *spi, int is_active)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+	int gpio = spi_imx->chipselect[spi->chip_select];
+	int active = is_active != BITBANG_CS_INACTIVE;
+	int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
+
+	if (gpio < 0)
+		return;
+
+	gpio_set_value(gpio, dev_is_lowactive ^ active);
+}
+
+static void spi_imx_push(struct spi_imx_data *spi_imx)
+{
+	while (spi_imx->txfifo < 8) {
+		if (!spi_imx->count)
+			break;
+		spi_imx->tx(spi_imx);
+		spi_imx->txfifo++;
+	}
+
+	spi_imx->trigger(spi_imx);
+}
+
+static irqreturn_t spi_imx_isr(int irq, void *dev_id)
+{
+	struct spi_imx_data *spi_imx = dev_id;
+
+	while (spi_imx->rx_available(spi_imx)) {
+		spi_imx->rx(spi_imx);
+		spi_imx->txfifo--;
+	}
+
+	if (spi_imx->count) {
+		spi_imx_push(spi_imx);
+		return IRQ_HANDLED;
+	}
+
+	if (spi_imx->txfifo) {
+		/* No data left to push, but still waiting for rx data,
+		 * enable receive data available interrupt.
+		 */
+		spi_imx->intctrl(spi_imx, MXC_INT_RR);
+		return IRQ_HANDLED;
+	}
+
+	spi_imx->intctrl(spi_imx, 0);
+	complete(&spi_imx->xfer_done);
+
+	return IRQ_HANDLED;
+}
+
+static int spi_imx_setupxfer(struct spi_device *spi,
+				 struct spi_transfer *t)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+	struct spi_imx_config config;
+
+	config.bpw = t ? t->bits_per_word : spi->bits_per_word;
+	config.speed_hz  = t ? t->speed_hz : spi->max_speed_hz;
+	config.mode = spi->mode;
+	config.cs = spi_imx->chipselect[spi->chip_select];
+
+	if (!config.speed_hz)
+		config.speed_hz = spi->max_speed_hz;
+	if (!config.bpw)
+		config.bpw = spi->bits_per_word;
+	if (!config.speed_hz)
+		config.speed_hz = spi->max_speed_hz;
+
+	/* Initialize the functions for transfer */
+	if (config.bpw <= 8) {
+		spi_imx->rx = spi_imx_buf_rx_u8;
+		spi_imx->tx = spi_imx_buf_tx_u8;
+	} else if (config.bpw <= 16) {
+		spi_imx->rx = spi_imx_buf_rx_u16;
+		spi_imx->tx = spi_imx_buf_tx_u16;
+	} else if (config.bpw <= 32) {
+		spi_imx->rx = spi_imx_buf_rx_u32;
+		spi_imx->tx = spi_imx_buf_tx_u32;
+	} else
+		BUG();
+
+	spi_imx->config(spi_imx, &config);
+
+	return 0;
+}
+
+static int spi_imx_transfer(struct spi_device *spi,
+				struct spi_transfer *transfer)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+
+	spi_imx->tx_buf = transfer->tx_buf;
+	spi_imx->rx_buf = transfer->rx_buf;
+	spi_imx->count = transfer->len;
+	spi_imx->txfifo = 0;
+
+	init_completion(&spi_imx->xfer_done);
+
+	spi_imx_push(spi_imx);
+
+	spi_imx->intctrl(spi_imx, MXC_INT_TE);
+
+	wait_for_completion(&spi_imx->xfer_done);
+
+	return transfer->len;
+}
+
+static int spi_imx_setup(struct spi_device *spi)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+	int gpio = spi_imx->chipselect[spi->chip_select];
+
+	pr_debug("%s: mode %d, %u bpw, %d hz\n", __func__,
+		 spi->mode, spi->bits_per_word, spi->max_speed_hz);
+
+	if (gpio >= 0)
+		gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
+
+	spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
+
+	return 0;
+}
+
+static void spi_imx_cleanup(struct spi_device *spi)
+{
+}
+
+static int __init spi_imx_probe(struct platform_device *pdev)
+{
+	struct spi_imx_master *mxc_platform_info;
+	struct spi_master *master;
+	struct spi_imx_data *spi_imx;
+	struct resource *res;
+	int i, ret;
+
+	mxc_platform_info = (struct spi_imx_master *)pdev->dev.platform_data;
+	if (!mxc_platform_info) {
+		dev_err(&pdev->dev, "can't get the platform data\n");
+		return -EINVAL;
+	}
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));
+	if (!master)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, master);
+
+	master->bus_num = pdev->id;
+	master->num_chipselect = mxc_platform_info->num_chipselect;
+
+	spi_imx = spi_master_get_devdata(master);
+	spi_imx->bitbang.master = spi_master_get(master);
+	spi_imx->chipselect = mxc_platform_info->chipselect;
+
+	for (i = 0; i < master->num_chipselect; i++) {
+		if (spi_imx->chipselect[i] < 0)
+			continue;
+		ret = gpio_request(spi_imx->chipselect[i], DRIVER_NAME);
+		if (ret) {
+			i--;
+			while (i > 0)
+				if (spi_imx->chipselect[i] >= 0)
+					gpio_free(spi_imx->chipselect[i--]);
+			dev_err(&pdev->dev, "can't get cs gpios");
+			goto out_master_put;
+		}
+	}
+
+	spi_imx->bitbang.chipselect = spi_imx_chipselect;
+	spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
+	spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
+	spi_imx->bitbang.master->setup = spi_imx_setup;
+	spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
+	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
+	init_completion(&spi_imx->xfer_done);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "can't get platform resource\n");
+		ret = -ENOMEM;
+		goto out_gpio_free;
+	}
+
+	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
+		dev_err(&pdev->dev, "request_mem_region failed\n");
+		ret = -EBUSY;
+		goto out_gpio_free;
+	}
+
+	spi_imx->base = ioremap(res->start, resource_size(res));
+	if (!spi_imx->base) {
+		ret = -EINVAL;
+		goto out_release_mem;
+	}
+
+	spi_imx->irq = platform_get_irq(pdev, 0);
+	if (!spi_imx->irq) {
+		ret = -EINVAL;
+		goto out_iounmap;
+	}
+
+	ret = request_irq(spi_imx->irq, spi_imx_isr, 0, DRIVER_NAME, spi_imx);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get irq%d: %d\n", spi_imx->irq, ret);
+		goto out_iounmap;
+	}
+
+	if (cpu_is_mx31() || cpu_is_mx35()) {
+		spi_imx->intctrl = mx31_intctrl;
+		spi_imx->config = mx31_config;
+		spi_imx->trigger = mx31_trigger;
+		spi_imx->rx_available = mx31_rx_available;
+	} else  if (cpu_is_mx27() || cpu_is_mx21()) {
+		spi_imx->intctrl = mx27_intctrl;
+		spi_imx->config = mx27_config;
+		spi_imx->trigger = mx27_trigger;
+		spi_imx->rx_available = mx27_rx_available;
+	} else if (cpu_is_mx1()) {
+		spi_imx->intctrl = mx1_intctrl;
+		spi_imx->config = mx1_config;
+		spi_imx->trigger = mx1_trigger;
+		spi_imx->rx_available = mx1_rx_available;
+	} else
+		BUG();
+
+	spi_imx->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(spi_imx->clk)) {
+		dev_err(&pdev->dev, "unable to get clock\n");
+		ret = PTR_ERR(spi_imx->clk);
+		goto out_free_irq;
+	}
+
+	clk_enable(spi_imx->clk);
+	spi_imx->spi_clk = clk_get_rate(spi_imx->clk);
+
+	if (!cpu_is_mx31() || !cpu_is_mx35())
+		writel(1, spi_imx->base + MXC_RESET);
+
+	spi_imx->intctrl(spi_imx, 0);
+
+	ret = spi_bitbang_start(&spi_imx->bitbang);
+	if (ret) {
+		dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
+		goto out_clk_put;
+	}
+
+	dev_info(&pdev->dev, "probed\n");
+
+	return ret;
+
+out_clk_put:
+	clk_disable(spi_imx->clk);
+	clk_put(spi_imx->clk);
+out_free_irq:
+	free_irq(spi_imx->irq, spi_imx);
+out_iounmap:
+	iounmap(spi_imx->base);
+out_release_mem:
+	release_mem_region(res->start, resource_size(res));
+out_gpio_free:
+	for (i = 0; i < master->num_chipselect; i++)
+		if (spi_imx->chipselect[i] >= 0)
+			gpio_free(spi_imx->chipselect[i]);
+out_master_put:
+	spi_master_put(master);
+	kfree(master);
+	platform_set_drvdata(pdev, NULL);
+	return ret;
+}
+
+static int __exit spi_imx_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+	int i;
+
+	spi_bitbang_stop(&spi_imx->bitbang);
+
+	writel(0, spi_imx->base + MXC_CSPICTRL);
+	clk_disable(spi_imx->clk);
+	clk_put(spi_imx->clk);
+	free_irq(spi_imx->irq, spi_imx);
+	iounmap(spi_imx->base);
+
+	for (i = 0; i < master->num_chipselect; i++)
+		if (spi_imx->chipselect[i] >= 0)
+			gpio_free(spi_imx->chipselect[i]);
+
+	spi_master_put(master);
+
+	release_mem_region(res->start, resource_size(res));
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver spi_imx_driver = {
+	.driver = {
+		   .name = DRIVER_NAME,
+		   .owner = THIS_MODULE,
+		   },
+	.probe = spi_imx_probe,
+	.remove = __exit_p(spi_imx_remove),
+};
+
+static int __init spi_imx_init(void)
+{
+	return platform_driver_register(&spi_imx_driver);
+}
+
+static void __exit spi_imx_exit(void)
+{
+	platform_driver_unregister(&spi_imx_driver);
+}
+
+module_init(spi_imx_init);
+module_exit(spi_imx_exit);
+
+MODULE_DESCRIPTION("SPI Master Controller driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_lm70llp.c

@@ -0,0 +1,352 @@
+/*
+ * spi_lm70llp.c - driver for LM70EVAL-LLP board for the LM70 sensor
+ *
+ * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/parport.h>
+#include <linux/sysfs.h>
+#include <linux/workqueue.h>
+
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+
+/*
+ * The LM70 communicates with a host processor using a 3-wire variant of
+ * the SPI/Microwire bus interface. This driver specifically supports an
+ * NS LM70 LLP Evaluation Board, interfacing to a PC using its parallel
+ * port to bitbang an SPI-parport bridge.  Accordingly, this is an SPI
+ * master controller driver.  The hwmon/lm70 driver is a "SPI protocol
+ * driver", layered on top of this one and usable without the lm70llp.
+ *
+ * Datasheet and Schematic:
+ * The LM70 is a temperature sensor chip from National Semiconductor; its
+ * datasheet is available at http://www.national.com/pf/LM/LM70.html
+ * The schematic for this particular board (the LM70EVAL-LLP) is
+ * available (on page 4) here:
+ *  http://www.national.com/appinfo/tempsensors/files/LM70LLPEVALmanual.pdf
+ *
+ * Also see Documentation/spi/spi-lm70llp.  The SPI<->parport code here is
+ * (heavily) based on spi-butterfly by David Brownell.
+ *
+ * The LM70 LLP connects to the PC parallel port in the following manner:
+ *
+ *   Parallel                 LM70 LLP
+ *     Port      Direction   JP2 Header
+ *  -----------  ---------  ------------
+ *      D0    2      -         -
+ *      D1    3     -->      V+   5
+ *      D2    4     -->      V+   5
+ *      D3    5     -->      V+   5
+ *      D4    6     -->      V+   5
+ *      D5    7     -->      nCS  8
+ *      D6    8     -->      SCLK 3
+ *      D7    9     -->      SI/O 5
+ *     GND   25      -       GND  7
+ *    Select 13     <--      SI/O 1
+ *
+ * Note that parport pin 13 actually gets inverted by the transistor
+ * arrangement which lets either the parport or the LM70 drive the
+ * SI/SO signal (see the schematic for details).
+ */
+
+#define DRVNAME		"spi-lm70llp"
+
+#define lm70_INIT	0xBE
+#define SIO		0x10
+#define nCS		0x20
+#define SCLK		0x40
+
+/*-------------------------------------------------------------------------*/
+
+struct spi_lm70llp {
+	struct spi_bitbang	bitbang;
+	struct parport		*port;
+	struct pardevice	*pd;
+	struct spi_device	*spidev_lm70;
+	struct spi_board_info	info;
+	//struct device		*dev;
+};
+
+/* REVISIT : ugly global ; provides "exclusive open" facility */
+static struct spi_lm70llp *lm70llp;
+
+
+/*-------------------------------------------------------------------*/
+
+static inline struct spi_lm70llp *spidev_to_pp(struct spi_device *spi)
+{
+	return spi->controller_data;
+}
+
+/*---------------------- LM70 LLP eval board-specific inlines follow */
+
+/* NOTE:  we don't actually need to reread the output values, since they'll
+ * still be what we wrote before.  Plus, going through parport builds in
+ * a ~1ms/operation delay; these SPI transfers could easily be faster.
+ */
+
+static inline void deassertCS(struct spi_lm70llp *pp)
+{
+	u8 data = parport_read_data(pp->port);
+
+	data &= ~0x80;		/* pull D7/SI-out low while de-asserted */
+	parport_write_data(pp->port, data | nCS);
+}
+
+static inline void assertCS(struct spi_lm70llp *pp)
+{
+	u8 data = parport_read_data(pp->port);
+
+	data |= 0x80;		/* pull D7/SI-out high so lm70 drives SO-in */
+	parport_write_data(pp->port, data & ~nCS);
+}
+
+static inline void clkHigh(struct spi_lm70llp *pp)
+{
+	u8 data = parport_read_data(pp->port);
+	parport_write_data(pp->port, data | SCLK);
+}
+
+static inline void clkLow(struct spi_lm70llp *pp)
+{
+	u8 data = parport_read_data(pp->port);
+	parport_write_data(pp->port, data & ~SCLK);
+}
+
+/*------------------------- SPI-LM70-specific inlines ----------------------*/
+
+static inline void spidelay(unsigned d)
+{
+	udelay(d);
+}
+
+static inline void setsck(struct spi_device *s, int is_on)
+{
+	struct spi_lm70llp *pp = spidev_to_pp(s);
+
+	if (is_on)
+		clkHigh(pp);
+	else
+		clkLow(pp);
+}
+
+static inline void setmosi(struct spi_device *s, int is_on)
+{
+	/* FIXME update D7 ... this way we can put the chip
+	 * into shutdown mode and read the manufacturer ID,
+	 * but we can't put it back into operational mode.
+	 */
+}
+
+/*
+ * getmiso:
+ * Why do we return 0 when the SIO line is high and vice-versa?
+ * The fact is, the lm70 eval board from NS (which this driver drives),
+ * is wired in just such a way : when the lm70's SIO goes high, a transistor
+ * switches it to low reflecting this on the parport (pin 13), and vice-versa.
+ */
+static inline int getmiso(struct spi_device *s)
+{
+	struct spi_lm70llp *pp = spidev_to_pp(s);
+	return ((SIO == (parport_read_status(pp->port) & SIO)) ? 0 : 1 );
+}
+/*--------------------------------------------------------------------*/
+
+#define EXPAND_BITBANG_TXRX 1
+#include <linux/spi/spi_bitbang.h>
+
+static void lm70_chipselect(struct spi_device *spi, int value)
+{
+	struct spi_lm70llp *pp = spidev_to_pp(spi);
+
+	if (value)
+		assertCS(pp);
+	else
+		deassertCS(pp);
+}
+
+/*
+ * Our actual bitbanger routine.
+ */
+static u32 lm70_txrx(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+static void spi_lm70llp_attach(struct parport *p)
+{
+	struct pardevice	*pd;
+	struct spi_lm70llp	*pp;
+	struct spi_master	*master;
+	int			status;
+
+	if (lm70llp) {
+		printk(KERN_WARNING
+			"%s: spi_lm70llp instance already loaded. Aborting.\n",
+			DRVNAME);
+		return;
+	}
+
+	/* TODO:  this just _assumes_ a lm70 is there ... no probe;
+	 * the lm70 driver could verify it, reading the manf ID.
+	 */
+
+	master = spi_alloc_master(p->physport->dev, sizeof *pp);
+	if (!master) {
+		status = -ENOMEM;
+		goto out_fail;
+	}
+	pp = spi_master_get_devdata(master);
+
+	master->bus_num = -1;	/* dynamic alloc of a bus number */
+	master->num_chipselect = 1;
+
+	/*
+	 * SPI and bitbang hookup.
+	 */
+	pp->bitbang.master = spi_master_get(master);
+	pp->bitbang.chipselect = lm70_chipselect;
+	pp->bitbang.txrx_word[SPI_MODE_0] = lm70_txrx;
+	pp->bitbang.flags = SPI_3WIRE;
+
+	/*
+	 * Parport hookup
+	 */
+	pp->port = p;
+	pd = parport_register_device(p, DRVNAME,
+			NULL, NULL, NULL,
+			PARPORT_FLAG_EXCL, pp);
+	if (!pd) {
+		status = -ENOMEM;
+		goto out_free_master;
+	}
+	pp->pd = pd;
+
+	status = parport_claim(pd);
+	if (status < 0)
+		goto out_parport_unreg;
+
+	/*
+	 * Start SPI ...
+	 */
+	status = spi_bitbang_start(&pp->bitbang);
+	if (status < 0) {
+		printk(KERN_WARNING
+			"%s: spi_bitbang_start failed with status %d\n",
+			DRVNAME, status);
+		goto out_off_and_release;
+	}
+
+	/*
+	 * The modalias name MUST match the device_driver name
+	 * for the bus glue code to match and subsequently bind them.
+	 * We are binding to the generic drivers/hwmon/lm70.c device
+	 * driver.
+	 */
+	strcpy(pp->info.modalias, "lm70");
+	pp->info.max_speed_hz = 6 * 1000 * 1000;
+	pp->info.chip_select = 0;
+	pp->info.mode = SPI_3WIRE | SPI_MODE_0;
+
+	/* power up the chip, and let the LM70 control SI/SO */
+	parport_write_data(pp->port, lm70_INIT);
+
+	/* Enable access to our primary data structure via
+	 * the board info's (void *)controller_data.
+	 */
+	pp->info.controller_data = pp;
+	pp->spidev_lm70 = spi_new_device(pp->bitbang.master, &pp->info);
+	if (pp->spidev_lm70)
+		dev_dbg(&pp->spidev_lm70->dev, "spidev_lm70 at %s\n",
+				dev_name(&pp->spidev_lm70->dev));
+	else {
+		printk(KERN_WARNING "%s: spi_new_device failed\n", DRVNAME);
+		status = -ENODEV;
+		goto out_bitbang_stop;
+	}
+	pp->spidev_lm70->bits_per_word = 8;
+
+	lm70llp = pp;
+	return;
+
+out_bitbang_stop:
+	spi_bitbang_stop(&pp->bitbang);
+out_off_and_release:
+	/* power down */
+	parport_write_data(pp->port, 0);
+	mdelay(10);
+	parport_release(pp->pd);
+out_parport_unreg:
+	parport_unregister_device(pd);
+out_free_master:
+	(void) spi_master_put(master);
+out_fail:
+	pr_info("%s: spi_lm70llp probe fail, status %d\n", DRVNAME, status);
+}
+
+static void spi_lm70llp_detach(struct parport *p)
+{
+	struct spi_lm70llp		*pp;
+
+	if (!lm70llp || lm70llp->port != p)
+		return;
+
+	pp = lm70llp;
+	spi_bitbang_stop(&pp->bitbang);
+
+	/* power down */
+	parport_write_data(pp->port, 0);
+
+	parport_release(pp->pd);
+	parport_unregister_device(pp->pd);
+
+	(void) spi_master_put(pp->bitbang.master);
+
+	lm70llp = NULL;
+}
+
+
+static struct parport_driver spi_lm70llp_drv = {
+	.name =		DRVNAME,
+	.attach =	spi_lm70llp_attach,
+	.detach =	spi_lm70llp_detach,
+};
+
+static int __init init_spi_lm70llp(void)
+{
+	return parport_register_driver(&spi_lm70llp_drv);
+}
+module_init(init_spi_lm70llp);
+
+static void __exit cleanup_spi_lm70llp(void)
+{
+	parport_unregister_driver(&spi_lm70llp_drv);
+}
+module_exit(cleanup_spi_lm70llp);
+
+MODULE_AUTHOR("Kaiwan N Billimoria <kaiwan@designergraphix.com>");
+MODULE_DESCRIPTION(
+	"Parport adapter for the National Semiconductor LM70 LLP eval board");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_mpc8xxx.c

