arch/arm/mach-footbridge/isa-irq.c

Source file repositories/reference/linux-study-clean/arch/arm/mach-footbridge/isa-irq.c

File Facts

System
Linux kernel
Corpus path
arch/arm/mach-footbridge/isa-irq.c
Extension
.c
Size
4248 bytes
Lines
178
Domain
Architecture Layer
Bucket
arch/arm
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/arch/arm/mach-footbridge/irq.c
 *
 *  Copyright (C) 1996-2000 Russell King
 *
 *  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(struct irq_desc *desc)
{
	unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE;

Annotation

Implementation Notes