alistair23-linux/arch/arm/mach-gemini/irq.c

/*
 *  Interrupt routines for Gemini
 *
 *  Copyright (C) 2001-2006 Storlink, Corp.
 *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/stddef.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/cpu.h>

#include <asm/irq.h>
#include <asm/mach/irq.h>
#include <asm/system_misc.h>
#include <mach/hardware.h>

#define IRQ_SOURCE(base_addr)	(base_addr + 0x00)
#define IRQ_MASK(base_addr)	(base_addr + 0x04)
#define IRQ_CLEAR(base_addr)	(base_addr + 0x08)
#define IRQ_TMODE(base_addr)	(base_addr + 0x0C)
#define IRQ_TLEVEL(base_addr)	(base_addr + 0x10)
#define IRQ_STATUS(base_addr)	(base_addr + 0x14)
#define FIQ_SOURCE(base_addr)	(base_addr + 0x20)
#define FIQ_MASK(base_addr)	(base_addr + 0x24)
#define FIQ_CLEAR(base_addr)	(base_addr + 0x28)
#define FIQ_TMODE(base_addr)	(base_addr + 0x2C)
#define FIQ_LEVEL(base_addr)	(base_addr + 0x30)
#define FIQ_STATUS(base_addr)	(base_addr + 0x34)

static void gemini_ack_irq(struct irq_data *d)
{
	__raw_writel(1 << d->irq, IRQ_CLEAR(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
}

static void gemini_mask_irq(struct irq_data *d)
{
	unsigned int mask;

	mask = __raw_readl(IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
	mask &= ~(1 << d->irq);
	__raw_writel(mask, IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
}

static void gemini_unmask_irq(struct irq_data *d)
{
	unsigned int mask;

	mask = __raw_readl(IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
	mask |= (1 << d->irq);
	__raw_writel(mask, IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
}

static struct irq_chip gemini_irq_chip = {
	.name		= "INTC",
	.irq_ack	= gemini_ack_irq,
	.irq_mask	= gemini_mask_irq,
	.irq_unmask	= gemini_unmask_irq,
};

static struct resource irq_resource = {
	.name	= "irq_handler",
	.start	= GEMINI_INTERRUPT_BASE,
	.end	= FIQ_STATUS(GEMINI_INTERRUPT_BASE) + 4,
};

void __init gemini_init_irq(void)
{
	unsigned int i, mode = 0, level = 0;

	/*
	 * Disable the idle handler by default since it is buggy
	 * For more info see arch/arm/mach-gemini/idle.c
	 */
	cpu_idle_poll_ctrl(true);

	request_resource(&iomem_resource, &irq_resource);

	for (i = 0; i < NR_IRQS; i++) {
		irq_set_chip(i, &gemini_irq_chip);
		if((i >= IRQ_TIMER1 && i <= IRQ_TIMER3) || (i >= IRQ_SERIRQ0 && i <= IRQ_SERIRQ1)) {
			irq_set_handler(i, handle_edge_irq);
			mode |= 1 << i;
			level |= 1 << i;
		} else {			
			irq_set_handler(i, handle_level_irq);
		}
		irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE);
	}

	/* Disable all interrupts */
	__raw_writel(0, IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
	__raw_writel(0, FIQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));

	/* Set interrupt mode */
	__raw_writel(mode, IRQ_TMODE(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
	__raw_writel(level, IRQ_TLEVEL(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
}