@@ -0,0 +1,945 @@
+/*
+ * MPC8xxx SPI controller driver.
+ *
+ * Maintainer: Kumar Gala
+ *
+ * Copyright (C) 2006 Polycom, Inc.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/bug.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/platform_device.h>
+#include <linux/fsl_devices.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/of_spi.h>
+
+#include <sysdev/fsl_soc.h>
+#include <asm/irq.h>
+
+/* SPI Controller registers */
+struct mpc8xxx_spi_reg {
+	u8 res1[0x20];
+	__be32 mode;
+	__be32 event;
+	__be32 mask;
+	__be32 command;
+	__be32 transmit;
+	__be32 receive;
+};
+
+/* SPI Controller mode register definitions */
+#define	SPMODE_LOOP		(1 << 30)
+#define	SPMODE_CI_INACTIVEHIGH	(1 << 29)
+#define	SPMODE_CP_BEGIN_EDGECLK	(1 << 28)
+#define	SPMODE_DIV16		(1 << 27)
+#define	SPMODE_REV		(1 << 26)
+#define	SPMODE_MS		(1 << 25)
+#define	SPMODE_ENABLE		(1 << 24)
+#define	SPMODE_LEN(x)		((x) << 20)
+#define	SPMODE_PM(x)		((x) << 16)
+#define	SPMODE_OP		(1 << 14)
+#define	SPMODE_CG(x)		((x) << 7)
+
+/*
+ * Default for SPI Mode:
+ * 	SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk
+ */
+#define	SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH | SPMODE_DIV16 | SPMODE_REV | \
+			 SPMODE_MS | SPMODE_LEN(7) | SPMODE_PM(0xf))
+
+/* SPIE register values */
+#define	SPIE_NE		0x00000200	/* Not empty */
+#define	SPIE_NF		0x00000100	/* Not full */
+
+/* SPIM register values */
+#define	SPIM_NE		0x00000200	/* Not empty */
+#define	SPIM_NF		0x00000100	/* Not full */
+
+/* SPI Controller driver's private data. */
+struct mpc8xxx_spi {
+	struct mpc8xxx_spi_reg __iomem *base;
+
+	/* rx & tx bufs from the spi_transfer */
+	const void *tx;
+	void *rx;
+
+	/* functions to deal with different sized buffers */
+	void (*get_rx) (u32 rx_data, struct mpc8xxx_spi *);
+	u32(*get_tx) (struct mpc8xxx_spi *);
+
+	unsigned int count;
+	unsigned int irq;
+
+	unsigned nsecs;		/* (clock cycle time)/2 */
+
+	u32 spibrg;		/* SPIBRG input clock */
+	u32 rx_shift;		/* RX data reg shift when in qe mode */
+	u32 tx_shift;		/* TX data reg shift when in qe mode */
+
+	bool qe_mode;
+
+	struct workqueue_struct *workqueue;
+	struct work_struct work;
+
+	struct list_head queue;
+	spinlock_t lock;
+
+	struct completion done;
+};
+
+struct spi_mpc8xxx_cs {
+	/* functions to deal with different sized buffers */
+	void (*get_rx) (u32 rx_data, struct mpc8xxx_spi *);
+	u32 (*get_tx) (struct mpc8xxx_spi *);
+	u32 rx_shift;		/* RX data reg shift when in qe mode */
+	u32 tx_shift;		/* TX data reg shift when in qe mode */
+	u32 hw_mode;		/* Holds HW mode register settings */
+};
+
+static inline void mpc8xxx_spi_write_reg(__be32 __iomem *reg, u32 val)
+{
+	out_be32(reg, val);
+}
+
+static inline u32 mpc8xxx_spi_read_reg(__be32 __iomem *reg)
+{
+	return in_be32(reg);
+}
+
+#define MPC83XX_SPI_RX_BUF(type) 					  \
+static									  \
+void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
+{									  \
+	type *rx = mpc8xxx_spi->rx;					  \
+	*rx++ = (type)(data >> mpc8xxx_spi->rx_shift);			  \
+	mpc8xxx_spi->rx = rx;						  \
+}
+
+#define MPC83XX_SPI_TX_BUF(type)				\
+static								\
+u32 mpc8xxx_spi_tx_buf_##type(struct mpc8xxx_spi *mpc8xxx_spi)	\
+{								\
+	u32 data;						\
+	const type *tx = mpc8xxx_spi->tx;			\
+	if (!tx)						\
+		return 0;					\
+	data = *tx++ << mpc8xxx_spi->tx_shift;			\
+	mpc8xxx_spi->tx = tx;					\
+	return data;						\
+}
+
+MPC83XX_SPI_RX_BUF(u8)
+MPC83XX_SPI_RX_BUF(u16)
+MPC83XX_SPI_RX_BUF(u32)
+MPC83XX_SPI_TX_BUF(u8)
+MPC83XX_SPI_TX_BUF(u16)
+MPC83XX_SPI_TX_BUF(u32)
+
+static void mpc8xxx_spi_chipselect(struct spi_device *spi, int value)
+{
+	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
+	struct fsl_spi_platform_data *pdata = spi->dev.parent->platform_data;
+	bool pol = spi->mode & SPI_CS_HIGH;
+	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
+
+	if (value == BITBANG_CS_INACTIVE) {
+		if (pdata->cs_control)
+			pdata->cs_control(spi, !pol);
+	}
+
+	if (value == BITBANG_CS_ACTIVE) {
+		u32 regval = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->mode);
+
+		mpc8xxx_spi->rx_shift = cs->rx_shift;
+		mpc8xxx_spi->tx_shift = cs->tx_shift;
+		mpc8xxx_spi->get_rx = cs->get_rx;
+		mpc8xxx_spi->get_tx = cs->get_tx;
+
+		if (cs->hw_mode != regval) {
+			unsigned long flags;
+			__be32 __iomem *mode = &mpc8xxx_spi->base->mode;
+
+			regval = cs->hw_mode;
+			/* Turn off IRQs locally to minimize time that
+			 * SPI is disabled
+			 */
+			local_irq_save(flags);
+			/* Turn off SPI unit prior changing mode */
+			mpc8xxx_spi_write_reg(mode, regval & ~SPMODE_ENABLE);
+			mpc8xxx_spi_write_reg(mode, regval);
+			local_irq_restore(flags);
+		}
+		if (pdata->cs_control)
+			pdata->cs_control(spi, pol);
+	}
+}
+
+static
+int mpc8xxx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct mpc8xxx_spi *mpc8xxx_spi;
+	u32 regval;
+	u8 bits_per_word, pm;
+	u32 hz;
+	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
+
+	mpc8xxx_spi = spi_master_get_devdata(spi->master);
+
+	if (t) {
+		bits_per_word = t->bits_per_word;
+		hz = t->speed_hz;
+	} else {
+		bits_per_word = 0;
+		hz = 0;
+	}
+
+	/* spi_transfer level calls that work per-word */
+	if (!bits_per_word)
+		bits_per_word = spi->bits_per_word;
+
+	/* Make sure its a bit width we support [4..16, 32] */
+	if ((bits_per_word < 4)
+	    || ((bits_per_word > 16) && (bits_per_word != 32)))
+		return -EINVAL;
+
+	if (!hz)
+		hz = spi->max_speed_hz;
+
+	cs->rx_shift = 0;
+	cs->tx_shift = 0;
+	if (bits_per_word <= 8) {
+		cs->get_rx = mpc8xxx_spi_rx_buf_u8;
+		cs->get_tx = mpc8xxx_spi_tx_buf_u8;
+		if (mpc8xxx_spi->qe_mode) {
+			cs->rx_shift = 16;
+			cs->tx_shift = 24;
+		}
+	} else if (bits_per_word <= 16) {
+		cs->get_rx = mpc8xxx_spi_rx_buf_u16;
+		cs->get_tx = mpc8xxx_spi_tx_buf_u16;
+		if (mpc8xxx_spi->qe_mode) {
+			cs->rx_shift = 16;
+			cs->tx_shift = 16;
+		}
+	} else if (bits_per_word <= 32) {
+		cs->get_rx = mpc8xxx_spi_rx_buf_u32;
+		cs->get_tx = mpc8xxx_spi_tx_buf_u32;
+	} else
+		return -EINVAL;
+
+	if (mpc8xxx_spi->qe_mode && spi->mode & SPI_LSB_FIRST) {
+		cs->tx_shift = 0;
+		if (bits_per_word <= 8)
+			cs->rx_shift = 8;
+		else
+			cs->rx_shift = 0;
+	}
+
+	mpc8xxx_spi->rx_shift = cs->rx_shift;
+	mpc8xxx_spi->tx_shift = cs->tx_shift;
+	mpc8xxx_spi->get_rx = cs->get_rx;
+	mpc8xxx_spi->get_tx = cs->get_tx;
+
+	if (bits_per_word == 32)
+		bits_per_word = 0;
+	else
+		bits_per_word = bits_per_word - 1;
+
+	/* mask out bits we are going to set */
+	cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
+				  | SPMODE_PM(0xF));
+
+	cs->hw_mode |= SPMODE_LEN(bits_per_word);
+
+	if ((mpc8xxx_spi->spibrg / hz) > 64) {
+		cs->hw_mode |= SPMODE_DIV16;
+		pm = mpc8xxx_spi->spibrg / (hz * 64);
+
+		WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
+			  "Will use %d Hz instead.\n", dev_name(&spi->dev),
+			  hz, mpc8xxx_spi->spibrg / 1024);
+		if (pm > 16)
+			pm = 16;
+	} else
+		pm = mpc8xxx_spi->spibrg / (hz * 4);
+	if (pm)
+		pm--;
+
+	cs->hw_mode |= SPMODE_PM(pm);
+	regval =  mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->mode);
+	if (cs->hw_mode != regval) {
+		unsigned long flags;
+		__be32 __iomem *mode = &mpc8xxx_spi->base->mode;
+
+		regval = cs->hw_mode;
+		/* Turn off IRQs locally to minimize time
+		 * that SPI is disabled
+		 */
+		local_irq_save(flags);
+		/* Turn off SPI unit prior changing mode */
+		mpc8xxx_spi_write_reg(mode, regval & ~SPMODE_ENABLE);
+		mpc8xxx_spi_write_reg(mode, regval);
+		local_irq_restore(flags);
+	}
+	return 0;
+}
+
+static int mpc8xxx_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct mpc8xxx_spi *mpc8xxx_spi;
+	u32 word, len, bits_per_word;
+
+	mpc8xxx_spi = spi_master_get_devdata(spi->master);
+
+	mpc8xxx_spi->tx = t->tx_buf;
+	mpc8xxx_spi->rx = t->rx_buf;
+	bits_per_word = spi->bits_per_word;
+	if (t->bits_per_word)
+		bits_per_word = t->bits_per_word;
+	len = t->len;
+	if (bits_per_word > 8) {
+		/* invalid length? */
+		if (len & 1)
+			return -EINVAL;
+		len /= 2;
+	}
+	if (bits_per_word > 16) {
+		/* invalid length? */
+		if (len & 1)
+			return -EINVAL;
+		len /= 2;
+	}
+	mpc8xxx_spi->count = len;
+
+	INIT_COMPLETION(mpc8xxx_spi->done);
+
+	/* enable rx ints */
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mask, SPIM_NE);
+
+	/* transmit word */
+	word = mpc8xxx_spi->get_tx(mpc8xxx_spi);
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->transmit, word);
+
+	wait_for_completion(&mpc8xxx_spi->done);
+
+	/* disable rx ints */
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mask, 0);
+
+	return mpc8xxx_spi->count;
+}
+
+static void mpc8xxx_spi_do_one_msg(struct spi_message *m)
+{
+	struct spi_device *spi = m->spi;
+	struct spi_transfer *t;
+	unsigned int cs_change;
+	const int nsecs = 50;
+	int status;
+
+	cs_change = 1;
+	status = 0;
+	list_for_each_entry(t, &m->transfers, transfer_list) {
+		if (t->bits_per_word || t->speed_hz) {
+			/* Don't allow changes if CS is active */
+			status = -EINVAL;
+
+			if (cs_change)
+				status = mpc8xxx_spi_setup_transfer(spi, t);
+			if (status < 0)
+				break;
+		}
+
+		if (cs_change) {
+			mpc8xxx_spi_chipselect(spi, BITBANG_CS_ACTIVE);
+			ndelay(nsecs);
+		}
+		cs_change = t->cs_change;
+		if (t->len)
+			status = mpc8xxx_spi_bufs(spi, t);
+		if (status) {
+			status = -EMSGSIZE;
+			break;
+		}
+		m->actual_length += t->len;
+
+		if (t->delay_usecs)
+			udelay(t->delay_usecs);
+
+		if (cs_change) {
+			ndelay(nsecs);
+			mpc8xxx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
+			ndelay(nsecs);
+		}
+	}
+
+	m->status = status;
+	m->complete(m->context);
+
+	if (status || !cs_change) {
+		ndelay(nsecs);
+		mpc8xxx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
+	}
+
+	mpc8xxx_spi_setup_transfer(spi, NULL);
+}
+
+static void mpc8xxx_spi_work(struct work_struct *work)
+{
+	struct mpc8xxx_spi *mpc8xxx_spi = container_of(work, struct mpc8xxx_spi,
+						       work);
+
+	spin_lock_irq(&mpc8xxx_spi->lock);
+	while (!list_empty(&mpc8xxx_spi->queue)) {
+		struct spi_message *m = container_of(mpc8xxx_spi->queue.next,
+						   struct spi_message, queue);
+
+		list_del_init(&m->queue);
+		spin_unlock_irq(&mpc8xxx_spi->lock);
+
+		mpc8xxx_spi_do_one_msg(m);
+
+		spin_lock_irq(&mpc8xxx_spi->lock);
+	}
+	spin_unlock_irq(&mpc8xxx_spi->lock);
+}
+
+static int mpc8xxx_spi_setup(struct spi_device *spi)
+{
+	struct mpc8xxx_spi *mpc8xxx_spi;
+	int retval;
+	u32 hw_mode;
+	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
+
+	if (!spi->max_speed_hz)
+		return -EINVAL;
+
+	if (!cs) {
+		cs = kzalloc(sizeof *cs, GFP_KERNEL);
+		if (!cs)
+			return -ENOMEM;
+		spi->controller_state = cs;
+	}
+	mpc8xxx_spi = spi_master_get_devdata(spi->master);
+
+	hw_mode = cs->hw_mode; /* Save orginal settings */
+	cs->hw_mode = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->mode);
+	/* mask out bits we are going to set */
+	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
+			 | SPMODE_REV | SPMODE_LOOP);
+
+	if (spi->mode & SPI_CPHA)
+		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
+	if (spi->mode & SPI_CPOL)
+		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
+	if (!(spi->mode & SPI_LSB_FIRST))
+		cs->hw_mode |= SPMODE_REV;
+	if (spi->mode & SPI_LOOP)
+		cs->hw_mode |= SPMODE_LOOP;
+
+	retval = mpc8xxx_spi_setup_transfer(spi, NULL);
+	if (retval < 0) {
+		cs->hw_mode = hw_mode; /* Restore settings */
+		return retval;
+	}
+	return 0;
+}
+
+static irqreturn_t mpc8xxx_spi_irq(s32 irq, void *context_data)
+{
+	struct mpc8xxx_spi *mpc8xxx_spi = context_data;
+	u32 event;
+	irqreturn_t ret = IRQ_NONE;
+
+	/* Get interrupt events(tx/rx) */
+	event = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->event);
+
+	/* We need handle RX first */
+	if (event & SPIE_NE) {
+		u32 rx_data = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->receive);
+
+		if (mpc8xxx_spi->rx)
+			mpc8xxx_spi->get_rx(rx_data, mpc8xxx_spi);
+
+		ret = IRQ_HANDLED;
+	}
+
+	if ((event & SPIE_NF) == 0)
+		/* spin until TX is done */
+		while (((event =
+			 mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->event)) &
+						SPIE_NF) == 0)
+			cpu_relax();
+
+	mpc8xxx_spi->count -= 1;
+	if (mpc8xxx_spi->count) {
+		u32 word = mpc8xxx_spi->get_tx(mpc8xxx_spi);
+		mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->transmit, word);
+	} else {
+		complete(&mpc8xxx_spi->done);
+	}
+
+	/* Clear the events */
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->event, event);
+
+	return ret;
+}
+static int mpc8xxx_spi_transfer(struct spi_device *spi,
+				struct spi_message *m)
+{
+	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	m->actual_length = 0;
+	m->status = -EINPROGRESS;
+
+	spin_lock_irqsave(&mpc8xxx_spi->lock, flags);
+	list_add_tail(&m->queue, &mpc8xxx_spi->queue);
+	queue_work(mpc8xxx_spi->workqueue, &mpc8xxx_spi->work);
+	spin_unlock_irqrestore(&mpc8xxx_spi->lock, flags);
+
+	return 0;
+}
+
+
+static void mpc8xxx_spi_cleanup(struct spi_device *spi)
+{
+	kfree(spi->controller_state);
+}
+
+static struct spi_master * __devinit
+mpc8xxx_spi_probe(struct device *dev, struct resource *mem, unsigned int irq)
+{
+	struct fsl_spi_platform_data *pdata = dev->platform_data;
+	struct spi_master *master;
+	struct mpc8xxx_spi *mpc8xxx_spi;
+	u32 regval;
+	int ret = 0;
+
+	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
+	if (master == NULL) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	dev_set_drvdata(dev, master);
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
+			| SPI_LSB_FIRST | SPI_LOOP;
+
+	master->setup = mpc8xxx_spi_setup;
+	master->transfer = mpc8xxx_spi_transfer;
+	master->cleanup = mpc8xxx_spi_cleanup;
+
+	mpc8xxx_spi = spi_master_get_devdata(master);
+	mpc8xxx_spi->qe_mode = pdata->qe_mode;
+	mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
+	mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
+	mpc8xxx_spi->spibrg = pdata->sysclk;
+
+	mpc8xxx_spi->rx_shift = 0;
+	mpc8xxx_spi->tx_shift = 0;
+	if (mpc8xxx_spi->qe_mode) {
+		mpc8xxx_spi->rx_shift = 16;
+		mpc8xxx_spi->tx_shift = 24;
+	}
+
+	init_completion(&mpc8xxx_spi->done);
+
+	mpc8xxx_spi->base = ioremap(mem->start, mem->end - mem->start + 1);
+	if (mpc8xxx_spi->base == NULL) {
+		ret = -ENOMEM;
+		goto put_master;
+	}
+
+	mpc8xxx_spi->irq = irq;
+
+	/* Register for SPI Interrupt */
+	ret = request_irq(mpc8xxx_spi->irq, mpc8xxx_spi_irq,
+			  0, "mpc8xxx_spi", mpc8xxx_spi);
+
+	if (ret != 0)
+		goto unmap_io;
+
+	master->bus_num = pdata->bus_num;
+	master->num_chipselect = pdata->max_chipselect;
+
+	/* SPI controller initializations */
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mode, 0);
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mask, 0);
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->command, 0);
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->event, 0xffffffff);
+
+	/* Enable SPI interface */
+	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
+	if (pdata->qe_mode)
+		regval |= SPMODE_OP;
+
+	mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mode, regval);
+	spin_lock_init(&mpc8xxx_spi->lock);
+	init_completion(&mpc8xxx_spi->done);
+	INIT_WORK(&mpc8xxx_spi->work, mpc8xxx_spi_work);
+	INIT_LIST_HEAD(&mpc8xxx_spi->queue);
+
+	mpc8xxx_spi->workqueue = create_singlethread_workqueue(
+		dev_name(master->dev.parent));
+	if (mpc8xxx_spi->workqueue == NULL) {
+		ret = -EBUSY;
+		goto free_irq;
+	}
+
+	ret = spi_register_master(master);
+	if (ret < 0)
+		goto unreg_master;
+
+	printk(KERN_INFO
+	       "%s: MPC8xxx SPI Controller driver at 0x%p (irq = %d)\n",
+	       dev_name(dev), mpc8xxx_spi->base, mpc8xxx_spi->irq);
+
+	return master;
+
+unreg_master:
+	destroy_workqueue(mpc8xxx_spi->workqueue);
+free_irq:
+	free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
+unmap_io:
+	iounmap(mpc8xxx_spi->base);
+put_master:
+	spi_master_put(master);
+err:
+	return ERR_PTR(ret);
+}
+
+static int __devexit mpc8xxx_spi_remove(struct device *dev)
+{
+	struct mpc8xxx_spi *mpc8xxx_spi;
+	struct spi_master *master;
+
+	master = dev_get_drvdata(dev);
+	mpc8xxx_spi = spi_master_get_devdata(master);
+
+	flush_workqueue(mpc8xxx_spi->workqueue);
+	destroy_workqueue(mpc8xxx_spi->workqueue);
+	spi_unregister_master(master);
+
+	free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
+	iounmap(mpc8xxx_spi->base);
+
+	return 0;
+}
+
+struct mpc8xxx_spi_probe_info {
+	struct fsl_spi_platform_data pdata;
+	int *gpios;
+	bool *alow_flags;
+};
+
+static struct mpc8xxx_spi_probe_info *
+to_of_pinfo(struct fsl_spi_platform_data *pdata)
+{
+	return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
+}
+
+static void mpc8xxx_spi_cs_control(struct spi_device *spi, bool on)
+{
+	struct device *dev = spi->dev.parent;
+	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(dev->platform_data);
+	u16 cs = spi->chip_select;
+	int gpio = pinfo->gpios[cs];
+	bool alow = pinfo->alow_flags[cs];
+
+	gpio_set_value(gpio, on ^ alow);
+}
+
+static int of_mpc8xxx_spi_get_chipselects(struct device *dev)
+{
+	struct device_node *np = dev_archdata_get_node(&dev->archdata);
+	struct fsl_spi_platform_data *pdata = dev->platform_data;
+	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
+	unsigned int ngpios;
+	int i = 0;
+	int ret;
+
+	ngpios = of_gpio_count(np);
+	if (!ngpios) {
+		/*
+		 * SPI w/o chip-select line. One SPI device is still permitted
+		 * though.
+		 */
+		pdata->max_chipselect = 1;
+		return 0;
+	}
+
+	pinfo->gpios = kmalloc(ngpios * sizeof(*pinfo->gpios), GFP_KERNEL);
+	if (!pinfo->gpios)
+		return -ENOMEM;
+	memset(pinfo->gpios, -1, ngpios * sizeof(*pinfo->gpios));
+
+	pinfo->alow_flags = kzalloc(ngpios * sizeof(*pinfo->alow_flags),
+				    GFP_KERNEL);
+	if (!pinfo->alow_flags) {
+		ret = -ENOMEM;
+		goto err_alloc_flags;
+	}
+
+	for (; i < ngpios; i++) {
+		int gpio;
+		enum of_gpio_flags flags;
+
+		gpio = of_get_gpio_flags(np, i, &flags);
+		if (!gpio_is_valid(gpio)) {
+			dev_err(dev, "invalid gpio #%d: %d\n", i, gpio);
+			goto err_loop;
+		}
+
+		ret = gpio_request(gpio, dev_name(dev));
+		if (ret) {
+			dev_err(dev, "can't request gpio #%d: %d\n", i, ret);
+			goto err_loop;
+		}
+
+		pinfo->gpios[i] = gpio;
+		pinfo->alow_flags[i] = flags & OF_GPIO_ACTIVE_LOW;
+
+		ret = gpio_direction_output(pinfo->gpios[i],
+					    pinfo->alow_flags[i]);
+		if (ret) {
+			dev_err(dev, "can't set output direction for gpio "
+				"#%d: %d\n", i, ret);
+			goto err_loop;
+		}
+	}
+
+	pdata->max_chipselect = ngpios;
+	pdata->cs_control = mpc8xxx_spi_cs_control;
+
+	return 0;
+
+err_loop:
+	while (i >= 0) {
+		if (gpio_is_valid(pinfo->gpios[i]))
+			gpio_free(pinfo->gpios[i]);
+		i--;
+	}
+
+	kfree(pinfo->alow_flags);
+	pinfo->alow_flags = NULL;
+err_alloc_flags:
+	kfree(pinfo->gpios);
+	pinfo->gpios = NULL;
+	return ret;
+}
+
+static int of_mpc8xxx_spi_free_chipselects(struct device *dev)
+{
+	struct fsl_spi_platform_data *pdata = dev->platform_data;
+	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
+	int i;
+
+	if (!pinfo->gpios)
+		return 0;
+
+	for (i = 0; i < pdata->max_chipselect; i++) {
+		if (gpio_is_valid(pinfo->gpios[i]))
+			gpio_free(pinfo->gpios[i]);
+	}
+
+	kfree(pinfo->gpios);
+	kfree(pinfo->alow_flags);
+	return 0;
+}
+
+static int __devinit of_mpc8xxx_spi_probe(struct of_device *ofdev,
+					  const struct of_device_id *ofid)
+{
+	struct device *dev = &ofdev->dev;
+	struct device_node *np = ofdev->node;
+	struct mpc8xxx_spi_probe_info *pinfo;
+	struct fsl_spi_platform_data *pdata;
+	struct spi_master *master;
+	struct resource mem;
+	struct resource irq;
+	const void *prop;
+	int ret = -ENOMEM;
+
+	pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
+	if (!pinfo)
+		return -ENOMEM;
+
+	pdata = &pinfo->pdata;
+	dev->platform_data = pdata;
+
+	/* Allocate bus num dynamically. */
+	pdata->bus_num = -1;
+
+	/* SPI controller is either clocked from QE or SoC clock. */
+	pdata->sysclk = get_brgfreq();
+	if (pdata->sysclk == -1) {
+		pdata->sysclk = fsl_get_sys_freq();
+		if (pdata->sysclk == -1) {
+			ret = -ENODEV;
+			goto err_clk;
+		}
+	}
+
+	prop = of_get_property(np, "mode", NULL);
+	if (prop && !strcmp(prop, "cpu-qe"))
+		pdata->qe_mode = 1;
+
+	ret = of_mpc8xxx_spi_get_chipselects(dev);
+	if (ret)
+		goto err;
+
+	ret = of_address_to_resource(np, 0, &mem);
+	if (ret)
+		goto err;
+
+	ret = of_irq_to_resource(np, 0, &irq);
+	if (!ret) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	master = mpc8xxx_spi_probe(dev, &mem, irq.start);
+	if (IS_ERR(master)) {
+		ret = PTR_ERR(master);
+		goto err;
+	}
+
+	of_register_spi_devices(master, np);
+
+	return 0;
+
+err:
+	of_mpc8xxx_spi_free_chipselects(dev);
+err_clk:
+	kfree(pinfo);
+	return ret;
+}
+
+static int __devexit of_mpc8xxx_spi_remove(struct of_device *ofdev)
+{
+	int ret;
+
+	ret = mpc8xxx_spi_remove(&ofdev->dev);
+	if (ret)
+		return ret;
+	of_mpc8xxx_spi_free_chipselects(&ofdev->dev);
+	return 0;
+}
+
+static const struct of_device_id of_mpc8xxx_spi_match[] = {
+	{ .compatible = "fsl,spi" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_mpc8xxx_spi_match);
+
+static struct of_platform_driver of_mpc8xxx_spi_driver = {
+	.name		= "mpc8xxx_spi",
+	.match_table	= of_mpc8xxx_spi_match,
+	.probe		= of_mpc8xxx_spi_probe,
+	.remove		= __devexit_p(of_mpc8xxx_spi_remove),
+};
+
+#ifdef CONFIG_MPC832x_RDB
+/*
+ * 				XXX XXX XXX
+ * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
+ * only. The driver should go away soon, since newer MPC8323E-RDB's device
+ * tree can work with OpenFirmware driver. But for now we support old trees
+ * as well.
+ */
+static int __devinit plat_mpc8xxx_spi_probe(struct platform_device *pdev)
+{
+	struct resource *mem;
+	unsigned int irq;
+	struct spi_master *master;
+
+	if (!pdev->dev.platform_data)
+		return -EINVAL;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem)
+		return -EINVAL;
+
+	irq = platform_get_irq(pdev, 0);
+	if (!irq)
+		return -EINVAL;
+
+	master = mpc8xxx_spi_probe(&pdev->dev, mem, irq);
+	if (IS_ERR(master))
+		return PTR_ERR(master);
+	return 0;
+}
+
+static int __devexit plat_mpc8xxx_spi_remove(struct platform_device *pdev)
+{
+	return mpc8xxx_spi_remove(&pdev->dev);
+}
+
+MODULE_ALIAS("platform:mpc8xxx_spi");
+static struct platform_driver mpc8xxx_spi_driver = {
+	.probe = plat_mpc8xxx_spi_probe,
+	.remove = __exit_p(plat_mpc8xxx_spi_remove),
+	.driver = {
+		.name = "mpc8xxx_spi",
+		.owner = THIS_MODULE,
+	},
+};
+
+static bool legacy_driver_failed;
+
+static void __init legacy_driver_register(void)
+{
+	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
+}
+
+static void __exit legacy_driver_unregister(void)
+{
+	if (legacy_driver_failed)
+		return;
+	platform_driver_unregister(&mpc8xxx_spi_driver);
+}
+#else
+static void __init legacy_driver_register(void) {}
+static void __exit legacy_driver_unregister(void) {}
+#endif /* CONFIG_MPC832x_RDB */
+
+static int __init mpc8xxx_spi_init(void)
+{
+	legacy_driver_register();
+	return of_register_platform_driver(&of_mpc8xxx_spi_driver);
+}
+
+static void __exit mpc8xxx_spi_exit(void)
+{
+	of_unregister_platform_driver(&of_mpc8xxx_spi_driver);
+	legacy_driver_unregister();
+}
+
+module_init(mpc8xxx_spi_init);
+module_exit(mpc8xxx_spi_exit);
+
+MODULE_AUTHOR("Kumar Gala");
+MODULE_DESCRIPTION("Simple MPC8xxx SPI Driver");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_ppc4xx.c

