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