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satip-axe/kernel/drivers/i2c/busses/i2c-stm.c

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/*
* --------------------------------------------------------------------
*
* i2c-stm.c
* i2c algorithms for STMicroelectronics device
* Version: 2.0 (1 April 2007)
* Version: 2.0.1 (20 Dec 2007)
* + Removed the ssc layer.
* Version: 2.1 (3 Jan 2008)
* + Added the timing glitch suppression support
* Version: 2.2 (25th Apr 2008)
* + Added hardware glitch filter support
* + Improved reset and register configuration
* + Switch to using FIFO mode all the time
* + Use standard I2C clock settings
* + Adjust baud rate to give true 100/400 kHz operation
* + Fix bug in clock rounding
* + Use stpio_request_set_pin on init to set SDA and SCL to high
* + Fix compile-time warnings
* Version: 2.3 (9th Mar 2008)
* + Added manual PIO reset on arbitration/slave mode detection
* + Ensure that clock stretching is always cleared (even in 1 byte read)
* + Check for an unexpected stop condition on the bus
* + Fix auto-retry on address error condition
* + Clear repstart bit
* Version 2.4 (23rd Jul 2008)
* + Remove clock stretch check
* + Improve manual PIO reset
* + Add delay after stop to ensure I2C tBUF satisfied
* + Clear SSC status after reset
* + Reorder TX & I2C config register pokes in prepare to read phase
* Version 2.5 (24th Oct 2008) Carl Shaw <carl.shaw@st.com>
* + Rewrite START state - in case of write it now preloads TX FIFO
* and it is also shared for REPSTART address
* + Change RX prepare - checks for NACK, reads address and then falls
* through to read state
* + Change RX state - Use TEEN interrupt to reduce unnecessary interrupt
* loading. Previously, RIR was used which generated
* an interrupt per byte
* + Change TX state - correctly unload RX FIFO (using both FIFO status
* AND RIR bit)
* - use TEEN interrupt rather than TIR
* + Change repstart address - just call START state but suppress STARTG
* + Only use PIO recovery as last-ditch effort
* + Fix retry method
* + Add auto retry in case of arbitration problem
* + Allow a PIO mode for clock of push-pull rather than BIDIR. This
* can help with spurious noise glitches on the SCK line and in the
* case where SCK rise times are marginal due to capacitance on the
* bus.
* Version 2.6 (1 Apr 2010) Francesco Virlinzi <francesco.virlinzi@st.com>
* + Added the new state (IDLE) in the i2c fsm.
* Now each transaction completed with a STOP condition
* leaves the SSC in I2C-Slave more. In this state the SSC
* seems less sensible to the noise on the bus.
* Version 2.7 (01 Jun 2010) Bruno Strudel <bruno.strudel@st.com>
* + Fixed the IIC_FSM_REPSTART_ADDR to wait in case of clock stretching
*
* --------------------------------------------------------------------
*
* Copyright (C) 2006 - 2010 STMicroelectronics
* Author: Francesco Virlinzi <francesco.virlinzi@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.
*
*/
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/pm_runtime.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/errno.h>
#include <linux/stm/platform.h>
#include <linux/stm/ssc.h>
#include "i2c-stm.h"
#undef dbg_print
#ifdef CONFIG_I2C_DEBUG_BUS
#define dbg_print(fmt, args...) \
printk(KERN_DEBUG "%s: " fmt, __func__ , ## args)
#else
#define dbg_print(fmt, args...)
#endif
#undef dbg_print2
#ifdef CONFIG_I2C_DEBUG_ALGO
#define dbg_print2(fmt, args...) \
printk(KERN_DEBUG "%s: " fmt, __func__ , ## args)
#else
#define dbg_print2(fmt, args...)
#endif
/* --- Defines for I2C --- */
/* These values WILL produce physical clocks which are slower */
/* Especially if hardware glitch suppression is enabled */
/* They should probably be made board dependent? */
#define I2C_RATE_NORMAL 100000
#define I2C_RATE_FASTMODE 400000
#define NANOSEC_PER_SEC 1000000000
/* Standard I2C timings */
#define REP_START_HOLD_TIME_NORMAL 4000
#define START_HOLD_TIME_NORMAL 4000
#define REP_START_SETUP_TIME_NORMAL 4700
#define DATA_SETUP_TIME_NORMAL 250
#define STOP_SETUP_TIME_NORMAL 4000
#define BUS_FREE_TIME_NORMAL 4700
#define REP_START_HOLD_TIME_FAST 600
#define START_HOLD_TIME_FAST 600
#define REP_START_SETUP_TIME_FAST 600
#define DATA_SETUP_TIME_FAST 100
#define STOP_SETUP_TIME_FAST 600
#define BUS_FREE_TIME_FAST 1300
/* Define for glitch suppression support */
#ifdef CONFIG_I2C_STM_GLITCH_SUPPORT
#if CONFIG_GLITCH_CLK_WIDTH > 0
#define GLITCH_WIDTH_CLOCK CONFIG_GLITCH_CLK_WIDTH
#else
#define GLITCH_WIDTH_CLOCK 500 /* in nanosecs */
#endif
#if CONFIG_GLITCH_DATA_WIDTH > 0
#define GLITCH_WIDTH_DATA CONFIG_GLITCH_DATA_WIDTH
#else
#define GLITCH_WIDTH_DATA 500 /* in nanosecs */
#endif
#else
#define GLITCH_WIDTH_DATA 0
#define GLITCH_WIDTH_CLOCK 0
#endif
#ifdef CONFIG_I2C_STM_HW_GLITCH
#if CONFIG_HW_GLITCH_WIDTH > 0
#define HW_GLITCH_WIDTH CONFIG_HW_GLITCH_WIDTH
#else
#define HW_GLITCH_WIDTH 1 /* in microseconds */
#endif
#endif
/* To manage normal vs fast mode */
#define IIC_STM_CONFIG_SPEED_MASK 0x1
#define IIC_STM_CONFIG_SPEED_FAST 0x1
#define IIC_STM_READY_SPEED_MASK 0x2
#define IIC_STM_READY_SPEED_FAST 0x2
enum iic_state_machine {
IIC_FSM_VOID = 0,
IIC_FSM_IDLE,
IIC_FSM_PREPARE,
IIC_FSM_NOREPSTART,
IIC_FSM_START,
IIC_FSM_DATA_WRITE,
IIC_FSM_PREPARE_2_READ,
IIC_FSM_DATA_READ,
IIC_FSM_STOP,
IIC_FSM_COMPLETE,
IIC_FSM_REPSTART,
IIC_FSM_REPSTART_ADDR,
IIC_FSM_ABORT
};
#ifdef CONFIG_I2C_DEBUG_ALGO
char *statename[] = {
"VOID", "PREPARE", "START", "DATA_WRITE", "PREPARE_2_READ",
"DATA_READ", "STOP", "COMPLETE", "REPSTART", "REPSTART_ADDR", "ABORT"
};
#endif
enum iic_fsm_error {
IIC_E_NO_ERROR = 0x0,
IIC_E_RUNNING = 0x1,
IIC_E_NOTACK = 0x2,
IIC_E_ARBL = 0x4,
IIC_E_BUSY = 0x8
};
/*
* With the struct iic_transaction more information
* on the required transaction are moved on
* the thread stack instead of (iic_ssc) adapter descriptor...
