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(port: PIC_MASK_LO) | mask, port: 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(port: PIC_MASK_LO) | mask, port: PIC_MASK_LO); |
42 | outb(value: 0x20, port: 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(port: PIC_MASK_LO) & ~mask, port: 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(port: PIC_MASK_HI) | mask, port: 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(port: PIC_MASK_HI) | mask, port: PIC_MASK_HI); |
70 | outb(value: 0x62, port: PIC_LO); |
71 | outb(value: 0x20, port: 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(port: PIC_MASK_HI) & ~mask, port: 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 resource pic1_resource = { |
100 | .name = "pic1" , |
101 | .start = 0x20, |
102 | .end = 0x3f, |
103 | }; |
104 | |
105 | static struct resource pic2_resource = { |
106 | .name = "pic2" , |
107 | .start = 0xa0, |
108 | .end = 0xbf, |
109 | }; |
110 | |
111 | void __init isa_init_irq(unsigned int host_irq) |
112 | { |
113 | unsigned int irq; |
114 | |
115 | /* |
116 | * Setup, and then probe for an ISA PIC |
117 | * If the PIC is not there, then we |
118 | * ignore the PIC. |
119 | */ |
120 | outb(value: 0x11, port: PIC_LO); |
121 | outb(value: _ISA_IRQ(0), port: PIC_MASK_LO); /* IRQ number */ |
122 | outb(value: 0x04, port: PIC_MASK_LO); /* Slave on Ch2 */ |
123 | outb(value: 0x01, port: PIC_MASK_LO); /* x86 */ |
124 | outb(value: 0xf5, port: PIC_MASK_LO); /* pattern: 11110101 */ |
125 | |
126 | outb(value: 0x11, port: PIC_HI); |
127 | outb(value: _ISA_IRQ(8), port: PIC_MASK_HI); /* IRQ number */ |
128 | outb(value: 0x02, port: PIC_MASK_HI); /* Slave on Ch1 */ |
129 | outb(value: 0x01, port: PIC_MASK_HI); /* x86 */ |
130 | outb(value: 0xfa, port: PIC_MASK_HI); /* pattern: 11111010 */ |
131 | |
132 | outb(value: 0x0b, port: PIC_LO); |
133 | outb(value: 0x0b, port: PIC_HI); |
134 | |
135 | if (inb(port: PIC_MASK_LO) == 0xf5 && inb(port: PIC_MASK_HI) == 0xfa) { |
136 | outb(value: 0xff, port: PIC_MASK_LO);/* mask all IRQs */ |
137 | outb(value: 0xff, port: PIC_MASK_HI);/* mask all IRQs */ |
138 | } else { |
139 | printk(KERN_INFO "IRQ: ISA PIC not found\n" ); |
140 | host_irq = (unsigned int)-1; |
141 | } |
142 | |
143 | if (host_irq != (unsigned int)-1) { |
144 | for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) { |
145 | irq_set_chip_and_handler(irq, &isa_lo_chip, |
146 | handle_level_irq); |
147 | irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE); |
148 | } |
149 | |
150 | for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) { |
151 | irq_set_chip_and_handler(irq, &isa_hi_chip, |
152 | handle_level_irq); |
153 | irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE); |
154 | } |
155 | |
156 | request_resource(root: &ioport_resource, new: &pic1_resource); |
157 | request_resource(root: &ioport_resource, new: &pic2_resource); |
158 | |
159 | irq = IRQ_ISA_CASCADE; |
160 | if (request_irq(irq, handler: no_action, flags: 0, name: "cascade" , NULL)) |
161 | pr_err("Failed to request irq %u (cascade)\n" , irq); |
162 | |
163 | irq_set_chained_handler(host_irq, isa_irq_handler); |
164 | |
165 | /* |
166 | * On the NetWinder, don't automatically |
167 | * enable ISA IRQ11 when it is requested. |
168 | * There appears to be a missing pull-up |
169 | * resistor on this line. |
170 | */ |
171 | if (machine_is_netwinder()) |
172 | irq_modify_status(_ISA_IRQ(11), |
173 | IRQ_NOREQUEST | IRQ_NOPROBE, IRQ_NOAUTOEN); |
174 | } |
175 | } |
176 | |
177 | |
178 | |