aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/lasat/interrupt.c
blob: d608b6ef0edd7712aa9d34c5668d2590a8e3a962 (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
/*
 * Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
 *
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Routines for generic manipulation of the interrupts found on the
 * Lasat boards.
 */
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>

#include <asm/irq_cpu.h>
#include <asm/lasat/lasat.h>
#include <asm/lasat/lasatint.h>

#include <irq.h>

static volatile int *lasat_int_status;
static volatile int *lasat_int_mask;
static volatile int lasat_int_mask_shift;

void disable_lasat_irq(struct irq_data *d)
{
	unsigned int irq_nr = d->irq - LASAT_IRQ_BASE;

	*lasat_int_mask &= ~(1 << irq_nr) << lasat_int_mask_shift;
}

void enable_lasat_irq(struct irq_data *d)
{
	unsigned int irq_nr = d->irq - LASAT_IRQ_BASE;

	*lasat_int_mask |= (1 << irq_nr) << lasat_int_mask_shift;
}

static struct irq_chip lasat_irq_type = {
	.name = "Lasat",
	.irq_mask = disable_lasat_irq,
	.irq_unmask = enable_lasat_irq,
};

static inline int ls1bit32(unsigned int x)
{
	int b = 31, s;

	s = 16; if (x << 16 == 0) s = 0; b -= s; x <<= s;
	s =  8; if (x <<  8 == 0) s = 0; b -= s; x <<= s;
	s =  4; if (x <<  4 == 0) s = 0; b -= s; x <<= s;
	s =  2; if (x <<  2 == 0) s = 0; b -= s; x <<= s;
	s =  1; if (x <<  1 == 0) s = 0; b -= s;

	return b;
}

static unsigned long (*get_int_status)(void);

static unsigned long get_int_status_100(void)
{
	return *lasat_int_status & *lasat_int_mask;
}

static unsigned long get_int_status_200(void)
{
	unsigned long int_status;

	int_status = *lasat_int_status;
	int_status &= (int_status >> LASATINT_MASK_SHIFT_200) & 0xffff;
	return int_status;
}

asmlinkage void plat_irq_dispatch(void)
{
	unsigned long int_status;
	unsigned int cause = read_c0_cause();
	int irq;

	if (cause & CAUSEF_IP7) {	/* R4000 count / compare IRQ */
		do_IRQ(7);
		return;
	}

	int_status = get_int_status();

	/* if int_status == 0, then the interrupt has already been cleared */
	if (int_status) {
		irq = LASAT_IRQ_BASE + ls1bit32(int_status);

		do_IRQ(irq);
	}
}

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

void __init arch_init_irq(void)
{
	int i;

	if (IS_LASAT_200()) {
		lasat_int_status = (void *)LASAT_INT_STATUS_REG_200;
		lasat_int_mask = (void *)LASAT_INT_MASK_REG_200;
		lasat_int_mask_shift = LASATINT_MASK_SHIFT_200;
		get_int_status = get_int_status_200;
		*lasat_int_mask &= 0xffff;
	} else {
		lasat_int_status = (void *)LASAT_INT_STATUS_REG_100;
		lasat_int_mask = (void *)LASAT_INT_MASK_REG_100;
		lasat_int_mask_shift = LASATINT_MASK_SHIFT_100;
		get_int_status = get_int_status_100;
		*lasat_int_mask = 0;
	}

	mips_cpu_irq_init();

	for (i = LASAT_IRQ_BASE; i <= LASAT_IRQ_END; i++)
		irq_set_chip_and_handler(i, &lasat_irq_type, handle_level_irq);

	setup_irq(LASAT_CASCADE_IRQ, &cascade);
}

Privacy Policy