arch/arm/mach-footbridge/isa-irq.c

   1 /*
   2  *  linux/arch/arm/mach-footbridge/irq.c
   3  *
   4  *  Copyright (C) 1996-2000 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  Changelog:
  11  *   22-Aug-1998 RMK    Restructured IRQ routines
  12  *   03-Sep-1998 PJB    Merged CATS support
  13  *   20-Jan-1998 RMK    Started merge of EBSA286, CATS and NetWinder
  14  *   26-Jan-1999 PJB    Don't use IACK on CATS
  15  *   16-Mar-1999 RMK    Added autodetect of ISA PICs
  16  */
  17 #include <linux/ioport.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/list.h>
  20 #include <linux/init.h>
  21 #include <linux/io.h>
  22 #include <linux/spinlock.h>
  23
  24 #include <asm/mach/irq.h>
  25
  26 #include <mach/hardware.h>
  27 #include <asm/hardware/dec21285.h>
  28 #include <asm/irq.h>
  29 #include <asm/mach-types.h>
  30
  31 #include "common.h"
  32
  33 static void isa_mask_pic_lo_irq(unsigned int irq)
  34 {
  35         unsigned int mask = 1 << (irq & 7);
  36
  37         outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
  38 }
  39
  40 static void isa_ack_pic_lo_irq(unsigned int irq)
  41 {
  42         unsigned int mask = 1 << (irq & 7);
  43
  44         outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
  45         outb(0x20, PIC_LO);
  46 }
  47
  48 static void isa_unmask_pic_lo_irq(unsigned int irq)
  49 {
  50         unsigned int mask = 1 << (irq & 7);
  51
  52         outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO);
  53 }
  54
  55 static struct irq_chip isa_lo_chip = {
  56         .ack    = isa_ack_pic_lo_irq,
  57         .mask   = isa_mask_pic_lo_irq,
  58         .unmask = isa_unmask_pic_lo_irq,
  59 };
  60
  61 static void isa_mask_pic_hi_irq(unsigned int irq)
  62 {
  63         unsigned int mask = 1 << (irq & 7);
  64
  65         outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
  66 }
  67
  68 static void isa_ack_pic_hi_irq(unsigned int irq)
  69 {
  70         unsigned int mask = 1 << (irq & 7);
  71
  72         outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
  73         outb(0x62, PIC_LO);
  74         outb(0x20, PIC_HI);
  75 }
  76
  77 static void isa_unmask_pic_hi_irq(unsigned int irq)
  78 {
  79         unsigned int mask = 1 << (irq & 7);
  80
  81         outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI);
  82 }
  83
  84 static struct irq_chip isa_hi_chip = {
  85         .ack    = isa_ack_pic_hi_irq,
  86         .mask   = isa_mask_pic_hi_irq,
  87         .unmask = isa_unmask_pic_hi_irq,
  88 };
  89
  90 static void
  91 isa_irq_handler(unsigned int irq, struct irq_desc *desc)
  92 {
  93         unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE;
  94
  95         if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) {
  96                 do_bad_IRQ(isa_irq, desc);
  97                 return;
  98         }
  99
 100         generic_handle_irq(isa_irq);
 101 }
 102
 103 static struct irqaction irq_cascade = {
 104         .handler = no_action,
 105         .name = "cascade",
 106 };
 107
 108 static struct resource pic1_resource = {
 109         .name   = "pic1",
 110         .start  = 0x20,
 111         .end    = 0x3f,
 112 };
 113
 114 static struct resource pic2_resource = {
 115         .name   = "pic2",
 116         .start  = 0xa0,
 117         .end    = 0xbf,
 118 };
 119
 120 void __init isa_init_irq(unsigned int host_irq)
 121 {
 122         unsigned int irq;
 123
 124         /*
 125          * Setup, and then probe for an ISA PIC
 126          * If the PIC is not there, then we
 127          * ignore the PIC.
 128          */
 129         outb(0x11, PIC_LO);
 130         outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number           */
 131         outb(0x04, PIC_MASK_LO);        /* Slave on Ch2         */
 132         outb(0x01, PIC_MASK_LO);        /* x86                  */
 133         outb(0xf5, PIC_MASK_LO);        /* pattern: 11110101    */
 134
 135         outb(0x11, PIC_HI);
 136         outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number           */
 137         outb(0x02, PIC_MASK_HI);        /* Slave on Ch1         */
 138         outb(0x01, PIC_MASK_HI);        /* x86                  */
 139         outb(0xfa, PIC_MASK_HI);        /* pattern: 11111010    */
 140
 141         outb(0x0b, PIC_LO);
 142         outb(0x0b, PIC_HI);
 143
 144         if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) {
 145                 outb(0xff, PIC_MASK_LO);/* mask all IRQs        */
 146                 outb(0xff, PIC_MASK_HI);/* mask all IRQs        */
 147         } else {
 148                 printk(KERN_INFO "IRQ: ISA PIC not found\n");
 149                 host_irq = (unsigned int)-1;
 150         }
 151
 152         if (host_irq != (unsigned int)-1) {
 153                 for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) {
 154                         set_irq_chip(irq, &isa_lo_chip);
 155                         set_irq_handler(irq, handle_level_irq);
 156                         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 157                 }
 158
 159                 for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) {
 160                         set_irq_chip(irq, &isa_hi_chip);
 161                         set_irq_handler(irq, handle_level_irq);
 162                         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 163                 }
 164
 165                 request_resource(&ioport_resource, &pic1_resource);
 166                 request_resource(&ioport_resource, &pic2_resource);
 167                 setup_irq(IRQ_ISA_CASCADE, &irq_cascade);
 168
 169                 set_irq_chained_handler(host_irq, isa_irq_handler);
 170
 171                 /*
 172                  * On the NetWinder, don't automatically
 173                  * enable ISA IRQ11 when it is requested.
 174                  * There appears to be a missing pull-up
 175                  * resistor on this line.
 176                  */
 177                 if (machine_is_netwinder())
 178                         set_irq_flags(_ISA_IRQ(11), IRQF_VALID |
 179                                       IRQF_PROBE | IRQF_NOAUTOEN);
 180         }
 181 }
 182
 183