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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
30static 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
37static 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
45static 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
52static 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
58static 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
65static 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
74static 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
81static 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
87static void
88isa_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;
Russell King664399e2005-09-04 19:45:00 +010098 desc_handle_irq(isa_irq, desc, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099}
100
Russell King020732a2006-07-03 13:18:04 +0100101static struct irqaction irq_cascade = {
102 .handler = no_action,
103 .name = "cascade",
104};
105
106static struct resource pic1_resource = {
107 .name = "pic1",
108 .start = 0x20,
109 .end = 0x3f,
110};
111
112static struct resource pic2_resource = {
113 .name = "pic2",
114 .start = 0xa0,
115 .end = 0xbf,
116};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
118void __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, do_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, do_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