Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[linux-2.6] / arch / mips / ddb5xxx / ddb5476 / vrc5476_irq.c
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
25 static void vrc5476_irq_enable(uint irq)
26 {
27         nile4_enable_irq(irq - irq_base);
28 }
29
30 static void vrc5476_irq_disable(uint irq)
31 {
32         nile4_disable_irq(irq - irq_base);
33 }
34
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
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
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         .typename = "vrc5476",
57         .startup = vrc5476_irq_startup,
58         .shutdown = vrc5476_irq_shutdown,
59         .enable = vrc5476_irq_enable,
60         .disable = vrc5476_irq_disable,
61         .ack = vrc5476_irq_ack,
62         .end = vrc5476_irq_end
63 };
64
65 void __init
66 vrc5476_irq_init(u32 base)
67 {
68         u32 i;
69
70         irq_base = base;
71         for (i= base; i< base + NUM_VRC5476_IRQ; i++) {
72                 irq_desc[i].status = IRQ_DISABLED;
73                 irq_desc[i].action = NULL;
74                 irq_desc[i].depth = 1;
75                 irq_desc[i].handler = &vrc5476_irq_controller;
76         }
77 }
78
79
80 asmlinkage void
81 vrc5476_irq_dispatch(struct pt_regs *regs)
82 {
83         extern void spurious_interrupt(void);
84
85         u32 mask;
86         int nile4_irq;
87
88         mask = nile4_get_irq_stat(0);
89
90         /* quick check for possible time interrupt */
91         if (mask & (1 << VRC5476_IRQ_GPT)) {
92                 do_IRQ(VRC5476_IRQ_BASE + VRC5476_IRQ_GPT, regs);
93                 return;
94         }
95
96         /* check for i8259 interrupts */
97         if (mask & (1 << VRC5476_I8259_CASCADE)) {
98                 int i8259_irq = nile4_i8259_iack();
99                 do_IRQ(I8259_IRQ_BASE + i8259_irq, regs);
100                 return;
101         }
102
103         /* regular nile4 interrupts (we should not really have any */
104         for (nile4_irq = 0; mask; nile4_irq++, mask >>= 1) {
105                 if (mask & 1) {
106                         do_IRQ(VRC5476_IRQ_BASE + nile4_irq, regs);
107                         return;
108                 }
109         }
110         spurious_interrupt();
111 }