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 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 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