target/linux/xburst/files-2.6.32/arch/mips/jz4740/irq.c

   1 /*
   2  *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
   3  *      JZ4740 platform IRQ support
   4  *
   5  *  This program is free software; you can redistribute  it and/or modify it
   6  *  under  the terms of  the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the  License, or (at your
   8  *  option) any later version.
   9  *
  10  *  You should have received a copy of the  GNU General Public License along
  11  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  12  *  675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  */
  15
  16 #include <linux/errno.h>
  17 #include <linux/init.h>
  18 #include <linux/types.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/ioport.h>
  21 #include <linux/timex.h>
  22 #include <linux/slab.h>
  23 #include <linux/delay.h>
  24
  25 #include <linux/debugfs.h>
  26 #include <linux/seq_file.h>
  27
  28 #include <asm/io.h>
  29 #include <asm/mipsregs.h>
  30 #include <asm/irq_cpu.h>
  31
  32 static void __iomem *jz_intc_base;
  33 static uint32_t jz_intc_wakeup;
  34 static uint32_t jz_intc_saved;
  35
  36 #define JZ_REG_BASE_INTC 0x10001000
  37
  38 #define JZ_REG_INTC_STATUS      0x00
  39 #define JZ_REG_INTC_MASK        0x04
  40 #define JZ_REG_INTC_SET_MASK    0x08
  41 #define JZ_REG_INTC_CLEAR_MASK  0x0c
  42 #define JZ_REG_INTC_PENDING     0x10
  43
  44 #define IRQ_BIT(x) BIT((x) - JZ_IRQ_BASE)
  45
  46 static void intc_irq_unmask(unsigned int irq)
  47 {
  48         writel(IRQ_BIT(irq), jz_intc_base + JZ_REG_INTC_CLEAR_MASK);
  49 }
  50
  51 static void intc_irq_mask(unsigned int irq)
  52 {
  53         writel(IRQ_BIT(irq), jz_intc_base + JZ_REG_INTC_SET_MASK);
  54 }
  55
  56 static void intc_irq_ack(unsigned int irq)
  57 {
  58         writel(IRQ_BIT(irq), jz_intc_base + JZ_REG_INTC_PENDING);
  59 }
  60
  61 static int intc_irq_set_wake(unsigned int irq, unsigned int on)
  62 {
  63         if (on)
  64                 jz_intc_wakeup |= IRQ_BIT(irq);
  65         else
  66                 jz_intc_wakeup &= ~IRQ_BIT(irq);
  67
  68         return 0;
  69 }
  70
  71 static struct irq_chip intc_irq_type = {
  72         .name =         "INTC",
  73         .mask =         intc_irq_mask,
  74         .unmask =       intc_irq_unmask,
  75         .ack =          intc_irq_ack,
  76         .set_wake =     intc_irq_set_wake,
  77 };
  78
  79 static irqreturn_t jz4740_cascade(int irq, void *data)
  80 {
  81         uint32_t irq_reg;
  82
  83         irq_reg = readl(jz_intc_base + JZ_REG_INTC_PENDING);
  84         generic_handle_irq(ffs(irq_reg) - 1 + JZ_IRQ_BASE);
  85
  86         return IRQ_HANDLED;
  87 }
  88
  89 static struct irqaction jz4740_cascade_action = {
  90         .handler = jz4740_cascade,
  91         .name = "JZ4740 cascade interrupt"
  92 };
  93
  94 void __init arch_init_irq(void)
  95 {
  96         int i;
  97         mips_cpu_irq_init();
  98
  99         jz_intc_base = ioremap(JZ_REG_BASE_INTC, 0x14);
 100
 101         for (i = JZ_IRQ_BASE; i < JZ_IRQ_BASE + 32; i++) {
 102                 intc_irq_mask(i);
 103                 set_irq_chip_and_handler(i, &intc_irq_type, handle_level_irq);
 104         }
 105
 106         setup_irq(2, &jz4740_cascade_action);
 107 }
 108
 109 asmlinkage void plat_irq_dispatch(void)
 110 {
 111         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
 112         if (pending & STATUSF_IP2)
 113                 jz4740_cascade(2, NULL);
 114         else if(pending & STATUSF_IP3)
 115                 do_IRQ(3);
 116         else
 117                 spurious_interrupt();
 118 }
 119
 120 /* TODO: Use sysdev */
 121 void jz4740_intc_suspend(void)
 122 {
 123         jz_intc_saved = readl(jz_intc_base + JZ_REG_INTC_MASK);
 124         writel(~jz_intc_wakeup, jz_intc_base + JZ_REG_INTC_SET_MASK);
 125 }
 126
 127 void jz4740_intc_resume(void)
 128 {
 129         writel(~jz_intc_saved, jz_intc_base + JZ_REG_INTC_CLEAR_MASK);
 130 }
 131
 132 #ifdef CONFIG_DEBUG_FS
 133
 134 static int intc_regs_show(struct seq_file *s, void *unused)
 135 {
 136         seq_printf(s, "Status:\t\t%08x\n", readl(jz_intc_base + JZ_REG_INTC_STATUS));
 137         seq_printf(s, "Mask\t\t%08x\n", readl(jz_intc_base + JZ_REG_INTC_MASK));
 138         seq_printf(s, "Pending:\t%08x\n", readl(jz_intc_base + JZ_REG_INTC_PENDING));
 139
 140         return 0;
 141 }
 142
 143 static int intc_regs_open(struct inode *inode, struct file *file)
 144 {
 145         return single_open(file, intc_regs_show, NULL);
 146 }
 147
 148 static const struct file_operations intc_regs_operations = {
 149         .open           = intc_regs_open,
 150         .read           = seq_read,
 151         .llseek         = seq_lseek,
 152         .release        = single_release,
 153 };
 154
 155 static int __init intc_debugfs_init(void)
 156 {
 157         (void) debugfs_create_file("jz_regs_intc", S_IFREG | S_IRUGO,
 158                                 NULL, NULL, &intc_regs_operations);
 159         return 0;
 160 }
 161 subsys_initcall(intc_debugfs_init);
 162
 163 #endif