Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Carsten Langgaard, carstenl@mips.com
4 * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved.
5 *
6 * Routines for generic manipulation of the interrupts found on the
7 * Lasat boards.
8 */
9#include <linux/init.h>
10#include <linux/interrupt.h>
11#include <linux/irq.h>
12
13#include <asm/irq_cpu.h>
14#include <asm/lasat/lasat.h>
15#include <asm/lasat/lasatint.h>
16
17#include <irq.h>
18
19static volatile int *lasat_int_status;
20static volatile int *lasat_int_mask;
21static volatile int lasat_int_mask_shift;
22
23void disable_lasat_irq(struct irq_data *d)
24{
25 unsigned int irq_nr = d->irq - LASAT_IRQ_BASE;
26
27 *lasat_int_mask &= ~(1 << irq_nr) << lasat_int_mask_shift;
28}
29
30void enable_lasat_irq(struct irq_data *d)
31{
32 unsigned int irq_nr = d->irq - LASAT_IRQ_BASE;
33
34 *lasat_int_mask |= (1 << irq_nr) << lasat_int_mask_shift;
35}
36
37static struct irq_chip lasat_irq_type = {
38 .name = "Lasat",
39 .irq_mask = disable_lasat_irq,
40 .irq_unmask = enable_lasat_irq,
41};
42
43static inline int ls1bit32(unsigned int x)
44{
45 int b = 31, s;
46
47 s = 16; if (x << 16 == 0) s = 0; b -= s; x <<= s;
48 s = 8; if (x << 8 == 0) s = 0; b -= s; x <<= s;
49 s = 4; if (x << 4 == 0) s = 0; b -= s; x <<= s;
50 s = 2; if (x << 2 == 0) s = 0; b -= s; x <<= s;
51 s = 1; if (x << 1 == 0) s = 0; b -= s;
52
53 return b;
54}
55
56static unsigned long (*get_int_status)(void);
57
58static unsigned long get_int_status_100(void)
59{
60 return *lasat_int_status & *lasat_int_mask;
61}
62
63static unsigned long get_int_status_200(void)
64{
65 unsigned long int_status;
66
67 int_status = *lasat_int_status;
68 int_status &= (int_status >> LASATINT_MASK_SHIFT_200) & 0xffff;
69 return int_status;
70}
71
72asmlinkage void plat_irq_dispatch(void)
73{
74 unsigned long int_status;
75 unsigned int cause = read_c0_cause();
76 int irq;
77
78 if (cause & CAUSEF_IP7) { /* R4000 count / compare IRQ */
79 do_IRQ(7);
80 return;
81 }
82
83 int_status = get_int_status();
84
85 /* if int_status == 0, then the interrupt has already been cleared */
86 if (int_status) {
87 irq = LASAT_IRQ_BASE + ls1bit32(int_status);
88
89 do_IRQ(irq);
90 }
91}
92
93static struct irqaction cascade = {
94 .handler = no_action,
95 .name = "cascade",
96 .flags = IRQF_NO_THREAD,
97};
98
99void __init arch_init_irq(void)
100{
101 int i;
102
103 if (IS_LASAT_200()) {
104 lasat_int_status = (void *)LASAT_INT_STATUS_REG_200;
105 lasat_int_mask = (void *)LASAT_INT_MASK_REG_200;
106 lasat_int_mask_shift = LASATINT_MASK_SHIFT_200;
107 get_int_status = get_int_status_200;
108 *lasat_int_mask &= 0xffff;
109 } else {
110 lasat_int_status = (void *)LASAT_INT_STATUS_REG_100;
111 lasat_int_mask = (void *)LASAT_INT_MASK_REG_100;
112 lasat_int_mask_shift = LASATINT_MASK_SHIFT_100;
113 get_int_status = get_int_status_100;
114 *lasat_int_mask = 0;
115 }
116
117 mips_cpu_irq_init();
118
119 for (i = LASAT_IRQ_BASE; i <= LASAT_IRQ_END; i++)
120 irq_set_chip_and_handler(i, &lasat_irq_type, handle_level_irq);
121
122 setup_irq(LASAT_CASCADE_IRQ, &cascade);
123}