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 23 #include <asm/mach/irq.h> 24 25 #include <mach/hardware.h> 26 #include <asm/hardware/dec21285.h> 27 #include <asm/irq.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 generic_handle_irq(isa_irq); 98 } 99 100 static struct irqaction irq_cascade = { 101 .handler = no_action, 102 .name = "cascade", 103 }; 104 105 static struct resource pic1_resource = { 106 .name = "pic1", 107 .start = 0x20, 108 .end = 0x3f, 109 }; 110 111 static struct resource pic2_resource = { 112 .name = "pic2", 113 .start = 0xa0, 114 .end = 0xbf, 115 }; 116 117 void __init isa_init_irq(unsigned int host_irq) 118 { 119 unsigned int irq; 120 121 /* 122 * Setup, and then probe for an ISA PIC 123 * If the PIC is not there, then we 124 * ignore the PIC. 125 */ 126 outb(0x11, PIC_LO); 127 outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number */ 128 outb(0x04, PIC_MASK_LO); /* Slave on Ch2 */ 129 outb(0x01, PIC_MASK_LO); /* x86 */ 130 outb(0xf5, PIC_MASK_LO); /* pattern: 11110101 */ 131 132 outb(0x11, PIC_HI); 133 outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number */ 134 outb(0x02, PIC_MASK_HI); /* Slave on Ch1 */ 135 outb(0x01, PIC_MASK_HI); /* x86 */ 136 outb(0xfa, PIC_MASK_HI); /* pattern: 11111010 */ 137 138 outb(0x0b, PIC_LO); 139 outb(0x0b, PIC_HI); 140 141 if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) { 142 outb(0xff, PIC_MASK_LO);/* mask all IRQs */ 143 outb(0xff, PIC_MASK_HI);/* mask all IRQs */ 144 } else { 145 printk(KERN_INFO "IRQ: ISA PIC not found\n"); 146 host_irq = (unsigned int)-1; 147 } 148 149 if (host_irq != (unsigned int)-1) { 150 for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) { 151 set_irq_chip(irq, &isa_lo_chip); 152 set_irq_handler(irq, handle_level_irq); 153 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); 154 } 155 156 for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) { 157 set_irq_chip(irq, &isa_hi_chip); 158 set_irq_handler(irq, handle_level_irq); 159 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); 160 } 161 162 request_resource(&ioport_resource, &pic1_resource); 163 request_resource(&ioport_resource, &pic2_resource); 164 setup_irq(IRQ_ISA_CASCADE, &irq_cascade); 165 166 set_irq_chained_handler(host_irq, isa_irq_handler); 167 168 /* 169 * On the NetWinder, don't automatically 170 * enable ISA IRQ11 when it is requested. 171 * There appears to be a missing pull-up 172 * resistor on this line. 173 */ 174 if (machine_is_netwinder()) 175 set_irq_flags(_ISA_IRQ(11), IRQF_VALID | 176 IRQF_PROBE | IRQF_NOAUTOEN); 177 } 178 } 179 180 181