1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/arch/arm/mach-footbridge/irq.c 4 * 5 * Copyright (C) 1996-2000 Russell King 6 * 7 * Changelog: 8 * 22-Aug-1998 RMK Restructured IRQ routines 9 * 03-Sep-1998 PJB Merged CATS support 10 * 20-Jan-1998 RMK Started merge of EBSA286, CATS and NetWinder 11 * 26-Jan-1999 PJB Don't use IACK on CATS 12 * 16-Mar-1999 RMK Added autodetect of ISA PICs 13 */ 14 #include <linux/ioport.h> 15 #include <linux/interrupt.h> 16 #include <linux/list.h> 17 #include <linux/init.h> 18 #include <linux/io.h> 19 #include <linux/spinlock.h> 20 21 #include <asm/mach/irq.h> 22 23 #include <mach/hardware.h> 24 #include <asm/hardware/dec21285.h> 25 #include <asm/irq.h> 26 #include <asm/mach-types.h> 27 28 #include "common.h" 29 30 static void isa_mask_pic_lo_irq(struct irq_data *d) 31 { 32 unsigned int mask = 1 << (d->irq & 7); 33 34 outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO); 35 } 36 37 static void isa_ack_pic_lo_irq(struct irq_data *d) 38 { 39 unsigned int mask = 1 << (d->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(struct irq_data *d) 46 { 47 unsigned int mask = 1 << (d->irq & 7); 48 49 outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO); 50 } 51 52 static struct irq_chip isa_lo_chip = { 53 .irq_ack = isa_ack_pic_lo_irq, 54 .irq_mask = isa_mask_pic_lo_irq, 55 .irq_unmask = isa_unmask_pic_lo_irq, 56 }; 57 58 static void isa_mask_pic_hi_irq(struct irq_data *d) 59 { 60 unsigned int mask = 1 << (d->irq & 7); 61 62 outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI); 63 } 64 65 static void isa_ack_pic_hi_irq(struct irq_data *d) 66 { 67 unsigned int mask = 1 << (d->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(struct irq_data *d) 75 { 76 unsigned int mask = 1 << (d->irq & 7); 77 78 outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI); 79 } 80 81 static struct irq_chip isa_hi_chip = { 82 .irq_ack = isa_ack_pic_hi_irq, 83 .irq_mask = isa_mask_pic_hi_irq, 84 .irq_unmask = isa_unmask_pic_hi_irq, 85 }; 86 87 static void isa_irq_handler(struct irq_desc *desc) 88 { 89 unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE; 90 91 if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) { 92 do_bad_IRQ(desc); 93 return; 94 } 95 96 generic_handle_irq(isa_irq); 97 } 98 99 static struct irqaction irq_cascade = { 100 .handler = no_action, 101 .name = "cascade", 102 }; 103 104 static struct resource pic1_resource = { 105 .name = "pic1", 106 .start = 0x20, 107 .end = 0x3f, 108 }; 109 110 static struct resource pic2_resource = { 111 .name = "pic2", 112 .start = 0xa0, 113 .end = 0xbf, 114 }; 115 116 void __init isa_init_irq(unsigned int host_irq) 117 { 118 unsigned int irq; 119 120 /* 121 * Setup, and then probe for an ISA PIC 122 * If the PIC is not there, then we 123 * ignore the PIC. 124 */ 125 outb(0x11, PIC_LO); 126 outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number */ 127 outb(0x04, PIC_MASK_LO); /* Slave on Ch2 */ 128 outb(0x01, PIC_MASK_LO); /* x86 */ 129 outb(0xf5, PIC_MASK_LO); /* pattern: 11110101 */ 130 131 outb(0x11, PIC_HI); 132 outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number */ 133 outb(0x02, PIC_MASK_HI); /* Slave on Ch1 */ 134 outb(0x01, PIC_MASK_HI); /* x86 */ 135 outb(0xfa, PIC_MASK_HI); /* pattern: 11111010 */ 136 137 outb(0x0b, PIC_LO); 138 outb(0x0b, PIC_HI); 139 140 if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) { 141 outb(0xff, PIC_MASK_LO);/* mask all IRQs */ 142 outb(0xff, PIC_MASK_HI);/* mask all IRQs */ 143 } else { 144 printk(KERN_INFO "IRQ: ISA PIC not found\n"); 145 host_irq = (unsigned int)-1; 146 } 147 148 if (host_irq != (unsigned int)-1) { 149 for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) { 150 irq_set_chip_and_handler(irq, &isa_lo_chip, 151 handle_level_irq); 152 irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE); 153 } 154 155 for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) { 156 irq_set_chip_and_handler(irq, &isa_hi_chip, 157 handle_level_irq); 158 irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE); 159 } 160 161 request_resource(&ioport_resource, &pic1_resource); 162 request_resource(&ioport_resource, &pic2_resource); 163 setup_irq(IRQ_ISA_CASCADE, &irq_cascade); 164 165 irq_set_chained_handler(host_irq, isa_irq_handler); 166 167 /* 168 * On the NetWinder, don't automatically 169 * enable ISA IRQ11 when it is requested. 170 * There appears to be a missing pull-up 171 * resistor on this line. 172 */ 173 if (machine_is_netwinder()) 174 irq_modify_status(_ISA_IRQ(11), 175 IRQ_NOREQUEST | IRQ_NOPROBE, IRQ_NOAUTOEN); 176 } 177 } 178 179 180