@@ -0,0 +1,612 @@
+/*
+ * SPI_PPC4XX SPI controller driver.
+ *
+ * Copyright (C) 2007 Gary Jennejohn <garyj@denx.de>
+ * Copyright 2008 Stefan Roese <sr@denx.de>, DENX Software Engineering
+ * Copyright 2009 Harris Corporation, Steven A. Falco <sfalco@harris.com>
+ *
+ * Based in part on drivers/spi/spi_s3c24xx.c
+ *
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+/*
+ * The PPC4xx SPI controller has no FIFO so each sent/received byte will
+ * generate an interrupt to the CPU. This can cause high CPU utilization.
+ * This driver allows platforms to reduce the interrupt load on the CPU
+ * during SPI transfers by setting max_speed_hz via the device tree.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/of_platform.h>
+#include <linux/of_spi.h>
+#include <linux/of_gpio.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <asm/io.h>
+#include <asm/dcr.h>
+#include <asm/dcr-regs.h>
+
+/* bits in mode register - bit 0 is MSb */
+
+/*
+ * SPI_PPC4XX_MODE_SCP = 0 means "data latched on trailing edge of clock"
+ * SPI_PPC4XX_MODE_SCP = 1 means "data latched on leading edge of clock"
+ * Note: This is the inverse of CPHA.
+ */
+#define SPI_PPC4XX_MODE_SCP	(0x80 >> 3)
+
+/* SPI_PPC4XX_MODE_SPE = 1 means "port enabled" */
+#define SPI_PPC4XX_MODE_SPE	(0x80 >> 4)
+
+/*
+ * SPI_PPC4XX_MODE_RD = 0 means "MSB first" - this is the normal mode
+ * SPI_PPC4XX_MODE_RD = 1 means "LSB first" - this is bit-reversed mode
+ * Note: This is identical to SPI_LSB_FIRST.
+ */
+#define SPI_PPC4XX_MODE_RD	(0x80 >> 5)
+
+/*
+ * SPI_PPC4XX_MODE_CI = 0 means "clock idles low"
+ * SPI_PPC4XX_MODE_CI = 1 means "clock idles high"
+ * Note: This is identical to CPOL.
+ */
+#define SPI_PPC4XX_MODE_CI	(0x80 >> 6)
+
+/*
+ * SPI_PPC4XX_MODE_IL = 0 means "loopback disable"
+ * SPI_PPC4XX_MODE_IL = 1 means "loopback enable"
+ */
+#define SPI_PPC4XX_MODE_IL	(0x80 >> 7)
+
+/* bits in control register */
+/* starts a transfer when set */
+#define SPI_PPC4XX_CR_STR	(0x80 >> 7)
+
+/* bits in status register */
+/* port is busy with a transfer */
+#define SPI_PPC4XX_SR_BSY	(0x80 >> 6)
+/* RxD ready */
+#define SPI_PPC4XX_SR_RBR	(0x80 >> 7)
+
+/* clock settings (SCP and CI) for various SPI modes */
+#define SPI_CLK_MODE0	(SPI_PPC4XX_MODE_SCP | 0)
+#define SPI_CLK_MODE1	(0 | 0)
+#define SPI_CLK_MODE2	(SPI_PPC4XX_MODE_SCP | SPI_PPC4XX_MODE_CI)
+#define SPI_CLK_MODE3	(0 | SPI_PPC4XX_MODE_CI)
+
+#define DRIVER_NAME	"spi_ppc4xx_of"
+
+struct spi_ppc4xx_regs {
+	u8 mode;
+	u8 rxd;
+	u8 txd;
+	u8 cr;
+	u8 sr;
+	u8 dummy;
+	/*
+	 * Clock divisor modulus register
+	 * This uses the follwing formula:
+	 *    SCPClkOut = OPBCLK/(4(CDM + 1))
+	 * or
+	 *    CDM = (OPBCLK/4*SCPClkOut) - 1
+	 * bit 0 is the MSb!
+	 */
+	u8 cdm;
+};
+
+/* SPI Controller driver's private data. */
+struct ppc4xx_spi {
+	/* bitbang has to be first */
+	struct spi_bitbang bitbang;
+	struct completion done;
+
+	u64 mapbase;
+	u64 mapsize;
+	int irqnum;
+	/* need this to set the SPI clock */
+	unsigned int opb_freq;
+
+	/* for transfers */
+	int len;
+	int count;
+	/* data buffers */
+	const unsigned char *tx;
+	unsigned char *rx;
+
+	int *gpios;
+
+	struct spi_ppc4xx_regs __iomem *regs; /* pointer to the registers */
+	struct spi_master *master;
+	struct device *dev;
+};
+
+/* need this so we can set the clock in the chipselect routine */
+struct spi_ppc4xx_cs {
+	u8 mode;
+};
+
+static int spi_ppc4xx_txrx(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct ppc4xx_spi *hw;
+	u8 data;
+
+	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
+		t->tx_buf, t->rx_buf, t->len);
+
+	hw = spi_master_get_devdata(spi->master);
+
+	hw->tx = t->tx_buf;
+	hw->rx = t->rx_buf;
+	hw->len = t->len;
+	hw->count = 0;
+
+	/* send the first byte */
+	data = hw->tx ? hw->tx[0] : 0;
+	out_8(&hw->regs->txd, data);
+	out_8(&hw->regs->cr, SPI_PPC4XX_CR_STR);
+	wait_for_completion(&hw->done);
+
+	return hw->count;
+}
+
+static int spi_ppc4xx_setupxfer(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct ppc4xx_spi *hw = spi_master_get_devdata(spi->master);
+	struct spi_ppc4xx_cs *cs = spi->controller_state;
+	int scr;
+	u8 cdm = 0;
+	u32 speed;
+	u8 bits_per_word;
+
+	/* Start with the generic configuration for this device. */
+	bits_per_word = spi->bits_per_word;
+	speed = spi->max_speed_hz;
+
+	/*
+	 * Modify the configuration if the transfer overrides it.  Do not allow
+	 * the transfer to overwrite the generic configuration with zeros.
+	 */
+	if (t) {
+		if (t->bits_per_word)
+			bits_per_word = t->bits_per_word;
+
+		if (t->speed_hz)
+			speed = min(t->speed_hz, spi->max_speed_hz);
+	}
+
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "invalid bits-per-word (%d)\n",
+				bits_per_word);
+		return -EINVAL;
+	}
+
+	if (!speed || (speed > spi->max_speed_hz)) {
+		dev_err(&spi->dev, "invalid speed_hz (%d)\n", speed);
+		return -EINVAL;
+	}
+
+	/* Write new configration */
+	out_8(&hw->regs->mode, cs->mode);
+
+	/* Set the clock */
+	/* opb_freq was already divided by 4 */
+	scr = (hw->opb_freq / speed) - 1;
+	if (scr > 0)
+		cdm = min(scr, 0xff);
+
+	dev_dbg(&spi->dev, "setting pre-scaler to %d (hz %d)\n", cdm, speed);
+
+	if (in_8(&hw->regs->cdm) != cdm)
+		out_8(&hw->regs->cdm, cdm);
+
+	spin_lock(&hw->bitbang.lock);
+	if (!hw->bitbang.busy) {
+		hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE);
+		/* Need to ndelay here? */
+	}
+	spin_unlock(&hw->bitbang.lock);
+
+	return 0;
+}
+
+static int spi_ppc4xx_setup(struct spi_device *spi)
+{
+	struct spi_ppc4xx_cs *cs = spi->controller_state;
+
+	if (spi->bits_per_word != 8) {
+		dev_err(&spi->dev, "invalid bits-per-word (%d)\n",
+			spi->bits_per_word);
+		return -EINVAL;
+	}
+
+	if (!spi->max_speed_hz) {
+		dev_err(&spi->dev, "invalid max_speed_hz (must be non-zero)\n");
+		return -EINVAL;
+	}
+
+	if (cs == NULL) {
+		cs = kzalloc(sizeof *cs, GFP_KERNEL);
+		if (!cs)
+			return -ENOMEM;
+		spi->controller_state = cs;
+	}
+
+	/*
+	 * We set all bits of the SPI0_MODE register, so,
+	 * no need to read-modify-write
+	 */
+	cs->mode = SPI_PPC4XX_MODE_SPE;
+
+	switch (spi->mode & (SPI_CPHA | SPI_CPOL)) {
+	case SPI_MODE_0:
+		cs->mode |= SPI_CLK_MODE0;
+		break;
+	case SPI_MODE_1:
+		cs->mode |= SPI_CLK_MODE1;
+		break;
+	case SPI_MODE_2:
+		cs->mode |= SPI_CLK_MODE2;
+		break;
+	case SPI_MODE_3:
+		cs->mode |= SPI_CLK_MODE3;
+		break;
+	}
+
+	if (spi->mode & SPI_LSB_FIRST)
+		cs->mode |= SPI_PPC4XX_MODE_RD;
+
+	return 0;
+}
+
+static void spi_ppc4xx_chipsel(struct spi_device *spi, int value)
+{
+	struct ppc4xx_spi *hw = spi_master_get_devdata(spi->master);
+	unsigned int cs = spi->chip_select;
+	unsigned int cspol;
+
+	/*
+	 * If there are no chip selects at all, or if this is the special
+	 * case of a non-existent (dummy) chip select, do nothing.
+	 */
+
+	if (!hw->master->num_chipselect || hw->gpios[cs] == -EEXIST)
+		return;
+
+	cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
+	if (value == BITBANG_CS_INACTIVE)
+		cspol = !cspol;
+
+	gpio_set_value(hw->gpios[cs], cspol);
+}
+
+static irqreturn_t spi_ppc4xx_int(int irq, void *dev_id)
+{
+	struct ppc4xx_spi *hw;
+	u8 status;
+	u8 data;
+	unsigned int count;
+
+	hw = (struct ppc4xx_spi *)dev_id;
+
+	status = in_8(&hw->regs->sr);
+	if (!status)
+		return IRQ_NONE;
+
+	/*
+	 * BSY de-asserts one cycle after the transfer is complete.  The
+	 * interrupt is asserted after the transfer is complete.  The exact
+	 * relationship is not documented, hence this code.
+	 */
+
+	if (unlikely(status & SPI_PPC4XX_SR_BSY)) {
+		u8 lstatus;
+		int cnt = 0;
+
+		dev_dbg(hw->dev, "got interrupt but spi still busy?\n");
+		do {
+			ndelay(10);
+			lstatus = in_8(&hw->regs->sr);
+		} while (++cnt < 100 && lstatus & SPI_PPC4XX_SR_BSY);
+
+		if (cnt >= 100) {
+			dev_err(hw->dev, "busywait: too many loops!\n");
+			complete(&hw->done);
+			return IRQ_HANDLED;
+		} else {
+			/* status is always 1 (RBR) here */
+			status = in_8(&hw->regs->sr);
+			dev_dbg(hw->dev, "loops %d status %x\n", cnt, status);
+		}
+	}
+
+	count = hw->count;
+	hw->count++;
+
+	/* RBR triggered this interrupt.  Therefore, data must be ready. */
+	data = in_8(&hw->regs->rxd);
+	if (hw->rx)
+		hw->rx[count] = data;
+
+	count++;
+
+	if (count < hw->len) {
+		data = hw->tx ? hw->tx[count] : 0;
+		out_8(&hw->regs->txd, data);
+		out_8(&hw->regs->cr, SPI_PPC4XX_CR_STR);
+	} else {
+		complete(&hw->done);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void spi_ppc4xx_cleanup(struct spi_device *spi)
+{
+	kfree(spi->controller_state);
+}
+
+static void spi_ppc4xx_enable(struct ppc4xx_spi *hw)
+{
+	/*
+	 * On all 4xx PPC's the SPI bus is shared/multiplexed with
+	 * the 2nd I2C bus. We need to enable the the SPI bus before
+	 * using it.
+	 */
+
+	/* need to clear bit 14 to enable SPC */
+	dcri_clrset(SDR0, SDR0_PFC1, 0x80000000 >> 14, 0);
+}
+
+static void free_gpios(struct ppc4xx_spi *hw)
+{
+	if (hw->master->num_chipselect) {
+		int i;
+		for (i = 0; i < hw->master->num_chipselect; i++)
+			if (gpio_is_valid(hw->gpios[i]))
+				gpio_free(hw->gpios[i]);
+
+		kfree(hw->gpios);
+		hw->gpios = NULL;
+	}
+}
+
+/*
+ * of_device layer stuff...
+ */
+static int __init spi_ppc4xx_of_probe(struct of_device *op,
+				      const struct of_device_id *match)
+{
+	struct ppc4xx_spi *hw;
+	struct spi_master *master;
+	struct spi_bitbang *bbp;
+	struct resource resource;
+	struct device_node *np = op->node;
+	struct device *dev = &op->dev;
+	struct device_node *opbnp;
+	int ret;
+	int num_gpios;
+	const unsigned int *clk;
+
+	master = spi_alloc_master(dev, sizeof *hw);
+	if (master == NULL)
+		return -ENOMEM;
+	dev_set_drvdata(dev, master);
+	hw = spi_master_get_devdata(master);
+	hw->master = spi_master_get(master);
+	hw->dev = dev;
+
+	init_completion(&hw->done);
+
+	/*
+	 * A count of zero implies a single SPI device without any chip-select.
+	 * Note that of_gpio_count counts all gpios assigned to this spi master.
+	 * This includes both "null" gpio's and real ones.
+	 */
+	num_gpios = of_gpio_count(np);
+	if (num_gpios) {
+		int i;
+
+		hw->gpios = kzalloc(sizeof(int) * num_gpios, GFP_KERNEL);
+		if (!hw->gpios) {
+			ret = -ENOMEM;
+			goto free_master;
+		}
+
+		for (i = 0; i < num_gpios; i++) {
+			int gpio;
+			enum of_gpio_flags flags;
+
+			gpio = of_get_gpio_flags(np, i, &flags);
+			hw->gpios[i] = gpio;
+
+			if (gpio_is_valid(gpio)) {
+				/* Real CS - set the initial state. */
+				ret = gpio_request(gpio, np->name);
+				if (ret < 0) {
+					dev_err(dev, "can't request gpio "
+							"#%d: %d\n", i, ret);
+					goto free_gpios;
+				}
+
+				gpio_direction_output(gpio,
+						!!(flags & OF_GPIO_ACTIVE_LOW));
+			} else if (gpio == -EEXIST) {
+				; /* No CS, but that's OK. */
+			} else {
+				dev_err(dev, "invalid gpio #%d: %d\n", i, gpio);
+				ret = -EINVAL;
+				goto free_gpios;
+			}
+		}
+	}
+
+	/* Setup the state for the bitbang driver */
+	bbp = &hw->bitbang;
+	bbp->master = hw->master;
+	bbp->setup_transfer = spi_ppc4xx_setupxfer;
+	bbp->chipselect = spi_ppc4xx_chipsel;
+	bbp->txrx_bufs = spi_ppc4xx_txrx;
+	bbp->use_dma = 0;
+	bbp->master->setup = spi_ppc4xx_setup;
+	bbp->master->cleanup = spi_ppc4xx_cleanup;
+
+	/* Allocate bus num dynamically. */
+	bbp->master->bus_num = -1;
+
+	/* the spi->mode bits understood by this driver: */
+	bbp->master->mode_bits =
+		SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST;
+
+	/* this many pins in all GPIO controllers */
+	bbp->master->num_chipselect = num_gpios;
+
+	/* Get the clock for the OPB */
+	opbnp = of_find_compatible_node(NULL, NULL, "ibm,opb");
+	if (opbnp == NULL) {
+		dev_err(dev, "OPB: cannot find node\n");
+		ret = -ENODEV;
+		goto free_gpios;
+	}
+	/* Get the clock (Hz) for the OPB */
+	clk = of_get_property(opbnp, "clock-frequency", NULL);
+	if (clk == NULL) {
+		dev_err(dev, "OPB: no clock-frequency property set\n");
+		of_node_put(opbnp);
+		ret = -ENODEV;
+		goto free_gpios;
+	}
+	hw->opb_freq = *clk;
+	hw->opb_freq >>= 2;
+	of_node_put(opbnp);
+
+	ret = of_address_to_resource(np, 0, &resource);
+	if (ret) {
+		dev_err(dev, "error while parsing device node resource\n");
+		goto free_gpios;
+	}
+	hw->mapbase = resource.start;
+	hw->mapsize = resource.end - resource.start + 1;
+
+	/* Sanity check */
+	if (hw->mapsize < sizeof(struct spi_ppc4xx_regs)) {
+		dev_err(dev, "too small to map registers\n");
+		ret = -EINVAL;
+		goto free_gpios;
+	}
+
+	/* Request IRQ */
+	hw->irqnum = irq_of_parse_and_map(np, 0);
+	ret = request_irq(hw->irqnum, spi_ppc4xx_int,
+			  IRQF_DISABLED, "spi_ppc4xx_of", (void *)hw);
+	if (ret) {
+		dev_err(dev, "unable to allocate interrupt\n");
+		goto free_gpios;
+	}
+
+	if (!request_mem_region(hw->mapbase, hw->mapsize, DRIVER_NAME)) {
+		dev_err(dev, "resource unavailable\n");
+		ret = -EBUSY;
+		goto request_mem_error;
+	}
+
+	hw->regs = ioremap(hw->mapbase, sizeof(struct spi_ppc4xx_regs));
+
+	if (!hw->regs) {
+		dev_err(dev, "unable to memory map registers\n");
+		ret = -ENXIO;
+		goto map_io_error;
+	}
+
+	spi_ppc4xx_enable(hw);
+
+	/* Finally register our spi controller */
+	dev->dma_mask = 0;
+	ret = spi_bitbang_start(bbp);
+	if (ret) {
+		dev_err(dev, "failed to register SPI master\n");
+		goto unmap_regs;
+	}
+
+	dev_info(dev, "driver initialized\n");
+	of_register_spi_devices(master, np);
+
+	return 0;
+
+unmap_regs:
+	iounmap(hw->regs);
+map_io_error:
+	release_mem_region(hw->mapbase, hw->mapsize);
+request_mem_error:
+	free_irq(hw->irqnum, hw);
+free_gpios:
+	free_gpios(hw);
+free_master:
+	dev_set_drvdata(dev, NULL);
+	spi_master_put(master);
+
+	dev_err(dev, "initialization failed\n");
+	return ret;
+}
+
+static int __exit spi_ppc4xx_of_remove(struct of_device *op)
+{
+	struct spi_master *master = dev_get_drvdata(&op->dev);
+	struct ppc4xx_spi *hw = spi_master_get_devdata(master);
+
+	spi_bitbang_stop(&hw->bitbang);
+	dev_set_drvdata(&op->dev, NULL);
+	release_mem_region(hw->mapbase, hw->mapsize);
+	free_irq(hw->irqnum, hw);
+	iounmap(hw->regs);
+	free_gpios(hw);
+	return 0;
+}
+
+static struct of_device_id spi_ppc4xx_of_match[] = {
+	{ .compatible = "ibm,ppc4xx-spi", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, spi_ppc4xx_of_match);
+
+static struct of_platform_driver spi_ppc4xx_of_driver = {
+	.match_table = spi_ppc4xx_of_match,
+	.probe = spi_ppc4xx_of_probe,
+	.remove = __exit_p(spi_ppc4xx_of_remove),
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init spi_ppc4xx_init(void)
+{
+	return of_register_platform_driver(&spi_ppc4xx_of_driver);
+}
+module_init(spi_ppc4xx_init);
+
+static void __exit spi_ppc4xx_exit(void)
+{
+	of_unregister_platform_driver(&spi_ppc4xx_of_driver);
+}
+module_exit(spi_ppc4xx_exit);
+
+MODULE_AUTHOR("Gary Jennejohn & Stefan Roese");
+MODULE_DESCRIPTION("Simple PPC4xx SPI Driver");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_s3c24xx.c

