Merge branch 'parisc' from /home/kyle/repos/parisc-2.6.git
[linux-2.6] / arch / mips / vr41xx / common / irq.c
1 /*
2  *  Interrupt handing routines for NEC VR4100 series.
3  *
4  *  Copyright (C) 2005-2007  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20 #include <linux/interrupt.h>
21 #include <linux/module.h>
22
23 #include <asm/irq_cpu.h>
24 #include <asm/system.h>
25 #include <asm/vr41xx/irq.h>
26
27 typedef struct irq_cascade {
28         int (*get_irq)(unsigned int);
29 } irq_cascade_t;
30
31 static irq_cascade_t irq_cascade[NR_IRQS] __cacheline_aligned;
32
33 static struct irqaction cascade_irqaction = {
34         .handler        = no_action,
35         .mask           = CPU_MASK_NONE,
36         .name           = "cascade",
37 };
38
39 int cascade_irq(unsigned int irq, int (*get_irq)(unsigned int))
40 {
41         int retval = 0;
42
43         if (irq >= NR_IRQS)
44                 return -EINVAL;
45
46         if (irq_cascade[irq].get_irq != NULL)
47                 free_irq(irq, NULL);
48
49         irq_cascade[irq].get_irq = get_irq;
50
51         if (get_irq != NULL) {
52                 retval = setup_irq(irq, &cascade_irqaction);
53                 if (retval < 0)
54                         irq_cascade[irq].get_irq = NULL;
55         }
56
57         return retval;
58 }
59
60 EXPORT_SYMBOL_GPL(cascade_irq);
61
62 static void irq_dispatch(unsigned int irq)
63 {
64         irq_cascade_t *cascade;
65         struct irq_desc *desc;
66
67         if (irq >= NR_IRQS) {
68                 atomic_inc(&irq_err_count);
69                 return;
70         }
71
72         cascade = irq_cascade + irq;
73         if (cascade->get_irq != NULL) {
74                 unsigned int source_irq = irq;
75                 desc = irq_desc + source_irq;
76                 if (desc->chip->mask_ack)
77                         desc->chip->mask_ack(source_irq);
78                 else {
79                         desc->chip->mask(source_irq);
80                         desc->chip->ack(source_irq);
81                 }
82                 irq = cascade->get_irq(irq);
83                 if (irq < 0)
84                         atomic_inc(&irq_err_count);
85                 else
86                         irq_dispatch(irq);
87                 if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
88                         desc->chip->unmask(source_irq);
89         } else
90                 do_IRQ(irq);
91 }
92
93 asmlinkage void plat_irq_dispatch(void)
94 {
95         unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
96
97         if (pending & CAUSEF_IP7)
98                 do_IRQ(7);
99         else if (pending & 0x7800) {
100                 if (pending & CAUSEF_IP3)
101                         irq_dispatch(3);
102                 else if (pending & CAUSEF_IP4)
103                         irq_dispatch(4);
104                 else if (pending & CAUSEF_IP5)
105                         irq_dispatch(5);
106                 else if (pending & CAUSEF_IP6)
107                         irq_dispatch(6);
108         } else if (pending & CAUSEF_IP2)
109                 irq_dispatch(2);
110         else if (pending & CAUSEF_IP0)
111                 do_IRQ(0);
112         else if (pending & CAUSEF_IP1)
113                 do_IRQ(1);
114         else
115                 spurious_interrupt();
116 }
117
118 void __init arch_init_irq(void)
119 {
120         mips_cpu_irq_init(MIPS_CPU_IRQ_BASE);
121 }