328 lines
8.4 KiB
C
328 lines
8.4 KiB
C
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/*
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* Copyright (C) 2008 Ilya Yanok, Emcraft Systems
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/irq.h>
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#include <linux/of_platform.h>
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#include <linux/io.h>
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/*
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* The FPGA supports 9 interrupt sources, which can be routed to 3
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* interrupt request lines of the MPIC. The line to be used can be
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* specified through the third cell of FDT property "interrupts".
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*/
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#define SOCRATES_FPGA_NUM_IRQS 9
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#define FPGA_PIC_IRQCFG (0x0)
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#define FPGA_PIC_IRQMASK(n) (0x4 + 0x4 * (n))
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#define SOCRATES_FPGA_IRQ_MASK ((1 << SOCRATES_FPGA_NUM_IRQS) - 1)
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struct socrates_fpga_irq_info {
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unsigned int irq_line;
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int type;
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};
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/*
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* Interrupt routing and type table
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*
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* IRQ_TYPE_NONE means the interrupt type is configurable,
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* otherwise it's fixed to the specified value.
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*/
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static struct socrates_fpga_irq_info fpga_irqs[SOCRATES_FPGA_NUM_IRQS] = {
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[0] = {0, IRQ_TYPE_NONE},
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[1] = {0, IRQ_TYPE_LEVEL_HIGH},
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[2] = {0, IRQ_TYPE_LEVEL_LOW},
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[3] = {0, IRQ_TYPE_NONE},
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[4] = {0, IRQ_TYPE_NONE},
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[5] = {0, IRQ_TYPE_NONE},
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[6] = {0, IRQ_TYPE_NONE},
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[7] = {0, IRQ_TYPE_NONE},
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[8] = {0, IRQ_TYPE_LEVEL_HIGH},
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};
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#define socrates_fpga_irq_to_hw(virq) ((unsigned int)irq_map[virq].hwirq)
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static DEFINE_SPINLOCK(socrates_fpga_pic_lock);
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static void __iomem *socrates_fpga_pic_iobase;
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static struct irq_host *socrates_fpga_pic_irq_host;
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static unsigned int socrates_fpga_irqs[3];
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static inline uint32_t socrates_fpga_pic_read(int reg)
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{
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return in_be32(socrates_fpga_pic_iobase + reg);
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}
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static inline void socrates_fpga_pic_write(int reg, uint32_t val)
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{
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out_be32(socrates_fpga_pic_iobase + reg, val);
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}
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static inline unsigned int socrates_fpga_pic_get_irq(unsigned int irq)
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{
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uint32_t cause;
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unsigned long flags;
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int i;
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/* Check irq line routed to the MPIC */
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for (i = 0; i < 3; i++) {
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if (irq == socrates_fpga_irqs[i])
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break;
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}
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if (i == 3)
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return NO_IRQ;
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spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
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cause = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(i));
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spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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for (i = SOCRATES_FPGA_NUM_IRQS - 1; i >= 0; i--) {
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if (cause >> (i + 16))
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break;
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}
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return irq_linear_revmap(socrates_fpga_pic_irq_host,
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(irq_hw_number_t)i);
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}
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void socrates_fpga_pic_cascade(unsigned int irq, struct irq_desc *desc)
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{
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unsigned int cascade_irq;
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/*
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* See if we actually have an interrupt, call generic handling code if
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* we do.
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*/
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cascade_irq = socrates_fpga_pic_get_irq(irq);
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if (cascade_irq != NO_IRQ)
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generic_handle_irq(cascade_irq);
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desc->chip->eoi(irq);
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}
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static void socrates_fpga_pic_ack(unsigned int virq)
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{
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unsigned long flags;
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unsigned int hwirq, irq_line;
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uint32_t mask;
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hwirq = socrates_fpga_irq_to_hw(virq);
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irq_line = fpga_irqs[hwirq].irq_line;
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spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
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mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
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& SOCRATES_FPGA_IRQ_MASK;
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mask |= (1 << (hwirq + 16));
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socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
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spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static void socrates_fpga_pic_mask(unsigned int virq)
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{
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unsigned long flags;
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unsigned int hwirq;
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int irq_line;
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u32 mask;
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hwirq = socrates_fpga_irq_to_hw(virq);
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irq_line = fpga_irqs[hwirq].irq_line;
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spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
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mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
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& SOCRATES_FPGA_IRQ_MASK;
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mask &= ~(1 << hwirq);
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socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
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spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static void socrates_fpga_pic_mask_ack(unsigned int virq)
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{
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unsigned long flags;
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unsigned int hwirq;
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int irq_line;
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u32 mask;
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hwirq = socrates_fpga_irq_to_hw(virq);
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irq_line = fpga_irqs[hwirq].irq_line;
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spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
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mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
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& SOCRATES_FPGA_IRQ_MASK;
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mask &= ~(1 << hwirq);
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mask |= (1 << (hwirq + 16));
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socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
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spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static void socrates_fpga_pic_unmask(unsigned int virq)
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{
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unsigned long flags;
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unsigned int hwirq;
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int irq_line;
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u32 mask;
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hwirq = socrates_fpga_irq_to_hw(virq);