@@ -0,0 +1,527 @@
+/* linux/drivers/spi/spi_s3c24xx.c
+ *
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+*/
+
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <plat/regs-spi.h>
+#include <mach/spi.h>
+
+/**
+ * s3c24xx_spi_devstate - per device data
+ * @hz: Last frequency calculated for @sppre field.
+ * @mode: Last mode setting for the @spcon field.
+ * @spcon: Value to write to the SPCON register.
+ * @sppre: Value to write to the SPPRE register.
+ */
+struct s3c24xx_spi_devstate {
+	unsigned int	hz;
+	unsigned int	mode;
+	u8		spcon;
+	u8		sppre;
+};
+
+struct s3c24xx_spi {
+	/* bitbang has to be first */
+	struct spi_bitbang	 bitbang;
+	struct completion	 done;
+
+	void __iomem		*regs;
+	int			 irq;
+	int			 len;
+	int			 count;
+
+	void			(*set_cs)(struct s3c2410_spi_info *spi,
+					  int cs, int pol);
+
+	/* data buffers */
+	const unsigned char	*tx;
+	unsigned char		*rx;
+
+	struct clk		*clk;
+	struct resource		*ioarea;
+	struct spi_master	*master;
+	struct spi_device	*curdev;
+	struct device		*dev;
+	struct s3c2410_spi_info *pdata;
+};
+
+#define SPCON_DEFAULT (S3C2410_SPCON_MSTR | S3C2410_SPCON_SMOD_INT)
+#define SPPIN_DEFAULT (S3C2410_SPPIN_KEEP)
+
+static inline struct s3c24xx_spi *to_hw(struct spi_device *sdev)
+{
+	return spi_master_get_devdata(sdev->master);
+}
+
+static void s3c24xx_spi_gpiocs(struct s3c2410_spi_info *spi, int cs, int pol)
+{
+	gpio_set_value(spi->pin_cs, pol);
+}
+
+static void s3c24xx_spi_chipsel(struct spi_device *spi, int value)
+{
+	struct s3c24xx_spi_devstate *cs = spi->controller_state;
+	struct s3c24xx_spi *hw = to_hw(spi);
+	unsigned int cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
+
+	/* change the chipselect state and the state of the spi engine clock */
+
+	switch (value) {
+	case BITBANG_CS_INACTIVE:
+		hw->set_cs(hw->pdata, spi->chip_select, cspol^1);
+		writeb(cs->spcon, hw->regs + S3C2410_SPCON);
+		break;
+
+	case BITBANG_CS_ACTIVE:
+		writeb(cs->spcon | S3C2410_SPCON_ENSCK,
+		       hw->regs + S3C2410_SPCON);
+		hw->set_cs(hw->pdata, spi->chip_select, cspol);
+		break;
+	}
+}
+
+static int s3c24xx_spi_update_state(struct spi_device *spi,
+				    struct spi_transfer *t)
+{
+	struct s3c24xx_spi *hw = to_hw(spi);
+	struct s3c24xx_spi_devstate *cs = spi->controller_state;
+	unsigned int bpw;
+	unsigned int hz;
+	unsigned int div;
+	unsigned long clk;
+
+	bpw = t ? t->bits_per_word : spi->bits_per_word;
+	hz  = t ? t->speed_hz : spi->max_speed_hz;
+
+	if (!bpw)
+		bpw = 8;
+
+	if (!hz)
+		hz = spi->max_speed_hz;
+
+	if (bpw != 8) {
+		dev_err(&spi->dev, "invalid bits-per-word (%d)\n", bpw);
+		return -EINVAL;
+	}
+
+	if (spi->mode != cs->mode) {
+		u8 spcon = SPCON_DEFAULT;
+
+		if (spi->mode & SPI_CPHA)
+			spcon |= S3C2410_SPCON_CPHA_FMTB;
+
+		if (spi->mode & SPI_CPOL)
+			spcon |= S3C2410_SPCON_CPOL_HIGH;
+
+		cs->mode = spi->mode;
+		cs->spcon = spcon;
+	}
+
+	if (cs->hz != hz) {
+		clk = clk_get_rate(hw->clk);
+		div = DIV_ROUND_UP(clk, hz * 2) - 1;
+
+		if (div > 255)
+			div = 255;
+
+		dev_dbg(&spi->dev, "pre-scaler=%d (wanted %d, got %ld)\n",
+			div, hz, clk / (2 * (div + 1)));
+
+		cs->hz = hz;
+		cs->sppre = div;
+	}
+
+	return 0;
+}
+
+static int s3c24xx_spi_setupxfer(struct spi_device *spi,
+				 struct spi_transfer *t)
+{
+	struct s3c24xx_spi_devstate *cs = spi->controller_state;
+	struct s3c24xx_spi *hw = to_hw(spi);
+	int ret;
+
+	ret = s3c24xx_spi_update_state(spi, t);
+	if (!ret)
+		writeb(cs->sppre, hw->regs + S3C2410_SPPRE);
+
+	return ret;
+}
+
+static int s3c24xx_spi_setup(struct spi_device *spi)
+{
+	struct s3c24xx_spi_devstate *cs = spi->controller_state;
+	struct s3c24xx_spi *hw = to_hw(spi);
+	int ret;
+
+	/* allocate settings on the first call */
+	if (!cs) {
+		cs = kzalloc(sizeof(struct s3c24xx_spi_devstate), GFP_KERNEL);
+		if (!cs) {
+			dev_err(&spi->dev, "no memory for controller state\n");
+			return -ENOMEM;
+		}
+
+		cs->spcon = SPCON_DEFAULT;
+		cs->hz = -1;
+		spi->controller_state = cs;
+	}
+
+	/* initialise the state from the device */
+	ret = s3c24xx_spi_update_state(spi, NULL);
+	if (ret)
+		return ret;
+
+	spin_lock(&hw->bitbang.lock);
+	if (!hw->bitbang.busy) {
+		hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE);
+		/* need to ndelay for 0.5 clocktick ? */
+	}
+	spin_unlock(&hw->bitbang.lock);
+
+	return 0;
+}
+
+static void s3c24xx_spi_cleanup(struct spi_device *spi)
+{
+	kfree(spi->controller_state);
+}
+
+static inline unsigned int hw_txbyte(struct s3c24xx_spi *hw, int count)
+{
+	return hw->tx ? hw->tx[count] : 0;
+}
+
+static int s3c24xx_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct s3c24xx_spi *hw = to_hw(spi);
+
+	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
+		t->tx_buf, t->rx_buf, t->len);
+
+	hw->tx = t->tx_buf;
+	hw->rx = t->rx_buf;
+	hw->len = t->len;
+	hw->count = 0;
+
+	init_completion(&hw->done);
+
+	/* send the first byte */
+	writeb(hw_txbyte(hw, 0), hw->regs + S3C2410_SPTDAT);
+
+	wait_for_completion(&hw->done);
+
+	return hw->count;
+}
+
+static irqreturn_t s3c24xx_spi_irq(int irq, void *dev)
+{
+	struct s3c24xx_spi *hw = dev;
+	unsigned int spsta = readb(hw->regs + S3C2410_SPSTA);
+	unsigned int count = hw->count;
+
+	if (spsta & S3C2410_SPSTA_DCOL) {
+		dev_dbg(hw->dev, "data-collision\n");
+		complete(&hw->done);
+		goto irq_done;
+	}
+
+	if (!(spsta & S3C2410_SPSTA_READY)) {
+		dev_dbg(hw->dev, "spi not ready for tx?\n");
+		complete(&hw->done);
+		goto irq_done;
+	}
+
+	hw->count++;
+
+	if (hw->rx)
+		hw->rx[count] = readb(hw->regs + S3C2410_SPRDAT);
+
+	count++;
+
+	if (count < hw->len)
+		writeb(hw_txbyte(hw, count), hw->regs + S3C2410_SPTDAT);
+	else
+		complete(&hw->done);
+
+ irq_done:
+	return IRQ_HANDLED;
+}
+
+static void s3c24xx_spi_initialsetup(struct s3c24xx_spi *hw)
+{
+	/* for the moment, permanently enable the clock */
+
+	clk_enable(hw->clk);
+
+	/* program defaults into the registers */
+
+	writeb(0xff, hw->regs + S3C2410_SPPRE);
+	writeb(SPPIN_DEFAULT, hw->regs + S3C2410_SPPIN);
+	writeb(SPCON_DEFAULT, hw->regs + S3C2410_SPCON);
+
+	if (hw->pdata) {
+		if (hw->set_cs == s3c24xx_spi_gpiocs)
+			gpio_direction_output(hw->pdata->pin_cs, 1);
+
+		if (hw->pdata->gpio_setup)
+			hw->pdata->gpio_setup(hw->pdata, 1);
+	}
+}
+
+static int __init s3c24xx_spi_probe(struct platform_device *pdev)
+{
+	struct s3c2410_spi_info *pdata;
+	struct s3c24xx_spi *hw;
+	struct spi_master *master;
+	struct resource *res;
+	int err = 0;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct s3c24xx_spi));
+	if (master == NULL) {
+		dev_err(&pdev->dev, "No memory for spi_master\n");
+		err = -ENOMEM;
+		goto err_nomem;
+	}
+
+	hw = spi_master_get_devdata(master);
+	memset(hw, 0, sizeof(struct s3c24xx_spi));
+
+	hw->master = spi_master_get(master);
+	hw->pdata = pdata = pdev->dev.platform_data;
+	hw->dev = &pdev->dev;
+
+	if (pdata == NULL) {
+		dev_err(&pdev->dev, "No platform data supplied\n");
+		err = -ENOENT;
+		goto err_no_pdata;
+	}
+
+	platform_set_drvdata(pdev, hw);
+	init_completion(&hw->done);
+
+	/* setup the master state. */
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
+	master->num_chipselect = hw->pdata->num_cs;
+	master->bus_num = pdata->bus_num;
+
+	/* setup the state for the bitbang driver */
+
+	hw->bitbang.master         = hw->master;
+	hw->bitbang.setup_transfer = s3c24xx_spi_setupxfer;
+	hw->bitbang.chipselect     = s3c24xx_spi_chipsel;
+	hw->bitbang.txrx_bufs      = s3c24xx_spi_txrx;
+
+	hw->master->setup  = s3c24xx_spi_setup;
+	hw->master->cleanup = s3c24xx_spi_cleanup;
+
+	dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang);
+
+	/* find and map our resources */
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
+		err = -ENOENT;
+		goto err_no_iores;
+	}
+
+	hw->ioarea = request_mem_region(res->start, resource_size(res),
+					pdev->name);
+
+	if (hw->ioarea == NULL) {
+		dev_err(&pdev->dev, "Cannot reserve region\n");
+		err = -ENXIO;
+		goto err_no_iores;
+	}
+
+	hw->regs = ioremap(res->start, resource_size(res));
+	if (hw->regs == NULL) {
+		dev_err(&pdev->dev, "Cannot map IO\n");
+		err = -ENXIO;
+		goto err_no_iomap;
+	}
+
+	hw->irq = platform_get_irq(pdev, 0);
+	if (hw->irq < 0) {
+		dev_err(&pdev->dev, "No IRQ specified\n");
+		err = -ENOENT;
+		goto err_no_irq;
+	}
+
+	err = request_irq(hw->irq, s3c24xx_spi_irq, 0, pdev->name, hw);
+	if (err) {
+		dev_err(&pdev->dev, "Cannot claim IRQ\n");
+		goto err_no_irq;
+	}
+
+	hw->clk = clk_get(&pdev->dev, "spi");
+	if (IS_ERR(hw->clk)) {
+		dev_err(&pdev->dev, "No clock for device\n");
+		err = PTR_ERR(hw->clk);
+		goto err_no_clk;
+	}
+
+	/* setup any gpio we can */
+
+	if (!pdata->set_cs) {
+		if (pdata->pin_cs < 0) {
+			dev_err(&pdev->dev, "No chipselect pin\n");
+			goto err_register;
+		}
+
+		err = gpio_request(pdata->pin_cs, dev_name(&pdev->dev));
+		if (err) {
+			dev_err(&pdev->dev, "Failed to get gpio for cs\n");
+			goto err_register;
+		}
+
+		hw->set_cs = s3c24xx_spi_gpiocs;
+		gpio_direction_output(pdata->pin_cs, 1);
+	} else
+		hw->set_cs = pdata->set_cs;
+
+	s3c24xx_spi_initialsetup(hw);
+
+	/* register our spi controller */
+
+	err = spi_bitbang_start(&hw->bitbang);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to register SPI master\n");
+		goto err_register;
+	}
+
+	return 0;
+
+ err_register:
+	if (hw->set_cs == s3c24xx_spi_gpiocs)
+		gpio_free(pdata->pin_cs);
+
+	clk_disable(hw->clk);
+	clk_put(hw->clk);
+
+ err_no_clk:
+	free_irq(hw->irq, hw);
+
+ err_no_irq:
+	iounmap(hw->regs);
+
+ err_no_iomap:
+	release_resource(hw->ioarea);
+	kfree(hw->ioarea);
+
+ err_no_iores:
+ err_no_pdata:
+	spi_master_put(hw->master);
+
+ err_nomem:
+	return err;
+}
+
+static int __exit s3c24xx_spi_remove(struct platform_device *dev)
+{
+	struct s3c24xx_spi *hw = platform_get_drvdata(dev);
+
+	platform_set_drvdata(dev, NULL);
+
+	spi_unregister_master(hw->master);
+
+	clk_disable(hw->clk);
+	clk_put(hw->clk);
+
+	free_irq(hw->irq, hw);
+	iounmap(hw->regs);
+
+	if (hw->set_cs == s3c24xx_spi_gpiocs)
+		gpio_free(hw->pdata->pin_cs);
+
+	release_resource(hw->ioarea);
+	kfree(hw->ioarea);
+
+	spi_master_put(hw->master);
+	return 0;
+}
+
+
+#ifdef CONFIG_PM
+
+static int s3c24xx_spi_suspend(struct device *dev)
+{
+	struct s3c24xx_spi *hw = platform_get_drvdata(to_platform_device(dev));
+
+	if (hw->pdata && hw->pdata->gpio_setup)
+		hw->pdata->gpio_setup(hw->pdata, 0);
+
+	clk_disable(hw->clk);
+	return 0;
+}
+
+static int s3c24xx_spi_resume(struct device *dev)
+{
+	struct s3c24xx_spi *hw = platform_get_drvdata(to_platform_device(dev));
+
+	s3c24xx_spi_initialsetup(hw);
+	return 0;
+}
+
+static struct dev_pm_ops s3c24xx_spi_pmops = {
+	.suspend	= s3c24xx_spi_suspend,
+	.resume		= s3c24xx_spi_resume,
+};
+
+#define S3C24XX_SPI_PMOPS &s3c24xx_spi_pmops
+#else
+#define S3C24XX_SPI_PMOPS NULL
+#endif /* CONFIG_PM */
+
+MODULE_ALIAS("platform:s3c2410-spi");
+static struct platform_driver s3c24xx_spi_driver = {
+	.remove		= __exit_p(s3c24xx_spi_remove),
+	.driver		= {
+		.name	= "s3c2410-spi",
+		.owner	= THIS_MODULE,
+		.pm	= S3C24XX_SPI_PMOPS,
+	},
+};
+
+static int __init s3c24xx_spi_init(void)
+{
+        return platform_driver_probe(&s3c24xx_spi_driver, s3c24xx_spi_probe);
+}
+
+static void __exit s3c24xx_spi_exit(void)
+{
+        platform_driver_unregister(&s3c24xx_spi_driver);
+}
+
+module_init(s3c24xx_spi_init);
+module_exit(s3c24xx_spi_exit);
+
+MODULE_DESCRIPTION("S3C24XX SPI Driver");
+MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_s3c24xx_gpio.c

@@ -0,0 +1,202 @@
+/* linux/drivers/spi/spi_s3c24xx_gpio.c
+ *
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ *
+ * S3C24XX GPIO based SPI driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+*/
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <mach/regs-gpio.h>
+#include <mach/spi-gpio.h>
+#include <mach/hardware.h>
+
+struct s3c2410_spigpio {
+	struct spi_bitbang		 bitbang;
+
+	struct s3c2410_spigpio_info	*info;
+	struct platform_device		*dev;
+};
+
+static inline struct s3c2410_spigpio *spidev_to_sg(struct spi_device *spi)
+{
+	return spi_master_get_devdata(spi->master);
+}
+
+static inline void setsck(struct spi_device *dev, int on)
+{
+	struct s3c2410_spigpio *sg = spidev_to_sg(dev);
+	s3c2410_gpio_setpin(sg->info->pin_clk, on ? 1 : 0);
+}
+
+static inline void setmosi(struct spi_device *dev, int on)
+{
+	struct s3c2410_spigpio *sg = spidev_to_sg(dev);
+	s3c2410_gpio_setpin(sg->info->pin_mosi, on ? 1 : 0);
+}
+
+static inline u32 getmiso(struct spi_device *dev)
+{
+	struct s3c2410_spigpio *sg = spidev_to_sg(dev);
+	return s3c2410_gpio_getpin(sg->info->pin_miso) ? 1 : 0;
+}
+
+#define spidelay(x) ndelay(x)
+
+#define	EXPAND_BITBANG_TXRX
+#include <linux/spi/spi_bitbang.h>
+
+
+static u32 s3c2410_spigpio_txrx_mode0(struct spi_device *spi,
+				      unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+static u32 s3c2410_spigpio_txrx_mode1(struct spi_device *spi,
+				      unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
+}
+
+static u32 s3c2410_spigpio_txrx_mode2(struct spi_device *spi,
+				      unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
+}
+
+static u32 s3c2410_spigpio_txrx_mode3(struct spi_device *spi,
+				      unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
+}
+
+
+static void s3c2410_spigpio_chipselect(struct spi_device *dev, int value)
+{
+	struct s3c2410_spigpio *sg = spidev_to_sg(dev);
+
+	if (sg->info && sg->info->chip_select)
+		(sg->info->chip_select)(sg->info, value);
+}
+
+static int s3c2410_spigpio_probe(struct platform_device *dev)
+{
+	struct s3c2410_spigpio_info *info;
+	struct spi_master	*master;
+	struct s3c2410_spigpio  *sp;
+	int ret;
+
+	master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio));
+	if (master == NULL) {
+		dev_err(&dev->dev, "failed to allocate spi master\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	sp = spi_master_get_devdata(master);
+
+	platform_set_drvdata(dev, sp);
+
+	/* copy in the plkatform data */
+	info = sp->info = dev->dev.platform_data;
+
+	/* setup spi bitbang adaptor */
+	sp->bitbang.master = spi_master_get(master);
+	sp->bitbang.master->bus_num = info->bus_num;
+	sp->bitbang.master->num_chipselect = info->num_chipselect;
+	sp->bitbang.chipselect = s3c2410_spigpio_chipselect;
+
+	sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;
+	sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;
+	sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2;
+	sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3;
+
+	/* set state of spi pins, always assume that the clock is
+	 * available, but do check the MOSI and MISO. */
+	s3c2410_gpio_setpin(info->pin_clk, 0);
+	s3c2410_gpio_cfgpin(info->pin_clk, S3C2410_GPIO_OUTPUT);
+
+	if (info->pin_mosi < S3C2410_GPH10) {
+		s3c2410_gpio_setpin(info->pin_mosi, 0);
+		s3c2410_gpio_cfgpin(info->pin_mosi, S3C2410_GPIO_OUTPUT);
+	}
+
+	if (info->pin_miso != S3C2410_GPA0 && info->pin_miso < S3C2410_GPH10)
+		s3c2410_gpio_cfgpin(info->pin_miso, S3C2410_GPIO_INPUT);
+
+	ret = spi_bitbang_start(&sp->bitbang);
+	if (ret)
+		goto err_no_bitbang;
+
+	return 0;
+
+ err_no_bitbang:
+	spi_master_put(sp->bitbang.master);
+ err:
+	return ret;
+
+}
+
+static int s3c2410_spigpio_remove(struct platform_device *dev)
+{
+	struct s3c2410_spigpio *sp = platform_get_drvdata(dev);
+
+	spi_bitbang_stop(&sp->bitbang);
+	spi_master_put(sp->bitbang.master);
+
+	return 0;
+}
+
+/* all gpio should be held over suspend/resume, so we should
+ * not need to deal with this
+*/
+
+#define s3c2410_spigpio_suspend NULL
+#define s3c2410_spigpio_resume NULL
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:spi_s3c24xx_gpio");
+
+static struct platform_driver s3c2410_spigpio_drv = {
+	.probe		= s3c2410_spigpio_probe,
+        .remove		= s3c2410_spigpio_remove,
+        .suspend	= s3c2410_spigpio_suspend,
+        .resume		= s3c2410_spigpio_resume,
+        .driver		= {
+		.name	= "spi_s3c24xx_gpio",
+		.owner	= THIS_MODULE,
+        },
+};
+
+static int __init s3c2410_spigpio_init(void)
+{
+        return platform_driver_register(&s3c2410_spigpio_drv);
+}
+
+static void __exit s3c2410_spigpio_exit(void)
+{
+        platform_driver_unregister(&s3c2410_spigpio_drv);
+}
+
+module_init(s3c2410_spigpio_init);
+module_exit(s3c2410_spigpio_exit);
+
+MODULE_DESCRIPTION("S3C24XX SPI Driver");
+MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_sh_sci.c

@@ -0,0 +1,206 @@
+/*
+ * SH SCI SPI interface
+ *
+ * Copyright (c) 2008 Magnus Damm
+ *
+ * Based on S3C24XX GPIO based SPI driver, which is:
+ *   Copyright (c) 2006 Ben Dooks
+ *   Copyright (c) 2006 Simtec Electronics
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <asm/spi.h>
+#include <asm/io.h>
+
+struct sh_sci_spi {
+	struct spi_bitbang bitbang;
+
+	void __iomem *membase;
+	unsigned char val;
+	struct sh_spi_info *info;
+	struct platform_device *dev;
+};
+
+#define SCSPTR(sp)	(sp->membase + 0x1c)
+#define PIN_SCK		(1 << 2)
+#define PIN_TXD		(1 << 0)
+#define PIN_RXD		PIN_TXD
+#define PIN_INIT	((1 << 1) | (1 << 3) | PIN_SCK | PIN_TXD)
+
+static inline void setbits(struct sh_sci_spi *sp, int bits, int on)
+{
+	/*
+	 * We are the only user of SCSPTR so no locking is required.
+	 * Reading bit 2 and 0 in SCSPTR gives pin state as input.
+	 * Writing the same bits sets the output value.
+	 * This makes regular read-modify-write difficult so we
+	 * use sp->val to keep track of the latest register value.
+	 */
+
+	if (on)
+		sp->val |= bits;
+	else
+		sp->val &= ~bits;
+
+	iowrite8(sp->val, SCSPTR(sp));
+}
+
+static inline void setsck(struct spi_device *dev, int on)
+{
+	setbits(spi_master_get_devdata(dev->master), PIN_SCK, on);
+}
+
+static inline void setmosi(struct spi_device *dev, int on)
+{
+	setbits(spi_master_get_devdata(dev->master), PIN_TXD, on);
+}
+
+static inline u32 getmiso(struct spi_device *dev)
+{
+	struct sh_sci_spi *sp = spi_master_get_devdata(dev->master);
+
+	return (ioread8(SCSPTR(sp)) & PIN_RXD) ? 1 : 0;
+}
+
+#define spidelay(x) ndelay(x)
+
+#define EXPAND_BITBANG_TXRX
+#include <linux/spi/spi_bitbang.h>
+
+static u32 sh_sci_spi_txrx_mode0(struct spi_device *spi,
+				      unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+static u32 sh_sci_spi_txrx_mode1(struct spi_device *spi,
+				      unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
+}
+
+static u32 sh_sci_spi_txrx_mode2(struct spi_device *spi,
+				      unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
+}
+
+static u32 sh_sci_spi_txrx_mode3(struct spi_device *spi,
+				      unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
+}
+
+static void sh_sci_spi_chipselect(struct spi_device *dev, int value)
+{
+	struct sh_sci_spi *sp = spi_master_get_devdata(dev->master);
+
+	if (sp->info && sp->info->chip_select)
+		(sp->info->chip_select)(sp->info, dev->chip_select, value);
+}
+
+static int sh_sci_spi_probe(struct platform_device *dev)
+{
+	struct resource	*r;
+	struct spi_master *master;
+	struct sh_sci_spi *sp;
+	int ret;
+
+	master = spi_alloc_master(&dev->dev, sizeof(struct sh_sci_spi));
+	if (master == NULL) {
+		dev_err(&dev->dev, "failed to allocate spi master\n");
+		ret = -ENOMEM;
+		goto err0;
+	}
+
+	sp = spi_master_get_devdata(master);
+
+	platform_set_drvdata(dev, sp);
+	sp->info = dev->dev.platform_data;
+
+	/* setup spi bitbang adaptor */
+	sp->bitbang.master = spi_master_get(master);
+	sp->bitbang.master->bus_num = sp->info->bus_num;
+	sp->bitbang.master->num_chipselect = sp->info->num_chipselect;
+	sp->bitbang.chipselect = sh_sci_spi_chipselect;
+
+	sp->bitbang.txrx_word[SPI_MODE_0] = sh_sci_spi_txrx_mode0;
+	sp->bitbang.txrx_word[SPI_MODE_1] = sh_sci_spi_txrx_mode1;
+	sp->bitbang.txrx_word[SPI_MODE_2] = sh_sci_spi_txrx_mode2;
+	sp->bitbang.txrx_word[SPI_MODE_3] = sh_sci_spi_txrx_mode3;
+
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		ret = -ENOENT;
+		goto err1;
+	}
+	sp->membase = ioremap(r->start, r->end - r->start + 1);
+	if (!sp->membase) {
+		ret = -ENXIO;
+		goto err1;
+	}
+	sp->val = ioread8(SCSPTR(sp));
+	setbits(sp, PIN_INIT, 1);
+
+	ret = spi_bitbang_start(&sp->bitbang);
+	if (!ret)
+		return 0;
+
+	setbits(sp, PIN_INIT, 0);
+	iounmap(sp->membase);
+ err1:
+	spi_master_put(sp->bitbang.master);
+ err0:
+	return ret;
+}
+
+static int sh_sci_spi_remove(struct platform_device *dev)
+{
+	struct sh_sci_spi *sp = platform_get_drvdata(dev);
+
+	iounmap(sp->membase);
+	setbits(sp, PIN_INIT, 0);
+	spi_bitbang_stop(&sp->bitbang);
+	spi_master_put(sp->bitbang.master);
+	return 0;
+}
+
+static struct platform_driver sh_sci_spi_drv = {
+	.probe		= sh_sci_spi_probe,
+	.remove		= sh_sci_spi_remove,
+	.driver		= {
+		.name	= "spi_sh_sci",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init sh_sci_spi_init(void)
+{
+	return platform_driver_register(&sh_sci_spi_drv);
+}
+module_init(sh_sci_spi_init);
+
+static void __exit sh_sci_spi_exit(void)
+{
+	platform_driver_unregister(&sh_sci_spi_drv);
+}
+module_exit(sh_sci_spi_exit);
+
+MODULE_DESCRIPTION("SH SCI SPI Driver");
+MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:spi_sh_sci");

