target/linux/adm8668/files/arch/mips/adm8668/irq.c

   1 /*
   2  * Copyright (C) 2010 Scott Nicholas <neutronscott@scottn.us>
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/kernel_stat.h>
  11 #include <linux/signal.h>
  12 #include <linux/sched.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/slab.h>
  15 #include <linux/random.h>
  16 #include <linux/pm.h>
  17 #include <linux/irq.h>
  18 #include <asm/mipsregs.h>
  19 #include <asm/irq_cpu.h>
  20 #include <asm/irq.h>
  21 #include <adm8668.h>
  22
  23 static void adm8668_irq_cascade(void)
  24 {
  25         int i;
  26         unsigned long intsrc;
  27
  28         intsrc = ADM8668_INTC_REG(IRQ_STATUS_REG) & IRQ_MASK;
  29         for (i = 0; intsrc; intsrc >>= 1, i++)
  30                 if (intsrc & 0x1)
  31                         do_IRQ(i);
  32 }
  33
  34 /*
  35  * System irq dispatch
  36  */
  37 void plat_irq_dispatch(void)
  38 {
  39         unsigned int pending;
  40
  41         pending = read_c0_cause() & read_c0_status() & ST0_IM;
  42
  43         /* timer interrupt, that we renumbered */
  44         if (pending & STATUSF_IP7)
  45                 do_IRQ(MIPS_CPU_IRQ_BASE + 7);
  46         if (pending & STATUSF_IP2)
  47                 adm8668_irq_cascade();
  48 }
  49
  50 /*
  51  * enable 8668 irq
  52  */
  53 static void enable_adm8668_irq(struct irq_data *d)
  54 {
  55         int irq = d->irq;
  56
  57         if ((irq < 0) || (irq > NR_IRQS))
  58                 return;
  59
  60         ADM8668_INTC_REG(IRQ_ENABLE_REG) = (1 << irq);
  61 }
  62
  63
  64 /*
  65  * disable 8668 irq
  66  */
  67 static void disable_adm8668_irq(struct irq_data *d)
  68 {
  69         int irq = d->irq;
  70
  71         if ((irq < 0) || (irq > NR_IRQS))
  72                 return;
  73
  74         ADM8668_INTC_REG(IRQ_DISABLE_REG) = (1 << irq);
  75 }
  76
  77 static void ack_adm8668_irq(struct irq_data *d)
  78 {
  79         int irq = d->irq;
  80
  81         ADM8668_INTC_REG(IRQ_DISABLE_REG) = (1 << irq);
  82 }
  83
  84 /*
  85  * system irq type
  86  */
  87
  88 static struct irq_chip adm8668_irq_type = {
  89         .name = "adm8668",
  90         .irq_ack = ack_adm8668_irq,
  91         .irq_mask = disable_adm8668_irq,
  92         .irq_unmask = enable_adm8668_irq
  93 };
  94
  95 /*
  96  * irq init
  97  */
  98 static void __init init_adm8668_irqs(void)
  99 {
 100         int i;
 101
 102         for (i = 0; i <= INT_LVL_MAX; i++)
 103                 irq_set_chip_and_handler(i, &adm8668_irq_type,
 104                         handle_level_irq);
 105
 106         /* hw0 is where our interrupts are uh.. interrupted at. */
 107         set_c0_status(IE_IRQ0);
 108 }
 109
 110 /*
 111  * system init
 112  */
 113 void __init arch_init_irq(void)
 114 {
 115         mips_cpu_irq_init();
 116         init_adm8668_irqs();
 117 }