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 } 181 182 183