kernel/drivers/spi/spi_stm.c

@@ -0,0 +1,563 @@
+/*
+ *  ------------------------------------------------------------------------
+ *  spi_stm.c SPI/SSC driver for STMicroelectronics platforms
+ *  ------------------------------------------------------------------------
+ *
+ *  Copyright (c) 2008 STMicroelectronics Limited
+ *  Author: Angus Clark <Angus.Clark@st.com>
+ *
+ *  May be copied or modified under the terms of the GNU General Public
+ *  License Version 2.0 only.  See linux/COPYING for more information.
+ *
+ *  ------------------------------------------------------------------------
+ *  Changelog:
+ *  2008-01-24 (angus.clark@st.com)
+ *    - Initial version
+ *  2008-08-28 (angus.clark@st.com)
+ *    - Updates to fit with changes to 'ssc_pio_t'
+ *    - SSC accesses now all 32-bit, for compatibility with 7141 Comms block
+ *    - Updated to handle 7141 PIO ALT configuration
+ *    - Support for user-defined, per-bus, chip_select function.  Specified
+ *      in board setup
+ *    - Bug fix for rx_bytes_pending updates
+ *
+ *  ------------------------------------------------------------------------
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <linux/completion.h>
+#include <linux/uaccess.h>
+#include <linux/param.h>
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/stm/platform.h>
+#include <linux/stm/ssc.h>
+
+#define NAME "spi-stm"
+
+struct spi_stm {
+	/* SSC SPI Controller */
+	struct spi_bitbang	bitbang;
+	void __iomem		*base;
+	struct clk		*clk;
+	struct platform_device  *pdev;
+
+	/* Resources */
+	struct resource r_mem;
+	struct resource r_irq;
+	struct stm_pad_state *pad_state;
+
+	/* SSC SPI current transaction */
+	const u8		*tx_ptr;
+	u8			*rx_ptr;
+	u16			bits_per_word;
+	u16			bytes_per_word;
+	unsigned int		baud;
+	unsigned int		words_remaining;
+	struct completion	done;
+};
+
+static void spi_stm_gpio_chipselect(struct spi_device *spi, int value)
+{
+	unsigned int out;
+
+	if (spi->chip_select == (typeof(spi->chip_select))(STM_GPIO_INVALID))
+		return;
+
+	if (!spi->controller_data) {
+		if (gpio_request(spi->chip_select, "spi_stm cs")) {
+			dev_err(&spi->dev, "failed to allocate CS pin\n");
+			return;
+		}
+		spi->controller_data = (void *)1;
+		gpio_direction_output(spi->chip_select,
+				      spi->mode & SPI_CS_HIGH);
+	}
+
+	if (value == BITBANG_CS_ACTIVE)
+		out = spi->mode & SPI_CS_HIGH ? 1 : 0;
+	else
+		out = spi->mode & SPI_CS_HIGH ? 0 : 1;
+
+	gpio_set_value(spi->chip_select, out);
+
+	dev_dbg(&spi->dev, "%s PIO%d[%d] -> %d \n",
+		value == BITBANG_CS_ACTIVE ? "select" : "deselect",
+		stm_gpio_port(spi->chip_select),
+		stm_gpio_pin(spi->chip_select), out);
+
+	return;
+}
+
+static int spi_stm_setup_transfer(struct spi_device *spi,
+				     struct spi_transfer *t)
+{
+	struct spi_stm *spi_stm;
+	u32 hz;
+	u8 bits_per_word;
+	u32 reg;
+	u32 sscbrg;
+
+	spi_stm = spi_master_get_devdata(spi->master);
+	bits_per_word = (t) ? t->bits_per_word : 0;
+	hz = (t) ? t->speed_hz : 0;
+
+	/* If not specified, use defaults */
+	if (!bits_per_word)
+		bits_per_word = spi->bits_per_word;
+	if (!hz)
+		hz = spi->max_speed_hz;
+
+	/* Actually, can probably support 2-16 without any other change!!! */
+	if (bits_per_word != 8 && bits_per_word != 16) {
+		dev_err(&spi->dev, "unsupported bits_per_word=%d\n",
+			bits_per_word);
+		return -EINVAL;
+	}
+	spi_stm->bits_per_word = bits_per_word;
+
+	/* Set SSC_BRF */
+	sscbrg = clk_get_rate(spi_stm->clk) / (2*hz);
+	if (sscbrg < 0x07 || sscbrg > (0x1 << 16)) {
+		dev_err(&spi->dev, "baudrate outside valid range"
+			" %d (sscbrg = %d)\n", hz, sscbrg);
+		return -EINVAL;
+	}
+	spi_stm->baud = clk_get_rate(spi_stm->clk) / (2 * sscbrg);
+	if (sscbrg == (0x1 << 16)) /* 16-bit counter wraps */
+		sscbrg = 0x0;
+	ssc_store32(spi_stm, SSC_BRG, sscbrg);
+
+	dev_dbg(&spi->dev, "setting baudrate: target = %u hz, "
+		"actual = %u hz, sscbrg = %u\n",
+		hz, spi_stm->baud, sscbrg);
+
+	 /* Set SSC_CTL and enable SSC */
+	 reg = ssc_load32(spi_stm, SSC_CTL);
+	 reg |= SSC_CTL_MS;
+
+	 if (spi->mode & SPI_CPOL)
+		 reg |= SSC_CTL_PO;
+	 else
+		 reg &= ~SSC_CTL_PO;
+
+	 if (spi->mode & SPI_CPHA)
+		 reg |= SSC_CTL_PH;
+	 else
+		 reg &= ~SSC_CTL_PH;
+
+	 if ((spi->mode & SPI_LSB_FIRST) == 0)
+		 reg |= SSC_CTL_HB;
+	 else
+		 reg &= ~SSC_CTL_HB;
+
+	 if (spi->mode & SPI_LOOP)
+		 reg |= SSC_CTL_LPB;
+	 else
+		 reg &= ~SSC_CTL_LPB;
+
+	 reg &= 0xfffffff0;
+	 reg |= (bits_per_word - 1);
+
+	 reg |= SSC_CTL_EN_TX_FIFO | SSC_CTL_EN_RX_FIFO;
+	 reg |= SSC_CTL_EN;
+
+	 dev_dbg(&spi->dev, "ssc_ctl = 0x%04x\n", reg);
+	 ssc_store32(spi_stm, SSC_CTL, reg);
+
+	 /* Clear the status register */
+	 ssc_load32(spi_stm, SSC_RBUF);
+
+	 return 0;
+}
+
+static void spi_stm_cleanup(struct spi_device *spi)
+{
+	if (spi->controller_data) {
+		gpio_free(spi->chip_select);
+		spi->controller_data = (void *)0;
+	}
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS  (SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_LOOP | SPI_CS_HIGH)
+static int spi_stm_setup(struct spi_device *spi)
+{
+	struct spi_stm *spi_stm;
+
+	spi_stm = spi_master_get_devdata(spi->master);
+
+	if (spi->mode & ~MODEBITS) {
+		dev_err(&spi->dev, "unsupported mode bits %x\n",
+			spi->mode & ~MODEBITS);
+		return -EINVAL;
+	}
+
+	if (!spi->max_speed_hz)  {
+		dev_err(&spi->dev, "max_speed_hz unspecified\n");
+		return -EINVAL;
+	}
+
+	if (!spi->bits_per_word)
+		spi->bits_per_word = 8;
+
+	return spi_stm_setup_transfer(spi, NULL);
+}
+
+/* Load the TX FIFO */
+static void ssc_write_tx_fifo(struct spi_stm *spi_stm)
+{
+
+	uint32_t count;
+	uint32_t word = 0;
+	int i;
+
+	if (spi_stm->words_remaining > 8)
+		count = 8;
+	else
+		count = spi_stm->words_remaining;
+
+	for (i = 0; i < count; i++) {
+		if (spi_stm->tx_ptr) {
+			if (spi_stm->bytes_per_word == 1) {
+				word = *spi_stm->tx_ptr++;
+			} else {
+				word = *spi_stm->tx_ptr++;
+				word = *spi_stm->tx_ptr++ | (word << 8);
+			}
+		}
+		ssc_store32(spi_stm, SSC_TBUF, word);
+	}
+}
+
+/* Read the RX FIFO */
+static void ssc_read_rx_fifo(struct spi_stm *spi_stm)
+{
+
+	uint32_t count;
+	uint32_t word = 0;
+	int i;
+
+	if (spi_stm->words_remaining > 8)
+		count = 8;
+	else
+		count = spi_stm->words_remaining;
+
+	for (i = 0; i < count; i++) {
+		word = ssc_load32(spi_stm, SSC_RBUF);
+		if (spi_stm->rx_ptr) {
+			if (spi_stm->bytes_per_word == 1) {
+				*spi_stm->rx_ptr++ = (uint8_t)word;
+			} else {
+				*spi_stm->rx_ptr++ = (word >> 8);
+				*spi_stm->rx_ptr++ = word & 0xff;
+			}
+		}
+	}
+
+	spi_stm->words_remaining -= count;
+}
+
+/* Interrupt fired when TX shift register becomes empty */
+static irqreturn_t spi_stm_irq(int irq, void *dev_id)
+{
+	struct spi_stm *spi_stm = (struct spi_stm *)dev_id;
+
+	/* Read RX FIFO */
+	ssc_read_rx_fifo(spi_stm);
+
+	/* Fill TX FIFO */
+	if (spi_stm->words_remaining) {
+		ssc_write_tx_fifo(spi_stm);
+	} else {
+		/* TX/RX complete */
+		ssc_store32(spi_stm, SSC_IEN, 0x0);
+		complete(&spi_stm->done);
+	}
+
+	return IRQ_HANDLED;
+}
+
+
+static int spi_stm_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct spi_stm *spi_stm;
+	uint32_t ctl = 0;
+
+	spi_stm = spi_master_get_devdata(spi->master);
+
+	/* Setup transfer */
+	spi_stm->tx_ptr = t->tx_buf;
+	spi_stm->rx_ptr = t->rx_buf;
+
+	if (spi_stm->bits_per_word > 8) {
+		/* Anything greater than 8 bits-per-word requires 2
+		 * bytes-per-word in the RX/TX buffers */
+		spi_stm->bytes_per_word = 2;
+		spi_stm->words_remaining = t->len/2;
+	} else if (spi_stm->bits_per_word == 8 &&
+		   ((t->len & 0x1) == 0)) {
+		/* If transfer is even-length, and 8 bits-per-word, then
+		 * implement as half-length 16 bits-per-word transfer */
+		spi_stm->bytes_per_word = 2;
+		spi_stm->words_remaining = t->len/2;
+
+		/* Set SSC_CTL to 16 bits-per-word */
+		ctl = ssc_load32(spi_stm, SSC_CTL);
+		ssc_store32(spi_stm, SSC_CTL, (ctl | 0xf));
+
+		ssc_load32(spi_stm, SSC_RBUF);
+
+	} else {
+		spi_stm->bytes_per_word = 1;
+		spi_stm->words_remaining = t->len;
+	}
+
+	INIT_COMPLETION(spi_stm->done);
+
+	/* Start transfer by writing to the TX FIFO */
+	ssc_write_tx_fifo(spi_stm);
+	ssc_store32(spi_stm, SSC_IEN, SSC_IEN_TEEN);
+
+	/* Wait for transfer to complete */
+	wait_for_completion(&spi_stm->done);
+
+	/* Restore SSC_CTL if necessary */
+	if (ctl)
+		ssc_store32(spi_stm, SSC_CTL, ctl);
+
+	return t->len;
+
+}
+
+static int __init spi_stm_probe(struct platform_device *pdev)
+{
+	struct stm_plat_ssc_data *plat_data = pdev->dev.platform_data;
+	struct spi_master *master;
+	struct resource *res;
+	struct spi_stm *spi_stm;
+	u32 reg;
+	int status = 0;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_stm));
+	if (!master) {
+		dev_err(&pdev->dev, "failed to allocate spi master\n");
+		status = -ENOMEM;
+		goto err0;
+	}
+
+	platform_set_drvdata(pdev, master);
+
+	spi_stm = spi_master_get_devdata(master);
+	spi_stm->bitbang.master = spi_master_get(master);
+	spi_stm->bitbang.setup_transfer = spi_stm_setup_transfer;
+	spi_stm->bitbang.txrx_bufs = spi_stm_txrx_bufs;
+	spi_stm->bitbang.master->setup = spi_stm_setup;
+	spi_stm->bitbang.master->cleanup = spi_stm_cleanup;
+
+	if (plat_data->spi_chipselect)
+		spi_stm->bitbang.chipselect = plat_data->spi_chipselect;
+	else
+		spi_stm->bitbang.chipselect = spi_stm_gpio_chipselect;
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = MODEBITS;
+
+	/* chip_select field of spi_device is declared as u8 and therefore
+	 * limits number of GPIOs that can be used as a CS line. Sorry. */
+	master->num_chipselect =
+		sizeof(((struct spi_device *)0)->chip_select) * 256;
+	master->bus_num = pdev->id;
+	init_completion(&spi_stm->done);
+
+	/* Get resources */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "failed to find IOMEM resource\n");
+		status = -ENOENT;
+		goto err1;
+	}
+	spi_stm->r_mem = *res;
+
+	if (!request_mem_region(res->start,
+				res->end - res->start + 1, NAME)) {
+		dev_err(&pdev->dev, "request memory region failed [0x%x]\n",
+			res->start);
+		status = -EBUSY;
+		goto err1;
+	}
+
+	spi_stm->base = ioremap_nocache(res->start, res->end - res->start + 1);
+	if (!spi_stm->base) {
+		dev_err(&pdev->dev, "ioremap memory failed [0x%x]\n",
+			res->start);
+		status = -ENXIO;
+		goto err2;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "failed to find IRQ resource\n");
+		status = -ENOENT;
+		goto err3;
+	}
+	spi_stm->r_irq = *res;
+
+	if (request_irq(res->start, spi_stm_irq,
+			IRQF_DISABLED, dev_name(&pdev->dev), spi_stm)) {
+		dev_err(&pdev->dev, "irq request failed\n");
+		status = -EBUSY;
+		goto err3;
+	}
+
+	spi_stm->pad_state = stm_pad_claim(plat_data->pad_config,
+					   dev_name(&pdev->dev));
+	if (!spi_stm->pad_state) {
+		dev_err(&pdev->dev, "pads request failed\n");
+		status = -EBUSY;
+		goto err4;
+	}
+
+	/* Disable I2C and Reset SSC */
+	ssc_store32(spi_stm, SSC_I2C, 0x0);
+	reg = ssc_load16(spi_stm, SSC_CTL);
+	reg |= SSC_CTL_SR;
+	ssc_store32(spi_stm, SSC_CTL, reg);
+
+	udelay(1);
+	reg = ssc_load32(spi_stm, SSC_CTL);
+	reg &= ~SSC_CTL_SR;
+	ssc_store32(spi_stm, SSC_CTL, reg);
+
+	/* Set SSC into slave mode before reconfiguring PIO pins */
+	reg = ssc_load32(spi_stm, SSC_CTL);
+	reg &= ~SSC_CTL_MS;
+	ssc_store32(spi_stm, SSC_CTL, reg);
+
+	spi_stm->clk = clk_get(&pdev->dev, "comms_clk");
+	if (!spi_stm->clk) {
+		dev_err(&pdev->dev, "Comms clock not found!\n");
+		goto err5;
+	}
+
+	clk_enable(spi_stm->clk);
+	/* Start "bitbang" worker */
+	status = spi_bitbang_start(&spi_stm->bitbang);
+	if (status) {
+		dev_err(&pdev->dev, "bitbang start failed [%d]\n", status);
+		goto err5;
+	}
+
+	dev_info(&pdev->dev, "registered SPI Bus %d\n", master->bus_num);
+
+	return status;
+
+ err5:
+	stm_pad_release(spi_stm->pad_state);
+ err4:
+	free_irq(spi_stm->r_irq.start, spi_stm);
+ err3:
+	iounmap(spi_stm->base);
+ err2:
+	release_mem_region(spi_stm->r_mem.start,
+			   resource_size(&spi_stm->r_mem));
+ err1:
+	spi_master_put(spi_stm->bitbang.master);
+	platform_set_drvdata(pdev, NULL);
+ err0:
+	return status;
+}
+
+static int spi_stm_remove(struct platform_device *pdev)
+{
+	struct spi_stm *spi_stm;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	spi_stm = spi_master_get_devdata(master);
+
+	spi_bitbang_stop(&spi_stm->bitbang);
+
+	clk_disable(spi_stm->clk);
+
+	stm_pad_release(spi_stm->pad_state);
+	free_irq(spi_stm->r_irq.start, spi_stm);
+	iounmap(spi_stm->base);
+	release_mem_region(spi_stm->r_mem.start,
+			   resource_size(&spi_stm->r_mem));
+
+	spi_master_put(spi_stm->bitbang.master);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+#ifdef CONFIG_PM
+static int spi_stm_suspend(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct spi_stm *spi_stm;
+
+	spi_stm = spi_master_get_devdata(master);
+
+	ssc_store32(spi_stm, SSC_IEN, 0);
+
+	clk_disable(spi_stm->clk);
+	return 0;
+}
+
+static int spi_stm_resume(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct spi_stm *spi_stm;
+
+	spi_stm = spi_master_get_devdata(master);
+
+	clk_enable(spi_stm->clk);
+	return 0;
+}
+
+static struct dev_pm_ops spi_stm_pm = {
+	.suspend = spi_stm_suspend,
+	.resume = spi_stm_resume,
+	.freeze = spi_stm_suspend,
+	.restore = spi_stm_resume,
+	.runtime_suspend = spi_stm_suspend,
+	.runtime_resume = spi_stm_resume,
+};
+#else
+static struct dev_pm_ops spi_stm_pm;
+#endif
+
+static struct platform_driver spi_stm_driver = {
+	.driver.name = NAME,
+	.driver.owner = THIS_MODULE,
+	.driver.pm = &spi_stm_pm,
+	.probe = spi_stm_probe,
+	.remove = spi_stm_remove,
+};
+
+
+static int __init spi_stm_init(void)
+{
+	return platform_driver_register(&spi_stm_driver);
+}
+
+static void __exit spi_stm_exit(void)
+{
+	platform_driver_unregister(&spi_stm_driver);
+}
+
+module_init(spi_stm_init);
+module_exit(spi_stm_exit);
+
+MODULE_AUTHOR("STMicroelectronics <www.st.com>");
+MODULE_DESCRIPTION("STM SSC SPI driver");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_stmp.c

