bast-irq.c
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/* linux/arch/arm/mach-s3c2410/bast-irq.c
*
* Copyright 2003-2005 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* http://www.simtec.co.uk/products/EB2410ITX/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <asm/mach-types.h>
#include <asm/mach/irq.h>
#include <mach/hardware.h>
#include <mach/regs-irq.h>
#include "bast.h"
#define irqdbf(x...)
#define irqdbf2(x...)
/* handle PC104 ISA interrupts from the system CPLD */
/* table of ISA irq nos to the relevant mask... zero means
* the irq is not implemented
*/
static unsigned char bast_pc104_irqmasks[] = {
0, /* 0 */
0, /* 1 */
0, /* 2 */
1, /* 3 */
0, /* 4 */
2, /* 5 */
0, /* 6 */
4, /* 7 */
0, /* 8 */
0, /* 9 */
8, /* 10 */
0, /* 11 */
0, /* 12 */
0, /* 13 */
0, /* 14 */
0, /* 15 */
};
static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
static void
bast_pc104_mask(struct irq_data *data)
{
unsigned long temp;
temp = __raw_readb(BAST_VA_PC104_IRQMASK);
temp &= ~bast_pc104_irqmasks[data->irq];
__raw_writeb(temp, BAST_VA_PC104_IRQMASK);
}
static void
bast_pc104_maskack(struct irq_data *data)
{
struct irq_desc *desc = irq_desc + BAST_IRQ_ISA;
bast_pc104_mask(data);
desc->irq_data.chip->irq_ack(&desc->irq_data);
}
static void
bast_pc104_unmask(struct irq_data *data)
{
unsigned long temp;
temp = __raw_readb(BAST_VA_PC104_IRQMASK);
temp |= bast_pc104_irqmasks[data->irq];
__raw_writeb(temp, BAST_VA_PC104_IRQMASK);
}
static struct irq_chip bast_pc104_chip = {
.irq_mask = bast_pc104_mask,
.irq_unmask = bast_pc104_unmask,
.irq_ack = bast_pc104_maskack
};
static void
bast_irq_pc104_demux(unsigned int irq,
struct irq_desc *desc)
{
unsigned int stat;
unsigned int irqno;
int i;
stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
if (unlikely(stat == 0)) {
/* ack if we get an irq with nothing (ie, startup) */
desc = irq_desc + BAST_IRQ_ISA;
desc->irq_data.chip->irq_ack(&desc->irq_data);
} else {
/* handle the IRQ */
for (i = 0; stat != 0; i++, stat >>= 1) {
if (stat & 1) {
irqno = bast_pc104_irqs[i];
generic_handle_irq(irqno);
}
}
}
}
static __init int bast_irq_init(void)
{
unsigned int i;
if (machine_is_bast()) {
printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n");
/* zap all the IRQs */
__raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
irq_set_chained_handler(BAST_IRQ_ISA, bast_irq_pc104_demux);
/* register our IRQs */
for (i = 0; i < 4; i++) {
unsigned int irqno = bast_pc104_irqs[i];
irq_set_chip_and_handler(irqno, &bast_pc104_chip,
handle_level_irq);
set_irq_flags(irqno, IRQF_VALID);
}
}
return 0;
}
arch_initcall(bast_irq_init);