irq-zevio.c
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/*
* linux/drivers/irqchip/irq-zevio.c
*
* Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2, as
* published by the Free Software Foundation.
*
*/
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <asm/mach/irq.h>
#include <asm/exception.h>
#define IO_STATUS 0x000
#define IO_RAW_STATUS 0x004
#define IO_ENABLE 0x008
#define IO_DISABLE 0x00C
#define IO_CURRENT 0x020
#define IO_RESET 0x028
#define IO_MAX_PRIOTY 0x02C
#define IO_IRQ_BASE 0x000
#define IO_FIQ_BASE 0x100
#define IO_INVERT_SEL 0x200
#define IO_STICKY_SEL 0x204
#define IO_PRIORITY_SEL 0x300
#define MAX_INTRS 32
#define FIQ_START MAX_INTRS
static struct irq_domain *zevio_irq_domain;
static void __iomem *zevio_irq_io;
static void zevio_irq_ack(struct irq_data *irqd)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(irqd);
struct irq_chip_regs *regs =
&container_of(irqd->chip, struct irq_chip_type, chip)->regs;
readl(gc->reg_base + regs->ack);
}
static void __exception_irq_entry zevio_handle_irq(struct pt_regs *regs)
{
int irqnr;
while (readl(zevio_irq_io + IO_STATUS)) {
irqnr = readl(zevio_irq_io + IO_CURRENT);
handle_domain_irq(zevio_irq_domain, irqnr, regs);
};
}
static void __init zevio_init_irq_base(void __iomem *base)
{
/* Disable all interrupts */
writel(~0, base + IO_DISABLE);
/* Accept interrupts of all priorities */
writel(0xF, base + IO_MAX_PRIOTY);
/* Reset existing interrupts */
readl(base + IO_RESET);
}
static int __init zevio_of_init(struct device_node *node,
struct device_node *parent)
{
unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
struct irq_chip_generic *gc;
int ret;
if (WARN_ON(zevio_irq_io || zevio_irq_domain))
return -EBUSY;
zevio_irq_io = of_iomap(node, 0);
BUG_ON(!zevio_irq_io);
/* Do not invert interrupt status bits */
writel(~0, zevio_irq_io + IO_INVERT_SEL);
/* Disable sticky interrupts */
writel(0, zevio_irq_io + IO_STICKY_SEL);
/* We don't use IRQ priorities. Set each IRQ to highest priority. */
memset_io(zevio_irq_io + IO_PRIORITY_SEL, 0, MAX_INTRS * sizeof(u32));
/* Init IRQ and FIQ */
zevio_init_irq_base(zevio_irq_io + IO_IRQ_BASE);
zevio_init_irq_base(zevio_irq_io + IO_FIQ_BASE);
zevio_irq_domain = irq_domain_add_linear(node, MAX_INTRS,
&irq_generic_chip_ops, NULL);
BUG_ON(!zevio_irq_domain);
ret = irq_alloc_domain_generic_chips(zevio_irq_domain, MAX_INTRS, 1,
"zevio_intc", handle_level_irq,
clr, 0, IRQ_GC_INIT_MASK_CACHE);
BUG_ON(ret);
gc = irq_get_domain_generic_chip(zevio_irq_domain, 0);
gc->reg_base = zevio_irq_io;
gc->chip_types[0].chip.irq_ack = zevio_irq_ack;
gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
gc->chip_types[0].regs.mask = IO_IRQ_BASE + IO_ENABLE;
gc->chip_types[0].regs.enable = IO_IRQ_BASE + IO_ENABLE;
gc->chip_types[0].regs.disable = IO_IRQ_BASE + IO_DISABLE;
gc->chip_types[0].regs.ack = IO_IRQ_BASE + IO_RESET;
set_handle_irq(zevio_handle_irq);
pr_info("TI-NSPIRE classic IRQ controller\n");
return 0;
}
IRQCHIP_DECLARE(zevio_irq, "lsi,zevio-intc", zevio_of_init);