@@ -0,0 +1,679 @@
+/*
+ * Freescale STMP378X SPI master driver
+ *
+ * Author: dmitry pervushin <dimka@embeddedalley.com>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+
+#include <mach/platform.h>
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-ssp.h>
+#include <mach/regs-apbh.h>
+
+
+/* 0 means DMA mode(recommended, default), !0 - PIO mode */
+static int pio;
+static int clock;
+
+/* default timeout for busy waits is 2 seconds */
+#define STMP_SPI_TIMEOUT	(2 * HZ)
+
+struct stmp_spi {
+	int		id;
+
+	void *  __iomem regs;	/* vaddr of the control registers */
+
+	int		irq, err_irq;
+	u32		dma;
+	struct stmp3xxx_dma_descriptor d;
+
+	u32		speed_khz;
+	u32		saved_timings;
+	u32		divider;
+
+	struct clk	*clk;
+	struct device	*master_dev;
+
+	struct work_struct work;
+	struct workqueue_struct *workqueue;
+
+	/* lock protects queue access */
+	spinlock_t lock;
+	struct list_head queue;
+
+	struct completion done;
+};
+
+#define busy_wait(cond)							\
+	({								\
+	unsigned long end_jiffies = jiffies + STMP_SPI_TIMEOUT;		\
+	bool succeeded = false;						\
+	do {								\
+		if (cond) {						\
+			succeeded = true;				\
+			break;						\
+		}							\
+		cpu_relax();						\
+	} while (time_before(end_jiffies, jiffies));			\
+	succeeded;							\
+	})
+
+/**
+ * stmp_spi_init_hw
+ * Initialize the SSP port
+ */
+static int stmp_spi_init_hw(struct stmp_spi *ss)
+{
+	int err = 0;
+	void *pins = ss->master_dev->platform_data;
+
+	err = stmp3xxx_request_pin_group(pins, dev_name(ss->master_dev));
+	if (err)
+		goto out;
+
+	ss->clk = clk_get(NULL, "ssp");
+	if (IS_ERR(ss->clk)) {
+		err = PTR_ERR(ss->clk);
+		goto out_free_pins;
+	}
+	clk_enable(ss->clk);
+
+	stmp3xxx_reset_block(ss->regs, false);
+	stmp3xxx_dma_reset_channel(ss->dma);
+
+	return 0;
+
+out_free_pins:
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+out:
+	return err;
+}
+
+static void stmp_spi_release_hw(struct stmp_spi *ss)
+{
+	void *pins = ss->master_dev->platform_data;
+
+	if (ss->clk && !IS_ERR(ss->clk)) {
+		clk_disable(ss->clk);
+		clk_put(ss->clk);
+	}
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+}
+
+static int stmp_spi_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	u8 bits_per_word;
+	u32 hz;
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	u16 rate;
+
+	bits_per_word = spi->bits_per_word;
+	if (t && t->bits_per_word)
+		bits_per_word = t->bits_per_word;
+
+	/*
+	 * Calculate speed:
+	 *	- by default, use maximum speed from ssp clk
+	 *	- if device overrides it, use it
+	 *	- if transfer specifies other speed, use transfer's one
+	 */
+	hz = 1000 * ss->speed_khz / ss->divider;
+	if (spi->max_speed_hz)
+		hz = min(hz, spi->max_speed_hz);
+	if (t && t->speed_hz)
+		hz = min(hz, t->speed_hz);
+
+	if (hz == 0) {
+		dev_err(&spi->dev, "Cannot continue with zero clock\n");
+		return -EINVAL;
+	}
+
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+
+	dev_dbg(&spi->dev, "Requested clk rate = %uHz, max = %uHz/%d = %uHz\n",
+		hz, ss->speed_khz, ss->divider,
+		ss->speed_khz * 1000 / ss->divider);
+
+	if (ss->speed_khz * 1000 / ss->divider < hz) {
+		dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
+			__func__, hz);
+		return -EINVAL;
+	}
+
+	rate = 1000 * ss->speed_khz/ss->divider/hz;
+
+	writel(BF(ss->divider, SSP_TIMING_CLOCK_DIVIDE)		|
+	       BF(rate - 1, SSP_TIMING_CLOCK_RATE),
+	       HW_SSP_TIMING + ss->regs);
+
+	writel(BF(1 /* mode SPI */, SSP_CTRL1_SSP_MODE)		|
+	       BF(4 /* 8 bits   */, SSP_CTRL1_WORD_LENGTH)	|
+	       ((spi->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
+	       ((spi->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0) |
+	       (pio ? 0 : BM_SSP_CTRL1_DMA_ENABLE),
+	       ss->regs + HW_SSP_CTRL1);
+
+	return 0;
+}
+
+static int stmp_spi_setup(struct spi_device *spi)
+{
+	/* spi_setup() does basic checks,
+	 * stmp_spi_setup_transfer() does more later
+	 */
+	if (spi->bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, spi->bits_per_word);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static inline u32 stmp_spi_cs(unsigned cs)
+{
+	return  ((cs & 1) ? BM_SSP_CTRL0_WAIT_FOR_CMD : 0) |
+		((cs & 2) ? BM_SSP_CTRL0_WAIT_FOR_IRQ : 0);
+}
+
+static int stmp_spi_txrx_dma(struct stmp_spi *ss, int cs,
+		unsigned char *buf, dma_addr_t dma_buf, int len,
+		int first, int last, bool write)
+{
+	u32 c0 = 0;
+	dma_addr_t spi_buf_dma = dma_buf;
+	int status = 0;
+	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	c0 |= (first ? BM_SSP_CTRL0_LOCK_CS : 0);
+	c0 |= (last ? BM_SSP_CTRL0_IGNORE_CRC : 0);
+	c0 |= (write ? 0 : BM_SSP_CTRL0_READ);
+	c0 |= BM_SSP_CTRL0_DATA_XFER;
+
+	c0 |= stmp_spi_cs(cs);
+
+	c0 |= BF(len, SSP_CTRL0_XFER_COUNT);
+
+	if (!dma_buf)
+		spi_buf_dma = dma_map_single(ss->master_dev, buf, len, dir);
+
+	ss->d.command->cmd =
+		BF(len, APBH_CHn_CMD_XFER_COUNT)	|
+		BF(1, APBH_CHn_CMD_CMDWORDS)		|
+		BM_APBH_CHn_CMD_WAIT4ENDCMD		|
+		BM_APBH_CHn_CMD_IRQONCMPLT		|
+		BF(write ? BV_APBH_CHn_CMD_COMMAND__DMA_READ :
+			   BV_APBH_CHn_CMD_COMMAND__DMA_WRITE,
+		   APBH_CHn_CMD_COMMAND);
+	ss->d.command->pio_words[0] = c0;
+	ss->d.command->buf_ptr = spi_buf_dma;
+
+	stmp3xxx_dma_reset_channel(ss->dma);
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	stmp3xxx_dma_enable_interrupt(ss->dma);
+	init_completion(&ss->done);
+	stmp3xxx_dma_go(ss->dma, &ss->d, 1);
+	wait_for_completion(&ss->done);
+
+	if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) & BM_SSP_CTRL0_RUN))
+		status = -ETIMEDOUT;
+
+	if (!dma_buf)
+		dma_unmap_single(ss->master_dev, spi_buf_dma, len, dir);
+
+	return status;
+}
+
+static inline void stmp_spi_enable(struct stmp_spi *ss)
+{
+	stmp3xxx_setl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_clearl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static inline void stmp_spi_disable(struct stmp_spi *ss)
+{
+	stmp3xxx_clearl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_setl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static int stmp_spi_txrx_pio(struct stmp_spi *ss, int cs,
+		unsigned char *buf, int len,
+		bool first, bool last, bool write)
+{
+	if (first)
+		stmp_spi_enable(ss);
+
+	stmp3xxx_setl(stmp_spi_cs(cs), ss->regs + HW_SSP_CTRL0);
+
+	while (len--) {
+		if (last && len <= 0)
+			stmp_spi_disable(ss);
+
+		stmp3xxx_clearl(BM_SSP_CTRL0_XFER_COUNT,
+				ss->regs + HW_SSP_CTRL0);
+		stmp3xxx_setl(1, ss->regs + HW_SSP_CTRL0);
+
+		if (write)
+			stmp3xxx_clearl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+		else
+			stmp3xxx_setl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+
+		/* Run! */
+		stmp3xxx_setl(BM_SSP_CTRL0_RUN, ss->regs + HW_SSP_CTRL0);
+
+		if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+				BM_SSP_CTRL0_RUN))
+			break;
+
+		if (write)
+			writel(*buf, ss->regs + HW_SSP_DATA);
+
+		/* Set TRANSFER */
+		stmp3xxx_setl(BM_SSP_CTRL0_DATA_XFER, ss->regs + HW_SSP_CTRL0);
+
+		if (!write) {
+			if (busy_wait((readl(ss->regs + HW_SSP_STATUS) &
+					BM_SSP_STATUS_FIFO_EMPTY)))
+				break;
+			*buf = readl(ss->regs + HW_SSP_DATA) & 0xFF;
+		}
+
+		if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+					BM_SSP_CTRL0_RUN))
+			break;
+
+		/* advance to the next byte */
+		buf++;
+	}
+
+	return len < 0 ? 0 : -ETIMEDOUT;
+}
+
+static int stmp_spi_handle_message(struct stmp_spi *ss, struct spi_message *m)
+{
+	bool first, last;
+	struct spi_transfer *t, *tmp_t;
+	int status = 0;
+	int cs;
+
+	cs = m->spi->chip_select;
+
+	list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) {
+
+		first = (&t->transfer_list == m->transfers.next);
+		last = (&t->transfer_list == m->transfers.prev);
+
+		if (first || t->speed_hz || t->bits_per_word)
+			stmp_spi_setup_transfer(m->spi, t);
+
+		/* reject "not last" transfers which request to change cs */
+		if (t->cs_change && !last) {
+			dev_err(&m->spi->dev,
+				"Message with t->cs_change has been skipped\n");
+			continue;
+		}
+
+		if (t->tx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, (void *)t->tx_buf,
+				   t->len, first, last, true) :
+			   stmp_spi_txrx_dma(ss, cs, (void *)t->tx_buf,
+				   t->tx_dma, t->len, first, last, true);
+#ifdef DEBUG
+			if (t->len < 0x10)
+				print_hex_dump_bytes("Tx ",
+					DUMP_PREFIX_OFFSET,
+					t->tx_buf, t->len);
+			else
+				pr_debug("Tx: %d bytes\n", t->len);
+#endif
+		}
+		if (t->rx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, t->rx_buf,
+				   t->len, first, last, false) :
+			   stmp_spi_txrx_dma(ss, cs, t->rx_buf,
+				   t->rx_dma, t->len, first, last, false);
+#ifdef DEBUG
+			if (t->len < 0x10)
+				print_hex_dump_bytes("Rx ",
+					DUMP_PREFIX_OFFSET,
+					t->rx_buf, t->len);
+			else
+				pr_debug("Rx: %d bytes\n", t->len);
+#endif
+		}
+
+		if (t->delay_usecs)
+			udelay(t->delay_usecs);
+
+		if (status)
+			break;
+
+	}
+	return status;
+}
+
+/**
+ * stmp_spi_handle - handle messages from the queue
+ */
+static void stmp_spi_handle(struct work_struct *w)
+{
+	struct stmp_spi *ss = container_of(w, struct stmp_spi, work);
+	unsigned long flags;
+	struct spi_message *m;
+
+	spin_lock_irqsave(&ss->lock, flags);
+	while (!list_empty(&ss->queue)) {
+		m = list_entry(ss->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&ss->lock, flags);
+
+		m->status = stmp_spi_handle_message(ss, m);
+		m->complete(m->context);
+
+		spin_lock_irqsave(&ss->lock, flags);
+	}
+	spin_unlock_irqrestore(&ss->lock, flags);
+
+	return;
+}
+
+/**
+ * stmp_spi_transfer - perform message transfer.
+ * Called indirectly from spi_async, queues all the messages to
+ * spi_handle_message.
+ * @spi: spi device
+ * @m: message to be queued
+ */
+static int stmp_spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	m->status = -EINPROGRESS;
+	spin_lock_irqsave(&ss->lock, flags);
+	list_add_tail(&m->queue, &ss->queue);
+	queue_work(ss->workqueue, &ss->work);
+	spin_unlock_irqrestore(&ss->lock, flags);
+	return 0;
+}
+
+static irqreturn_t stmp_spi_irq(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	complete(&ss->done);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stmp_spi_irq_err(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+	u32 c1, st;
+
+	c1 = readl(ss->regs + HW_SSP_CTRL1);
+	st = readl(ss->regs + HW_SSP_STATUS);
+	dev_err(ss->master_dev, "%s: status = 0x%08X, c1 = 0x%08X\n",
+		__func__, st, c1);
+	stmp3xxx_clearl(c1 & 0xCCCC0000, ss->regs + HW_SSP_CTRL1);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit stmp_spi_probe(struct platform_device *dev)
+{
+	int err = 0;
+	struct spi_master *master;
+	struct stmp_spi *ss;
+	struct resource *r;
+
+	master = spi_alloc_master(&dev->dev, sizeof(struct stmp_spi));
+	if (master == NULL) {
+		err = -ENOMEM;
+		goto out0;
+	}
+	master->flags = SPI_MASTER_HALF_DUPLEX;
+
+	ss = spi_master_get_devdata(master);
+	platform_set_drvdata(dev, master);
+
+	/* Get resources(memory, IRQ) associated with the device */
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+	ss->regs = ioremap(r->start, resource_size(r));
+	if (!ss->regs) {
+		err = -EINVAL;
+		goto out_put_master;
+	}
+
+	ss->master_dev = &dev->dev;
+	ss->id = dev->id;
+
+	INIT_WORK(&ss->work, stmp_spi_handle);
+	INIT_LIST_HEAD(&ss->queue);
+	spin_lock_init(&ss->lock);
+
+	ss->workqueue = create_singlethread_workqueue(dev_name(&dev->dev));
+	if (!ss->workqueue) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+	master->transfer = stmp_spi_transfer;
+	master->setup = stmp_spi_setup;
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
+
+	ss->irq = platform_get_irq(dev, 0);
+	if (ss->irq < 0) {
+		err = ss->irq;
+		goto out_put_master;
+	}
+	ss->err_irq = platform_get_irq(dev, 1);
+	if (ss->err_irq < 0) {
+		err = ss->err_irq;
+		goto out_put_master;
+	}
+
+	r = platform_get_resource(dev, IORESOURCE_DMA, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+
+	ss->dma = r->start;
+	err = stmp3xxx_dma_request(ss->dma, &dev->dev, dev_name(&dev->dev));
+	if (err)
+		goto out_put_master;
+
+	err = stmp3xxx_dma_allocate_command(ss->dma, &ss->d);
+	if (err)
+		goto out_free_dma;
+
+	master->bus_num = dev->id;
+	master->num_chipselect = 1;
+
+	/* SPI controller initializations */
+	err = stmp_spi_init_hw(ss);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot initialize hardware\n");
+		goto out_free_dma_desc;
+	}
+
+	if (clock) {
+		dev_info(&dev->dev, "clock rate forced to %d\n", clock);
+		clk_set_rate(ss->clk, clock);
+	}
+	ss->speed_khz = clk_get_rate(ss->clk);
+	ss->divider = 2;
+	dev_info(&dev->dev, "max possible speed %d = %ld/%d kHz\n",
+		ss->speed_khz, clk_get_rate(ss->clk), ss->divider);
+
+	/* Register for SPI interrupt */
+	err = request_irq(ss->irq, stmp_spi_irq, 0,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq failed, %d\n", err);
+		goto out_release_hw;
+	}
+
+	/* ..and shared interrupt for all SSP controllers */
+	err = request_irq(ss->err_irq, stmp_spi_irq_err, IRQF_SHARED,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq(error) failed, %d\n", err);
+		goto out_free_irq;
+	}
+
+	err = spi_register_master(master);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot register spi master, %d\n", err);
+		goto out_free_irq_2;
+	}
+	dev_info(&dev->dev, "at (mapped) 0x%08X, irq=%d, bus %d, %s mode\n",
+			(u32)ss->regs, ss->irq, master->bus_num,
+			pio ? "PIO" : "DMA");
+	return 0;
+
+out_free_irq_2:
+	free_irq(ss->err_irq, ss);
+out_free_irq:
+	free_irq(ss->irq, ss);
+out_free_dma_desc:
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+out_free_dma:
+	stmp3xxx_dma_release(ss->dma);
+out_release_hw:
+	stmp_spi_release_hw(ss);
+out_put_master:
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+	if (ss->regs)
+		iounmap(ss->regs);
+	platform_set_drvdata(dev, NULL);
+	spi_master_put(master);
+out0:
+	return err;
+}
+
+static int __devexit stmp_spi_remove(struct platform_device *dev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(dev);
+	if (master == NULL)
+		goto out0;
+	ss = spi_master_get_devdata(master);
+
+	spi_unregister_master(master);
+
+	free_irq(ss->err_irq, ss);
+	free_irq(ss->irq, ss);
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+	stmp3xxx_dma_release(ss->dma);
+	stmp_spi_release_hw(ss);
+	destroy_workqueue(ss->workqueue);
+	iounmap(ss->regs);
+	spi_master_put(master);
+	platform_set_drvdata(dev, NULL);
+out0:
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int stmp_spi_suspend(struct platform_device *pdev, pm_message_t pmsg)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	ss->saved_timings = readl(HW_SSP_TIMING + ss->regs);
+	clk_disable(ss->clk);
+
+	return 0;
+}
+
+static int stmp_spi_resume(struct platform_device *pdev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	clk_enable(ss->clk);
+	stmp3xxx_reset_block(ss->regs, false);
+	writel(ss->saved_timings, ss->regs + HW_SSP_TIMING);
+
+	return 0;
+}
+
+#else
+#define stmp_spi_suspend NULL
+#define stmp_spi_resume  NULL
+#endif
+
+static struct platform_driver stmp_spi_driver = {
+	.probe	= stmp_spi_probe,
+	.remove	= __devexit_p(stmp_spi_remove),
+	.driver = {
+		.name = "stmp3xxx_ssp",
+		.owner = THIS_MODULE,
+	},
+	.suspend = stmp_spi_suspend,
+	.resume  = stmp_spi_resume,
+};
+
+static int __init stmp_spi_init(void)
+{
+	return platform_driver_register(&stmp_spi_driver);
+}
+
+static void __exit stmp_spi_exit(void)
+{
+	platform_driver_unregister(&stmp_spi_driver);
+}
+
+module_init(stmp_spi_init);
+module_exit(stmp_spi_exit);
+module_param(pio, int, S_IRUGO);
+module_param(clock, int, S_IRUGO);
+MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com>");
+MODULE_DESCRIPTION("STMP3xxx SPI/SSP driver");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spi_txx9.c

@@ -0,0 +1,474 @@
+/*
+ * spi_txx9.c - TXx9 SPI controller driver.
+ *
+ * Based on linux/arch/mips/tx4938/toshiba_rbtx4938/spi_txx9.c
+ * Copyright (C) 2000-2001 Toshiba Corporation
+ *
+ * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
+ * terms of the GNU General Public License version 2. This program is
+ * licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
+ *
+ * Convert to generic SPI framework - Atsushi Nemoto (anemo@mba.ocn.ne.jp)
+ */
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <asm/gpio.h>
+
+
+#define SPI_FIFO_SIZE 4
+#define SPI_MAX_DIVIDER 0xff	/* Max. value for SPCR1.SER */
+#define SPI_MIN_DIVIDER 1	/* Min. value for SPCR1.SER */
+
+#define TXx9_SPMCR		0x00
+#define TXx9_SPCR0		0x04
+#define TXx9_SPCR1		0x08
+#define TXx9_SPFS		0x0c
+#define TXx9_SPSR		0x14
+#define TXx9_SPDR		0x18
+
+/* SPMCR : SPI Master Control */
+#define TXx9_SPMCR_OPMODE	0xc0
+#define TXx9_SPMCR_CONFIG	0x40
+#define TXx9_SPMCR_ACTIVE	0x80
+#define TXx9_SPMCR_SPSTP	0x02
+#define TXx9_SPMCR_BCLR		0x01
+
+/* SPCR0 : SPI Control 0 */
+#define TXx9_SPCR0_TXIFL_MASK	0xc000
+#define TXx9_SPCR0_RXIFL_MASK	0x3000
+#define TXx9_SPCR0_SIDIE	0x0800
+#define TXx9_SPCR0_SOEIE	0x0400
+#define TXx9_SPCR0_RBSIE	0x0200
+#define TXx9_SPCR0_TBSIE	0x0100
+#define TXx9_SPCR0_IFSPSE	0x0010
+#define TXx9_SPCR0_SBOS		0x0004
+#define TXx9_SPCR0_SPHA		0x0002
+#define TXx9_SPCR0_SPOL		0x0001
+
+/* SPSR : SPI Status */
+#define TXx9_SPSR_TBSI		0x8000
+#define TXx9_SPSR_RBSI		0x4000
+#define TXx9_SPSR_TBS_MASK	0x3800
+#define TXx9_SPSR_RBS_MASK	0x0700
+#define TXx9_SPSR_SPOE		0x0080
+#define TXx9_SPSR_IFSD		0x0008
+#define TXx9_SPSR_SIDLE		0x0004
+#define TXx9_SPSR_STRDY		0x0002
+#define TXx9_SPSR_SRRDY		0x0001
+
+
+struct txx9spi {
+	struct workqueue_struct	*workqueue;
+	struct work_struct work;
+	spinlock_t lock;	/* protect 'queue' */
+	struct list_head queue;
+	wait_queue_head_t waitq;
+	void __iomem *membase;
+	int baseclk;
+	struct clk *clk;
+	u32 max_speed_hz, min_speed_hz;
+	int last_chipselect;
+	int last_chipselect_val;
+};
+
+static u32 txx9spi_rd(struct txx9spi *c, int reg)
+{
+	return __raw_readl(c->membase + reg);
+}
+static void txx9spi_wr(struct txx9spi *c, u32 val, int reg)
+{
+	__raw_writel(val, c->membase + reg);
+}
+
+static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c,
+		int on, unsigned int cs_delay)
+{
+	int val = (spi->mode & SPI_CS_HIGH) ? on : !on;
+	if (on) {
+		/* deselect the chip with cs_change hint in last transfer */
+		if (c->last_chipselect >= 0)
+			gpio_set_value(c->last_chipselect,
+					!c->last_chipselect_val);
+		c->last_chipselect = spi->chip_select;
+		c->last_chipselect_val = val;
+	} else {
+		c->last_chipselect = -1;
+		ndelay(cs_delay);	/* CS Hold Time */
+	}
+	gpio_set_value(spi->chip_select, val);
+	ndelay(cs_delay);	/* CS Setup Time / CS Recovery Time */
+}
+
+static int txx9spi_setup(struct spi_device *spi)
+{
+	struct txx9spi *c = spi_master_get_devdata(spi->master);
+	u8 bits_per_word;
+
+	if (!spi->max_speed_hz
+			|| spi->max_speed_hz > c->max_speed_hz
+			|| spi->max_speed_hz < c->min_speed_hz)
+		return -EINVAL;
+
+	bits_per_word = spi->bits_per_word;
+	if (bits_per_word != 8 && bits_per_word != 16)
+		return -EINVAL;
+
+	if (gpio_direction_output(spi->chip_select,
+			!(spi->mode & SPI_CS_HIGH))) {
+		dev_err(&spi->dev, "Cannot setup GPIO for chipselect.\n");
+		return -EINVAL;
+	}
+
+	/* deselect chip */
+	spin_lock(&c->lock);
+	txx9spi_cs_func(spi, c, 0, (NSEC_PER_SEC / 2) / spi->max_speed_hz);
+	spin_unlock(&c->lock);
+
+	return 0;
+}
+
+static irqreturn_t txx9spi_interrupt(int irq, void *dev_id)
+{
+	struct txx9spi *c = dev_id;
+
+	/* disable rx intr */
+	txx9spi_wr(c, txx9spi_rd(c, TXx9_SPCR0) & ~TXx9_SPCR0_RBSIE,
+			TXx9_SPCR0);
+	wake_up(&c->waitq);
+	return IRQ_HANDLED;
+}
+
+static void txx9spi_work_one(struct txx9spi *c, struct spi_message *m)
+{
+	struct spi_device *spi = m->spi;
+	struct spi_transfer *t;
+	unsigned int cs_delay;
+	unsigned int cs_change = 1;
+	int status = 0;
+	u32 mcr;
+	u32 prev_speed_hz = 0;
+	u8 prev_bits_per_word = 0;
+
+	/* CS setup/hold/recovery time in nsec */
+	cs_delay = 100 + (NSEC_PER_SEC / 2) / spi->max_speed_hz;
+
+	mcr = txx9spi_rd(c, TXx9_SPMCR);
+	if (unlikely((mcr & TXx9_SPMCR_OPMODE) == TXx9_SPMCR_ACTIVE)) {
+		dev_err(&spi->dev, "Bad mode.\n");
+		status = -EIO;
+		goto exit;
+	}
+	mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
+
+	/* enter config mode */
+	txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
+	txx9spi_wr(c, TXx9_SPCR0_SBOS
+			| ((spi->mode & SPI_CPOL) ? TXx9_SPCR0_SPOL : 0)
+			| ((spi->mode & SPI_CPHA) ? TXx9_SPCR0_SPHA : 0)
+			| 0x08,
+			TXx9_SPCR0);
+
+	list_for_each_entry (t, &m->transfers, transfer_list) {
+		const void *txbuf = t->tx_buf;
+		void *rxbuf = t->rx_buf;
+		u32 data;
+		unsigned int len = t->len;
+		unsigned int wsize;
+		u32 speed_hz = t->speed_hz ? : spi->max_speed_hz;
+		u8 bits_per_word = t->bits_per_word ? : spi->bits_per_word;
+
+		bits_per_word = bits_per_word ? : 8;
+		wsize = bits_per_word >> 3; /* in bytes */
+
+		if (prev_speed_hz != speed_hz
+				|| prev_bits_per_word != bits_per_word) {
+			int n = DIV_ROUND_UP(c->baseclk, speed_hz) - 1;
+			n = clamp(n, SPI_MIN_DIVIDER, SPI_MAX_DIVIDER);
+			/* enter config mode */
+			txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR,
+					TXx9_SPMCR);
+			txx9spi_wr(c, (n << 8) | bits_per_word, TXx9_SPCR1);
+			/* enter active mode */
+			txx9spi_wr(c, mcr | TXx9_SPMCR_ACTIVE, TXx9_SPMCR);
+
+			prev_speed_hz = speed_hz;
+			prev_bits_per_word = bits_per_word;
+		}
+
+		if (cs_change)
+			txx9spi_cs_func(spi, c, 1, cs_delay);
+		cs_change = t->cs_change;
+		while (len) {
+			unsigned int count = SPI_FIFO_SIZE;
+			int i;
+			u32 cr0;
+
+			if (len < count * wsize)
+				count = len / wsize;
+			/* now tx must be idle... */
+			while (!(txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_SIDLE))
+				cpu_relax();
+			cr0 = txx9spi_rd(c, TXx9_SPCR0);
+			cr0 &= ~TXx9_SPCR0_RXIFL_MASK;
+			cr0 |= (count - 1) << 12;
+			/* enable rx intr */
+			cr0 |= TXx9_SPCR0_RBSIE;
+			txx9spi_wr(c, cr0, TXx9_SPCR0);
+			/* send */
+			for (i = 0; i < count; i++) {
+				if (txbuf) {
+					data = (wsize == 1)
+						? *(const u8 *)txbuf
+						: *(const u16 *)txbuf;
+					txx9spi_wr(c, data, TXx9_SPDR);
+					txbuf += wsize;
+				} else
+					txx9spi_wr(c, 0, TXx9_SPDR);
+			}
+			/* wait all rx data */
+			wait_event(c->waitq,
+				txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_RBSI);
+			/* receive */
+			for (i = 0; i < count; i++) {
+				data = txx9spi_rd(c, TXx9_SPDR);
+				if (rxbuf) {
+					if (wsize == 1)
+						*(u8 *)rxbuf = data;
+					else
+						*(u16 *)rxbuf = data;
+					rxbuf += wsize;
+				}
+			}
+			len -= count * wsize;
+		}
+		m->actual_length += t->len;
+		if (t->delay_usecs)
+			udelay(t->delay_usecs);
+
+		if (!cs_change)
+			continue;
+		if (t->transfer_list.next == &m->transfers)
+			break;
+		/* sometimes a short mid-message deselect of the chip
+		 * may be needed to terminate a mode or command
+		 */
+		txx9spi_cs_func(spi, c, 0, cs_delay);
+	}
+
+exit:
+	m->status = status;
+	m->complete(m->context);
+
+	/* normally deactivate chipselect ... unless no error and
+	 * cs_change has hinted that the next message will probably
+	 * be for this chip too.
+	 */
+	if (!(status == 0 && cs_change))
+		txx9spi_cs_func(spi, c, 0, cs_delay);
+
+	/* enter config mode */
+	txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
+}
+
+static void txx9spi_work(struct work_struct *work)
+{
+	struct txx9spi *c = container_of(work, struct txx9spi, work);
+	unsigned long flags;
+
+	spin_lock_irqsave(&c->lock, flags);
+	while (!list_empty(&c->queue)) {
+		struct spi_message *m;
+
+		m = container_of(c->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&c->lock, flags);
+
+		txx9spi_work_one(c, m);
+
+		spin_lock_irqsave(&c->lock, flags);
+	}
+	spin_unlock_irqrestore(&c->lock, flags);
+}
+
+static int txx9spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct spi_master *master = spi->master;
+	struct txx9spi *c = spi_master_get_devdata(master);
+	struct spi_transfer *t;
+	unsigned long flags;
+
+	m->actual_length = 0;
+
+	/* check each transfer's parameters */
+	list_for_each_entry (t, &m->transfers, transfer_list) {
+		u32 speed_hz = t->speed_hz ? : spi->max_speed_hz;
+		u8 bits_per_word = t->bits_per_word ? : spi->bits_per_word;
+
+		bits_per_word = bits_per_word ? : 8;
+		if (!t->tx_buf && !t->rx_buf && t->len)
+			return -EINVAL;
+		if (bits_per_word != 8 && bits_per_word != 16)
+			return -EINVAL;
+		if (t->len & ((bits_per_word >> 3) - 1))
+			return -EINVAL;
+		if (speed_hz < c->min_speed_hz || speed_hz > c->max_speed_hz)
+			return -EINVAL;
+	}
+
+	spin_lock_irqsave(&c->lock, flags);
+	list_add_tail(&m->queue, &c->queue);
+	queue_work(c->workqueue, &c->work);
+	spin_unlock_irqrestore(&c->lock, flags);
+
+	return 0;
+}
+
+static int __init txx9spi_probe(struct platform_device *dev)
+{
+	struct spi_master *master;
+	struct txx9spi *c;
+	struct resource *res;
+	int ret = -ENODEV;
+	u32 mcr;
+	int irq;
+
+	master = spi_alloc_master(&dev->dev, sizeof(*c));
+	if (!master)
+		return ret;
+	c = spi_master_get_devdata(master);
+	platform_set_drvdata(dev, master);
+
+	INIT_WORK(&c->work, txx9spi_work);
+	spin_lock_init(&c->lock);
+	INIT_LIST_HEAD(&c->queue);
+	init_waitqueue_head(&c->waitq);
+
+	c->clk = clk_get(&dev->dev, "spi-baseclk");
+	if (IS_ERR(c->clk)) {
+		ret = PTR_ERR(c->clk);
+		c->clk = NULL;
+		goto exit;
+	}
+	ret = clk_enable(c->clk);
+	if (ret) {
+		clk_put(c->clk);
+		c->clk = NULL;
+		goto exit;
+	}
+	c->baseclk = clk_get_rate(c->clk);
+	c->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1);
+	c->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1);
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!res)
+		goto exit_busy;
+	if (!devm_request_mem_region(&dev->dev,
+				     res->start, res->end - res->start + 1,
+				     "spi_txx9"))
+		goto exit_busy;
+	c->membase = devm_ioremap(&dev->dev,
+				  res->start, res->end - res->start + 1);
+	if (!c->membase)
+		goto exit_busy;
+
+	/* enter config mode */
+	mcr = txx9spi_rd(c, TXx9_SPMCR);
+	mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
+	txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
+
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0)
+		goto exit_busy;
+	ret = devm_request_irq(&dev->dev, irq, txx9spi_interrupt, 0,
+			       "spi_txx9", c);
+	if (ret)
+		goto exit;
+
+	c->workqueue = create_singlethread_workqueue(
+				dev_name(master->dev.parent));
+	if (!c->workqueue)
+		goto exit_busy;
+	c->last_chipselect = -1;
+
+	dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n",
+		 (unsigned long long)res->start, irq,
+		 (c->baseclk + 500000) / 1000000);
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
+
+	master->bus_num = dev->id;
+	master->setup = txx9spi_setup;
+	master->transfer = txx9spi_transfer;
+	master->num_chipselect = (u16)UINT_MAX; /* any GPIO numbers */
+
+	ret = spi_register_master(master);
+	if (ret)
+		goto exit;
+	return 0;
+exit_busy:
+	ret = -EBUSY;
+exit:
+	if (c->workqueue)
+		destroy_workqueue(c->workqueue);
+	if (c->clk) {
+		clk_disable(c->clk);
+		clk_put(c->clk);
+	}
+	platform_set_drvdata(dev, NULL);
+	spi_master_put(master);
+	return ret;
+}
+
+static int __exit txx9spi_remove(struct platform_device *dev)
+{
+	struct spi_master *master = spi_master_get(platform_get_drvdata(dev));
+	struct txx9spi *c = spi_master_get_devdata(master);
+
+	spi_unregister_master(master);
+	platform_set_drvdata(dev, NULL);
+	destroy_workqueue(c->workqueue);
+	clk_disable(c->clk);
+	clk_put(c->clk);
+	spi_master_put(master);
+	return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:spi_txx9");
+
+static struct platform_driver txx9spi_driver = {
+	.remove = __exit_p(txx9spi_remove),
+	.driver = {
+		.name = "spi_txx9",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init txx9spi_init(void)
+{
+	return platform_driver_probe(&txx9spi_driver, txx9spi_probe);
+}
+subsys_initcall(txx9spi_init);
+
+static void __exit txx9spi_exit(void)
+{
+	platform_driver_unregister(&txx9spi_driver);
+}
+module_exit(txx9spi_exit);
+
+MODULE_DESCRIPTION("TXx9 SPI Driver");
+MODULE_LICENSE("GPL");

