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 #include <asm/mach-jz4740/base.h>
  33
  34 static void __iomem *jz_intc_base;
  35
  36 #define JZ_REG_INTC_STATUS      0x00
  37 #define JZ_REG_INTC_MASK        0x04
  38 #define JZ_REG_INTC_SET_MASK    0x08
  39 #define JZ_REG_INTC_CLEAR_MASK  0x0c
  40 #define JZ_REG_INTC_PENDING     0x10
  41
  42 static irqreturn_t jz4740_cascade(int irq, void *data)
  43 {
  44         uint32_t irq_reg;
  45
  46         irq_reg = readl(jz_intc_base + JZ_REG_INTC_PENDING);
  47
  48         if (irq_reg)
  49                 generic_handle_irq(__fls(irq_reg) + JZ4740_IRQ_BASE);
  50
  51         return IRQ_HANDLED;
  52 }
  53
  54 static void jz4740_irq_set_mask(struct irq_chip_generic *gc, uint32_t mask)
  55 {
  56         struct irq_chip_regs *regs = &gc->chip_types->regs;
  57
  58         writel(mask, gc->reg_base + regs->enable);
  59         writel(~mask, gc->reg_base + regs->disable);
  60 }
  61
  62 void jz4740_irq_suspend(struct irq_data *data)
  63 {
  64         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
  65         jz4740_irq_set_mask(gc, gc->wake_active);
  66 }
  67
  68 void jz4740_irq_resume(struct irq_data *data)
  69 {
  70         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
  71         jz4740_irq_set_mask(gc, gc->mask_cache);
  72 }
  73
  74 static struct irqaction jz4740_cascade_action = {
  75         .handler = jz4740_cascade,
  76         .name = "JZ4740 cascade interrupt",
  77 };
  78
  79 void __init arch_init_irq(void)
  80 {
  81         struct irq_chip_generic *gc;
  82         struct irq_chip_type *ct;
  83
  84         mips_cpu_irq_init();
  85
  86         jz_intc_base = ioremap(JZ4740_INTC_BASE_ADDR, 0x14);
  87
  88         /* Mask all irqs */
  89         writel(0xffffffff, jz_intc_base + JZ_REG_INTC_SET_MASK);
  90
  91         gc = irq_alloc_generic_chip("INTC", 1, JZ4740_IRQ_BASE, jz_intc_base,
  92                 handle_level_irq);
  93
  94         gc->wake_enabled = IRQ_MSK(32);
  95
  96         ct = gc->chip_types;
  97         ct->regs.enable = JZ_REG_INTC_CLEAR_MASK;
  98         ct->regs.disable = JZ_REG_INTC_SET_MASK;
  99         ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
 100         ct->chip.irq_mask = irq_gc_mask_disable_reg;
 101         ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
 102         ct->chip.irq_set_wake = irq_gc_set_wake;
 103         ct->chip.irq_suspend = jz4740_irq_suspend;
 104         ct->chip.irq_resume = jz4740_irq_resume;
 105
 106         irq_setup_generic_chip(gc, IRQ_MSK(32), 0, 0, IRQ_NOPROBE | IRQ_LEVEL);
 107
 108         setup_irq(2, &jz4740_cascade_action);
 109 }
 110
 111 asmlinkage void plat_irq_dispatch(void)
 112 {
 113         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
 114         if (pending & STATUSF_IP2)
 115                 do_IRQ(2);
 116         else if (pending & STATUSF_IP3)
 117                 do_IRQ(3);
 118         else
 119                 spurious_interrupt();
 120 }
 121
 122 #ifdef CONFIG_DEBUG_FS
 123
 124 static inline void intc_seq_reg(struct seq_file *s, const char *name,
 125         unsigned int reg)
 126 {
 127         seq_printf(s, "%s:\t\t%08x\n", name, readl(jz_intc_base + reg));
 128 }
 129
 130 static int intc_regs_show(struct seq_file *s, void *unused)
 131 {
 132         intc_seq_reg(s, "Status", JZ_REG_INTC_STATUS);
 133         intc_seq_reg(s, "Mask", JZ_REG_INTC_MASK);
 134         intc_seq_reg(s, "Pending", JZ_REG_INTC_PENDING);
 135
 136         return 0;
 137 }
 138
 139 static int intc_regs_open(struct inode *inode, struct file *file)
 140 {
 141         return single_open(file, intc_regs_show, NULL);
 142 }
 143
 144 static const struct file_operations intc_regs_operations = {
 145         .open           = intc_regs_open,
 146         .read           = seq_read,
 147         .llseek         = seq_lseek,
 148         .release        = single_release,
 149 };
 150
 151 static int __init intc_debugfs_init(void)
 152 {
 153         (void) debugfs_create_file("jz_regs_intc", S_IFREG | S_IRUGO,
 154                                 NULL, NULL, &intc_regs_operations);
 155         return 0;
 156 }
 157 subsys_initcall(intc_debugfs_init);
 158
 159 #endif