summaryrefslogtreecommitdiff
path: root/arch/arm/mach-footbridge/isa-irq.c
blob: 88a553932c331bd6bc8821edcce594e850594810 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/arch/arm/mach-footbridge/irq.c
 *
 *  Copyright (C) 1996-2000 Russell King
 *
 *  Changelog:
 *   22-Aug-1998 RMK	Restructured IRQ routines
 *   03-Sep-1998 PJB	Merged CATS support
 *   20-Jan-1998 RMK	Started merge of EBSA286, CATS and NetWinder
 *   26-Jan-1999 PJB	Don't use IACK on CATS
 *   16-Mar-1999 RMK	Added autodetect of ISA PICs
 */
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>

#include <asm/mach/irq.h>

#include <mach/hardware.h>
#include <asm/hardware/dec21285.h>
#include <asm/irq.h>
#include <asm/mach-types.h>

#include "common.h"

static void isa_mask_pic_lo_irq(struct irq_data *d)
{
	unsigned int mask = 1 << (d->irq & 7);

	outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
}

static void isa_ack_pic_lo_irq(struct irq_data *d)
{
	unsigned int mask = 1 << (d->irq & 7);

	outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
	outb(0x20, PIC_LO);
}

static void isa_unmask_pic_lo_irq(struct irq_data *d)
{
	unsigned int mask = 1 << (d->irq & 7);

	outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO);
}

static struct irq_chip isa_lo_chip = {
	.irq_ack	= isa_ack_pic_lo_irq,
	.irq_mask	= isa_mask_pic_lo_irq,
	.irq_unmask	= isa_unmask_pic_lo_irq,
};

static void isa_mask_pic_hi_irq(struct irq_data *d)
{
	unsigned int mask = 1 << (d->irq & 7);

	outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
}

static void isa_ack_pic_hi_irq(struct irq_data *d)
{
	unsigned int mask = 1 << (d->irq & 7);

	outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
	outb(0x62, PIC_LO);
	outb(0x20, PIC_HI);
}

static void isa_unmask_pic_hi_irq(struct irq_data *d)
{
	unsigned int mask = 1 << (d->irq & 7);

	outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI);
}

static struct irq_chip isa_hi_chip = {
	.irq_ack	= isa_ack_pic_hi_irq,
	.irq_mask	= isa_mask_pic_hi_irq,
	.irq_unmask	= isa_unmask_pic_hi_irq,
};

static void isa_irq_handler(struct irq_desc *desc)
{
	unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE;

	if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) {
		do_bad_IRQ(desc);
		return;
	}

	generic_handle_irq(isa_irq);
}

static struct irqaction irq_cascade = {
	.handler = no_action,
	.name = "cascade",
};

static struct resource pic1_resource = {
	.name	= "pic1",
	.start	= 0x20,
	.end	= 0x3f,
};

static struct resource pic2_resource = {
	.name	= "pic2",
	.start	= 0xa0,
	.end	= 0xbf,
};

void __init isa_init_irq(unsigned int host_irq)
{
	unsigned int irq;

	/*
	 * Setup, and then probe for an ISA PIC
	 * If the PIC is not there, then we
	 * ignore the PIC.
	 */
	outb(0x11, PIC_LO);
	outb(_ISA_IRQ(0), PIC_MASK_LO);	/* IRQ number		*/
	outb(0x04, PIC_MASK_LO);	/* Slave on Ch2		*/
	outb(0x01, PIC_MASK_LO);	/* x86			*/
	outb(0xf5, PIC_MASK_LO);	/* pattern: 11110101	*/

	outb(0x11, PIC_HI);
	outb(_ISA_IRQ(8), PIC_MASK_HI);	/* IRQ number		*/
	outb(0x02, PIC_MASK_HI);	/* Slave on Ch1		*/
	outb(0x01, PIC_MASK_HI);	/* x86			*/
	outb(0xfa, PIC_MASK_HI);	/* pattern: 11111010	*/

	outb(0x0b, PIC_LO);
	outb(0x0b, PIC_HI);

	if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) {
		outb(0xff, PIC_MASK_LO);/* mask all IRQs	*/
		outb(0xff, PIC_MASK_HI);/* mask all IRQs	*/
	} else {
		printk(KERN_INFO "IRQ: ISA PIC not found\n");
		host_irq = (unsigned int)-1;
	}

	if (host_irq != (unsigned int)-1) {
		for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) {
			irq_set_chip_and_handler(irq, &isa_lo_chip,
						 handle_level_irq);
			irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
		}

		for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) {
			irq_set_chip_and_handler(irq, &isa_hi_chip,
						 handle_level_irq);
			irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
		}

		request_resource(&ioport_resource, &pic1_resource);
		request_resource(&ioport_resource, &pic2_resource);
		setup_irq(IRQ_ISA_CASCADE, &irq_cascade);

		irq_set_chained_handler(host_irq, isa_irq_handler);

		/*
		 * On the NetWinder, don't automatically
		 * enable ISA IRQ11 when it is requested.
		 * There appears to be a missing pull-up
		 * resistor on this line.
		 */
		if (machine_is_netwinder())
			irq_modify_status(_ISA_IRQ(11),
				IRQ_NOREQUEST | IRQ_NOPROBE, IRQ_NOAUTOEN);
	}
}