arch/arm/mach-dove/irq.c

   1 /*
   2  * arch/arm/mach-dove/irq.c
   3  *
   4  * Dove IRQ handling.
   5  *
   6  * This file is licensed under the terms of the GNU General Public
   7  * License version 2.  This program is licensed "as is" without any
   8  * warranty of any kind, whether express or implied.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/irq.h>
  14 #include <linux/gpio.h>
  15 #include <linux/io.h>
  16 #include <asm/mach/arch.h>
  17 #include <plat/irq.h>
  18 #include <asm/mach/irq.h>
  19 #include <mach/pm.h>
  20 #include <mach/bridge-regs.h>
  21 #include <plat/orion-gpio.h>
  22 #include "common.h"
  23
  24 static void pmu_irq_mask(struct irq_data *d)
  25 {
  26         int pin = irq_to_pmu(d->irq);
  27         u32 u;
  28
  29         u = readl(PMU_INTERRUPT_MASK);
  30         u &= ~(1 << (pin & 31));
  31         writel(u, PMU_INTERRUPT_MASK);
  32 }
  33
  34 static void pmu_irq_unmask(struct irq_data *d)
  35 {
  36         int pin = irq_to_pmu(d->irq);
  37         u32 u;
  38
  39         u = readl(PMU_INTERRUPT_MASK);
  40         u |= 1 << (pin & 31);
  41         writel(u, PMU_INTERRUPT_MASK);
  42 }
  43
  44 static void pmu_irq_ack(struct irq_data *d)
  45 {
  46         int pin = irq_to_pmu(d->irq);
  47         u32 u;
  48
  49         /*
  50          * The PMU mask register is not RW0C: it is RW.  This means that
  51          * the bits take whatever value is written to them; if you write
  52          * a '1', you will set the interrupt.
  53          *
  54          * Unfortunately this means there is NO race free way to clear
  55          * these interrupts.
  56          *
  57          * So, let's structure the code so that the window is as small as
  58          * possible.
  59          */
  60         u = ~(1 << (pin & 31));
  61         u &= readl_relaxed(PMU_INTERRUPT_CAUSE);
  62         writel_relaxed(u, PMU_INTERRUPT_CAUSE);
  63 }
  64
  65 static struct irq_chip pmu_irq_chip = {
  66         .name           = "pmu_irq",
  67         .irq_mask       = pmu_irq_mask,
  68         .irq_unmask     = pmu_irq_unmask,
  69         .irq_ack        = pmu_irq_ack,
  70 };
  71
  72 static void pmu_irq_handler(struct irq_desc *desc)
  73 {
  74         unsigned long cause = readl(PMU_INTERRUPT_CAUSE);
  75         unsigned int irq;
  76
  77         cause &= readl(PMU_INTERRUPT_MASK);
  78         if (cause == 0) {
  79                 do_bad_IRQ(desc);
  80                 return;
  81         }
  82
  83         for (irq = 0; irq < NR_PMU_IRQS; irq++) {
  84                 if (!(cause & (1 << irq)))
  85                         continue;
  86                 irq = pmu_to_irq(irq);
  87                 generic_handle_irq(irq);
  88         }
  89 }
  90
  91 static int __initdata gpio0_irqs[4] = {
  92         IRQ_DOVE_GPIO_0_7,
  93         IRQ_DOVE_GPIO_8_15,
  94         IRQ_DOVE_GPIO_16_23,
  95         IRQ_DOVE_GPIO_24_31,
  96 };
  97
  98 static int __initdata gpio1_irqs[4] = {
  99         IRQ_DOVE_HIGH_GPIO,
 100         0,
 101         0,
 102         0,
 103 };
 104
 105 static int __initdata gpio2_irqs[4] = {
 106         0,
 107         0,
 108         0,
 109         0,
 110 };
 111
 112 #ifdef CONFIG_MULTI_IRQ_HANDLER
 113 /*
 114  * Compiling with both non-DT and DT support enabled, will
 115  * break asm irq handler used by non-DT boards. Therefore,
 116  * we provide a C-style irq handler even for non-DT boards,
 117  * if MULTI_IRQ_HANDLER is set.
 118  */
 119
 120 static void __iomem *dove_irq_base = IRQ_VIRT_BASE;
 121
 122 static asmlinkage void
 123 __exception_irq_entry dove_legacy_handle_irq(struct pt_regs *regs)
 124 {
 125         u32 stat;
 126
 127         stat = readl_relaxed(dove_irq_base + IRQ_CAUSE_LOW_OFF);
 128         stat &= readl_relaxed(dove_irq_base + IRQ_MASK_LOW_OFF);
 129         if (stat) {
 130                 unsigned int hwirq = 1 + __fls(stat);
 131                 handle_IRQ(hwirq, regs);
 132                 return;
 133         }
 134         stat = readl_relaxed(dove_irq_base + IRQ_CAUSE_HIGH_OFF);
 135         stat &= readl_relaxed(dove_irq_base + IRQ_MASK_HIGH_OFF);
 136         if (stat) {
 137                 unsigned int hwirq = 33 + __fls(stat);
 138                 handle_IRQ(hwirq, regs);
 139                 return;
 140         }
 141 }
 142 #endif
 143
 144 void __init dove_init_irq(void)
 145 {
 146         int i;
 147
 148         orion_irq_init(1, IRQ_VIRT_BASE + IRQ_MASK_LOW_OFF);
 149         orion_irq_init(33, IRQ_VIRT_BASE + IRQ_MASK_HIGH_OFF);
 150
 151 #ifdef CONFIG_MULTI_IRQ_HANDLER
 152         set_handle_irq(dove_legacy_handle_irq);
 153 #endif
 154
 155         /*
 156          * Initialize gpiolib for GPIOs 0-71.
 157          */
 158         orion_gpio_init(NULL, 0, 32, DOVE_GPIO_LO_VIRT_BASE, 0,
 159                         IRQ_DOVE_GPIO_START, gpio0_irqs);
 160
 161         orion_gpio_init(NULL, 32, 32, DOVE_GPIO_HI_VIRT_BASE, 0,
 162                         IRQ_DOVE_GPIO_START + 32, gpio1_irqs);
 163
 164         orion_gpio_init(NULL, 64, 8, DOVE_GPIO2_VIRT_BASE, 0,
 165                         IRQ_DOVE_GPIO_START + 64, gpio2_irqs);
 166
 167         /*
 168          * Mask and clear PMU interrupts
 169          */
 170         writel(0, PMU_INTERRUPT_MASK);
 171         writel(0, PMU_INTERRUPT_CAUSE);
 172
 173         for (i = IRQ_DOVE_PMU_START; i < NR_IRQS; i++) {
 174                 irq_set_chip_and_handler(i, &pmu_irq_chip, handle_level_irq);
 175                 irq_set_status_flags(i, IRQ_LEVEL);
 176                 irq_clear_status_flags(i, IRQ_NOREQUEST);
 177         }
 178         irq_set_chained_handler(IRQ_DOVE_PMU, pmu_irq_handler);
 179 }