irq.c

/*
 * linux/arch/arm/mach-omap2/irq.c
 *
 * Interrupt handler for OMAP2 boards.
 *
 * Copyright (C) 2005 Nokia Corporation
 * Author: Paul Mundt <paul.mundt@nokia.com>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/hardware.h>
#include <asm/mach/irq.h>
#include <asm/irq.h>
#include <asm/io.h>

#define INTC_REVISION	0x0000
#define INTC_SYSCONFIG	0x0010
#define INTC_SYSSTATUS	0x0014
#define INTC_CONTROL	0x0048
#define INTC_MIR_CLEAR0	0x0088
#define INTC_MIR_SET0	0x008c

/*
 * OMAP2 has a number of different interrupt controllers, each interrupt
 * controller is identified as its own "bank". Register definitions are
 * fairly consistent for each bank, but not all registers are implemented
 * for each bank.. when in doubt, consult the TRM.
 */
static struct omap_irq_bank {
	unsigned long base_reg;
	unsigned int nr_irqs;
} __attribute__ ((aligned(4))) irq_banks[] = {
	{
		/* MPU INTC */
		.base_reg	= OMAP24XX_IC_BASE,
		.nr_irqs	= 96,
	}, {
		/* XXX: DSP INTC */
	}
};

/* XXX: FIQ and additional INTC support (only MPU at the moment) */
static void omap_ack_irq(unsigned int irq)
{
	omap_writel(0x1, irq_banks[0].base_reg + INTC_CONTROL);
}

static void omap_mask_irq(unsigned int irq)
{
	int offset = (irq >> 5) << 5;

	if (irq >= 64) {
		irq %= 64;
	} else if (irq >= 32) {
		irq %= 32;
	}

	omap_writel(1 << irq, irq_banks[0].base_reg + INTC_MIR_SET0 + offset);
}

static void omap_unmask_irq(unsigned int irq)
{
	int offset = (irq >> 5) << 5;

	if (irq >= 64) {
		irq %= 64;
	} else if (irq >= 32) {
		irq %= 32;
	}

	omap_writel(1 << irq, irq_banks[0].base_reg + INTC_MIR_CLEAR0 + offset);
}

static void omap_mask_ack_irq(unsigned int irq)
{
	omap_mask_irq(irq);
	omap_ack_irq(irq);
}

static struct irq_chip omap_irq_chip = {
	.name	= "INTC",
	.ack	= omap_mask_ack_irq,
	.mask	= omap_mask_irq,
	.unmask	= omap_unmask_irq,
};

static void __init omap_irq_bank_init_one(struct omap_irq_bank *bank)
{
	unsigned long tmp;

	tmp = omap_readl(bank->base_reg + INTC_REVISION) & 0xff;
	printk(KERN_INFO "IRQ: Found an INTC at 0x%08lx "
			 "(revision %ld.%ld) with %d interrupts\n",
			 bank->base_reg, tmp >> 4, tmp & 0xf, bank->nr_irqs);

	tmp = omap_readl(bank->base_reg + INTC_SYSCONFIG);
	tmp |= 1 << 1;	/* soft reset */
	omap_writel(tmp, bank->base_reg + INTC_SYSCONFIG);

	while (!(omap_readl(bank->base_reg + INTC_SYSSTATUS) & 0x1))
		/* Wait for reset to complete */;
}

void __init omap_init_irq(void)
{
	unsigned long nr_irqs = 0;
	unsigned int nr_banks = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(irq_banks); i++) {
		struct omap_irq_bank *bank = irq_banks + i;

		/* XXX */
		if (!bank->base_reg)
			continue;

		omap_irq_bank_init_one(bank);

		nr_irqs += bank->nr_irqs;
		nr_banks++;
	}

	printk(KERN_INFO "Total of %ld interrupts on %d active controller%s\n",
	       nr_irqs, nr_banks, nr_banks > 1 ? "s" : "");

	for (i = 0; i < nr_irqs; i++) {
		set_irq_chip(i, &omap_irq_chip);
		set_irq_handler(i, handle_level_irq);
		set_irq_flags(i, IRQF_VALID);
	}
}