kernel/drivers/spi/spidev.c

@@ -0,0 +1,691 @@
+/*
+ * spidev.c -- simple synchronous userspace interface to SPI devices
+ *
+ * Copyright (C) 2006 SWAPP
+ *	Andrea Paterniani <a.paterniani@swapp-eng.it>
+ * Copyright (C) 2007 David Brownell (simplification, cleanup)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/ioctl.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spidev.h>
+
+#include <asm/uaccess.h>
+
+
+/*
+ * This supports acccess to SPI devices using normal userspace I/O calls.
+ * Note that while traditional UNIX/POSIX I/O semantics are half duplex,
+ * and often mask message boundaries, full SPI support requires full duplex
+ * transfers.  There are several kinds of of internal message boundaries to
+ * handle chipselect management and other protocol options.
+ *
+ * SPI has a character major number assigned.  We allocate minor numbers
+ * dynamically using a bitmask.  You must use hotplug tools, such as udev
+ * (or mdev with busybox) to create and destroy the /dev/spidevB.C device
+ * nodes, since there is no fixed association of minor numbers with any
+ * particular SPI bus or device.
+ */
+#define SPIDEV_MAJOR			153	/* assigned */
+#define N_SPI_MINORS			32	/* ... up to 256 */
+
+static unsigned long	minors[N_SPI_MINORS / BITS_PER_LONG];
+
+
+/* Bit masks for spi_device.mode management.  Note that incorrect
+ * settings for some settings can cause *lots* of trouble for other
+ * devices on a shared bus:
+ *
+ *  - CS_HIGH ... this device will be active when it shouldn't be
+ *  - 3WIRE ... when active, it won't behave as it should
+ *  - NO_CS ... there will be no explicit message boundaries; this
+ *	is completely incompatible with the shared bus model
+ *  - READY ... transfers may proceed when they shouldn't.
+ *
+ * REVISIT should changing those flags be privileged?
+ */
+#define SPI_MODE_MASK		(SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \
+				| SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
+				| SPI_NO_CS | SPI_READY)
+
+struct spidev_data {
+	dev_t			devt;
+	spinlock_t		spi_lock;
+	struct spi_device	*spi;
+	struct list_head	device_entry;
+
+	/* buffer is NULL unless this device is open (users > 0) */
+	struct mutex		buf_lock;
+	unsigned		users;
+	u8			*buffer;
+};
+
+static LIST_HEAD(device_list);
+static DEFINE_MUTEX(device_list_lock);
+
+static unsigned bufsiz = 4096;
+module_param(bufsiz, uint, S_IRUGO);
+MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message");
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * We can't use the standard synchronous wrappers for file I/O; we
+ * need to protect against async removal of the underlying spi_device.
+ */
+static void spidev_complete(void *arg)
+{
+	complete(arg);
+}
+
+static ssize_t
+spidev_sync(struct spidev_data *spidev, struct spi_message *message)
+{
+	DECLARE_COMPLETION_ONSTACK(done);
+	int status;
+
+	message->complete = spidev_complete;
+	message->context = &done;
+
+	spin_lock_irq(&spidev->spi_lock);
+	if (spidev->spi == NULL)
+		status = -ESHUTDOWN;
+	else
+		status = spi_async(spidev->spi, message);
+	spin_unlock_irq(&spidev->spi_lock);
+
+	if (status == 0) {
+		wait_for_completion(&done);
+		status = message->status;
+		if (status == 0)
+			status = message->actual_length;
+	}
+	return status;
+}
+
+static inline ssize_t
+spidev_sync_write(struct spidev_data *spidev, size_t len)
+{
+	struct spi_transfer	t = {
+			.tx_buf		= spidev->buffer,
+			.len		= len,
+		};
+	struct spi_message	m;
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t, &m);
+	return spidev_sync(spidev, &m);
+}
+
+static inline ssize_t
+spidev_sync_read(struct spidev_data *spidev, size_t len)
+{
+	struct spi_transfer	t = {
+			.rx_buf		= spidev->buffer,
+			.len		= len,
+		};
+	struct spi_message	m;
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t, &m);
+	return spidev_sync(spidev, &m);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* Read-only message with current device setup */
+static ssize_t
+spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
+{
+	struct spidev_data	*spidev;
+	ssize_t			status = 0;
+
+	/* chipselect only toggles at start or end of operation */
+	if (count > bufsiz)
+		return -EMSGSIZE;
+
+	spidev = filp->private_data;
+
+	mutex_lock(&spidev->buf_lock);
+	status = spidev_sync_read(spidev, count);
+	if (status > 0) {
+		unsigned long	missing;
+
+		missing = copy_to_user(buf, spidev->buffer, status);
+		if (missing == status)
+			status = -EFAULT;
+		else
+			status = status - missing;
+	}
+	mutex_unlock(&spidev->buf_lock);
+
+	return status;
+}
+
+/* Write-only message with current device setup */
+static ssize_t
+spidev_write(struct file *filp, const char __user *buf,
+		size_t count, loff_t *f_pos)
+{
+	struct spidev_data	*spidev;
+	ssize_t			status = 0;
+	unsigned long		missing;
+
+	/* chipselect only toggles at start or end of operation */
+	if (count > bufsiz)
+		return -EMSGSIZE;
+
+	spidev = filp->private_data;
+
+	mutex_lock(&spidev->buf_lock);
+	missing = copy_from_user(spidev->buffer, buf, count);
+	if (missing == 0) {
+		status = spidev_sync_write(spidev, count);
+	} else
+		status = -EFAULT;
+	mutex_unlock(&spidev->buf_lock);
+
+	return status;
+}
+
+static int spidev_message(struct spidev_data *spidev,
+		struct spi_ioc_transfer *u_xfers, unsigned n_xfers)
+{
+	struct spi_message	msg;
+	struct spi_transfer	*k_xfers;
+	struct spi_transfer	*k_tmp;
+	struct spi_ioc_transfer *u_tmp;
+	unsigned		n, total;
+	u8			*buf;
+	int			status = -EFAULT;
+
+	spi_message_init(&msg);
+	k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL);
+	if (k_xfers == NULL)
+		return -ENOMEM;
+
+	/* Construct spi_message, copying any tx data to bounce buffer.
+	 * We walk the array of user-provided transfers, using each one
+	 * to initialize a kernel version of the same transfer.
+	 */
+	buf = spidev->buffer;
+	total = 0;
+	for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
+			n;
+			n--, k_tmp++, u_tmp++) {
+		k_tmp->len = u_tmp->len;
+
+		total += k_tmp->len;
+		if (total > bufsiz) {
+			status = -EMSGSIZE;
+			goto done;
+		}
+
+		if (u_tmp->rx_buf) {
+			k_tmp->rx_buf = buf;
+			if (!access_ok(VERIFY_WRITE, (u8 __user *)
+						(uintptr_t) u_tmp->rx_buf,
+						u_tmp->len))
+				goto done;
+		}
+		if (u_tmp->tx_buf) {
+			k_tmp->tx_buf = buf;
+			if (copy_from_user(buf, (const u8 __user *)
+						(uintptr_t) u_tmp->tx_buf,
+					u_tmp->len))
+				goto done;
+		}
+		buf += k_tmp->len;
+
+		k_tmp->cs_change = !!u_tmp->cs_change;
+		k_tmp->bits_per_word = u_tmp->bits_per_word;
+		k_tmp->delay_usecs = u_tmp->delay_usecs;
+		k_tmp->speed_hz = u_tmp->speed_hz;
+#ifdef VERBOSE
+		dev_dbg(&spi->dev,
+			"  xfer len %zd %s%s%s%dbits %u usec %uHz\n",
+			u_tmp->len,
+			u_tmp->rx_buf ? "rx " : "",
+			u_tmp->tx_buf ? "tx " : "",
+			u_tmp->cs_change ? "cs " : "",
+			u_tmp->bits_per_word ? : spi->bits_per_word,
+			u_tmp->delay_usecs,
+			u_tmp->speed_hz ? : spi->max_speed_hz);
+#endif
+		spi_message_add_tail(k_tmp, &msg);
+	}
+
+	status = spidev_sync(spidev, &msg);
+	if (status < 0)
+		goto done;
+
+	/* copy any rx data out of bounce buffer */
+	buf = spidev->buffer;
+	for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) {
+		if (u_tmp->rx_buf) {
+			if (__copy_to_user((u8 __user *)
+					(uintptr_t) u_tmp->rx_buf, buf,
+					u_tmp->len)) {
+				status = -EFAULT;
+				goto done;
+			}
+		}
+		buf += u_tmp->len;
+	}
+	status = total;
+
+done:
+	kfree(k_xfers);
+	return status;
+}
+
+static long
+spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	int			err = 0;
+	int			retval = 0;
+	struct spidev_data	*spidev;
+	struct spi_device	*spi;
+	u32			tmp;
+	unsigned		n_ioc;
+	struct spi_ioc_transfer	*ioc;
+
+	/* Check type and command number */
+	if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC)
+		return -ENOTTY;
+
+	/* Check access direction once here; don't repeat below.
+	 * IOC_DIR is from the user perspective, while access_ok is
+	 * from the kernel perspective; so they look reversed.
+	 */
+	if (_IOC_DIR(cmd) & _IOC_READ)
+		err = !access_ok(VERIFY_WRITE,
+				(void __user *)arg, _IOC_SIZE(cmd));
+	if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE)
+		err = !access_ok(VERIFY_READ,
+				(void __user *)arg, _IOC_SIZE(cmd));
+	if (err)
+		return -EFAULT;
+
+	/* guard against device removal before, or while,
+	 * we issue this ioctl.
+	 */
+	spidev = filp->private_data;
+	spin_lock_irq(&spidev->spi_lock);
+	spi = spi_dev_get(spidev->spi);
+	spin_unlock_irq(&spidev->spi_lock);
+
+	if (spi == NULL)
+		return -ESHUTDOWN;
+
+	/* use the buffer lock here for triple duty:
+	 *  - prevent I/O (from us) so calling spi_setup() is safe;
+	 *  - prevent concurrent SPI_IOC_WR_* from morphing
+	 *    data fields while SPI_IOC_RD_* reads them;
+	 *  - SPI_IOC_MESSAGE needs the buffer locked "normally".
+	 */
+	mutex_lock(&spidev->buf_lock);
+
+	switch (cmd) {
+	/* read requests */
+	case SPI_IOC_RD_MODE:
+		retval = __put_user(spi->mode & SPI_MODE_MASK,
+					(__u8 __user *)arg);
+		break;
+	case SPI_IOC_RD_LSB_FIRST:
+		retval = __put_user((spi->mode & SPI_LSB_FIRST) ?  1 : 0,
+					(__u8 __user *)arg);
+		break;
+	case SPI_IOC_RD_BITS_PER_WORD:
+		retval = __put_user(spi->bits_per_word, (__u8 __user *)arg);
+		break;
+	case SPI_IOC_RD_MAX_SPEED_HZ:
+		retval = __put_user(spi->max_speed_hz, (__u32 __user *)arg);
+		break;
+
+	/* write requests */
+	case SPI_IOC_WR_MODE:
+		retval = __get_user(tmp, (u8 __user *)arg);
+		if (retval == 0) {
+			u8	save = spi->mode;
+
+			if (tmp & ~SPI_MODE_MASK) {
+				retval = -EINVAL;
+				break;
+			}
+
+			tmp |= spi->mode & ~SPI_MODE_MASK;
+			spi->mode = (u8)tmp;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->mode = save;
+			else
+				dev_dbg(&spi->dev, "spi mode %02x\n", tmp);
+		}
+		break;
+	case SPI_IOC_WR_LSB_FIRST:
+		retval = __get_user(tmp, (__u8 __user *)arg);
+		if (retval == 0) {
+			u8	save = spi->mode;
+
+			if (tmp)
+				spi->mode |= SPI_LSB_FIRST;
+			else
+				spi->mode &= ~SPI_LSB_FIRST;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->mode = save;
+			else
+				dev_dbg(&spi->dev, "%csb first\n",
+						tmp ? 'l' : 'm');
+		}
+		break;
+	case SPI_IOC_WR_BITS_PER_WORD:
+		retval = __get_user(tmp, (__u8 __user *)arg);
+		if (retval == 0) {
+			u8	save = spi->bits_per_word;
+
+			spi->bits_per_word = tmp;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->bits_per_word = save;
+			else
+				dev_dbg(&spi->dev, "%d bits per word\n", tmp);
+		}
+		break;
+	case SPI_IOC_WR_MAX_SPEED_HZ:
+		retval = __get_user(tmp, (__u32 __user *)arg);
+		if (retval == 0) {
+			u32	save = spi->max_speed_hz;
+
+			spi->max_speed_hz = tmp;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->max_speed_hz = save;
+			else
+				dev_dbg(&spi->dev, "%d Hz (max)\n", tmp);
+		}
+		break;
+
+	default:
+		/* segmented and/or full-duplex I/O request */
+		if (_IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0))
+				|| _IOC_DIR(cmd) != _IOC_WRITE) {
+			retval = -ENOTTY;
+			break;
+		}
+
+		tmp = _IOC_SIZE(cmd);
+		if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) {
+			retval = -EINVAL;
+			break;
+		}
+		n_ioc = tmp / sizeof(struct spi_ioc_transfer);
+		if (n_ioc == 0)
+			break;
+
+		/* copy into scratch area */
+		ioc = kmalloc(tmp, GFP_KERNEL);
+		if (!ioc) {
+			retval = -ENOMEM;
+			break;
+		}
+		if (__copy_from_user(ioc, (void __user *)arg, tmp)) {
+			kfree(ioc);
+			retval = -EFAULT;
+			break;
+		}
+
+		/* translate to spi_message, execute */
+		retval = spidev_message(spidev, ioc, n_ioc);
+		kfree(ioc);
+		break;
+	}
+
+	mutex_unlock(&spidev->buf_lock);
+	spi_dev_put(spi);
+	return retval;
+}
+
+static int spidev_open(struct inode *inode, struct file *filp)
+{
+	struct spidev_data	*spidev;
+	int			status = -ENXIO;
+
+	lock_kernel();
+	mutex_lock(&device_list_lock);
+
+	list_for_each_entry(spidev, &device_list, device_entry) {
+		if (spidev->devt == inode->i_rdev) {
+			status = 0;
+			break;
+		}
+	}
+	if (status == 0) {
+		if (!spidev->buffer) {
+			spidev->buffer = kmalloc(bufsiz, GFP_KERNEL);
+			if (!spidev->buffer) {
+				dev_dbg(&spidev->spi->dev, "open/ENOMEM\n");
+				status = -ENOMEM;
+			}
+		}
+		if (status == 0) {
+			spidev->users++;
+			filp->private_data = spidev;
+			nonseekable_open(inode, filp);
+		}
+	} else
+		pr_debug("spidev: nothing for minor %d\n", iminor(inode));
+
+	mutex_unlock(&device_list_lock);
+	unlock_kernel();
+	return status;
+}
+
+static int spidev_release(struct inode *inode, struct file *filp)
+{
+	struct spidev_data	*spidev;
+	int			status = 0;
+
+	mutex_lock(&device_list_lock);
+	spidev = filp->private_data;
+	filp->private_data = NULL;
+
+	/* last close? */
+	spidev->users--;
+	if (!spidev->users) {
+		int		dofree;
+
+		kfree(spidev->buffer);
+		spidev->buffer = NULL;
+
+		/* ... after we unbound from the underlying device? */
+		spin_lock_irq(&spidev->spi_lock);
+		dofree = (spidev->spi == NULL);
+		spin_unlock_irq(&spidev->spi_lock);
+
+		if (dofree)
+			kfree(spidev);
+	}
+	mutex_unlock(&device_list_lock);
+
+	return status;
+}
+
+static const struct file_operations spidev_fops = {
+	.owner =	THIS_MODULE,
+	/* REVISIT switch to aio primitives, so that userspace
+	 * gets more complete API coverage.  It'll simplify things
+	 * too, except for the locking.
+	 */
+	.write =	spidev_write,
+	.read =		spidev_read,
+	.unlocked_ioctl = spidev_ioctl,
+	.open =		spidev_open,
+	.release =	spidev_release,
+};
+
+/*-------------------------------------------------------------------------*/
+
+/* The main reason to have this class is to make mdev/udev create the
+ * /dev/spidevB.C character device nodes exposing our userspace API.
+ * It also simplifies memory management.
+ */
+
+static struct class *spidev_class;
+
+/*-------------------------------------------------------------------------*/
+
+static int spidev_probe(struct spi_device *spi)
+{
+	struct spidev_data	*spidev;
+	int			status;
+	unsigned long		minor;
+
+	/* Allocate driver data */
+	spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
+	if (!spidev)
+		return -ENOMEM;
+
+	/* Initialize the driver data */
+	spidev->spi = spi;
+	spin_lock_init(&spidev->spi_lock);
+	mutex_init(&spidev->buf_lock);
+
+	INIT_LIST_HEAD(&spidev->device_entry);
+
+	/* If we can allocate a minor number, hook up this device.
+	 * Reusing minors is fine so long as udev or mdev is working.
+	 */
+	mutex_lock(&device_list_lock);
+	minor = find_first_zero_bit(minors, N_SPI_MINORS);
+	if (minor < N_SPI_MINORS) {
+		struct device *dev;
+
+		spidev->devt = MKDEV(SPIDEV_MAJOR, minor);
+		dev = device_create(spidev_class, &spi->dev, spidev->devt,
+				    spidev, "spidev%d.%d",
+				    spi->master->bus_num, spi->chip_select);
+		status = IS_ERR(dev) ? PTR_ERR(dev) : 0;
+	} else {
+		dev_dbg(&spi->dev, "no minor number available!\n");
+		status = -ENODEV;
+	}
+	if (status == 0) {
+		set_bit(minor, minors);
+		list_add(&spidev->device_entry, &device_list);
+	}
+	mutex_unlock(&device_list_lock);
+
+	if (status == 0)
+		spi_set_drvdata(spi, spidev);
+	else
+		kfree(spidev);
+
+	return status;
+}
+
+static int spidev_remove(struct spi_device *spi)
+{
+	struct spidev_data	*spidev = spi_get_drvdata(spi);
+
+	/* make sure ops on existing fds can abort cleanly */
+	spin_lock_irq(&spidev->spi_lock);
+	spidev->spi = NULL;
+	spi_set_drvdata(spi, NULL);
+	spin_unlock_irq(&spidev->spi_lock);
+
+	/* prevent new opens */
+	mutex_lock(&device_list_lock);
+	list_del(&spidev->device_entry);
+	device_destroy(spidev_class, spidev->devt);
+	clear_bit(MINOR(spidev->devt), minors);
+	if (spidev->users == 0)
+		kfree(spidev);
+	mutex_unlock(&device_list_lock);
+
+	return 0;
+}
+
+static struct spi_driver spidev_spi = {
+	.driver = {
+		.name =		"spidev",
+		.owner =	THIS_MODULE,
+	},
+	.probe =	spidev_probe,
+	.remove =	__devexit_p(spidev_remove),
+
+	/* NOTE:  suspend/resume methods are not necessary here.
+	 * We don't do anything except pass the requests to/from
+	 * the underlying controller.  The refrigerator handles
+	 * most issues; the controller driver handles the rest.
+	 */
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int __init spidev_init(void)
+{
+	int status;
+
+	/* Claim our 256 reserved device numbers.  Then register a class
+	 * that will key udev/mdev to add/remove /dev nodes.  Last, register
+	 * the driver which manages those device numbers.
+	 */
+	BUILD_BUG_ON(N_SPI_MINORS > 256);
+	status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops);
+	if (status < 0)
+		return status;
+
+	spidev_class = class_create(THIS_MODULE, "spidev");
+	if (IS_ERR(spidev_class)) {
+		unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
+		return PTR_ERR(spidev_class);
+	}
+
+	status = spi_register_driver(&spidev_spi);
+	if (status < 0) {
+		class_destroy(spidev_class);
+		unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
+	}
+	return status;
+}
+module_init(spidev_init);
+
+static void __exit spidev_exit(void)
+{
+	spi_unregister_driver(&spidev_spi);
+	class_destroy(spidev_class);
+	unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
+}
+module_exit(spidev_exit);
+
+MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
+MODULE_DESCRIPTION("User mode SPI device interface");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:spidev");