*/
struct iic_transaction {
enum iic_state_machine start_state;
enum iic_state_machine state;
enum iic_state_machine next_state;
struct i2c_msg *msgs_queue;
int attempt;
int queue_length;
int current_msg; /* the message on going */
int idx_current_msg; /* the byte in the message */
enum iic_fsm_error status_error;
int waitcondition;
};
struct iic_ssc {
void __iomem *base;
struct clk *clk;
struct iic_transaction *trns;
struct i2c_adapter adapter;
unsigned long config;
wait_queue_head_t wait_queue;
struct stm_pad_state *pad_state;
};
#define jump_on_fsm_start(x) { (x)->state = IIC_FSM_START; \
goto be_fsm_start; }
#define jump_on_fsm_stop(x) do { (x)->state = IIC_FSM_STOP; \
goto be_fsm_stop; } while (0)
#define jump_on_fsm_abort(x) do { (x)->state = IIC_FSM_ABORT; \
goto be_fsm_abort; } while (0)
#define jump_on_fsm_complete(x) { (x)->state = IIC_FSM_STOP; \
goto be_fsm_complete; }
#define check_fastmode(adap) \
(!!((adap)->config & IIC_STM_CONFIG_SPEED_MASK))
#define check_ready_fastmode(adap) \
(!!((adap)->config & IIC_STM_READY_SPEED_FAST))
#define set_ready_fastmode(adap) ((adap)->config |= IIC_STM_READY_SPEED_FAST)
#define clear_ready_fastmode(adap) ((adap)->config &= ~IIC_STM_READY_SPEED_FAST)
#if defined(CONFIG_I2C_STM_NOSTOP_API)
#define LAST_I2C_WAS_NO_STOP 0x4
#define LAST_I2C_WAS_NO_STOP_MASK 0x4
#define check_lasti2cwas_nostop(adap) (((adap)->config & \
LAST_I2C_WAS_NO_STOP_MASK) ? 1 : 0 )
#define set_lasti2cwas_nostop(adap) ((adap)->config |= LAST_I2C_WAS_NO_STOP)
#define clear_lasti2cwas_nostop(adap) ((adap)->config &= ~LAST_I2C_WAS_NO_STOP_MASK)
#else
#define check_lasti2cwas_nostop(adap) (1==0)
#define set_lasti2cwas_nostop(adap) {}
#define clear_lasti2cwas_nostop(adap) {}
#endif
static void iic_stm_setup_timing(struct iic_ssc *adap);
static irqreturn_t iic_state_machine(int this_irq, void *data)
{
struct iic_ssc *adap = (struct iic_ssc *)data;
struct iic_transaction *trsc = adap->trns;
unsigned int status;
unsigned int idx, previntmask, lim, intflags, conflags = 0;
#ifdef CONFIG_I2C_DEBUG_ALGO
unsigned int cw;
#endif
unsigned short address;
struct i2c_msg *pmsg;
char fast_mode;
union {
char bytes[2];
unsigned short word;
} tmp;
unsigned short txbuff[SSC_TXFIFO_SIZE];
unsigned int txbuffcount;
unsigned int cnt = 0;
fast_mode = check_fastmode(adap);
pmsg = trsc->msgs_queue + trsc->current_msg;
/* Disable interrupts */
previntmask = ssc_load32(adap, SSC_IEN);
ssc_store32(adap, SSC_IEN, 0);
status = ssc_load32(adap, SSC_STA);
dbg_print2("ISR status = 0x%08x\n", status);
/*
* Slave mode detection
* this should never happen as we don't support multi-master
*/
if (trsc->state > IIC_FSM_START && ((status & SSC_STA_ARBL)
|| !(ssc_load32(adap, SSC_CTL) &
SSC_CTL_MS))) {
dbg_print2("SLAVE mode (state %d, status %08x)\n",
trsc->state, status);
dbg_print2(" Message [%d of %d] is %s address 0x%02x bus %d\n",
trsc->current_msg + 1, trsc->queue_length,
(pmsg->flags & I2C_M_RD) ? "READ from" : "WRITE to",
pmsg->addr, adap->adapter.nr);
dbg_print2
(" data is %d bytes, currently at %d, last 0x%02x\n",
pmsg->len, trsc->idx_current_msg,
(trsc->idx_current_msg >
0) ? pmsg->buf[trsc->idx_current_msg - 1] : 0);
dbg_print2("Prev State: %s Changing to state: %s \n",
statename[trsc->state], statename[trsc->next_state]);
dbg_print2
("Status: 0x%08x SSC_IEN 0x%08x "
"SSC_CTL 0x%08x SSC_I2C 0x%08x\n",
status, previntmask, ssc_load32(adap, SSC_CTL),
ssc_load32(adap, SSC_I2C));
trsc->status_error = IIC_E_ARBL;
ssc_store32(adap, SSC_CLR, 0xdc0);
trsc->waitcondition = 0;
wake_up(&(adap->wait_queue));
return IRQ_HANDLED;
}
trsc->state = trsc->next_state;
switch (trsc->state) {
case IIC_FSM_PREPARE:
dbg_print2("-Prepare\n");
if (check_lasti2cwas_nostop(adap)) {
clear_lasti2cwas_nostop(adap);
/* repstart */
dbg_print(" STOP - REPSTART\n");
trsc->next_state = IIC_FSM_REPSTART_ADDR;
ssc_store32(adap, SSC_I2C,
SSC_I2C_I2CM |
SSC_I2C_TXENB |
SSC_I2C_REPSTRTG);
