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/*
* linux/arch/arm/mach-shark/irq.c
*
* by Alexander Schulz
*
* derived from linux/arch/ppc/kernel/i8259.c and:
* include/asm-arm/arch-ebsa110/irq.h
* Copyright (C) 1996-1998 Russell King
*/
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/mach/irq.h>
/*
* 8259A PIC functions to handle ISA devices:
*/
/*
* This contains the irq mask for both 8259A irq controllers,
* Let through the cascade-interrupt no. 2 (ff-(1<<2)==fb)
*/
static unsigned char cached_irq_mask[2] = { 0xfb, 0xff };
/*
* These have to be protected by the irq controller spinlock
* before being called.
*/
static void shark_disable_8259A_irq(unsigned int irq)
{
unsigned int mask;
if (irq<8) {
mask = 1 << irq;
cached_irq_mask[0] |= mask;
outb(cached_irq_mask[1],0xA1);
} else {
mask = 1 << (irq-8);
cached_irq_mask[1] |= mask;
outb(cached_irq_mask[0],0x21);
}
}
static void shark_enable_8259A_irq(unsigned int irq)
{
unsigned int mask;
if (irq<8) {
mask = ~(1 << irq);
cached_irq_mask[0] &= mask;
outb(cached_irq_mask[0],0x21);
} else {
mask = ~(1 << (irq-8));
cached_irq_mask[1] &= mask;
outb(cached_irq_mask[1],0xA1);
}
}
static void shark_ack_8259A_irq(unsigned int irq){}
static irqreturn_t bogus_int(int irq, void *dev_id)
{
printk("Got interrupt %i!\n",irq);
return IRQ_NONE;
}
static struct irqaction cascade;
static struct irq_chip fb_chip = {
.name = "XT-PIC",
.ack = shark_ack_8259A_irq,
.mask = shark_disable_8259A_irq,
.unmask = shark_enable_8259A_irq,
};
void __init shark_init_irq(void)
{
int irq;
for (irq = 0; irq < NR_IRQS; irq++) {
set_irq_chip(irq, &fb_chip);
set_irq_handler(irq, handle_edge_irq);
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
}
/* init master interrupt controller */
outb(0x11, 0x20); /* Start init sequence, edge triggered (level: 0x19)*/
outb(0x00, 0x21); /* Vector base */
outb(0x04, 0x21); /* Cascade (slave) on IRQ2 */
outb(0x03, 0x21); /* Select 8086 mode , auto eoi*/
outb(0x0A, 0x20);
/* init slave interrupt controller */
outb(0x11, 0xA0); /* Start init sequence, edge triggered */
outb(0x08, 0xA1); /* Vector base */
outb(0x02, 0xA1); /* Cascade (slave) on IRQ2 */
outb(0x03, 0xA1); /* Select 8086 mode, auto eoi */
outb(0x0A, 0xA0);
outb(cached_irq_mask[1],0xA1);
outb(cached_irq_mask[0],0x21);
//request_region(0x20,0x2,"pic1");
//request_region(0xA0,0x2,"pic2");
cascade.handler = bogus_int;
cascade.name = "cascade";
setup_irq(2,&cascade);
}
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