arch/arm/mach-shark/irq.c

   1 /*
   2  *  linux/arch/arm/mach-shark/irq.c
   3  *
   4  * by Alexander Schulz
   5  *
   6  * derived from linux/arch/ppc/kernel/i8259.c and:
   7  * include/asm-arm/arch-ebsa110/irq.h
   8  * Copyright (C) 1996-1998 Russell King
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/fs.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/interrupt.h>
  15
  16 #include <asm/irq.h>
  17 #include <asm/io.h>
  18 #include <asm/mach/irq.h>
  19
  20 /*
  21  * 8259A PIC functions to handle ISA devices:
  22  */
  23
  24 /*
  25  * This contains the irq mask for both 8259A irq controllers,
  26  * Let through the cascade-interrupt no. 2 (ff-(1<<2)==fb)
  27  */
  28 static unsigned char cached_irq_mask[2] = { 0xfb, 0xff };
  29
  30 /*
  31  * These have to be protected by the irq controller spinlock
  32  * before being called.
  33  */
  34 static void shark_disable_8259A_irq(unsigned int irq)
  35 {
  36         unsigned int mask;
  37         if (irq<8) {
  38           mask = 1 << irq;
  39           cached_irq_mask[0] |= mask;
  40           outb(cached_irq_mask[1],0xA1);
  41         } else {
  42           mask = 1 << (irq-8);
  43           cached_irq_mask[1] |= mask;
  44           outb(cached_irq_mask[0],0x21);
  45         }
  46 }
  47
  48 static void shark_enable_8259A_irq(unsigned int irq)
  49 {
  50         unsigned int mask;
  51         if (irq<8) {
  52           mask = ~(1 << irq);
  53           cached_irq_mask[0] &= mask;
  54           outb(cached_irq_mask[0],0x21);
  55         } else {
  56           mask = ~(1 << (irq-8));
  57           cached_irq_mask[1] &= mask;
  58           outb(cached_irq_mask[1],0xA1);
  59         }
  60 }
  61
  62 static void shark_ack_8259A_irq(unsigned int irq){}
  63
  64 static irqreturn_t bogus_int(int irq, void *dev_id, struct pt_regs *regs)
  65 {
  66         printk("Got interrupt %i!\n",irq);
  67         return IRQ_NONE;
  68 }
  69
  70 static struct irqaction cascade;
  71
  72 static struct irq_chip fb_chip = {
  73         .name   = "XT-PIC",
  74         .ack    = shark_ack_8259A_irq,
  75         .mask   = shark_disable_8259A_irq,
  76         .unmask = shark_enable_8259A_irq,
  77 };
  78
  79 void __init shark_init_irq(void)
  80 {
  81         int irq;
  82
  83         for (irq = 0; irq < NR_IRQS; irq++) {
  84                 set_irq_chip(irq, &fb_chip);
  85                 set_irq_handler(irq, do_edge_IRQ);
  86                 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
  87         }
  88
  89         /* init master interrupt controller */
  90         outb(0x11, 0x20); /* Start init sequence, edge triggered (level: 0x19)*/
  91         outb(0x00, 0x21); /* Vector base */
  92         outb(0x04, 0x21); /* Cascade (slave) on IRQ2 */
  93         outb(0x03, 0x21); /* Select 8086 mode , auto eoi*/
  94         outb(0x0A, 0x20);
  95         /* init slave interrupt controller */
  96         outb(0x11, 0xA0); /* Start init sequence, edge triggered */
  97         outb(0x08, 0xA1); /* Vector base */
  98         outb(0x02, 0xA1); /* Cascade (slave) on IRQ2 */
  99         outb(0x03, 0xA1); /* Select 8086 mode, auto eoi */
 100         outb(0x0A, 0xA0);
 101         outb(cached_irq_mask[1],0xA1);
 102         outb(cached_irq_mask[0],0x21);
 103         //request_region(0x20,0x2,"pic1");
 104         //request_region(0xA0,0x2,"pic2");
 105
 106         cascade.handler = bogus_int;
 107         cascade.name = "cascade";
 108         setup_irq(2,&cascade);
 109 }
 110