// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2008 Ilya Yanok, Emcraft Systems
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*/
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#include <linux/irq.h>
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#include <linux/of_address.h>
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#include <linux/of_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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static DEFINE_RAW_SPINLOCK(socrates_fpga_pic_lock);
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static void __iomem *socrates_fpga_pic_iobase;
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static struct irq_domain *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 0;
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raw_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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raw_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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static void socrates_fpga_pic_cascade(struct irq_desc *desc)
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{
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struct irq_chip *chip = irq_desc_get_chip(desc);
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unsigned int irq = irq_desc_get_irq(desc);
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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)
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generic_handle_irq(cascade_irq);
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chip->irq_eoi(&desc->irq_data);
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}
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static void socrates_fpga_pic_ack(struct irq_data *d)
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{
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unsigned long flags;
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unsigned int irq_line, hwirq = irqd_to_hwirq(d);
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uint32_t mask;
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irq_line = fpga_irqs[hwirq].irq_line;
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raw_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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raw_spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static void socrates_fpga_pic_mask(struct irq_data *d)
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{
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unsigned long flags;
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unsigned int hwirq = irqd_to_hwirq(d);
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int irq_line;
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u32 mask;
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irq_line = fpga_irqs[hwirq].irq_line;
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raw_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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raw_spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static void socrates_fpga_pic_mask_ack(struct irq_data *d)
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{
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unsigned long flags;
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unsigned int hwirq = irqd_to_hwirq(d);
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int irq_line;
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u32 mask;
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irq_line = fpga_irqs[hwirq].irq_line;
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raw_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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raw_spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static void socrates_fpga_pic_unmask(struct irq_data *d)
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{
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unsigned long flags;
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unsigned int hwirq = irqd_to_hwirq(d);
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int irq_line;
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u32 mask;
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irq_line = fpga_irqs[hwirq].irq_line;
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raw_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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raw_spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static void socrates_fpga_pic_eoi(struct irq_data *d)
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{
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unsigned long flags;
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unsigned int hwirq = irqd_to_hwirq(d);
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int irq_line;
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u32 mask;
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irq_line = fpga_irqs[hwirq].irq_line;
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raw_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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raw_spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
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}
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static int socrates_fpga_pic_set_type(struct irq_data *d,
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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 = irqd_to_hwirq(d);
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int polarity;
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u32 mask;
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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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raw_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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raw_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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.name = "FPGA-PIC",
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.irq_ack = socrates_fpga_pic_ack,
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.irq_mask = socrates_fpga_pic_mask,
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.irq_mask_ack = socrates_fpga_pic_mask_ack,
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.irq_unmask = socrates_fpga_pic_unmask,
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.irq_eoi = socrates_fpga_pic_eoi,
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.irq_set_type = socrates_fpga_pic_set_type,
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};
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static int socrates_fpga_pic_host_map(struct irq_domain *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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irq_set_status_flags(virq, IRQ_LEVEL);
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irq_set_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_domain *h,
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struct device_node *ct, const 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_warn("FPGA PIC: invalid irq type, 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_warn("FPGA PIC: invalid irq routing\n");
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return 0;
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}
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static const struct irq_domain_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_domain structure */
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socrates_fpga_pic_irq_host = irq_domain_add_linear(pic,
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SOCRATES_FPGA_NUM_IRQS, &socrates_fpga_pic_host_ops, NULL);
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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]) {
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pr_warn("FPGA PIC: can't get irq%d\n", i);
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continue;
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}
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irq_set_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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raw_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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raw_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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