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/*
* Copyright (C) 2006 Atmel Corporation
*
* 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/clk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <asm/io.h>
#include "intc.h"
struct intc {
void __iomem *regs;
struct irq_chip chip;
};
extern struct platform_device at32_intc0_device;
/*
* TODO: We may be able to implement mask/unmask by setting IxM flags
* in the status register.
*/
static void intc_mask_irq(unsigned int irq)
{
}
static void intc_unmask_irq(unsigned int irq)
{
}
static struct intc intc0 = {
.chip = {
.name = "intc",
.mask = intc_mask_irq,
.unmask = intc_unmask_irq,
},
};
/*
* All interrupts go via intc at some point.
*/
asmlinkage void do_IRQ(int level, struct pt_regs *regs)
{
struct irq_desc *desc;
unsigned int irq;
unsigned long status_reg;
local_irq_disable();
irq_enter();
irq = intc_readl(&intc0, INTCAUSE0 - 4 * level);
desc = irq_desc + irq;
desc->handle_irq(irq, desc, regs);
/*
* Clear all interrupt level masks so that we may handle
* interrupts during softirq processing. If this is a nested
* interrupt, interrupts must stay globally disabled until we
* return.
*/
status_reg = sysreg_read(SR);
status_reg &= ~(SYSREG_BIT(I0M) | SYSREG_BIT(I1M)
| SYSREG_BIT(I2M) | SYSREG_BIT(I3M));
sysreg_write(SR, status_reg);
irq_exit();
}
void __init init_IRQ(void)
{
extern void _evba(void);
extern void irq_level0(void);
struct resource *regs;
struct clk *pclk;
unsigned int i;
u32 offset, readback;
regs = platform_get_resource(&at32_intc0_device, IORESOURCE_MEM, 0);
if (!regs) {
printk(KERN_EMERG "intc: no mmio resource defined\n");
goto fail;
}
pclk = clk_get(&at32_intc0_device.dev, "pclk");
if (IS_ERR(pclk)) {
printk(KERN_EMERG "intc: no clock defined\n");
goto fail;
}
clk_enable(pclk);
intc0.regs = ioremap(regs->start, regs->end - regs->start + 1);
if (!intc0.regs) {
printk(KERN_EMERG "intc: failed to map registers (0x%08lx)\n",
(unsigned long)regs->start);
goto fail;
}
/*
* Initialize all interrupts to level 0 (lowest priority). The
* priority level may be changed by calling
* irq_set_priority().
*
*/
offset = (unsigned long)&irq_level0 - (unsigned long)&_evba;
for (i = 0; i < NR_INTERNAL_IRQS; i++) {
intc_writel(&intc0, INTPR0 + 4 * i, offset);
readback = intc_readl(&intc0, INTPR0 + 4 * i);
if (readback == offset)
set_irq_chip_and_handler(i, &intc0.chip,
handle_simple_irq);
}
/* Unmask all interrupt levels */
sysreg_write(SR, (sysreg_read(SR)
& ~(SR_I3M | SR_I2M | SR_I1M | SR_I0M)));
return;
fail:
panic("Interrupt controller initialization failed!\n");
}
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