ssc_store32(adap, SSC_IEN,
SSC_IEN_REPSTRTEN |
SSC_IEN_ARBLEN);
break;
}
/*
* check if the i2c timing register
* of ssc are ready to use
*/
if ((check_fastmode(adap) && !check_ready_fastmode(adap)) ||
(!check_fastmode(adap) && check_ready_fastmode(adap)))
iic_stm_setup_timing(adap);
trsc->start_state = IIC_FSM_START;
/* Enable RX FIFO, enable clock stretch on TX empty */
ssc_store32(adap, SSC_CTL, SSC_CTL_EN | SSC_CTL_MS |
SSC_CTL_PO | SSC_CTL_PH | SSC_CTL_HB | 0x8 |
SSC_CTL_EN_RX_FIFO | SSC_CTL_EN_TX_FIFO);
ssc_store32(adap, SSC_I2C, SSC_I2C_I2CM);
/* NO break! */
case IIC_FSM_NOREPSTART:
ssc_store32(adap, SSC_CLR, 0xdc0);
trsc->state = IIC_FSM_START;
conflags = SSC_I2C_STRTG;
if (!check_fastmode(adap))
ndelay(4000);
else
ndelay(700);
/* NO break! */
case IIC_FSM_START:
be_fsm_start:
dbg_print2("-Start address 0x%x\n", pmsg->addr);
trsc->idx_current_msg = 0;
address = (pmsg->addr << 2) | 0x1;
if (pmsg->flags & I2C_M_RD) {
dbg_print2(" Reading %d bytes\n", pmsg->len);
address |= 0x2;
trsc->next_state = IIC_FSM_PREPARE_2_READ;
intflags =
SSC_IEN_NACKEN | SSC_IEN_TEEN | SSC_IEN_ARBLEN;
txbuff[0] = address;
txbuffcount = 1;
} else {
trsc->next_state = IIC_FSM_DATA_WRITE;
intflags =
SSC_IEN_NACKEN | SSC_IEN_TEEN | SSC_IEN_ARBLEN;
dbg_print2("-Writing %d bytes\n", pmsg->len);
txbuff[0] = address;
txbuffcount = 1;
idx = SSC_TXFIFO_SIZE - 1;
dbg_print2(" TX FIFO %d empty slots\n", idx);
/* In the write case, we also preload the TX buffer
* with some data to reduce the interrupt loading
*/
while (idx && trsc->idx_current_msg < pmsg->len) {
tmp.bytes[0] =
pmsg->buf[trsc->idx_current_msg++];
txbuff[txbuffcount] = tmp.word << 1 | 0x1;
dbg_print2(" write 0x%02x\n", tmp.bytes[0]);
txbuffcount++;
idx--;
}
}
/* drive SDA... */
ssc_store32(adap, SSC_I2C, SSC_I2C_I2CM | SSC_I2C_TXENB);
for (idx = 0; idx < txbuffcount; idx++)
ssc_store32(adap, SSC_TBUF, txbuff[idx]);
ssc_store32(adap, SSC_IEN, intflags);
/* Check for bus busy. This shouldn't happen but if the RX
* FIFOs are not empty in the last transaction BEFORE the SSC
* reset occurs, then we get a BUSY error here...
*/
if (trsc->start_state != IIC_FSM_REPSTART) {
if (ssc_load32(adap, SSC_STA) & SSC_STA_BUSY) {
dbg_print2(" bus BUSY!\n");
trsc->waitcondition = 0;
trsc->status_error = IIC_E_BUSY;
} else {
/* START! */
ssc_store32(adap, SSC_I2C,
SSC_I2C_I2CM | SSC_I2C_TXENB |
conflags);
}
}
break;
case IIC_FSM_REPSTART_ADDR:
dbg_print2("-Rep Start addr 0x%x\n", pmsg->addr);
/* Check that slave is not doing a clock stretch */
while (((ssc_load32(adap, SSC_STA) & SSC_STA_CLST)
!= SSC_STA_CLST) && (cnt++ < 1000))
ndelay(100);
if (cnt >= 1000)
jump_on_fsm_abort(trsc);
/* Check that slave is not doing a clock stretching */
while(((ssc_load32(adap, SSC_STA) & SSC_STA_CLST) != SSC_STA_CLST) &&
(cnt++<1000));
if(cnt>=1000){
jump_on_fsm_abort(trsc);
}
/* Clear NACK */
ssc_store32(adap, SSC_CLR, 0xdc0);
trsc->start_state = IIC_FSM_REPSTART;
conflags = 0;
jump_on_fsm_start(trsc);
case IIC_FSM_PREPARE_2_READ:
dbg_print2("-Prepare to Read...\n");
/* Read address */
ssc_load32(adap, SSC_RBUF);
/* Check for NACK */
if (status & SSC_STA_NACK) {
dbg_print2(" read: NACK detected\n");
jump_on_fsm_abort(trsc);
}
ssc_store32(adap, SSC_I2C, SSC_I2C_I2CM | SSC_I2C_ACKG);
trsc->next_state = IIC_FSM_DATA_READ;
/* NO break */
case IIC_FSM_DATA_READ:
dbg_print2("-Read\n");
/* Clear the RX buffer */
idx = (ssc_load32(adap, SSC_RX_FSTAT) & SSC_RX_FSTAT_STATUS);
if (!idx && (ssc_load32(adap, SSC_STA) & SSC_STA_RIR))
idx = SSC_RXFIFO_SIZE;
dbg_print2(" Rx %d bytes in FIFO...\n", idx);
while (idx && trsc->idx_current_msg < pmsg->len) {
tmp.word = ssc_load32(adap, SSC_RBUF);
tmp.word = tmp.word >> 1;
pmsg->buf[trsc->idx_current_msg++] = tmp.bytes[0];
dbg_print2(" Rx Data 0x%02x\n", tmp.bytes[0] & 0xff);
idx--;
}
/* If end of RX, issue STOP or REPSTART */
if (trsc->idx_current_msg == pmsg->len)
jump_on_fsm_stop(trsc);
/* Generate clock for another set of bytes.
