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 irqchip 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 irqchip 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 irqdesc *desc, struct pt_regs *regs) 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, regs); 94 return; 95 } 96 97 desc = irq_desc + isa_irq; 98 desc_handle_irq(isa_irq, desc, regs); 99 } 100 101 static struct irqaction irq_cascade = { .handler = no_action, .name = "cascade", }; 102 static struct resource pic1_resource = { "pic1", 0x20, 0x3f }; 103 static struct resource pic2_resource = { "pic2", 0xa0, 0xbf }; 104 105 void __init isa_init_irq(unsigned int host_irq) 106 { 107 unsigned int irq; 108 109 /* 110 * Setup, and then probe for an ISA PIC 111 * If the PIC is not there, then we 112 * ignore the PIC. 113 */ 114 outb(0x11, PIC_LO); 115 outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number */ 116 outb(0x04, PIC_MASK_LO); /* Slave on Ch2 */ 117 outb(0x01, PIC_MASK_LO); /* x86 */ 118 outb(0xf5, PIC_MASK_LO); /* pattern: 11110101 */ 119 120 outb(0x11, PIC_HI); 121 outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number */ 122 outb(0x02, PIC_MASK_HI); /* Slave on Ch1 */ 123 outb(0x01, PIC_MASK_HI); /* x86 */ 124 outb(0xfa, PIC_MASK_HI); /* pattern: 11111010 */ 125 126 outb(0x0b, PIC_LO); 127 outb(0x0b, PIC_HI); 128 129 if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) { 130 outb(0xff, PIC_MASK_LO);/* mask all IRQs */ 131 outb(0xff, PIC_MASK_HI);/* mask all IRQs */ 132 } else { 133 printk(KERN_INFO "IRQ: ISA PIC not found\n"); 134 host_irq = (unsigned int)-1; 135 } 136 137 if (host_irq != (unsigned int)-1) { 138 for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) { 139 set_irq_chip(irq, &isa_lo_chip); 140 set_irq_handler(irq, do_level_IRQ); 141 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); 142 } 143 144 for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) { 145 set_irq_chip(irq, &isa_hi_chip); 146 set_irq_handler(irq, do_level_IRQ); 147 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); 148 } 149 150 request_resource(&ioport_resource, &pic1_resource); 151 request_resource(&ioport_resource, &pic2_resource); 152 setup_irq(IRQ_ISA_CASCADE, &irq_cascade); 153 154 set_irq_chained_handler(host_irq, isa_irq_handler); 155 156 /* 157 * On the NetWinder, don't automatically 158 * enable ISA IRQ11 when it is requested. 159 * There appears to be a missing pull-up 160 * resistor on this line. 161 */ 162 if (machine_is_netwinder()) 163 set_irq_flags(_ISA_IRQ(11), IRQF_VALID | 164 IRQF_PROBE | IRQF_NOAUTOEN); 165 } 166 } 167 168 169