irq.c

来自「SMDK2440 boot code, base on vivi」· C语言 代码 · 共 165 行

/*
 * vivi/kernel/irq.c: simple interrupt core
 *
 * Copyright (C) 2001-2004 MIZI Research, Inc. All rights reserved.
 *
 * Author:	Janghoon Lyu
 * Created:	February 25, 2004
 *
 * 沥富 窜鉴窍霸 父甸妨绊 畴仿沁促. 磊盔档 力茄窍妨绊 沁扁 锭巩俊,
 * 窜鉴茄 硅凯肺 贸府沁促.
 */

#include <config.h>
#include <irq.h>
#include <vstring.h>
#include <armv.h>
#include <vmalloc.h>


irq_t irq_routines;
irq_handler_t *irq_handlers;

static irq_handler_t * search_handler(int irq_num)
{
	irq_handler_t *h = NULL;
	int i;

	for (i = 0; i < MAX_IRQ_HANDLERS; i++) {
		h = irq_handlers + i;
		if (h->function == NULL)
			continue;

		if (h->irq == irq_num) {
			break;
		}
	}

	if (i == MAX_IRQ_HANDLERS)
		h = NULL;

	return h;
}

static irq_handler_t * search_empty_handler(void)
{
	irq_handler_t *h = NULL;
	int i;

	for (i = 0; i < MAX_IRQ_HANDLERS; i++) {
		h = irq_handlers + i;
		if (h->function == NULL) {
			break;
		}
	}

	if (i == MAX_IRQ_HANDLERS)
		h = NULL;

	return h;
}

void do_irq(void)
{
	unsigned int irq_num = NR_IRQS;
	irq_handler_t *h = NULL;

	if (irq_routines.search == NULL)
		return;

	irq_num = irq_routines.search();

	irq_routines.mask_ack(irq_num);

	h = search_handler(irq_num);
	if (h == NULL)
		return;

	h->function(irq_num, h->data);

	irq_routines.unmask(irq_num);
	
	return;
}

int request_irq(int irq_num, void (*irq_handler) (int, void *), void *data)
{
	irq_handler_t *h = NULL;

	if (irq_handlers == NULL)
		return 1;

	if (irq_handler == NULL)
		return 2;

	if ((irq_num) < 0 || (irq_num) >= NR_IRQS)
		return 3;

	h = search_empty_handler();
	if (h == NULL)
		return 4;

	h->irq = irq_num;
	h->function = irq_handler;
	h->data = data;

	irq_routines.unmask(h->irq);

	return 0;
}

int free_irq(int irq_num)
{
	irq_handler_t *h = NULL;

	h = search_handler(irq_num);
	if (h == NULL)
		return 1;

	h->function = NULL;
	h->data = NULL;

	return 0;
}

void enable_irq(void)
{
	unsigned long cpsr;
	__asm__("mrs %0, cpsr" : "=r" (cpsr));
	cpsr &= ~(I_BIT);
	__asm__("msr cpsr_c, %0" : : "r" (cpsr));	/* enable IRQ */
}

void disable_irq(void)
{
	unsigned long cpsr;
	__asm__("mrs %0, cpsr" : "=r" (cpsr));
	cpsr |= (I_BIT);
	__asm__("msr cpsr_c, %0" : : "r" (cpsr));	/* enable IRQ */
}

void disable_irq_and_clear(void)
{
	disable_irq();
	irq_routines.clear();
}

int init_irq(void)
{
	irq_handlers = (irq_handler_t *)vmalloc(sizeof(irq_handler_t)
					       * MAX_IRQ_HANDLERS);
	if (irq_handlers == NULL)
		return 1;

	/* 伐捞 歹矾况廉 乐阑 荐档 乐促. */
	memset(irq_handlers, 0x00, sizeof(irq_handler_t)*MAX_IRQ_HANDLERS);

	enable_irq();

	arch_init_irq();

	irq_routines.clear();

	return 0;
}