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irq_line = fpga_irqs[hwirq].irq_line;
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spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
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mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
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& SOCRATES_FPGA_IRQ_MASK;
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mask |= (1 << hwirq);
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socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
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spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static void socrates_fpga_pic_eoi(unsigned int virq)
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{
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unsigned long flags;
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unsigned int hwirq;
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int irq_line;
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u32 mask;
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hwirq = socrates_fpga_irq_to_hw(virq);
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irq_line = fpga_irqs[hwirq].irq_line;
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spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
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mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
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& SOCRATES_FPGA_IRQ_MASK;
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mask |= (1 << (hwirq + 16));
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socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
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spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static int socrates_fpga_pic_set_type(unsigned int virq,
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unsigned int flow_type)
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{
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unsigned long flags;
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unsigned int hwirq;
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int polarity;
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u32 mask;
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hwirq = socrates_fpga_irq_to_hw(virq);
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if (fpga_irqs[hwirq].type != IRQ_TYPE_NONE)
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return -EINVAL;
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switch (flow_type & IRQ_TYPE_SENSE_MASK) {
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case IRQ_TYPE_LEVEL_HIGH:
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polarity = 1;
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break;
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case IRQ_TYPE_LEVEL_LOW:
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polarity = 0;
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break;
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default:
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return -EINVAL;
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}
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spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
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mask = socrates_fpga_pic_read(FPGA_PIC_IRQCFG);
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if (polarity)
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mask |= (1 << hwirq);
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else
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mask &= ~(1 << hwirq);
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socrates_fpga_pic_write(FPGA_PIC_IRQCFG, mask);
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spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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return 0;
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}
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static struct irq_chip socrates_fpga_pic_chip = {
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.typename = " FPGA-PIC ",
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.ack = socrates_fpga_pic_ack,
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.mask = socrates_fpga_pic_mask,
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.mask_ack = socrates_fpga_pic_mask_ack,
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.unmask = socrates_fpga_pic_unmask,
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.eoi = socrates_fpga_pic_eoi,
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.set_type = socrates_fpga_pic_set_type,
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};
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static int socrates_fpga_pic_host_map(struct irq_host *h, unsigned int virq,
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irq_hw_number_t hwirq)
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{
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/* All interrupts are LEVEL sensitive */
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get_irq_desc(virq)->status |= IRQ_LEVEL;
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set_irq_chip_and_handler(virq, &socrates_fpga_pic_chip,
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handle_fasteoi_irq);
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return 0;
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}
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static int socrates_fpga_pic_host_xlate(struct irq_host *h,
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struct device_node *ct, u32 *intspec, unsigned int intsize,
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irq_hw_number_t *out_hwirq, unsigned int *out_flags)
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{
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struct socrates_fpga_irq_info *fpga_irq = &fpga_irqs[intspec[0]];
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*out_hwirq = intspec[0];
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if (fpga_irq->type == IRQ_TYPE_NONE) {
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/* type is configurable */
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if (intspec[1] != IRQ_TYPE_LEVEL_LOW &&
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intspec[1] != IRQ_TYPE_LEVEL_HIGH) {
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pr_warning("FPGA PIC: invalid irq type, "
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"setting default active low\n");
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*out_flags = IRQ_TYPE_LEVEL_LOW;
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} else {
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*out_flags = intspec[1];
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}
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} else {
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/* type is fixed */
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*out_flags = fpga_irq->type;
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}
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/* Use specified interrupt routing */
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if (intspec[2] <= 2)
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fpga_irq->irq_line = intspec[2];
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else
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pr_warning("FPGA PIC: invalid irq routing\n");
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return 0;
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}
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static struct irq_host_ops socrates_fpga_pic_host_ops = {
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.map = socrates_fpga_pic_host_map,
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.xlate = socrates_fpga_pic_host_xlate,
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};
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void socrates_fpga_pic_init(struct device_node *pic)
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{
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unsigned long flags;
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int i;
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/* Setup an irq_host structure */
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socrates_fpga_pic_irq_host = irq_alloc_host(pic, IRQ_HOST_MAP_LINEAR,
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SOCRATES_FPGA_NUM_IRQS, &socrates_fpga_pic_host_ops,
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SOCRATES_FPGA_NUM_IRQS);
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if (socrates_fpga_pic_irq_host == NULL) {
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pr_err("FPGA PIC: Unable to allocate host\n");
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return;
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}
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for (i = 0; i < 3; i++) {
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socrates_fpga_irqs[i] = irq_of_parse_and_map(pic, i);
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if (socrates_fpga_irqs[i] == NO_IRQ) {
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pr_warning("FPGA PIC: can't get irq%d.\n", i);
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continue;
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}
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set_irq_chained_handler(socrates_fpga_irqs[i],
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socrates_fpga_pic_cascade);
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}
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socrates_fpga_pic_iobase = of_iomap(pic, 0);
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spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
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socrates_fpga_pic_write(FPGA_PIC_IRQMASK(0),
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SOCRATES_FPGA_IRQ_MASK << 16);
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socrates_fpga_pic_write(FPGA_PIC_IRQMASK(1),
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SOCRATES_FPGA_IRQ_MASK << 16);
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socrates_fpga_pic_write(FPGA_PIC_IRQMASK(2),
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SOCRATES_FPGA_IRQ_MASK << 16);
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spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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pr_info("FPGA PIC: Setting up Socrates FPGA PIC\n");
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}
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