arch/arm/mach-davinci/irq.c

/*
 * Interrupt handler for DaVinci boards.
 *
 * Copyright (C) 2006 Texas Instruments.
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/irqdomain.h>

#include <mach/hardware.h>
#include <mach/cputype.h>
#include <mach/common.h>
#include <asm/mach/irq.h>
#include <asm/exception.h>

#define FIQ_REG0_OFFSET		0x0000
#define FIQ_REG1_OFFSET		0x0004
#define IRQ_REG0_OFFSET		0x0008
#define IRQ_REG1_OFFSET		0x000C
#define IRQ_IRQENTRY_OFFSET	0x0014
#define IRQ_ENT_REG0_OFFSET	0x0018
#define IRQ_ENT_REG1_OFFSET	0x001C
#define IRQ_INCTL_REG_OFFSET	0x0020
#define IRQ_EABASE_REG_OFFSET	0x0024
#define IRQ_INTPRI0_REG_OFFSET	0x0030
#define IRQ_INTPRI7_REG_OFFSET	0x004C

static void __iomem *davinci_intc_base;
static struct irq_domain *davinci_irq_domain;

static inline void davinci_irq_writel(unsigned long value, int offset)
{
	__raw_writel(value, davinci_intc_base + offset);
}

static inline unsigned long davinci_irq_readl(int offset)
{
	return readl_relaxed(davinci_intc_base + offset);
}

static __init void
davinci_irq_setup_gc(void __iomem *base,
		     unsigned int irq_start, unsigned int num)
{
	struct irq_chip_generic *gc;
	struct irq_chip_type *ct;

	gc = irq_get_domain_generic_chip(davinci_irq_domain, irq_start);
	gc->reg_base = base;
	gc->irq_base = irq_start;

	ct = gc->chip_types;
	ct->chip.irq_ack = irq_gc_ack_set_bit;
	ct->chip.irq_mask = irq_gc_mask_clr_bit;
	ct->chip.irq_unmask = irq_gc_mask_set_bit;

	ct->regs.ack = IRQ_REG0_OFFSET;
	ct->regs.mask = IRQ_ENT_REG0_OFFSET;
	irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
			       IRQ_NOREQUEST | IRQ_NOPROBE, 0);
}

static asmlinkage void __exception_irq_entry
davinci_handle_irq(struct pt_regs *regs)
{
	int irqnr = davinci_irq_readl(IRQ_IRQENTRY_OFFSET);

	/*
	 * Use the formula for entry vector index generation from section
	 * 8.3.3 of the manual.
	 */
	irqnr >>= 2;
	irqnr -= 1;

	handle_domain_irq(davinci_irq_domain, irqnr, regs);
}

/* ARM Interrupt Controller Initialization */
void __init davinci_irq_init(void)
{
	unsigned i, j;
	const u8 *davinci_def_priorities = davinci_soc_info.intc_irq_prios;
	int ret, irq_base;

	davinci_intc_base = ioremap(davinci_soc_info.intc_base, SZ_4K);
	if (WARN_ON(!davinci_intc_base))
		return;

	/* Clear all interrupt requests */
	davinci_irq_writel(~0x0, FIQ_REG0_OFFSET);
	davinci_irq_writel(~0x0, FIQ_REG1_OFFSET);
	davinci_irq_writel(~0x0, IRQ_REG0_OFFSET);
	davinci_irq_writel(~0x0, IRQ_REG1_OFFSET);

	/* Disable all interrupts */
	davinci_irq_writel(0x0, IRQ_ENT_REG0_OFFSET);
	davinci_irq_writel(0x0, IRQ_ENT_REG1_OFFSET);

	/* Interrupts disabled immediately, IRQ entry reflects all */
	davinci_irq_writel(0x0, IRQ_INCTL_REG_OFFSET);

	/* we don't use the hardware vector table, just its entry addresses */
	davinci_irq_writel(0, IRQ_EABASE_REG_OFFSET);

	/* Clear all interrupt requests */
	davinci_irq_writel(~0x0, FIQ_REG0_OFFSET);
	davinci_irq_writel(~0x0, FIQ_REG1_OFFSET);
	davinci_irq_writel(~0x0, IRQ_REG0_OFFSET);
	davinci_irq_writel(~0x0, IRQ_REG1_OFFSET);

	for (i = IRQ_INTPRI0_REG_OFFSET; i <= IRQ_INTPRI7_REG_OFFSET; i += 4) {
		u32		pri;

		for (j = 0, pri = 0; j < 32; j += 4, davinci_def_priorities++)
			pri |= (*davinci_def_priorities & 0x07) << j;
		davinci_irq_writel(pri, i);
	}

	irq_base = irq_alloc_descs(-1, 0, davinci_soc_info.intc_irq_num, 0);
	if (WARN_ON(irq_base < 0))
		return;

	davinci_irq_domain = irq_domain_add_legacy(NULL,
					davinci_soc_info.intc_irq_num,
					irq_base, 0, &irq_domain_simple_ops,
					NULL);
	if (WARN_ON(!davinci_irq_domain))
		return;

	ret = irq_alloc_domain_generic_chips(davinci_irq_domain, 32, 1,
					    "AINTC", handle_edge_irq,
					    IRQ_NOREQUEST | IRQ_NOPROBE, 0, 0);
	if (WARN_ON(ret))
		return;

	for (i = 0, j = 0; i < davinci_soc_info.intc_irq_num; i += 32, j += 0x04)
		davinci_irq_setup_gc(davinci_intc_base + j, irq_base + i, 32);

	irq_set_handler(DAVINCI_INTC_IRQ(IRQ_TINT1_TINT34), handle_level_irq);
	set_handle_irq(davinci_handle_irq);
}