irq.c

/*
 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
 *
 * 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.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301, USA.
 */

#include <linux/module.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <mach/common.h>
#include <asm/mach/irq.h>
#include <mach/hardware.h>

#define AVIC_BASE		IO_ADDRESS(AVIC_BASE_ADDR)
#define AVIC_INTCNTL		(AVIC_BASE + 0x00)	/* int control reg */
#define AVIC_NIMASK		(AVIC_BASE + 0x04)	/* int mask reg */
#define AVIC_INTENNUM		(AVIC_BASE + 0x08)	/* int enable number reg */
#define AVIC_INTDISNUM		(AVIC_BASE + 0x0C)	/* int disable number reg */
#define AVIC_INTENABLEH		(AVIC_BASE + 0x10)	/* int enable reg high */
#define AVIC_INTENABLEL		(AVIC_BASE + 0x14)	/* int enable reg low */
#define AVIC_INTTYPEH		(AVIC_BASE + 0x18)	/* int type reg high */
#define AVIC_INTTYPEL		(AVIC_BASE + 0x1C)	/* int type reg low */
#define AVIC_NIPRIORITY(x)	(AVIC_BASE + (0x20 + 4 * (7 - (x)))) /* int priority */
#define AVIC_NIVECSR		(AVIC_BASE + 0x40)	/* norm int vector/status */
#define AVIC_FIVECSR		(AVIC_BASE + 0x44)	/* fast int vector/status */
#define AVIC_INTSRCH		(AVIC_BASE + 0x48)	/* int source reg high */
#define AVIC_INTSRCL		(AVIC_BASE + 0x4C)	/* int source reg low */
#define AVIC_INTFRCH		(AVIC_BASE + 0x50)	/* int force reg high */
#define AVIC_INTFRCL		(AVIC_BASE + 0x54)	/* int force reg low */
#define AVIC_NIPNDH		(AVIC_BASE + 0x58)	/* norm int pending high */
#define AVIC_NIPNDL		(AVIC_BASE + 0x5C)	/* norm int pending low */
#define AVIC_FIPNDH		(AVIC_BASE + 0x60)	/* fast int pending high */
#define AVIC_FIPNDL		(AVIC_BASE + 0x64)	/* fast int pending low */

#define SYSTEM_PREV_REG		IO_ADDRESS(IIM_BASE_ADDR + 0x20)
#define SYSTEM_SREV_REG		IO_ADDRESS(IIM_BASE_ADDR + 0x24)
#define IIM_PROD_REV_SH		3
#define IIM_PROD_REV_LEN	5

#ifdef CONFIG_MXC_IRQ_PRIOR
void imx_irq_set_priority(unsigned char irq, unsigned char prio)
{
	unsigned int temp;
	unsigned int mask = 0x0F << irq % 8 * 4;

	if (irq > 63)
		return;

	temp = __raw_readl(AVIC_NIPRIORITY(irq / 8));
	temp &= ~mask;
	temp |= prio & mask;

	__raw_writel(temp, AVIC_NIPRIORITY(irq / 8));
}
EXPORT_SYMBOL(imx_irq_set_priority);
#endif

#ifdef CONFIG_FIQ
int mxc_set_irq_fiq(unsigned int irq, unsigned int type)
{
	unsigned int irqt;

	if (irq >= MXC_INTERNAL_IRQS)
		return -EINVAL;

	if (irq < MXC_INTERNAL_IRQS / 2) {
		irqt = __raw_readl(AVIC_INTTYPEL) & ~(1 << irq);
		__raw_writel(irqt | (!!type << irq), AVIC_INTTYPEL);
	} else {
		irq -= MXC_INTERNAL_IRQS / 2;
		irqt = __raw_readl(AVIC_INTTYPEH) & ~(1 << irq);
		__raw_writel(irqt | (!!type << irq), AVIC_INTTYPEH);
	}

	return 0;
}
EXPORT_SYMBOL(mxc_set_irq_fiq);
#endif /* CONFIG_FIQ */

/* Disable interrupt number "irq" in the AVIC */
static void mxc_mask_irq(unsigned int irq)
{
	__raw_writel(irq, AVIC_INTDISNUM);
}

/* Enable interrupt number "irq" in the AVIC */
static void mxc_unmask_irq(unsigned int irq)
{
	__raw_writel(irq, AVIC_INTENNUM);
}

static struct irq_chip mxc_avic_chip = {
	.ack = mxc_mask_irq,
	.mask = mxc_mask_irq,
	.unmask = mxc_unmask_irq,
};

/*
 * This function initializes the AVIC hardware and disables all the
 * interrupts. It registers the interrupt enable and disable functions
 * to the kernel for each interrupt source.
 */
void __init mxc_init_irq(void)
{
	int i;

	/* put the AVIC into the reset value with
	 * all interrupts disabled
	 */
	__raw_writel(0, AVIC_INTCNTL);
	__raw_writel(0x1f, AVIC_NIMASK);

	/* disable all interrupts */
	__raw_writel(0, AVIC_INTENABLEH);
	__raw_writel(0, AVIC_INTENABLEL);

	/* all IRQ no FIQ */
	__raw_writel(0, AVIC_INTTYPEH);
	__raw_writel(0, AVIC_INTTYPEL);
	for (i = 0; i < MXC_INTERNAL_IRQS; i++) {
		set_irq_chip(i, &mxc_avic_chip);
		set_irq_handler(i, handle_level_irq);
		set_irq_flags(i, IRQF_VALID);
	}

	/* Set default priority value (0) for all IRQ's */
	for (i = 0; i < 8; i++)
		__raw_writel(0, AVIC_NIPRIORITY(i));

	/* init architectures chained interrupt handler */
	mxc_register_gpios();

#ifdef CONFIG_FIQ
	/* Initialize FIQ */
	init_FIQ();
#endif

	printk(KERN_INFO "MXC IRQ initialized\n");
}