kernel/drivers/spi/tle62x0.c

@@ -0,0 +1,332 @@
+/*
+ * tle62x0.c -- support Infineon TLE62x0 driver chips
+ *
+ * Copyright (c) 2007 Simtec Electronics
+ *	Ben Dooks, <ben@simtec.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/tle62x0.h>
+
+
+#define CMD_READ	0x00
+#define CMD_SET		0xff
+
+#define DIAG_NORMAL	0x03
+#define DIAG_OVERLOAD	0x02
+#define DIAG_OPEN	0x01
+#define DIAG_SHORTGND	0x00
+
+struct tle62x0_state {
+	struct spi_device	*us;
+	struct mutex		lock;
+	unsigned int		nr_gpio;
+	unsigned int		gpio_state;
+
+	unsigned char		tx_buff[4];
+	unsigned char		rx_buff[4];
+};
+
+static int to_gpio_num(struct device_attribute *attr);
+
+static inline int tle62x0_write(struct tle62x0_state *st)
+{
+	unsigned char *buff = st->tx_buff;
+	unsigned int gpio_state = st->gpio_state;
+
+	buff[0] = CMD_SET;
+
+	if (st->nr_gpio == 16) {
+		buff[1] = gpio_state >> 8;
+		buff[2] = gpio_state;
+	} else {
+		buff[1] = gpio_state;
+	}
+
+	dev_dbg(&st->us->dev, "buff %02x,%02x,%02x\n",
+		buff[0], buff[1], buff[2]);
+
+	return spi_write(st->us, buff, (st->nr_gpio == 16) ? 3 : 2);
+}
+
+static inline int tle62x0_read(struct tle62x0_state *st)
+{
+	unsigned char *txbuff = st->tx_buff;
+	struct spi_transfer xfer = {
+		.tx_buf		= txbuff,
+		.rx_buf		= st->rx_buff,
+		.len		= (st->nr_gpio * 2) / 8,
+	};
+	struct spi_message msg;
+
+	txbuff[0] = CMD_READ;
+	txbuff[1] = 0x00;
+	txbuff[2] = 0x00;
+	txbuff[3] = 0x00;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	return spi_sync(st->us, &msg);
+}
+
+static unsigned char *decode_fault(unsigned int fault_code)
+{
+	fault_code &= 3;
+
+	switch (fault_code) {
+	case DIAG_NORMAL:
+		return "N";
+	case DIAG_OVERLOAD:
+		return "V";
+	case DIAG_OPEN:
+		return "O";
+	case DIAG_SHORTGND:
+		return "G";
+	}
+
+	return "?";
+}
+
+static ssize_t tle62x0_status_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct tle62x0_state *st = dev_get_drvdata(dev);
+	char *bp = buf;
+	unsigned char *buff = st->rx_buff;
+	unsigned long fault = 0;
+	int ptr;
+	int ret;
+
+	mutex_lock(&st->lock);
+	ret = tle62x0_read(st);
+	dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
+	if (ret < 0) {
+		mutex_unlock(&st->lock);
+		return ret;
+	}
+
+	for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
+		fault <<= 8;
+		fault  |= ((unsigned long)buff[ptr]);
+
+		dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
+	}
+
+	for (ptr = 0; ptr < st->nr_gpio; ptr++) {
+		bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
+	}
+
+	*bp++ = '\n';
+
+	mutex_unlock(&st->lock);
+	return bp - buf;
+}
+
+static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
+
+static ssize_t tle62x0_gpio_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct tle62x0_state *st = dev_get_drvdata(dev);
+	int gpio_num = to_gpio_num(attr);
+	int value;
+
+	mutex_lock(&st->lock);
+	value = (st->gpio_state >> gpio_num) & 1;
+	mutex_unlock(&st->lock);
+
+	return snprintf(buf, PAGE_SIZE, "%d", value);
+}
+
+static ssize_t tle62x0_gpio_store(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf, size_t len)
+{
+	struct tle62x0_state *st = dev_get_drvdata(dev);
+	int gpio_num = to_gpio_num(attr);
+	unsigned long val;
+	char *endp;
+
+	val = simple_strtoul(buf, &endp, 0);
+	if (buf == endp)
+		return -EINVAL;
+
+	dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
+
+	mutex_lock(&st->lock);
+
+	if (val)
+		st->gpio_state |= 1 << gpio_num;
+	else
+		st->gpio_state &= ~(1 << gpio_num);
+
+	tle62x0_write(st);
+	mutex_unlock(&st->lock);
+
+	return len;
+}
+
+static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
+		tle62x0_gpio_show, tle62x0_gpio_store);
+
+static struct device_attribute *gpio_attrs[] = {
+	[0]		= &dev_attr_gpio1,
+	[1]		= &dev_attr_gpio2,
+	[2]		= &dev_attr_gpio3,
+	[3]		= &dev_attr_gpio4,
+	[4]		= &dev_attr_gpio5,
+	[5]		= &dev_attr_gpio6,
+	[6]		= &dev_attr_gpio7,
+	[7]		= &dev_attr_gpio8,
+	[8]		= &dev_attr_gpio9,
+	[9]		= &dev_attr_gpio10,
+	[10]		= &dev_attr_gpio11,
+	[11]		= &dev_attr_gpio12,
+	[12]		= &dev_attr_gpio13,
+	[13]		= &dev_attr_gpio14,
+	[14]		= &dev_attr_gpio15,
+	[15]		= &dev_attr_gpio16
+};
+
+static int to_gpio_num(struct device_attribute *attr)
+{
+	int ptr;
+
+	for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
+		if (gpio_attrs[ptr] == attr)
+			return ptr;
+	}
+
+	return -1;
+}
+
+static int __devinit tle62x0_probe(struct spi_device *spi)
+{
+	struct tle62x0_state *st;
+	struct tle62x0_pdata *pdata;
+	int ptr;
+	int ret;
+
+	pdata = spi->dev.platform_data;
+	if (pdata == NULL) {
+		dev_err(&spi->dev, "no device data specified\n");
+		return -EINVAL;
+	}
+
+	st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
+	if (st == NULL) {
+		dev_err(&spi->dev, "no memory for device state\n");
+		return -ENOMEM;
+	}
+
+	st->us = spi;
+	st->nr_gpio = pdata->gpio_count;
+	st->gpio_state = pdata->init_state;
+
+	mutex_init(&st->lock);
+
+	ret = device_create_file(&spi->dev, &dev_attr_status_show);
+	if (ret) {
+		dev_err(&spi->dev, "cannot create status attribute\n");
+		goto err_status;
+	}
+
+	for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
+		ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
+		if (ret) {
+			dev_err(&spi->dev, "cannot create gpio attribute\n");
+			goto err_gpios;
+		}
+	}
+
+	/* tle62x0_write(st); */
+	spi_set_drvdata(spi, st);
+	return 0;
+
+ err_gpios:
+	for (; ptr > 0; ptr--)
+		device_remove_file(&spi->dev, gpio_attrs[ptr]);
+
+	device_remove_file(&spi->dev, &dev_attr_status_show);
+
+ err_status:
+	kfree(st);
+	return ret;
+}
+
+static int __devexit tle62x0_remove(struct spi_device *spi)
+{
+	struct tle62x0_state *st = spi_get_drvdata(spi);
+	int ptr;
+
+	for (ptr = 0; ptr < st->nr_gpio; ptr++)
+		device_remove_file(&spi->dev, gpio_attrs[ptr]);
+
+	kfree(st);
+	return 0;
+}
+
+static struct spi_driver tle62x0_driver = {
+	.driver = {
+		.name	= "tle62x0",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= tle62x0_probe,
+	.remove		= __devexit_p(tle62x0_remove),
+};
+
+static __init int tle62x0_init(void)
+{
+	return spi_register_driver(&tle62x0_driver);
+}
+
+static __exit void tle62x0_exit(void)
+{
+	spi_unregister_driver(&tle62x0_driver);
+}
+
+module_init(tle62x0_init);
+module_exit(tle62x0_exit);
+
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_DESCRIPTION("TLE62x0 SPI driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("spi:tle62x0");

kernel/drivers/spi/xilinx_spi.c

@@ -0,0 +1,456 @@
+/*
+ * xilinx_spi.c
+ *
+ * Xilinx SPI controller driver (master mode only)
+ *
+ * Author: MontaVista Software, Inc.
+ *	source@mvista.com
+ *
+ * 2002-2007 (c) MontaVista Software, Inc.  This file is licensed under the
+ * terms of the GNU General Public License version 2.  This program is licensed
+ * "as is" without any warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <linux/of_platform.h>
+#include <linux/of_device.h>
+#include <linux/of_spi.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/io.h>
+
+#define XILINX_SPI_NAME "xilinx_spi"
+
+/* Register definitions as per "OPB Serial Peripheral Interface (SPI) (v1.00e)
+ * Product Specification", DS464
+ */
+#define XSPI_CR_OFFSET		0x62	/* 16-bit Control Register */
+
+#define XSPI_CR_ENABLE		0x02
+#define XSPI_CR_MASTER_MODE	0x04
+#define XSPI_CR_CPOL		0x08
+#define XSPI_CR_CPHA		0x10
+#define XSPI_CR_MODE_MASK	(XSPI_CR_CPHA | XSPI_CR_CPOL)
+#define XSPI_CR_TXFIFO_RESET	0x20
+#define XSPI_CR_RXFIFO_RESET	0x40
+#define XSPI_CR_MANUAL_SSELECT	0x80
+#define XSPI_CR_TRANS_INHIBIT	0x100
+
+#define XSPI_SR_OFFSET		0x67	/* 8-bit Status Register */
+
+#define XSPI_SR_RX_EMPTY_MASK	0x01	/* Receive FIFO is empty */
+#define XSPI_SR_RX_FULL_MASK	0x02	/* Receive FIFO is full */
+#define XSPI_SR_TX_EMPTY_MASK	0x04	/* Transmit FIFO is empty */
+#define XSPI_SR_TX_FULL_MASK	0x08	/* Transmit FIFO is full */
+#define XSPI_SR_MODE_FAULT_MASK	0x10	/* Mode fault error */
+
+#define XSPI_TXD_OFFSET		0x6b	/* 8-bit Data Transmit Register */
+#define XSPI_RXD_OFFSET		0x6f	/* 8-bit Data Receive Register */
+
+#define XSPI_SSR_OFFSET		0x70	/* 32-bit Slave Select Register */
+
+/* Register definitions as per "OPB IPIF (v3.01c) Product Specification", DS414
+ * IPIF registers are 32 bit
+ */
+#define XIPIF_V123B_DGIER_OFFSET	0x1c	/* IPIF global int enable reg */
+#define XIPIF_V123B_GINTR_ENABLE	0x80000000
+
+#define XIPIF_V123B_IISR_OFFSET		0x20	/* IPIF interrupt status reg */
+#define XIPIF_V123B_IIER_OFFSET		0x28	/* IPIF interrupt enable reg */
+
+#define XSPI_INTR_MODE_FAULT		0x01	/* Mode fault error */
+#define XSPI_INTR_SLAVE_MODE_FAULT	0x02	/* Selected as slave while
+						 * disabled */
+#define XSPI_INTR_TX_EMPTY		0x04	/* TxFIFO is empty */
+#define XSPI_INTR_TX_UNDERRUN		0x08	/* TxFIFO was underrun */
+#define XSPI_INTR_RX_FULL		0x10	/* RxFIFO is full */
+#define XSPI_INTR_RX_OVERRUN		0x20	/* RxFIFO was overrun */
+
+#define XIPIF_V123B_RESETR_OFFSET	0x40	/* IPIF reset register */
+#define XIPIF_V123B_RESET_MASK		0x0a	/* the value to write */
+
+struct xilinx_spi {
+	/* bitbang has to be first */
+	struct spi_bitbang bitbang;
+	struct completion done;
+
+	void __iomem	*regs;	/* virt. address of the control registers */
+
+	u32		irq;
+
+	u32		speed_hz; /* SCK has a fixed frequency of speed_hz Hz */
+
+	u8 *rx_ptr;		/* pointer in the Tx buffer */
+	const u8 *tx_ptr;	/* pointer in the Rx buffer */
+	int remaining_bytes;	/* the number of bytes left to transfer */
+};
+
+static void xspi_init_hw(void __iomem *regs_base)
+{
+	/* Reset the SPI device */
+	out_be32(regs_base + XIPIF_V123B_RESETR_OFFSET,
+		 XIPIF_V123B_RESET_MASK);
+	/* Disable all the interrupts just in case */
+	out_be32(regs_base + XIPIF_V123B_IIER_OFFSET, 0);
+	/* Enable the global IPIF interrupt */
+	out_be32(regs_base + XIPIF_V123B_DGIER_OFFSET,
+		 XIPIF_V123B_GINTR_ENABLE);
+	/* Deselect the slave on the SPI bus */
+	out_be32(regs_base + XSPI_SSR_OFFSET, 0xffff);
+	/* Disable the transmitter, enable Manual Slave Select Assertion,
+	 * put SPI controller into master mode, and enable it */
+	out_be16(regs_base + XSPI_CR_OFFSET,
+		 XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT
+		 | XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE);
+}
+
+static void xilinx_spi_chipselect(struct spi_device *spi, int is_on)
+{
+	struct xilinx_spi *xspi = spi_master_get_devdata(spi->master);
+
+	if (is_on == BITBANG_CS_INACTIVE) {
+		/* Deselect the slave on the SPI bus */
+		out_be32(xspi->regs + XSPI_SSR_OFFSET, 0xffff);
+	} else if (is_on == BITBANG_CS_ACTIVE) {
+		/* Set the SPI clock phase and polarity */
+		u16 cr = in_be16(xspi->regs + XSPI_CR_OFFSET)
+			 & ~XSPI_CR_MODE_MASK;
+		if (spi->mode & SPI_CPHA)
+			cr |= XSPI_CR_CPHA;
+		if (spi->mode & SPI_CPOL)
+			cr |= XSPI_CR_CPOL;
+		out_be16(xspi->regs + XSPI_CR_OFFSET, cr);
+
+		/* We do not check spi->max_speed_hz here as the SPI clock
+		 * frequency is not software programmable (the IP block design
+		 * parameter)
+		 */
+
+		/* Activate the chip select */
+		out_be32(xspi->regs + XSPI_SSR_OFFSET,
+			 ~(0x0001 << spi->chip_select));
+	}
+}
+
+/* spi_bitbang requires custom setup_transfer() to be defined if there is a
+ * custom txrx_bufs(). We have nothing to setup here as the SPI IP block
+ * supports just 8 bits per word, and SPI clock can't be changed in software.
+ * Check for 8 bits per word. Chip select delay calculations could be
+ * added here as soon as bitbang_work() can be made aware of the delay value.
+ */
+static int xilinx_spi_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	u8 bits_per_word;
+
+	bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int xilinx_spi_setup(struct spi_device *spi)
+{
+	struct spi_bitbang *bitbang;
+	struct xilinx_spi *xspi;
+	int retval;
+
+	xspi = spi_master_get_devdata(spi->master);
+	bitbang = &xspi->bitbang;
+
+	retval = xilinx_spi_setup_transfer(spi, NULL);
+	if (retval < 0)
+		return retval;
+
+	return 0;
+}
+
+static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi)
+{
+	u8 sr;
+
+	/* Fill the Tx FIFO with as many bytes as possible */
+	sr = in_8(xspi->regs + XSPI_SR_OFFSET);
+	while ((sr & XSPI_SR_TX_FULL_MASK) == 0 && xspi->remaining_bytes > 0) {
+		if (xspi->tx_ptr) {
+			out_8(xspi->regs + XSPI_TXD_OFFSET, *xspi->tx_ptr++);
+		} else {
+			out_8(xspi->regs + XSPI_TXD_OFFSET, 0);
+		}
+		xspi->remaining_bytes--;
+		sr = in_8(xspi->regs + XSPI_SR_OFFSET);
+	}
+}
+
+static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct xilinx_spi *xspi = spi_master_get_devdata(spi->master);
+	u32 ipif_ier;
+	u16 cr;
+
+	/* We get here with transmitter inhibited */
+
+	xspi->tx_ptr = t->tx_buf;
+	xspi->rx_ptr = t->rx_buf;
+	xspi->remaining_bytes = t->len;
+	INIT_COMPLETION(xspi->done);
+
+	xilinx_spi_fill_tx_fifo(xspi);
+
+	/* Enable the transmit empty interrupt, which we use to determine
+	 * progress on the transmission.
+	 */
+	ipif_ier = in_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET);
+	out_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET,
+		 ipif_ier | XSPI_INTR_TX_EMPTY);
+
+	/* Start the transfer by not inhibiting the transmitter any longer */
+	cr = in_be16(xspi->regs + XSPI_CR_OFFSET) & ~XSPI_CR_TRANS_INHIBIT;
+	out_be16(xspi->regs + XSPI_CR_OFFSET, cr);
+
+	wait_for_completion(&xspi->done);
+
+	/* Disable the transmit empty interrupt */
+	out_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET, ipif_ier);
+
+	return t->len - xspi->remaining_bytes;
+}
+
+
+/* This driver supports single master mode only. Hence Tx FIFO Empty
+ * is the only interrupt we care about.
+ * Receive FIFO Overrun, Transmit FIFO Underrun, Mode Fault, and Slave Mode
+ * Fault are not to happen.
+ */
+static irqreturn_t xilinx_spi_irq(int irq, void *dev_id)
+{
+	struct xilinx_spi *xspi = dev_id;
+	u32 ipif_isr;
+
+	/* Get the IPIF interrupts, and clear them immediately */
+	ipif_isr = in_be32(xspi->regs + XIPIF_V123B_IISR_OFFSET);
+	out_be32(xspi->regs + XIPIF_V123B_IISR_OFFSET, ipif_isr);
+
+	if (ipif_isr & XSPI_INTR_TX_EMPTY) {	/* Transmission completed */
+		u16 cr;
+		u8 sr;
+
+		/* A transmit has just completed. Process received data and
+		 * check for more data to transmit. Always inhibit the
+		 * transmitter while the Isr refills the transmit register/FIFO,
+		 * or make sure it is stopped if we're done.
+		 */
+		cr = in_be16(xspi->regs + XSPI_CR_OFFSET);
+		out_be16(xspi->regs + XSPI_CR_OFFSET,
+			 cr | XSPI_CR_TRANS_INHIBIT);
+
+		/* Read out all the data from the Rx FIFO */
+		sr = in_8(xspi->regs + XSPI_SR_OFFSET);
+		while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) {
+			u8 data;
+
+			data = in_8(xspi->regs + XSPI_RXD_OFFSET);
+			if (xspi->rx_ptr) {
+				*xspi->rx_ptr++ = data;
+			}
+			sr = in_8(xspi->regs + XSPI_SR_OFFSET);
+		}
+
+		/* See if there is more data to send */
+		if (xspi->remaining_bytes > 0) {
+			xilinx_spi_fill_tx_fifo(xspi);
+			/* Start the transfer by not inhibiting the
+			 * transmitter any longer
+			 */
+			out_be16(xspi->regs + XSPI_CR_OFFSET, cr);
+		} else {
+			/* No more data to send.
+			 * Indicate the transfer is completed.
+			 */
+			complete(&xspi->done);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int __init xilinx_spi_of_probe(struct of_device *ofdev,
+					const struct of_device_id *match)
+{
+	struct spi_master *master;
+	struct xilinx_spi *xspi;
+	struct resource r_irq_struct;
+	struct resource r_mem_struct;
+
+	struct resource *r_irq = &r_irq_struct;
+	struct resource *r_mem = &r_mem_struct;
+	int rc = 0;
+	const u32 *prop;
+	int len;
+
+	/* Get resources(memory, IRQ) associated with the device */
+	master = spi_alloc_master(&ofdev->dev, sizeof(struct xilinx_spi));
+
+	if (master == NULL) {
+		return -ENOMEM;
+	}
+
+	dev_set_drvdata(&ofdev->dev, master);
+
+	rc = of_address_to_resource(ofdev->node, 0, r_mem);
+	if (rc) {
+		dev_warn(&ofdev->dev, "invalid address\n");
+		goto put_master;
+	}
+
+	rc = of_irq_to_resource(ofdev->node, 0, r_irq);
+	if (rc == NO_IRQ) {
+		dev_warn(&ofdev->dev, "no IRQ found\n");
+		goto put_master;
+	}
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
+
+	xspi = spi_master_get_devdata(master);
+	xspi->bitbang.master = spi_master_get(master);
+	xspi->bitbang.chipselect = xilinx_spi_chipselect;
+	xspi->bitbang.setup_transfer = xilinx_spi_setup_transfer;
+	xspi->bitbang.txrx_bufs = xilinx_spi_txrx_bufs;
+	xspi->bitbang.master->setup = xilinx_spi_setup;
+	init_completion(&xspi->done);
+
+	xspi->irq = r_irq->start;
+
+	if (!request_mem_region(r_mem->start,
+			r_mem->end - r_mem->start + 1, XILINX_SPI_NAME)) {
+		rc = -ENXIO;
+		dev_warn(&ofdev->dev, "memory request failure\n");
+		goto put_master;
+	}
+
+	xspi->regs = ioremap(r_mem->start, r_mem->end - r_mem->start + 1);
+	if (xspi->regs == NULL) {
+		rc = -ENOMEM;
+		dev_warn(&ofdev->dev, "ioremap failure\n");
+		goto release_mem;
+	}
+	xspi->irq = r_irq->start;
+
+	/* dynamic bus assignment */
+	master->bus_num = -1;
+
+	/* number of slave select bits is required */
+	prop = of_get_property(ofdev->node, "xlnx,num-ss-bits", &len);
+	if (!prop || len < sizeof(*prop)) {
+		dev_warn(&ofdev->dev, "no 'xlnx,num-ss-bits' property\n");
+		goto unmap_io;
+	}
+	master->num_chipselect = *prop;
+
+	/* SPI controller initializations */
+	xspi_init_hw(xspi->regs);
+
+	/* Register for SPI Interrupt */
+	rc = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi);
+	if (rc != 0) {
+		dev_warn(&ofdev->dev, "irq request failure: %d\n", xspi->irq);
+		goto unmap_io;
+	}
+
+	rc = spi_bitbang_start(&xspi->bitbang);
+	if (rc != 0) {
+		dev_err(&ofdev->dev, "spi_bitbang_start FAILED\n");
+		goto free_irq;
+	}
+
+	dev_info(&ofdev->dev, "at 0x%08X mapped to 0x%08X, irq=%d\n",
+			(unsigned int)r_mem->start, (u32)xspi->regs, xspi->irq);
+
+	/* Add any subnodes on the SPI bus */
+	of_register_spi_devices(master, ofdev->node);
+
+	return rc;
+
+free_irq:
+	free_irq(xspi->irq, xspi);
+unmap_io:
+	iounmap(xspi->regs);
+release_mem:
+	release_mem_region(r_mem->start, resource_size(r_mem));
+put_master:
+	spi_master_put(master);
+	return rc;
+}
+
+static int __devexit xilinx_spi_remove(struct of_device *ofdev)
+{
+	struct xilinx_spi *xspi;
+	struct spi_master *master;
+	struct resource r_mem;
+
+	master = platform_get_drvdata(ofdev);
+	xspi = spi_master_get_devdata(master);
+
+	spi_bitbang_stop(&xspi->bitbang);
+	free_irq(xspi->irq, xspi);
+	iounmap(xspi->regs);
+	if (!of_address_to_resource(ofdev->node, 0, &r_mem))
+		release_mem_region(r_mem.start, resource_size(&r_mem));
+	dev_set_drvdata(&ofdev->dev, 0);
+	spi_master_put(xspi->bitbang.master);
+
+	return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:" XILINX_SPI_NAME);
+
+static int __exit xilinx_spi_of_remove(struct of_device *op)
+{
+	return xilinx_spi_remove(op);
+}
+
+static struct of_device_id xilinx_spi_of_match[] = {
+	{ .compatible = "xlnx,xps-spi-2.00.a", },
+	{ .compatible = "xlnx,xps-spi-2.00.b", },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, xilinx_spi_of_match);
+
+static struct of_platform_driver xilinx_spi_of_driver = {
+	.owner = THIS_MODULE,
+	.name = "xilinx-xps-spi",
+	.match_table = xilinx_spi_of_match,
+	.probe = xilinx_spi_of_probe,
+	.remove = __exit_p(xilinx_spi_of_remove),
+	.driver = {
+		.name = "xilinx-xps-spi",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init xilinx_spi_init(void)
+{
+	return of_register_platform_driver(&xilinx_spi_of_driver);
+}
+module_init(xilinx_spi_init);
+
+static void __exit xilinx_spi_exit(void)
+{
+	of_unregister_platform_driver(&xilinx_spi_of_driver);
+}
+module_exit(xilinx_spi_exit);
+MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
+MODULE_DESCRIPTION("Xilinx SPI driver");
+MODULE_LICENSE("GPL");