release/src-rt-6.x.4708/linux/linux-2.6.36/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/sysdev.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         struct sys_device       sysdev;
  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(unsigned int irq)
  38 {
  39
  40 }
  41
  42 static void intc_unmask_irq(unsigned int irq)
  43 {
  44
  45 }
  46
  47 static struct intc intc0 = {
  48         .chip = {
  49                 .name           = "intc",
  50                 .mask           = intc_mask_irq,
  51                 .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 irq_desc *desc;
  61         struct pt_regs *old_regs;
  62         unsigned int irq;
  63         unsigned long status_reg;
  64
  65         local_irq_disable();
  66
  67         old_regs = set_irq_regs(regs);
  68
  69         irq_enter();
  70
  71         irq = intc_readl(&intc0, INTCAUSE0 - 4 * level);
  72         desc = irq_desc + irq;
  73         desc->handle_irq(irq, desc);
  74
  75         /*
  76          * Clear all interrupt level masks so that we may handle
  77          * interrupts during softirq processing.  If this is a nested
  78          * interrupt, interrupts must stay globally disabled until we
  79          * return.
  80          */
  81         status_reg = sysreg_read(SR);
  82         status_reg &= ~(SYSREG_BIT(I0M) | SYSREG_BIT(I1M)
  83                         | SYSREG_BIT(I2M) | SYSREG_BIT(I3M));
  84         sysreg_write(SR, status_reg);
  85
  86         irq_exit();
  87
  88         set_irq_regs(old_regs);
  89 }
  90
  91 void __init init_IRQ(void)
  92 {
  93         extern void _evba(void);
  94         extern void irq_level0(void);
  95         struct resource *regs;
  96         struct clk *pclk;
  97         unsigned int i;
  98         u32 offset, readback;
  99
 100         regs = platform_get_resource(&at32_intc0_device, IORESOURCE_MEM, 0);
 101         if (!regs) {
 102                 printk(KERN_EMERG "intc: no mmio resource defined\n");
 103                 goto fail;
 104         }
 105         pclk = clk_get(&at32_intc0_device.dev, "pclk");
 106         if (IS_ERR(pclk)) {
 107                 printk(KERN_EMERG "intc: no clock defined\n");
 108                 goto fail;
 109         }
 110
 111         clk_enable(pclk);
 112
 113         intc0.regs = ioremap(regs->start, regs->end - regs->start + 1);
 114         if (!intc0.regs) {
 115                 printk(KERN_EMERG "intc: failed to map registers (0x%08lx)\n",
 116                        (unsigned long)regs->start);
 117                 goto fail;
 118         }
 119
 120         /*
 121          * Initialize all interrupts to level 0 (lowest priority). The
 122          * priority level may be changed by calling
 123          * irq_set_priority().
 124          *
 125          */
 126         offset = (unsigned long)&irq_level0 - (unsigned long)&_evba;
 127         for (i = 0; i < NR_INTERNAL_IRQS; i++) {
 128                 intc_writel(&intc0, INTPR0 + 4 * i, offset);
 129                 readback = intc_readl(&intc0, INTPR0 + 4 * i);
 130                 if (readback == offset)
 131                         set_irq_chip_and_handler(i, &intc0.chip,
 132                                                  handle_simple_irq);
 133         }
 134
 135         /* Unmask all interrupt levels */
 136         sysreg_write(SR, (sysreg_read(SR)
 137                           & ~(SR_I3M | SR_I2M | SR_I1M | SR_I0M)));
 138
 139         return;
 140
 141 fail:
 142         panic("Interrupt controller initialization failed!\n");
 143 }
 144
 145 #ifdef CONFIG_PM
 146 void intc_set_suspend_handler(unsigned long offset)
 147 {
 148         intc0.suspend_ipr = offset;
 149 }
 150
 151 static int intc_suspend(struct sys_device *sdev, pm_message_t state)
 152 {
 153         struct intc *intc = container_of(sdev, struct intc, sysdev);
 154         int i;
 155
 156         if (unlikely(!irqs_disabled())) {
 157                 pr_err("intc_suspend: called with interrupts enabled\n");
 158                 return -EINVAL;
 159         }
 160
 161         if (unlikely(!intc->suspend_ipr)) {
 162                 pr_err("intc_suspend: suspend_ipr not initialized\n");
 163                 return -EINVAL;
 164         }
 165
 166         for (i = 0; i < 64; i++) {
 167                 intc->saved_ipr[i] = intc_readl(intc, INTPR0 + 4 * i);
 168                 intc_writel(intc, INTPR0 + 4 * i, intc->suspend_ipr);
 169         }
 170
 171         return 0;
 172 }
 173
 174 static int intc_resume(struct sys_device *sdev)
 175 {
 176         struct intc *intc = container_of(sdev, struct intc, sysdev);
 177         int i;
 178
 179         WARN_ON(!irqs_disabled());
 180
 181         for (i = 0; i < 64; i++)
 182                 intc_writel(intc, INTPR0 + 4 * i, intc->saved_ipr[i]);
 183
 184         return 0;
 185 }
 186 #else
 187 #define intc_suspend    NULL
 188 #define intc_resume     NULL
 189 #endif
 190
 191 static struct sysdev_class intc_class = {
 192         .name           = "intc",
 193         .suspend        = intc_suspend,
 194         .resume         = intc_resume,
 195 };
 196
 197 static int __init intc_init_sysdev(void)
 198 {
 199         int ret;
 200
 201         ret = sysdev_class_register(&intc_class);
 202         if (ret)
 203                 return ret;
 204
 205         intc0.sysdev.id = 0;
 206         intc0.sysdev.cls = &intc_class;
 207         ret = sysdev_register(&intc0.sysdev);
 208
 209         return ret;
 210 }
 211 device_initcall(intc_init_sysdev);
 212
 213 unsigned long intc_get_pending(unsigned int group)
 214 {
 215         return intc_readl(&intc0, INTREQ0 + 4 * group);
 216 }
 217 EXPORT_SYMBOL_GPL(intc_get_pending);