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mips: Use common i8253 clockevent

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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20110609130622.133068765@linutronix.de
This commit is contained in:
Thomas Gleixner 2011-06-09 13:08:27 +00:00
parent 0a779c5713
commit 2d02612f61
2 changed files with 3 additions and 95 deletions
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1
arch/mips/Kconfig
View File

@ -2391,6 +2391,7 @@ config MMU
config I8253 config I8253
bool bool
select CLKSRC_I8253 select CLKSRC_I8253
select CLKEVT_I8253
select MIPS_EXTERNAL_TIMER select MIPS_EXTERNAL_TIMER
config ZONE_DMA32 config ZONE_DMA32

97
arch/mips/kernel/i8253.c
View File

@ -4,92 +4,15 @@
*/ */
#include <linux/clockchips.h> #include <linux/clockchips.h>
#include <linux/i8253.h> #include <linux/i8253.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/smp.h> #include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/irq.h> #include <linux/irq.h>
#include <asm/delay.h>
#include <asm/io.h>
#include <asm/time.h> #include <asm/time.h>
/*
* Initialize the PIT timer.
*
* This is also called after resume to bring the PIT into operation again.
*/
static void init_pit_timer(enum clock_event_mode mode,
struct clock_event_device *evt)
{
raw_spin_lock(&i8253_lock);
switch(mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* binary, mode 2, LSB/MSB, ch 0 */
outb_p(0x34, PIT_MODE);
outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
outb(LATCH >> 8 , PIT_CH0); /* MSB */
break;
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
if (evt->mode == CLOCK_EVT_MODE_PERIODIC ||
evt->mode == CLOCK_EVT_MODE_ONESHOT) {
outb_p(0x30, PIT_MODE);
outb_p(0, PIT_CH0);
outb_p(0, PIT_CH0);
}
break;
case CLOCK_EVT_MODE_ONESHOT:
/* One shot setup */
outb_p(0x38, PIT_MODE);
break;
case CLOCK_EVT_MODE_RESUME:
/* Nothing to do here */
break;
}
raw_spin_unlock(&i8253_lock);
}
/*
* Program the next event in oneshot mode
*
* Delta is given in PIT ticks
*/
static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
{
raw_spin_lock(&i8253_lock);
outb_p(delta & 0xff , PIT_CH0); /* LSB */
outb(delta >> 8 , PIT_CH0); /* MSB */
raw_spin_unlock(&i8253_lock);
return 0;
}
/*
* On UP the PIT can serve all of the possible timer functions. On SMP systems
* it can be solely used for the global tick.
*
* The profiling and update capabilites are switched off once the local apic is
* registered. This mechanism replaces the previous #ifdef LOCAL_APIC -
* !using_apic_timer decisions in do_timer_interrupt_hook()
*/
static struct clock_event_device pit_clockevent = {
.name = "pit",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = init_pit_timer,
.set_next_event = pit_next_event,
.irq = 0,
};
static irqreturn_t timer_interrupt(int irq, void *dev_id) static irqreturn_t timer_interrupt(int irq, void *dev_id)
{ {
pit_clockevent.event_handler(&pit_clockevent); i8253_clockevent.event_handler(&pit_clockevent);
return IRQ_HANDLED; return IRQ_HANDLED;
} }
@ -100,25 +23,9 @@ static struct irqaction irq0 = {
.name = "timer" .name = "timer"
}; };
/*
* Initialize the conversion factor and the min/max deltas of the clock event
* structure and register the clock event source with the framework.
*/
void __init setup_pit_timer(void) void __init setup_pit_timer(void)
{ {
struct clock_event_device *cd = &pit_clockevent; clockevent_i8253_init(true);
unsigned int cpu = smp_processor_id();
/*
* Start pit with the boot cpu mask and make it global after the
* IO_APIC has been initialized.
*/
cd->cpumask = cpumask_of(cpu);
clockevent_set_clock(cd, CLOCK_TICK_RATE);
cd->max_delta_ns = clockevent_delta2ns(0x7FFF, cd);
cd->min_delta_ns = clockevent_delta2ns(0xF, cd);
clockevents_register_device(cd);
setup_irq(0, &irq0); setup_irq(0, &irq0);
} }