* We have to process the last byte separately as we need to
* NOT generate an ACK
*/
if (trsc->idx_current_msg == (pmsg->len - 1)) {
/* last byte - disable ACKG */
dbg_print2(" Rx last byte\n");
ssc_store32(adap, SSC_I2C, SSC_I2C_I2CM);
ssc_store32(adap, SSC_IEN,
SSC_IEN_NACKEN | SSC_IEN_ARBLEN);
ssc_store32(adap, SSC_TBUF, 0x1ff);
} else {
#ifdef CONFIG_I2C_DEBUG_ALGO
cw = 0;
#endif
idx = SSC_TXFIFO_SIZE;
dbg_print2(" idx=%d status=0x%08x\n", idx,
ssc_load32(adap, SSC_STA));
while (idx
&& (trsc->idx_current_msg +
(SSC_TXFIFO_SIZE - idx)) < (pmsg->len - 1)) {
ssc_store32(adap, SSC_TBUF, 0x1ff);
#ifdef CONFIG_I2C_DEBUG_ALGO
cw++;
#endif
idx--;
}
dbg_print2("Clock writes: %d\n", cw);
/* only take one interrupt when transmit FIFO empty! */
ssc_store32(adap, SSC_IEN,
SSC_IEN_ARBLEN | SSC_IEN_TEEN);
}
break;
case IIC_FSM_DATA_WRITE:
dbg_print2("-Write\n");
/* Clear RX data from FIFO */
/* It is not clear from the SSC4 datasheet, but the RX_FSTAT
* register does not tell the whole story... if RIR is set in
* the STATUS reg then we need to read 8 words. RX_FSTAT only
* notifies us of at most 7 words - hence the extra check below
*/
lim = ssc_load32(adap, SSC_RX_FSTAT) & SSC_RX_FSTAT_STATUS;
if (!lim && (status & SSC_STA_RIR))
lim = 8;
dbg_print2(" clearing %d RX words\n", lim);
for (idx = 0; idx < lim; idx++)
ssc_load32(adap, SSC_RBUF);
/* Clear status bits EXCEPT NACK */
ssc_store32(adap, SSC_CLR, 0x9c0);
/* Check for NACK */
status = ssc_load32(adap, SSC_STA);
dbg_print2("write: status = 0x%08x\n", status);
if (status & SSC_STA_NACK) {
dbg_print2(" NACK detected\n");
jump_on_fsm_abort(trsc);
}
/* If end of TX, issue STOP or REPSTART */
if (trsc->idx_current_msg == pmsg->len)
jump_on_fsm_stop(trsc);
trsc->next_state = IIC_FSM_DATA_WRITE;
/* Interrupt when TX buffer empty */
ssc_store32(adap, SSC_IEN,
SSC_IEN_TEEN | SSC_IEN_NACKEN | SSC_IEN_ARBLEN);
idx = SSC_TXFIFO_SIZE;
while (idx && trsc->idx_current_msg < pmsg->len) {
tmp.bytes[0] = pmsg->buf[trsc->idx_current_msg++];
ssc_store32(adap, SSC_TBUF, tmp.word << 1 | 0x1);
dbg_print2(" Write 0x%02x\n", tmp.bytes[0]);
idx--;
}
break;
case IIC_FSM_ABORT:
be_fsm_abort:
dbg_print2("Abort - issuing STOP\n");
trsc->status_error |= IIC_E_NOTACK;
ssc_store32(adap, SSC_CLR, 0xdc0);
trsc->next_state = IIC_FSM_IDLE;
ssc_store32(adap, SSC_IEN, SSC_IEN_STOPEN | SSC_IEN_ARBLEN);
ssc_store32(adap, SSC_I2C, SSC_I2C_I2CM | SSC_I2C_STOPG);
break;
case IIC_FSM_STOP:
be_fsm_stop:
dbg_print2("-Stop\n");
if (++trsc->current_msg < trsc->queue_length) {
/* More transactions left... */
if (pmsg->flags & I2C_M_NOREPSTART) {
/* no repstart - stop then start */
dbg_print2(" STOP - STOP\n");
trsc->next_state = IIC_FSM_NOREPSTART;
ssc_store32(adap, SSC_I2C,
SSC_I2C_I2CM | SSC_I2C_TXENB |
SSC_I2C_STOPG);
ssc_store32(adap, SSC_IEN,
SSC_IEN_STOPEN | SSC_IEN_ARBLEN);
} else {
/* repstart */
dbg_print2(" STOP - REPSTART\n");
trsc->next_state = IIC_FSM_REPSTART_ADDR;
ssc_store32(adap, SSC_I2C,
SSC_I2C_I2CM |
SSC_I2C_TXENB |
SSC_I2C_REPSTRTG);
ssc_store32(adap, SSC_IEN,
SSC_IEN_REPSTRTEN |
SSC_IEN_ARBLEN);
}
} else {
/* stop */
dbg_print2(" STOP - STOP\n");
if (pmsg->flags & I2C_M_NOSTOP &&
!(status & SSC_STA_NACK)) {
dbg_print(" STOP - NOSTOP\n");
set_lasti2cwas_nostop(adap);
jump_on_fsm_complete(trsc);
}
clear_lasti2cwas_nostop(adap);
trsc->next_state = IIC_FSM_IDLE;
ssc_store32(adap, SSC_I2C,
SSC_I2C_I2CM | SSC_I2C_TXENB |
SSC_I2C_STOPG);
ssc_store32(adap, SSC_IEN,
SSC_IEN_STOPEN | SSC_IEN_ARBLEN);
}
break;
case IIC_FSM_IDLE:
/* In Idle state the SSC still remains
* in I2C mode but with the SSC_CTL.Master mode disabled.
