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(struct irq_data *d)
  34 {
  35         unsigned int mask = 1 << (d->irq & 7);
  36
  37         outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
  38 }
  39
  40 static void isa_ack_pic_lo_irq(struct irq_data *d)
  41 {
  42         unsigned int mask = 1 << (d->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(struct irq_data *d)
  49 {
  50         unsigned int mask = 1 << (d->irq & 7);
  51
  52         outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO);
  53 }
  54
  55 static struct irq_chip isa_lo_chip = {
  56         .irq_ack        = isa_ack_pic_lo_irq,
  57         .irq_mask       = isa_mask_pic_lo_irq,
  58         .irq_unmask     = isa_unmask_pic_lo_irq,
  59 };
  60
  61 static void isa_mask_pic_hi_irq(struct irq_data *d)
  62 {
  63         unsigned int mask = 1 << (d->irq & 7);
  64
  65         outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
  66 }
  67
  68 static void isa_ack_pic_hi_irq(struct irq_data *d)
  69 {
  70         unsigned int mask = 1 << (d->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(struct irq_data *d)
  78 {
  79         unsigned int mask = 1 << (d->irq & 7);
  80
  81         outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI);
  82 }
  83
  84 static struct irq_chip isa_hi_chip = {
  85         .irq_ack        = isa_ack_pic_hi_irq,
  86         .irq_mask       = isa_mask_pic_hi_irq,
  87         .irq_unmask     = isa_unmask_pic_hi_irq,
  88 };
  89
  90 static void isa_irq_handler(struct irq_desc *desc)
  91 {
  92         unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE;
  93
  94         if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) {
  95                 do_bad_IRQ(desc);
  96                 return;
  97         }
  98
  99         generic_handle_irq(isa_irq);
 100 }
 101
 102 static struct irqaction irq_cascade = {
 103         .handler = no_action,
 104         .name = "cascade",
 105 };
 106
 107 static struct resource pic1_resource = {
 108         .name   = "pic1",
 109         .start  = 0x20,
 110         .end    = 0x3f,
 111 };
 112
 113 static struct resource pic2_resource = {
 114         .name   = "pic2",
 115         .start  = 0xa0,
 116         .end    = 0xbf,
 117 };
 118
 119 void __init isa_init_irq(unsigned int host_irq)
 120 {
 121         unsigned int irq;
 122
 123         /*
 124          * Setup, and then probe for an ISA PIC
 125          * If the PIC is not there, then we
 126          * ignore the PIC.
 127          */
 128         outb(0x11, PIC_LO);
 129         outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number           */
 130         outb(0x04, PIC_MASK_LO);        /* Slave on Ch2         */
 131         outb(0x01, PIC_MASK_LO);        /* x86                  */
 132         outb(0xf5, PIC_MASK_LO);        /* pattern: 11110101    */
 133
 134         outb(0x11, PIC_HI);
 135         outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number           */
 136         outb(0x02, PIC_MASK_HI);        /* Slave on Ch1         */
 137         outb(0x01, PIC_MASK_HI);        /* x86                  */
 138         outb(0xfa, PIC_MASK_HI);        /* pattern: 11111010    */
 139
 140         outb(0x0b, PIC_LO);
 141         outb(0x0b, PIC_HI);
 142
 143         if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) {
 144                 outb(0xff, PIC_MASK_LO);/* mask all IRQs        */
 145                 outb(0xff, PIC_MASK_HI);/* mask all IRQs        */
 146         } else {
 147                 printk(KERN_INFO "IRQ: ISA PIC not found\n");
 148                 host_irq = (unsigned int)-1;
 149         }
 150
 151         if (host_irq != (unsigned int)-1) {
 152                 for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) {
 153                         irq_set_chip_and_handler(irq, &isa_lo_chip,
 154                                                  handle_level_irq);
 155                         irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
 156                 }
 157
 158                 for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) {
 159                         irq_set_chip_and_handler(irq, &isa_hi_chip,
 160                                                  handle_level_irq);
 161                         irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
 162                 }
 163
 164                 request_resource(&ioport_resource, &pic1_resource);
 165                 request_resource(&ioport_resource, &pic2_resource);
 166                 setup_irq(IRQ_ISA_CASCADE, &irq_cascade);
 167
 168                 irq_set_chained_handler(host_irq, isa_irq_handler);
 169
 170                 /*
 171                  * On the NetWinder, don't automatically
 172                  * enable ISA IRQ11 when it is requested.
 173                  * There appears to be a missing pull-up
 174                  * resistor on this line.
 175                  */
 176                 if (machine_is_netwinder())
 177                         irq_modify_status(_ISA_IRQ(11),
 178                                 IRQ_NOREQUEST | IRQ_NOPROBE, IRQ_NOAUTOEN);
 179         }
 180 }
 181
 182