arch/avr32/mach-at32ap/intc.c

   1 /*
   2  * Copyright (C) 2006, 2008 Atmel Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/err.h>
  11 #include <linux/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/irq.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/syscore_ops.h>
  16
  17 #include <asm/io.h>
  18
  19 #include "intc.h"
  20
  21 struct intc {
  22         void __iomem            *regs;
  23         struct irq_chip         chip;
  24 #ifdef CONFIG_PM
  25         unsigned long           suspend_ipr;
  26         unsigned long           saved_ipr[64];
  27 #endif
  28 };
  29
  30 extern struct platform_device at32_intc0_device;
  31
  32 /*
  33  * TODO: We may be able to implement mask/unmask by setting IxM flags
  34  * in the status register.
  35  */
  36 static void intc_mask_irq(struct irq_data *d)
  37 {
  38
  39 }
  40
  41 static void intc_unmask_irq(struct irq_data *d)
  42 {
  43
  44 }
  45
  46 static struct intc intc0 = {
  47         .chip = {
  48                 .name           = "intc",
  49                 .irq_mask       = intc_mask_irq,
  50                 .irq_unmask     = intc_unmask_irq,
  51         },
  52 };
  53
  54 /*
  55  * All interrupts go via intc at some point.
  56  */
  57 asmlinkage void do_IRQ(int level, struct pt_regs *regs)
  58 {
  59         struct pt_regs *old_regs;
  60         unsigned int irq;
  61         unsigned long status_reg;
  62
  63         local_irq_disable();
  64
  65         old_regs = set_irq_regs(regs);
  66
  67         irq_enter();
  68
  69         irq = intc_readl(&intc0, INTCAUSE0 - 4 * level);
  70         generic_handle_irq(irq);
  71
  72         /*
  73          * Clear all interrupt level masks so that we may handle
  74          * interrupts during softirq processing.  If this is a nested
  75          * interrupt, interrupts must stay globally disabled until we
  76          * return.
  77          */
  78         status_reg = sysreg_read(SR);
  79         status_reg &= ~(SYSREG_BIT(I0M) | SYSREG_BIT(I1M)
  80                         | SYSREG_BIT(I2M) | SYSREG_BIT(I3M));
  81         sysreg_write(SR, status_reg);
  82
  83         irq_exit();
  84
  85         set_irq_regs(old_regs);
  86 }
  87
  88 void __init init_IRQ(void)
  89 {
  90         extern void _evba(void);
  91         extern void irq_level0(void);
  92         struct resource *regs;
  93         struct clk *pclk;
  94         unsigned int i;
  95         u32 offset, readback;
  96
  97         regs = platform_get_resource(&at32_intc0_device, IORESOURCE_MEM, 0);
  98         if (!regs) {
  99                 printk(KERN_EMERG "intc: no mmio resource defined\n");
 100                 goto fail;
 101         }
 102         pclk = clk_get(&at32_intc0_device.dev, "pclk");
 103         if (IS_ERR(pclk)) {
 104                 printk(KERN_EMERG "intc: no clock defined\n");
 105                 goto fail;
 106         }
 107
 108         clk_enable(pclk);
 109
 110         intc0.regs = ioremap(regs->start, regs->end - regs->start + 1);
 111         if (!intc0.regs) {
 112                 printk(KERN_EMERG "intc: failed to map registers (0x%08lx)\n",
 113                        (unsigned long)regs->start);
 114                 goto fail;
 115         }
 116
 117         /*
 118          * Initialize all interrupts to level 0 (lowest priority). The
 119          * priority level may be changed by calling
 120          * irq_set_priority().
 121          *
 122          */
 123         offset = (unsigned long)&irq_level0 - (unsigned long)&_evba;
 124         for (i = 0; i < NR_INTERNAL_IRQS; i++) {
 125                 intc_writel(&intc0, INTPR0 + 4 * i, offset);
 126                 readback = intc_readl(&intc0, INTPR0 + 4 * i);
 127                 if (readback == offset)
 128                         irq_set_chip_and_handler(i, &intc0.chip,
 129                                                  handle_simple_irq);
 130         }
 131
 132         /* Unmask all interrupt levels */
 133         sysreg_write(SR, (sysreg_read(SR)
 134                           & ~(SR_I3M | SR_I2M | SR_I1M | SR_I0M)));
 135
 136         return;
 137
 138 fail:
 139         panic("Interrupt controller initialization failed!\n");
 140 }
 141
 142 #ifdef CONFIG_PM
 143 void intc_set_suspend_handler(unsigned long offset)
 144 {
 145         intc0.suspend_ipr = offset;
 146 }
 147
 148 static int intc_suspend(void)
 149 {
 150         int i;
 151
 152         if (unlikely(!irqs_disabled())) {
 153                 pr_err("intc_suspend: called with interrupts enabled\n");
 154                 return -EINVAL;
 155         }
 156
 157         if (unlikely(!intc0.suspend_ipr)) {
 158                 pr_err("intc_suspend: suspend_ipr not initialized\n");
 159                 return -EINVAL;
 160         }
 161
 162         for (i = 0; i < 64; i++) {
 163                 intc0.saved_ipr[i] = intc_readl(&intc0, INTPR0 + 4 * i);
 164                 intc_writel(&intc0, INTPR0 + 4 * i, intc0.suspend_ipr);
 165         }
 166
 167         return 0;
 168 }
 169
 170 static void intc_resume(void)
 171 {
 172         int i;
 173
 174         for (i = 0; i < 64; i++)
 175                 intc_writel(&intc0, INTPR0 + 4 * i, intc0.saved_ipr[i]);
 176 }
 177 #else
 178 #define intc_suspend    NULL
 179 #define intc_resume     NULL
 180 #endif
 181
 182 static struct syscore_ops intc_syscore_ops = {
 183         .suspend        = intc_suspend,
 184         .resume         = intc_resume,
 185 };
 186
 187 static int __init intc_init_syscore(void)
 188 {
 189         register_syscore_ops(&intc_syscore_ops);
 190
 191         return 0;
 192 }
 193 device_initcall(intc_init_syscore);
 194
 195 unsigned long intc_get_pending(unsigned int group)
 196 {
 197         return intc_readl(&intc0, INTREQ0 + 4 * group);
 198 }
 199 EXPORT_SYMBOL_GPL(intc_get_pending);