* In this configuration it seems much more stable
* during a plugging/unplugging of HDMI-cable
* i.e.: it is much less sensible to the noice on the cable
*/
dbg_print2("-Idle\n");
ssc_store32(adap, SSC_I2C, SSC_I2C_I2CM);
/* push the data line high */
ssc_store32(adap, SSC_TBUF, 0x1ff);
ssc_store32(adap, SSC_CTL, SSC_CTL_EN |
SSC_CTL_PO | SSC_CTL_PH | SSC_CTL_HB | 0x8);
/* No break here! */
case IIC_FSM_COMPLETE:
be_fsm_complete:
dbg_print2("-Complete\n");
if (!(trsc->status_error & IIC_E_NOTACK))
trsc->status_error = IIC_E_NO_ERROR;
trsc->waitcondition = 0;
wake_up(&(adap->wait_queue));
break;
default:
printk(KERN_ERR "i2c-stm: Error in the FSM\n");
;
}
return IRQ_HANDLED;
}
/*
* Wait for stop to be detected on bus
*/
static int iic_wait_stop_condition(struct iic_ssc *adap)
{
unsigned int idx;
dbg_print("\n");
for (idx = 0; idx < 5; ++idx) {
if (ssc_load32(adap, SSC_STA) & SSC_STA_STOP)
return 1;
mdelay(2);
}
printk(KERN_ERR "*** iic_wait_stop_condition: TIMED OUT ***\n");
return 0;
}
/*
* Reset SSC bus
*/
static void iic_ssc_reset(struct iic_ssc *adap)
{
unsigned int lim, status, idx;
/* Ensure RX buffer empty */
status = ssc_load32(adap, SSC_STA);
lim = ssc_load32(adap, SSC_RX_FSTAT) & SSC_RX_FSTAT_STATUS;
if (!lim && (status & SSC_STA_RIR))
lim = 8;
for (idx = 0; idx < lim; idx++)
ssc_load32(adap, SSC_RBUF);
/* Reset SSC */
ssc_store32(adap, SSC_CTL, SSC_CTL_SR | SSC_CTL_EN | SSC_CTL_MS |
SSC_CTL_PO | SSC_CTL_PH | SSC_CTL_HB | 0x8);
/* enable RX, TX FIFOs - clear SR bit */
ssc_store32(adap, SSC_CTL, SSC_CTL_EN | SSC_CTL_MS |
SSC_CTL_PO | SSC_CTL_PH | SSC_CTL_HB | 0x8 |
SSC_CTL_EN_TX_FIFO | SSC_CTL_EN_RX_FIFO);
}
/*
* Wait for bus to become free
*/
static int iic_wait_free_bus(struct iic_ssc *adap)
{
unsigned int reg = 0;
unsigned int idx;
dbg_print("\n");
if (check_lasti2cwas_nostop(adap)){
dbg_print("i2c-stm: wait_free_bus last transaction nostop.\n");
return 1;
}
iic_ssc_reset(adap);
for (idx = 0; idx < 10; ++idx) {
reg = ssc_load32(adap, SSC_STA);
dbg_print("iic_wait_free_bus: status = 0x%08x\n", reg);
if (!(reg & SSC_STA_BUSY))
return 1;
mdelay(2);
}
printk(KERN_ERR "*** iic_wait_free_bus: TIMED OUT ***\n");
return 0;
}
/*
* Issue stop condition on the bus by toggling PIO lines
*/
static void iic_pio_stop(struct iic_ssc *adap)
{
unsigned scl, sda;
int cnt = 0;
if (!adap->pad_state)
return; /* SSC hard wired */
printk(KERN_WARNING "i2c-stm: doing PIO stop!\n");
/* Send STOP */
scl = stm_pad_gpio_request_output(adap->pad_state, "SCL", 0);
BUG_ON(scl == STM_GPIO_INVALID);
sda = stm_pad_gpio_request_output(adap->pad_state, "SDA", 0);
BUG_ON(sda == STM_GPIO_INVALID);
udelay(20);
gpio_set_value(scl, 1);
udelay(20);
gpio_set_value(sda, 1);
udelay(30);
stm_pad_gpio_free(adap->pad_state, scl);
stm_pad_gpio_free(adap->pad_state, sda);
/* Reset SSC */
ssc_store32(adap, SSC_CTL, SSC_CTL_SR | SSC_CTL_EN | SSC_CTL_MS |
SSC_CTL_PO | SSC_CTL_PH | SSC_CTL_HB | 0x8);
ssc_store32(adap, SSC_CLR, 0xdc0);
/* Make sure SSC thinks the bus is free before continuing */
while (cnt < 10
&& (ssc_load32(adap, SSC_STA) & (SSC_STA_BUSY | SSC_STA_NACK))) {
mdelay(2);
cnt++;
}
if (cnt == 10)
printk(KERN_ERR
"i2c-stm: Cannot recover bus. Status: 0x%08x\n",
ssc_load32(adap, SSC_STA));
}
/*
* Description: Prepares the controller for a transaction
*/
static int iic_stm_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg msgs[], int num)
{
unsigned long flag;
int result;
int timeout;
#ifdef CONFIG_I2C_DEBUG_BUS
int i;
#endif
struct iic_ssc *adap =
(struct iic_ssc *)container_of(i2c_adap, struct iic_ssc, adapter);
struct iic_transaction transaction = {
.msgs_queue = msgs,
.queue_length = num,
.current_msg = 0x0,
.attempt = 0x0,
.status_error = IIC_E_RUNNING,
.next_state = IIC_FSM_PREPARE,
.waitcondition = 1,
};
dbg_print("\n");
adap->trns = &transaction;
#ifdef CONFIG_I2C_DEBUG_BUS
for (i = 0; i < num; ++i) {
if (msgs[i].len == 0)
printk(KERN_INFO
"[%d of %d] ZERO LENGTH TRANSACTION : "
"%s addr 0x%02x len %d\n",
i + 1, num,
(msgs[i].
flags & I2C_M_RD) ? "read from " :
"write to ",
msgs[i].addr, msgs[i].len);
else
printk(KERN_INFO
"[%d of %d] TRANSACTION : "
"%s addr 0x%02x len %d\n",
i + 1, num,
(msgs[i].
