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 22 #include <asm/mach/irq.h> 23 24 #include <asm/hardware.h> 25 #include <asm/hardware/dec21285.h> 26 #include <asm/irq.h> 27 #include <asm/io.h> 28 #include <asm/mach-types.h> 29 30 static void isa_mask_pic_lo_irq(unsigned int irq) 31 { 32 unsigned int mask = 1 << (irq & 7); 33 34 outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO); 35 } 36 37 static void isa_ack_pic_lo_irq(unsigned int irq) 38 { 39 unsigned int mask = 1 << (irq & 7); 40 41 outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO); 42 outb(0x20, PIC_LO); 43 } 44 45 static void isa_unmask_pic_lo_irq(unsigned int irq) 46 { 47 unsigned int mask = 1 << (irq & 7); 48 49 outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO); 50 } 51 52 static struct irq_chip isa_lo_chip = { 53 .ack = isa_ack_pic_lo_irq, 54 .mask = isa_mask_pic_lo_irq, 55 .unmask = isa_unmask_pic_lo_irq, 56 }; 57 58 static void isa_mask_pic_hi_irq(unsigned int irq) 59 { 60 unsigned int mask = 1 << (irq & 7); 61 62 outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI); 63 } 64 65 static void isa_ack_pic_hi_irq(unsigned int irq) 66 { 67 unsigned int mask = 1 << (irq & 7); 68 69 outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI); 70 outb(0x62, PIC_LO); 71 outb(0x20, PIC_HI); 72 } 73 74 static void isa_unmask_pic_hi_irq(unsigned int irq) 75 { 76 unsigned int mask = 1 << (irq & 7); 77 78 outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI); 79 } 80 81 static struct irq_chip isa_hi_chip = { 82 .ack = isa_ack_pic_hi_irq, 83 .mask = isa_mask_pic_hi_irq, 84 .unmask = isa_unmask_pic_hi_irq, 85 }; 86 87 static void 88 isa_irq_handler(unsigned int irq, struct irq_desc *desc) 89 { 90 unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE; 91 92 if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) { 93 do_bad_IRQ(isa_irq, desc); 94 return; 95 } 96 97 desc = irq_desc + isa_irq; 98 desc_handle_irq(isa_irq, desc); 99 } 100 101 static struct irqaction irq_cascade = { 102 .handler = no_action, 103 .name = "cascade", 104 }; 105 106 static struct resource pic1_resource = { 107 .name = "pic1", 108 .start = 0x20, 109 .end = 0x3f, 110 }; 111 112 static struct resource pic2_resource = { 113 .name = "pic2", 114 .start = 0xa0, 115 .end = 0xbf, 116 }; 117 118 void __init isa_init_irq(unsigned int host_irq) 119 { 120 unsigned int irq; 121 122 /* 123 * Setup, and then probe for an ISA PIC 124 * If the PIC is not there, then we 125 * ignore the PIC. 126 */ 127 outb(0x11, PIC_LO); 128 outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number */ 129 outb(0x04, PIC_MASK_LO); /* Slave on Ch2 */ 130 outb(0x01, PIC_MASK_LO); /* x86 */ 131 outb(0xf5, PIC_MASK_LO); /* pattern: 11110101 */ 132 133 outb(0x11, PIC_HI); 134 outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number */ 135 outb(0x02, PIC_MASK_HI); /* Slave on Ch1 */ 136 outb(0x01, PIC_MASK_HI); /* x86 */ 137 outb(0xfa, PIC_MASK_HI); /* pattern: 11111010 */ 138 139 outb(0x0b, PIC_LO); 140 outb(0x0b, PIC_HI); 141 142 if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) { 143 outb(0xff, PIC_MASK_LO);/* mask all IRQs */ 144 outb(0xff, PIC_MASK_HI);/* mask all IRQs */ 145 } else { 146 printk(KERN_INFO "IRQ: ISA PIC not found\n"); 147 host_irq = (unsigned int)-1; 148 } 149 150 if (host_irq != (unsigned int)-1) { 151 for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) { 152 set_irq_chip(irq, &isa_lo_chip); 153 set_irq_handler(irq, handle_level_irq); 154 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); 155 } 156 157 for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) { 158 set_irq_chip(irq, &isa_hi_chip); 159 set_irq_handler(irq, handle_level_irq); 160 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); 161 } 162 163 request_resource(&ioport_resource, &pic1_resource); 164 request_resource(&ioport_resource, &pic2_resource); 165 setup_irq(IRQ_ISA_CASCADE, &irq_cascade); 166 167 set_irq_chained_handler(host_irq, isa_irq_handler); 168 169 /* 170 * On the NetWinder, don't automatically 171 * enable ISA IRQ11 when it is requested. 172 * There appears to be a missing pull-up 173 * resistor on this line. 174 */ 175 if (machine_is_netwinder()) 176 set_irq_flags(_ISA_IRQ(11), IRQF_VALID | 177 IRQF_PROBE | IRQF_NOAUTOEN); 178 } 179 } 180 181 182