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/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*/
56static 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
75static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
76
77static void
78bast_pc104_mask(struct irq_data *data)
79{
80	unsigned long temp;
81
82	temp = __raw_readb(BAST_VA_PC104_IRQMASK);
83	temp &= ~bast_pc104_irqmasks[data->irq];
84	__raw_writeb(temp, BAST_VA_PC104_IRQMASK);
85}
86
87static void
88bast_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
96static void
97bast_pc104_unmask(struct irq_data *data)
98{
99	unsigned long temp;
100
101	temp = __raw_readb(BAST_VA_PC104_IRQMASK);
102	temp |= bast_pc104_irqmasks[data->irq];
103	__raw_writeb(temp, BAST_VA_PC104_IRQMASK);
104}
105
106static 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
112static void
113bast_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
139static __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
148		__raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
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,
158						 handle_level_irq);
159			set_irq_flags(irqno, IRQF_VALID);
160		}
161	}
162
163	return 0;
164}
165
166arch_initcall(bast_irq_init);
167