flags & I2C_M_RD) ? "read from " :
"write to ",
msgs[i].addr, msgs[i].len);
}
#endif /* CONFIG_I2C_DEBUG_BUS */
iic_xfer_retry:
/* Wait for bus to become free - do a forced PIO reset if necessary to
* recover the bus
*/
if (!iic_wait_free_bus(adap))
iic_pio_stop(adap);
adap->config &= ~IIC_STM_CONFIG_SPEED_MASK;
if (msgs[0].flags & I2C_M_FASTMODE)
adap->config |= IIC_STM_CONFIG_SPEED_FAST;
iic_state_machine(0, adap);
timeout = wait_event_interruptible_timeout(adap->wait_queue,
(transaction.waitcondition ==
0), i2c_adap->timeout * HZ);
local_irq_save(flag);
result = transaction.current_msg;
if (unlikely
(transaction.status_error != IIC_E_NO_ERROR || timeout <= 0)) {
dbg_print2(KERN_ERR
"xfer: ERROR status %d, timeout %d, attempt %d\n",
transaction.status_error, timeout,
transaction.attempt);
dbg_print2(KERN_ERR
"Status: 0x%08x SSC_IEN 0x%08x "
"SSC_CTL 0x%08x SSC_I2C 0x%08x\n",
ssc_load32(adap, SSC_STA), ssc_load32(adap, SSC_IEN),
ssc_load32(adap, SSC_CTL), ssc_load32(adap,
SSC_I2C));
if (((transaction.status_error & IIC_E_NOTACK)
&& transaction.start_state == IIC_FSM_START)
|| (transaction.status_error & IIC_E_BUSY)) {
clear_lasti2cwas_nostop(adap);
if (++transaction.attempt <= adap->adapter.retries) {
dbg_print2("RETRYING operation\n");
/*
* Error on the address - automatically retry
*
* This used to be done in the FSM complete
* but it was not safe there as we need to
* wait for the bus to not be busy before
* doing another transaction
*/
transaction.status_error = 0;
transaction.next_state = IIC_FSM_START;
transaction.waitcondition = 1;
local_irq_restore(flag);
goto iic_xfer_retry;
} else {
local_irq_restore(flag);
if (transaction.status_error & IIC_E_NOTACK) {
dbg_print("Error: Slave NACK\n");
result = -EREMOTEIO;
} else {
dbg_print("Error: Bus BUSY\n");
result = -EBUSY;
}
}
} else if (transaction.status_error == IIC_E_ARBL
|| (ssc_load32(adap, SSC_CTL) & SSC_CTL_MS) == 0) {
/* Arbitration error */
printk(KERN_ERR "i2c-stm: arbitration error\n");
ssc_store32(adap, SSC_CLR, SSC_CLR_SSCARBL);
ssc_store32(adap, SSC_CTL,
ssc_load32(adap, SSC_CTL) | SSC_CTL_MS);
transaction.status_error = 0;
transaction.next_state = IIC_FSM_START;
transaction.waitcondition = 1;
local_irq_restore(flag);
if (!iic_wait_free_bus(adap)) {
/* Last ditch effort */
iic_pio_stop(adap);
}
clear_lasti2cwas_nostop(adap);
if (++transaction.attempt <= adap->adapter.retries) {
dbg_print2("RETRYING operation\n");
goto iic_xfer_retry;
}
} else {
/* There was another problem */
if (timeout <= 0) {
/* There was a timeout or signal.
- disable the interrupt
- generate a stop condition on the bus
all this task are done without interrupt....
*/
dbg_print
("xfer: Wait cnd err %d, status error %d\n",
timeout, transaction.status_error);
ssc_store32(adap, SSC_IEN, 0x0);
/* Check if bus free */
if (!iic_wait_free_bus(adap)) {
/* No - generate stop condition */
ssc_store32(adap, SSC_I2C,
SSC_I2C_I2CM | SSC_I2C_STOPG
| SSC_I2C_TXENB);
local_irq_restore(flag);
if (!iic_wait_stop_condition(adap)) {
/* Reset SSC */
ssc_store32(adap, SSC_CTL,
SSC_CTL_SR |
SSC_CTL_EN |
SSC_CTL_MS |
SSC_CTL_PO |
SSC_CTL_PH |
SSC_CTL_HB | 0x8);
ssc_store32(adap, SSC_CLR,
0xdc0);
if (!iic_wait_free_bus(adap)) {
/* Last ditch effort */
iic_pio_stop(adap);
}
}
} else {
local_irq_restore(flag);
}
clear_lasti2cwas_nostop(adap);
} else
local_irq_restore(flag);
if (!timeout) {
dbg_print
("i2c-stm: Error timeout in the FSM\n");
result = -ETIMEDOUT;
} else if (timeout < 0) {
dbg_print
("i2c-stm: wait event interrupt/error\n");
result = timeout;
} else {
dbg_print("i2c-stm: slave failed to respond\n");
result = -EREMOTEIO;
}
}
} else
local_irq_restore(flag);
#ifdef CONFIG_I2C_DEBUG_BUS
printk(KERN_INFO "i2c-stm: i2c_stm_xfer returned %d\n", result);
#endif
return result;
}
#ifdef CONFIG_I2C_DEBUG_BUS
static void iic_stm_timing_trace(struct iic_ssc *adap)
{
dbg_print("SSC_BRG %d\n", ssc_load32(adap, SSC_BRG));
dbg_print("SSC_REP_START_HOLD %d\n",
ssc_load32(adap, SSC_REP_START_HOLD));
dbg_print("SSC_REP_START_SETUP %d\n",
ssc_load32(adap, SSC_REP_START_SETUP));
dbg_print("SSC_START_HOLD %d\n", ssc_load32(adap, SSC_START_HOLD));
dbg_print("SSC_DATA_SETUP %d\n", ssc_load32(adap, SSC_DATA_SETUP));
dbg_print("SSC_STOP_SETUP %d\n", ssc_load32(adap, SSC_STOP_SETUP));
dbg_print("SSC_BUS_FREE %d\n", ssc_load32(adap, SSC_BUS_FREE));
dbg_print("SSC_PRE_SCALER_BRG %d\n",
ssc_load32(adap, SSC_PRE_SCALER_BRG));
dbg_print("SSC_NOISE_SUPP_WIDTH %d\n",
ssc_load32(adap, SSC_NOISE_SUPP_WIDTH));
dbg_print("SSC_PRSCALER %d\n", ssc_load32(adap, SSC_PRSCALER));
dbg_print("SSC_NOISE_SUPP_WIDTH_DATAOUT %d\n",
ssc_load32(adap, SSC_NOISE_SUPP_WIDTH_DATAOUT));
dbg_print("SSC_PRSCALER_DATAOUT %d\n",
ssc_load32(adap, SSC_PRSCALER_DATAOUT));
}
#endif
static void iic_stm_setup_timing(struct iic_ssc *adap)
{
unsigned long iic_baudrate;
unsigned short iic_rep_start_hold;
unsigned short iic_start_hold;
unsigned short iic_rep_start_setup;
