arch/mips/loongson1/common/irq.c

   1 /*
   2  * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.com>
   3  *
   4  * This program is free software; you can redistribute  it and/or modify it
   5  * under  the terms of  the GNU General  Public License as published by the
   6  * Free Software Foundation;  either version 2 of the  License, or (at your
   7  * option) any later version.
   8  */
   9
  10 #include <linux/interrupt.h>
  11 #include <linux/irq.h>
  12 #include <asm/irq_cpu.h>
  13
  14 #include <loongson1.h>
  15 #include <irq.h>
  16
  17 #define LS1X_INTC_REG(n, x) \
  18                 ((void __iomem *)KSEG1ADDR(LS1X_INTC_BASE + (n * 0x18) + (x)))
  19
  20 #define LS1X_INTC_INTISR(n)             LS1X_INTC_REG(n, 0x0)
  21 #define LS1X_INTC_INTIEN(n)             LS1X_INTC_REG(n, 0x4)
  22 #define LS1X_INTC_INTSET(n)             LS1X_INTC_REG(n, 0x8)
  23 #define LS1X_INTC_INTCLR(n)             LS1X_INTC_REG(n, 0xc)
  24 #define LS1X_INTC_INTPOL(n)             LS1X_INTC_REG(n, 0x10)
  25 #define LS1X_INTC_INTEDGE(n)            LS1X_INTC_REG(n, 0x14)
  26
  27 static void ls1x_irq_ack(struct irq_data *d)
  28 {
  29         unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
  30         unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
  31
  32         __raw_writel(__raw_readl(LS1X_INTC_INTCLR(n))
  33                         | (1 << bit), LS1X_INTC_INTCLR(n));
  34 }
  35
  36 static void ls1x_irq_mask(struct irq_data *d)
  37 {
  38         unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
  39         unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
  40
  41         __raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
  42                         & ~(1 << bit), LS1X_INTC_INTIEN(n));
  43 }
  44
  45 static void ls1x_irq_mask_ack(struct irq_data *d)
  46 {
  47         unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
  48         unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
  49
  50         __raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
  51                         & ~(1 << bit), LS1X_INTC_INTIEN(n));
  52         __raw_writel(__raw_readl(LS1X_INTC_INTCLR(n))
  53                         | (1 << bit), LS1X_INTC_INTCLR(n));
  54 }
  55
  56 static void ls1x_irq_unmask(struct irq_data *d)
  57 {
  58         unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
  59         unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
  60
  61         __raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
  62                         | (1 << bit), LS1X_INTC_INTIEN(n));
  63 }
  64
  65 static struct irq_chip ls1x_irq_chip = {
  66         .name           = "LS1X-INTC",
  67         .irq_ack        = ls1x_irq_ack,
  68         .irq_mask       = ls1x_irq_mask,
  69         .irq_mask_ack   = ls1x_irq_mask_ack,
  70         .irq_unmask     = ls1x_irq_unmask,
  71 };
  72
  73 static void ls1x_irq_dispatch(int n)
  74 {
  75         u32 int_status, irq;
  76
  77         /* Get pending sources, masked by current enables */
  78         int_status = __raw_readl(LS1X_INTC_INTISR(n)) &
  79                         __raw_readl(LS1X_INTC_INTIEN(n));
  80
  81         if (int_status) {
  82                 irq = LS1X_IRQ(n, __ffs(int_status));
  83                 do_IRQ(irq);
  84         }
  85 }
  86
  87 asmlinkage void plat_irq_dispatch(void)
  88 {
  89         unsigned int pending;
  90
  91         pending = read_c0_cause() & read_c0_status() & ST0_IM;
  92
  93         if (pending & CAUSEF_IP7)
  94                 do_IRQ(TIMER_IRQ);
  95         else if (pending & CAUSEF_IP2)
  96                 ls1x_irq_dispatch(0); /* INT0 */
  97         else if (pending & CAUSEF_IP3)
  98                 ls1x_irq_dispatch(1); /* INT1 */
  99         else if (pending & CAUSEF_IP4)
 100                 ls1x_irq_dispatch(2); /* INT2 */
 101         else if (pending & CAUSEF_IP5)
 102                 ls1x_irq_dispatch(3); /* INT3 */
 103         else if (pending & CAUSEF_IP6)
 104                 ls1x_irq_dispatch(4); /* INT4 */
 105         else
 106                 spurious_interrupt();
 107
 108 }
 109
 110 struct irqaction cascade_irqaction = {
 111         .handler = no_action,
 112         .name = "cascade",
 113         .flags = IRQF_NO_THREAD,
 114 };
 115
 116 static void __init ls1x_irq_init(int base)
 117 {
 118         int n;
 119
 120         /* Disable interrupts and clear pending,
 121          * setup all IRQs as high level triggered
 122          */
 123         for (n = 0; n < 4; n++) {
 124                 __raw_writel(0x0, LS1X_INTC_INTIEN(n));
 125                 __raw_writel(0xffffffff, LS1X_INTC_INTCLR(n));
 126                 __raw_writel(0xffffffff, LS1X_INTC_INTPOL(n));
 127                 /* set DMA0, DMA1 and DMA2 to edge trigger */
 128                 __raw_writel(n ? 0x0 : 0xe000, LS1X_INTC_INTEDGE(n));
 129         }
 130
 131
 132         for (n = base; n < LS1X_IRQS; n++) {
 133                 irq_set_chip_and_handler(n, &ls1x_irq_chip,
 134                                          handle_level_irq);
 135         }
 136
 137         setup_irq(INT0_IRQ, &cascade_irqaction);
 138         setup_irq(INT1_IRQ, &cascade_irqaction);
 139         setup_irq(INT2_IRQ, &cascade_irqaction);
 140         setup_irq(INT3_IRQ, &cascade_irqaction);
 141 }
 142
 143 void __init arch_init_irq(void)
 144 {
 145         mips_cpu_irq_init();
 146         ls1x_irq_init(LS1X_IRQ_BASE);
 147 }