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bast-irq.c
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1 /* linux/arch/arm/mach-s3c2410/bast-irq.c
2  *
3  * Copyright 2003-2005 Simtec Electronics
4  * Ben Dooks <[email protected]>
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/mach-types.h>
31 
32 #include <mach/hardware.h>
33 #include <asm/irq.h>
34 
35 #include <asm/mach/irq.h>
36 
37 #include <mach/regs-irq.h>
38 #include <mach/bast-map.h>
39 #include <mach/bast-irq.h>
40 
41 #include <plat/irq.h>
42 
43 #if 0
44 #include <asm/debug-ll.h>
45 #endif
46 
47 #define irqdbf(x...)
48 #define irqdbf2(x...)
49 
50 
51 /* handle PC104 ISA interrupts from the system CPLD */
52 
53 /* table of ISA irq nos to the relevant mask... zero means
54  * the irq is not implemented
55 */
56 static unsigned char bast_pc104_irqmasks[] = {
57  0, /* 0 */
58  0, /* 1 */
59  0, /* 2 */
60  1, /* 3 */
61  0, /* 4 */
62  2, /* 5 */
63  0, /* 6 */
64  4, /* 7 */
65  0, /* 8 */
66  0, /* 9 */
67  8, /* 10 */
68  0, /* 11 */
69  0, /* 12 */
70  0, /* 13 */
71  0, /* 14 */
72  0, /* 15 */
73 };
74 
75 static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
76 
77 static void
78 bast_pc104_mask(struct irq_data *data)
79 {
80  unsigned long temp;
81 
83  temp &= ~bast_pc104_irqmasks[data->irq];
85 }
86 
87 static void
88 bast_pc104_maskack(struct irq_data *data)
89 {
90  struct irq_desc *desc = irq_desc + IRQ_ISA;
91 
92  bast_pc104_mask(data);
93  desc->irq_data.chip->irq_ack(&desc->irq_data);
94 }
95 
96 static void
97 bast_pc104_unmask(struct irq_data *data)
98 {
99  unsigned long temp;
100 
102  temp |= bast_pc104_irqmasks[data->irq];
104 }
105 
106 static struct irq_chip bast_pc104_chip = {
107  .irq_mask = bast_pc104_mask,
108  .irq_unmask = bast_pc104_unmask,
109  .irq_ack = bast_pc104_maskack
110 };
111 
112 static void
113 bast_irq_pc104_demux(unsigned int irq,
114  struct irq_desc *desc)
115 {
116  unsigned int stat;
117  unsigned int irqno;
118  int i;
119 
120  stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
121 
122  if (unlikely(stat == 0)) {
123  /* ack if we get an irq with nothing (ie, startup) */
124 
125  desc = irq_desc + IRQ_ISA;
126  desc->irq_data.chip->irq_ack(&desc->irq_data);
127  } else {
128  /* handle the IRQ */
129 
130  for (i = 0; stat != 0; i++, stat >>= 1) {
131  if (stat & 1) {
132  irqno = bast_pc104_irqs[i];
133  generic_handle_irq(irqno);
134  }
135  }
136  }
137 }
138 
139 static __init int bast_irq_init(void)
140 {
141  unsigned int i;
142 
143  if (machine_is_bast()) {
144  printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n");
145 
146  /* zap all the IRQs */
147 
149 
150  irq_set_chained_handler(IRQ_ISA, bast_irq_pc104_demux);
151 
152  /* register our IRQs */
153 
154  for (i = 0; i < 4; i++) {
155  unsigned int irqno = bast_pc104_irqs[i];
156 
157  irq_set_chip_and_handler(irqno, &bast_pc104_chip,
159  set_irq_flags(irqno, IRQF_VALID);
160  }
161  }
162 
163  return 0;
164 }
165 
166 arch_initcall(bast_irq_init);