1 /* linux/arch/arm/mach-s3c2410/bast-irq.c
2 *
3 * Copyright 2003-2005 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * http://www.simtec.co.uk/products/EB2410ITX/
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/ioport.h>
27 #include <linux/device.h>
28 #include <linux/io.h>
29
30 #include <asm/irq.h>
31 #include <asm/mach-types.h>
32 #include <asm/mach/irq.h>
33
34 #include <mach/hardware.h>
35 #include <mach/regs-irq.h>
36
37 #include "bast.h"
38
39 #define irqdbf(x...)
40 #define irqdbf2(x...)
41
42 /* handle PC104 ISA interrupts from the system CPLD */
43
44 /* table of ISA irq nos to the relevant mask... zero means
45 * the irq is not implemented
46 */
47 static unsigned char bast_pc104_irqmasks[] = {
48 0, /* 0 */
49 0, /* 1 */
50 0, /* 2 */
51 1, /* 3 */
52 0, /* 4 */
53 2, /* 5 */
54 0, /* 6 */
55 4, /* 7 */
56 0, /* 8 */
57 0, /* 9 */
58 8, /* 10 */
59 0, /* 11 */
60 0, /* 12 */
61 0, /* 13 */
62 0, /* 14 */
63 0, /* 15 */
64 };
65
66 static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
67
68 static void
bast_pc104_mask(struct irq_data * data)69 bast_pc104_mask(struct irq_data *data)
70 {
71 unsigned long temp;
72
73 temp = __raw_readb(BAST_VA_PC104_IRQMASK);
74 temp &= ~bast_pc104_irqmasks[data->irq];
75 __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
76 }
77
78 static void
bast_pc104_maskack(struct irq_data * data)79 bast_pc104_maskack(struct irq_data *data)
80 {
81 struct irq_desc *desc = irq_desc + BAST_IRQ_ISA;
82
83 bast_pc104_mask(data);
84 desc->irq_data.chip->irq_ack(&desc->irq_data);
85 }
86
87 static void
bast_pc104_unmask(struct irq_data * data)88 bast_pc104_unmask(struct irq_data *data)
89 {
90 unsigned long temp;
91
92 temp = __raw_readb(BAST_VA_PC104_IRQMASK);
93 temp |= bast_pc104_irqmasks[data->irq];
94 __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
95 }
96
97 static struct irq_chip bast_pc104_chip = {
98 .irq_mask = bast_pc104_mask,
99 .irq_unmask = bast_pc104_unmask,
100 .irq_ack = bast_pc104_maskack
101 };
102
bast_irq_pc104_demux(struct irq_desc * desc)103 static void bast_irq_pc104_demux(struct irq_desc *desc)
104 {
105 unsigned int stat;
106 unsigned int irqno;
107 int i;
108
109 stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
110
111 if (unlikely(stat == 0)) {
112 /* ack if we get an irq with nothing (ie, startup) */
113
114 desc = irq_desc + BAST_IRQ_ISA;
115 desc->irq_data.chip->irq_ack(&desc->irq_data);
116 } else {
117 /* handle the IRQ */
118
119 for (i = 0; stat != 0; i++, stat >>= 1) {
120 if (stat & 1) {
121 irqno = bast_pc104_irqs[i];
122 generic_handle_irq(irqno);
123 }
124 }
125 }
126 }
127
bast_irq_init(void)128 static __init int bast_irq_init(void)
129 {
130 unsigned int i;
131
132 if (machine_is_bast()) {
133 printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n");
134
135 /* zap all the IRQs */
136
137 __raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
138
139 irq_set_chained_handler(BAST_IRQ_ISA, bast_irq_pc104_demux);
140
141 /* register our IRQs */
142
143 for (i = 0; i < 4; i++) {
144 unsigned int irqno = bast_pc104_irqs[i];
145
146 irq_set_chip_and_handler(irqno, &bast_pc104_chip,
147 handle_level_irq);
148 irq_clear_status_flags(irqno, IRQ_NOREQUEST);
149 }
150 }
151
152 return 0;
153 }
154
155 arch_initcall(bast_irq_init);
156