unsigned short iic_data_setup;
unsigned short iic_stop_setup;
unsigned short iic_bus_free;
unsigned short iic_pre_scale_baudrate = 1;
#ifdef CONFIG_I2C_STM_HW_GLITCH
unsigned short iic_glitch_width;
unsigned short iic_glitch_width_dataout;
unsigned char iic_prescaler;
unsigned short iic_prescaler_dataout;
#endif
unsigned long ns_per_clk, clock ;
dbg_print("Assuming %lu MHz for the Timing Setup\n", clock / 1000000);
clock = clk_get_rate(adap->clk) + 500000; /* +0.5 Mhz for rounding */
ns_per_clk = NANOSEC_PER_SEC / clock;
printk("stm i2c clock = %lu, ns_per_clk = %lu\n", clock, ns_per_clk);
clock = clock / 2;
ns_per_clk = NANOSEC_PER_SEC / clock;
printk("stm i2c modified clock = %lu, ns_per_clk = %lu\n", clock, ns_per_clk);
if (check_fastmode(adap)) {
set_ready_fastmode(adap);
iic_baudrate = clock / (2 * I2C_RATE_FASTMODE);
iic_rep_start_hold =
(REP_START_HOLD_TIME_FAST + GLITCH_WIDTH_DATA) / ns_per_clk;
iic_rep_start_setup =
(REP_START_SETUP_TIME_FAST +
GLITCH_WIDTH_CLOCK) / ns_per_clk;
if (GLITCH_WIDTH_DATA < 200)
iic_start_hold =
(START_HOLD_TIME_FAST +
GLITCH_WIDTH_DATA) / ns_per_clk;
else
iic_start_hold = (5 * GLITCH_WIDTH_DATA) / ns_per_clk;
iic_data_setup =
(DATA_SETUP_TIME_FAST + GLITCH_WIDTH_DATA) / ns_per_clk;
iic_stop_setup =
(STOP_SETUP_TIME_FAST + GLITCH_WIDTH_CLOCK) / ns_per_clk;
iic_bus_free =
(BUS_FREE_TIME_FAST + GLITCH_WIDTH_DATA) / ns_per_clk;
} else {
clear_ready_fastmode(adap);
iic_baudrate = clock / (2 * I2C_RATE_NORMAL);
iic_rep_start_hold =
(REP_START_HOLD_TIME_NORMAL +
GLITCH_WIDTH_DATA) / ns_per_clk;
iic_rep_start_setup =
(REP_START_SETUP_TIME_NORMAL +
GLITCH_WIDTH_CLOCK) / ns_per_clk;
if (GLITCH_WIDTH_DATA < 1200)
iic_start_hold =
(START_HOLD_TIME_NORMAL +
GLITCH_WIDTH_DATA) / ns_per_clk;
else
iic_start_hold = (5 * GLITCH_WIDTH_DATA) / ns_per_clk;
iic_data_setup =
(DATA_SETUP_TIME_NORMAL + GLITCH_WIDTH_DATA) / ns_per_clk;
iic_stop_setup =
(STOP_SETUP_TIME_NORMAL + GLITCH_WIDTH_CLOCK) / ns_per_clk;
iic_bus_free =
(BUS_FREE_TIME_NORMAL + GLITCH_WIDTH_DATA) / ns_per_clk;
}
/* set baudrate */
ssc_store32(adap, SSC_BRG, iic_baudrate);
ssc_store32(adap, SSC_PRE_SCALER_BRG, iic_pre_scale_baudrate);
/* enable I2C mode */
ssc_store32(adap, SSC_I2C, SSC_I2C_I2CM);
/* set other timings */
ssc_store32(adap, SSC_REP_START_HOLD, iic_rep_start_hold);
ssc_store32(adap, SSC_START_HOLD, iic_start_hold);
ssc_store32(adap, SSC_REP_START_SETUP, iic_rep_start_setup);
ssc_store32(adap, SSC_DATA_SETUP, iic_data_setup);
ssc_store32(adap, SSC_STOP_SETUP, iic_stop_setup);
ssc_store32(adap, SSC_BUS_FREE, iic_bus_free);
/*
* Set Slave Address to allow 'General Call'
*/
ssc_store32(adap, SSC_SLAD, 0x7f);
#ifdef CONFIG_I2C_STM_HW_GLITCH
/* See DDTS GNBvd40668 */
iic_prescaler = 1;
iic_glitch_width = HW_GLITCH_WIDTH * clock / 100000000; /* in uS */
iic_glitch_width_dataout = 1;
iic_prescaler_dataout = clock / 10000000;
/* This should work, but causes lock-up after repstart
iic_prescaler = clock / 10000000;
iic_glitch_width = HW_GLITCH_WIDTH;
iic_glitch_width_dataout = 1;
iic_prescaler_dataout = clock / 10000000;
printk("*** iic_prescaler = %d *** \n", iic_prescaler);
*/
ssc_store32(adap, SSC_PRSCALER, iic_prescaler);
ssc_store32(adap, SSC_NOISE_SUPP_WIDTH, iic_glitch_width);
ssc_store32(adap, SSC_NOISE_SUPP_WIDTH_DATAOUT,
iic_glitch_width_dataout);
ssc_store32(adap, SSC_PRSCALER_DATAOUT, iic_prescaler_dataout);
#else
/* disable SSC glitch filter */
ssc_store32(adap, SSC_NOISE_SUPP_WIDTH, 0);
#endif
#ifdef CONFIG_I2C_DEBUG_BUS
iic_stm_timing_trace(adap);
#endif
return;
}
static int iic_stm_control(struct i2c_adapter *adapter,
unsigned int cmd, unsigned long arg)
{
struct iic_ssc *iic_adap =
container_of(adapter, struct iic_ssc, adapter);
switch (cmd) {
case I2C_STM_IOCTL_FAST:
dbg_print("ioctl fast 0x%lx\n", arg);
iic_adap->config &= ~IIC_STM_CONFIG_SPEED_MASK;
if (arg)
iic_adap->config |= IIC_STM_CONFIG_SPEED_FAST;
break;
default:
printk(KERN_WARNING " %s: i2c-ioctl not managed\n",
__func__);
}
return 0;
}
static u32 iic_stm_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static struct i2c_algorithm iic_stm_algo = {
.master_xfer = iic_stm_xfer,
.functionality = iic_stm_func,
/* .algo_control = iic_stm_control */
};
static ssize_t iic_bus_show_fastmode(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_adapter *adapter =
container_of(dev, struct i2c_adapter, dev);
struct iic_ssc *iic_stm =
container_of(adapter, struct iic_ssc, adapter);
return sprintf(buf, "%u\n", check_fastmode(iic_stm));
}
static ssize_t iic_bus_store_fastmode(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_adapter *adapter =
container_of(dev, struct i2c_adapter, dev);
unsigned long val = strict_strtoul(buf, 10, NULL);
iic_stm_control(adapter, I2C_STM_IOCTL_FAST, val);
return count;
}
static DEVICE_ATTR(fastmode, S_IRUGO | S_IWUSR, iic_bus_show_fastmode,
iic_bus_store_fastmode);
static int __init iic_stm_probe(struct platform_device *pdev)
