isa-irq.c
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/*
* linux/arch/arm/mach-footbridge/irq.c
*
* Copyright (C) 1996-2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Changelog:
* 22-Aug-1998 RMK Restructured IRQ routines
* 03-Sep-1998 PJB Merged CATS support
* 20-Jan-1998 RMK Started merge of EBSA286, CATS and NetWinder
* 26-Jan-1999 PJB Don't use IACK on CATS
* 16-Mar-1999 RMK Added autodetect of ISA PICs
*/
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <asm/mach/irq.h>
#include <mach/hardware.h>
#include <asm/hardware/dec21285.h>
#include <asm/irq.h>
#include <asm/mach-types.h>
#include "common.h"
static void isa_mask_pic_lo_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq & 7);
outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
}
static void isa_ack_pic_lo_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq & 7);
outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
outb(0x20, PIC_LO);
}
static void isa_unmask_pic_lo_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq & 7);
outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO);
}
static struct irq_chip isa_lo_chip = {
.irq_ack = isa_ack_pic_lo_irq,
.irq_mask = isa_mask_pic_lo_irq,
.irq_unmask = isa_unmask_pic_lo_irq,
};
static void isa_mask_pic_hi_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq & 7);
outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
}
static void isa_ack_pic_hi_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq & 7);
outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
outb(0x62, PIC_LO);
outb(0x20, PIC_HI);
}
static void isa_unmask_pic_hi_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq & 7);
outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI);
}
static struct irq_chip isa_hi_chip = {
.irq_ack = isa_ack_pic_hi_irq,
.irq_mask = isa_mask_pic_hi_irq,
.irq_unmask = isa_unmask_pic_hi_irq,
};
static void
isa_irq_handler(unsigned int irq, struct irq_desc *desc)
{
unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE;
if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) {
do_bad_IRQ(isa_irq, desc);
return;
}
generic_handle_irq(isa_irq);
}
static struct irqaction irq_cascade = {
.handler = no_action,
.name = "cascade",
};
static struct resource pic1_resource = {
.name = "pic1",
.start = 0x20,
.end = 0x3f,
};
static struct resource pic2_resource = {
.name = "pic2",
.start = 0xa0,
.end = 0xbf,
};
void __init isa_init_irq(unsigned int host_irq)
{
unsigned int irq;
/*
* Setup, and then probe for an ISA PIC
* If the PIC is not there, then we
* ignore the PIC.
*/
outb(0x11, PIC_LO);
outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number */
outb(0x04, PIC_MASK_LO); /* Slave on Ch2 */
outb(0x01, PIC_MASK_LO); /* x86 */
outb(0xf5, PIC_MASK_LO); /* pattern: 11110101 */
outb(0x11, PIC_HI);
outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number */
outb(0x02, PIC_MASK_HI); /* Slave on Ch1 */
outb(0x01, PIC_MASK_HI); /* x86 */
outb(0xfa, PIC_MASK_HI); /* pattern: 11111010 */
outb(0x0b, PIC_LO);
outb(0x0b, PIC_HI);
if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) {
outb(0xff, PIC_MASK_LO);/* mask all IRQs */
outb(0xff, PIC_MASK_HI);/* mask all IRQs */
} else {
printk(KERN_INFO "IRQ: ISA PIC not found\n");
host_irq = (unsigned int)-1;
}
if (host_irq != (unsigned int)-1) {
for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) {
irq_set_chip_and_handler(irq, &isa_lo_chip,
handle_level_irq);
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
}
for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) {
irq_set_chip_and_handler(irq, &isa_hi_chip,
handle_level_irq);
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
}
request_resource(&ioport_resource, &pic1_resource);
request_resource(&ioport_resource, &pic2_resource);
setup_irq(IRQ_ISA_CASCADE, &irq_cascade);
irq_set_chained_handler(host_irq, isa_irq_handler);
/*
* On the NetWinder, don't automatically
* enable ISA IRQ11 when it is requested.
* There appears to be a missing pull-up
* resistor on this line.
*/
if (machine_is_netwinder())
set_irq_flags(_ISA_IRQ(11), IRQF_VALID |
IRQF_PROBE | IRQF_NOAUTOEN);
}
}