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