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 33static 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 40static 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 48static 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 55static 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 61static 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 68static 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 77static 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 84static 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 90static void 91isa_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 103static struct irqaction irq_cascade = { 104 .handler = no_action, 105 .name = "cascade", 106}; 107 108static struct resource pic1_resource = { 109 .name = "pic1", 110 .start = 0x20, 111 .end = 0x3f, 112}; 113 114static struct resource pic2_resource = { 115 .name = "pic2", 116 .start = 0xa0, 117 .end = 0xbf, 118}; 119 120void __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 irq_set_chip_and_handler(irq, &isa_lo_chip, 155 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 irq_set_chip_and_handler(irq, &isa_hi_chip, 161 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 irq_set_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} 182 183 184