1 /*
2 * The irq controller for vrc5476.
3 *
4 * Copyright (C) 2001 MontaVista Software Inc.
5 * Author: jsun@mvista.com or jsun@junsun.net
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
11 *
12 */
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/types.h>
17 #include <linux/ptrace.h>
18
19 #include <asm/system.h>
20
21 #include <asm/ddb5xxx/ddb5xxx.h>
22
23 static int irq_base;
24
vrc5476_irq_enable(uint irq)25 static void vrc5476_irq_enable(uint irq)
26 {
27 nile4_enable_irq(irq - irq_base);
28 }
29
vrc5476_irq_disable(uint irq)30 static void vrc5476_irq_disable(uint irq)
31 {
32 nile4_disable_irq(irq - irq_base);
33 }
34
vrc5476_irq_startup(uint irq)35 static unsigned int vrc5476_irq_startup(uint irq)
36 {
37 nile4_enable_irq(irq - irq_base);
38 return 0;
39 }
40
41 #define vrc5476_irq_shutdown vrc5476_irq_disable
42
vrc5476_irq_ack(uint irq)43 static void vrc5476_irq_ack(uint irq)
44 {
45 nile4_clear_irq(irq - irq_base);
46 nile4_disable_irq(irq - irq_base);
47 }
48
vrc5476_irq_end(uint irq)49 static void vrc5476_irq_end(uint irq)
50 {
51 if(!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
52 vrc5476_irq_enable(irq);
53 }
54
55 static hw_irq_controller vrc5476_irq_controller = {
56 "vrc5476",
57 vrc5476_irq_startup,
58 vrc5476_irq_shutdown,
59 vrc5476_irq_enable,
60 vrc5476_irq_disable,
61 vrc5476_irq_ack,
62 vrc5476_irq_end,
63 NULL /* no affinity stuff for UP */
64 };
65
66 void __init
vrc5476_irq_init(u32 base)67 vrc5476_irq_init(u32 base)
68 {
69 extern irq_desc_t irq_desc[];
70 u32 i;
71
72 irq_base = base;
73 for (i= base; i< base + NUM_VRC5476_IRQ; i++) {
74 irq_desc[i].status = IRQ_DISABLED;
75 irq_desc[i].action = NULL;
76 irq_desc[i].depth = 1;
77 irq_desc[i].handler = &vrc5476_irq_controller;
78 }
79 }
80
81
82 asmlinkage void
vrc5476_irq_dispatch(struct pt_regs * regs)83 vrc5476_irq_dispatch(struct pt_regs *regs)
84 {
85 extern void spurious_interrupt(void);
86
87 u32 mask;
88 int nile4_irq;
89
90 mask = nile4_get_irq_stat(0);
91
92 /* quick check for possible time interrupt */
93 if (mask & (1 << VRC5476_IRQ_GPT)) {
94 do_IRQ(VRC5476_IRQ_BASE + VRC5476_IRQ_GPT, regs);
95 return;
96 }
97
98 /* check for i8259 interrupts */
99 if (mask & (1 << VRC5476_I8259_CASCADE)) {
100 int i8259_irq = nile4_i8259_iack();
101 do_IRQ(I8259_IRQ_BASE + i8259_irq, regs);
102 return;
103 }
104
105 /* regular nile4 interrupts (we should not really have any */
106 for (nile4_irq = 0; mask; nile4_irq++, mask >>= 1) {
107 if (mask & 1) {
108 do_IRQ(VRC5476_IRQ_BASE + nile4_irq, regs);
109 return;
110 }
111 }
112 spurious_interrupt();
113 }
114