{
struct stm_plat_ssc_data *plat_data = pdev->dev.platform_data;
struct iic_ssc *i2c_stm;
struct resource *res;
int err;
i2c_stm = devm_kzalloc(&pdev->dev, sizeof(struct iic_ssc), GFP_KERNEL);
if (!i2c_stm)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
if (!devm_request_mem_region
(&pdev->dev, res->start, resource_size(res), "i2c")) {
dev_err(&pdev->dev, "Request mem region %pR failed\n", res);
return -ENOMEM;
}
i2c_stm->base = devm_ioremap_nocache(&pdev->dev, res->start,
resource_size(res));
if (!i2c_stm->base) {
dev_err(&pdev->dev, "ioremap mem region %pR failed\n", res);
return -ENOMEM;
}
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res) {
dev_err(&pdev->dev, "Platform data does not specify IRQ\n");
return -ENODEV;
}
if (devm_request_irq(&pdev->dev, res->start, iic_state_machine,
IRQF_DISABLED, "i2c", i2c_stm) < 0) {
dev_err(&pdev->dev, "Request irq %d failed\n", res->start);
return -ENODEV;
}
/* If SSC is hard wired, there will be no pad configurations */
if (plat_data->pad_config) {
i2c_stm->pad_state = devm_stm_pad_claim(&pdev->dev,
plat_data->pad_config, "i2c-stm");
if (!i2c_stm->pad_state) {
dev_err(&pdev->dev, "Pads request failed\n");
return -ENODEV;
}
}
platform_set_drvdata(pdev, i2c_stm);
i2c_stm->adapter.timeout = 2;
i2c_stm->adapter.retries = 0;
i2c_stm->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_TV_ANALOG |
I2C_CLASS_TV_DIGITAL | I2C_CLASS_DDC | I2C_CLASS_SPD;;
sprintf(i2c_stm->adapter.name, "i2c-stm%d", pdev->id);
i2c_stm->adapter.nr = pdev->id;
i2c_stm->adapter.algo = &iic_stm_algo;
i2c_stm->adapter.dev.parent = &(pdev->dev);
i2c_stm->clk = clk_get(&(pdev->dev), "comms_clk");
if (!i2c_stm->clk) {
dev_err(&pdev->dev, "Comms clock not found!\n");
return -ENODEV;
}
clk_enable(i2c_stm->clk);
iic_stm_setup_timing(i2c_stm);
init_waitqueue_head(&(i2c_stm->wait_queue));
if (i2c_add_numbered_adapter(&(i2c_stm->adapter)) < 0) {
dev_err(&pdev->dev, "I2C core refuses the i2c/stm adapter\n");
return -ENODEV;
}
err = device_create_file(&(i2c_stm->adapter.dev), &dev_attr_fastmode);
if (err) {
dev_err(&pdev->dev, "Cannot create fastmode sysfs entry\n");
return err;
}
/* by default the device is on */
pm_runtime_set_active(&pdev->dev);
pm_suspend_ignore_children(&pdev->dev, 1);
pm_runtime_enable(&pdev->dev);
return 0;
}
static int iic_stm_remove(struct platform_device *pdev)
{
struct resource *res;
struct iic_ssc *iic_stm = platform_get_drvdata(pdev);
clk_disable(iic_stm->clk);
i2c_del_adapter(&iic_stm->adapter);
/* irq */
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
devm_free_irq(&pdev->dev, res->start, iic_stm);
/* mem */
devm_iounmap(&pdev->dev, iic_stm->base);
/* kmem */
devm_kfree(&pdev->dev, iic_stm);
return 0;
}
#ifdef CONFIG_PM
static int iic_stm_suspend(struct device *dev)
{
struct platform_device *pdev =
container_of(dev, struct platform_device, dev);
struct iic_ssc *i2c_bus = platform_get_drvdata(pdev);
#if 0
struct ssc_pio_t *pio_info =
(struct ssc_pio_t *)pdev->dev.platform_data;
if (pio_info->pio[0].pio_port != SSC_NO_PIO) {
stpio_configure_pin(pio_info->clk, STPIO_IN);
stpio_configure_pin(pio_info->sdout, STPIO_IN);
}
#endif
ssc_store32(i2c_bus, SSC_IEN, 0);
ssc_store32(i2c_bus, SSC_CTL, 0);
clk_disable(i2c_bus->clk);
return 0;
}
static int iic_stm_resume(struct device *dev)
{
struct platform_device *pdev =
container_of(dev, struct platform_device, dev);
struct iic_ssc *i2c_bus = platform_get_drvdata(pdev);
#if 0
struct ssc_pio_t *pio_info =
(struct ssc_pio_t *)pdev->dev.platform_data;
if (pio_info->pio[0].pio_port != SSC_NO_PIO) {
/* configure the pins */
stpio_configure_pin(pio_info->clk, (pio_info->clk_unidir ?
STPIO_ALT_BIDIR : STPIO_ALT_BIDIR));
stpio_configure_pin(pio_info->sdout, STPIO_ALT_BIDIR);
}
#endif
clk_enable(i2c_bus->clk);
/* enable RX, TX FIFOs - clear SR bit */
ssc_store32(i2c_bus, SSC_CTL, SSC_CTL_EN |
SSC_CTL_PO | SSC_CTL_PH | SSC_CTL_HB | 0x8);
ssc_store32(i2c_bus, SSC_I2C, SSC_I2C_I2CM);
iic_stm_setup_timing(i2c_bus);
return 0;
}
#else
#define iic_stm_suspend NULL
#define iic_stm_resume NULL
#endif
static struct dev_pm_ops stm_i2c_pm_ops = {
.suspend = iic_stm_suspend,
.resume = iic_stm_resume,
.freeze = iic_stm_suspend,
.restore = iic_stm_resume,
.runtime_suspend = iic_stm_suspend,
.runtime_resume = iic_stm_resume,
};
static struct platform_driver i2c_stm_driver = {
.driver = {
.name = "i2c-stm",
.owner = THIS_MODULE,
.pm = &stm_i2c_pm_ops,
},
.probe = iic_stm_probe,
.remove = iic_stm_remove,
};
static int __init iic_stm_init(void)
{
platform_driver_register(&i2c_stm_driver);
return 0;
}
static void __exit iic_stm_exit(void)
{
platform_driver_unregister(&i2c_stm_driver);
}
module_init(iic_stm_init);
module_exit(iic_stm_exit);
MODULE_AUTHOR("STMicroelectronics <www.st.com>");
MODULE_DESCRIPTION("i2c-stm algorithm for STMicroelectronics devices");
MODULE_LICENSE("GPL");
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