irq.c
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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1992 Linus Torvalds
* Copyright (C) 1994 - 2001, 2003, 07 Ralf Baechle
*/
#include <linux/clockchips.h>
#include <linux/i8253.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <asm/irq_cpu.h>
#include <asm/i8259.h>
#include <asm/io.h>
#include <asm/jazz.h>
#include <asm/pgtable.h>
#include <asm/tlbmisc.h>
static DEFINE_RAW_SPINLOCK(r4030_lock);
static void enable_r4030_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq - JAZZ_IRQ_START);
unsigned long flags;
raw_spin_lock_irqsave(&r4030_lock, flags);
mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
raw_spin_unlock_irqrestore(&r4030_lock, flags);
}
void disable_r4030_irq(struct irq_data *d)
{
unsigned int mask = ~(1 << (d->irq - JAZZ_IRQ_START));
unsigned long flags;
raw_spin_lock_irqsave(&r4030_lock, flags);
mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
raw_spin_unlock_irqrestore(&r4030_lock, flags);
}
static struct irq_chip r4030_irq_type = {
.name = "R4030",
.irq_mask = disable_r4030_irq,
.irq_unmask = enable_r4030_irq,
};
void __init init_r4030_ints(void)
{
int i;
for (i = JAZZ_IRQ_START; i <= JAZZ_IRQ_END; i++)
irq_set_chip_and_handler(i, &r4030_irq_type, handle_level_irq);
r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0);
r4030_read_reg16(JAZZ_IO_IRQ_SOURCE); /* clear pending IRQs */
r4030_read_reg32(JAZZ_R4030_INVAL_ADDR); /* clear error bits */
}
/*
* On systems with i8259-style interrupt controllers we assume for
* driver compatibility reasons interrupts 0 - 15 to be the i8259
* interrupts even if the hardware uses a different interrupt numbering.
*/
void __init arch_init_irq(void)
{
/*
* this is a hack to get back the still needed wired mapping
* killed by init_mm()
*/
/* Map 0xe0000000 -> 0x0:800005C0, 0xe0010000 -> 0x1:30000580 */
add_wired_entry(0x02000017, 0x03c00017, 0xe0000000, PM_64K);
/* Map 0xe2000000 -> 0x0:900005C0, 0xe3010000 -> 0x0:910005C0 */
add_wired_entry(0x02400017, 0x02440017, 0xe2000000, PM_16M);
/* Map 0xe4000000 -> 0x0:600005C0, 0xe4100000 -> 400005C0 */
add_wired_entry(0x01800017, 0x01000017, 0xe4000000, PM_4M);
init_i8259_irqs(); /* Integrated i8259 */
mips_cpu_irq_init();
init_r4030_ints();
change_c0_status(ST0_IM, IE_IRQ2 | IE_IRQ1);
}
asmlinkage void plat_irq_dispatch(void)
{
unsigned int pending = read_c0_cause() & read_c0_status();
unsigned int irq;
if (pending & IE_IRQ4) {
r4030_read_reg32(JAZZ_TIMER_REGISTER);
do_IRQ(JAZZ_TIMER_IRQ);
} else if (pending & IE_IRQ2) {
irq = *(volatile u8 *)JAZZ_EISA_IRQ_ACK;
do_IRQ(irq);
} else if (pending & IE_IRQ1) {
irq = *(volatile u8 *)JAZZ_IO_IRQ_SOURCE >> 2;
if (likely(irq > 0))
do_IRQ(irq + JAZZ_IRQ_START - 1);
else
panic("Unimplemented loc_no_irq handler");
}
}
static void r4030_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
/* Nothing to do ... */
}
struct clock_event_device r4030_clockevent = {
.name = "r4030",
.features = CLOCK_EVT_FEAT_PERIODIC,
.rating = 300,
.irq = JAZZ_TIMER_IRQ,
.set_mode = r4030_set_mode,
};
static irqreturn_t r4030_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *cd = dev_id;
cd->event_handler(cd);
return IRQ_HANDLED;
}
static struct irqaction r4030_timer_irqaction = {
.handler = r4030_timer_interrupt,
.flags = IRQF_TIMER,
.name = "R4030 timer",
};
void __init plat_time_init(void)
{
struct clock_event_device *cd = &r4030_clockevent;
struct irqaction *action = &r4030_timer_irqaction;
unsigned int cpu = smp_processor_id();
BUG_ON(HZ != 100);
cd->cpumask = cpumask_of(cpu);
clockevents_register_device(cd);
action->dev_id = cd;
setup_irq(JAZZ_TIMER_IRQ, action);
/*
* Set clock to 100Hz.
*
* The R4030 timer receives an input clock of 1kHz which is divieded by
* a programmable 4-bit divider. This makes it fairly inflexible.
*/
r4030_write_reg32(JAZZ_TIMER_INTERVAL, 9);
setup_pit_timer();
}