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[ARM] 4012/1: Clocksource for pxa 

Add a clocksource driver for pxa2xx systems

Signed-off-by: Luotao Fu <lfu@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Sascha Hauer 2006-12-12 09:21:50 +01:00 committed by Russell King
parent da2c12a279
commit c80204e5d6
1 changed files with 23 additions and 22 deletions
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45
arch/arm/mach-pxa/time.c
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@ -18,6 +18,7 @@
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/clocksource.h>
#include <asm/system.h>
#include <asm/hardware.h>
@ -48,27 +49,6 @@ static int pxa_set_rtc(void)
return 0;
}
/* IRQs are disabled before entering here from do_gettimeofday() */
static unsigned long pxa_gettimeoffset (void)
{
long ticks_to_match, elapsed, usec;
/* Get ticks before next timer match */
ticks_to_match = OSMR0 - OSCR;
/* We need elapsed ticks since last match */
elapsed = LATCH - ticks_to_match;
/* don't get fooled by the workaround in pxa_timer_interrupt() */
if (elapsed <= 0)
return 0;
/* Now convert them to usec */
usec = (unsigned long)(elapsed * (tick_nsec / 1000))/LATCH;
return usec;
}
#ifdef CONFIG_NO_IDLE_HZ
static unsigned long initial_match;
static int match_posponed;
@ -121,6 +101,20 @@ static struct irqaction pxa_timer_irq = {
.handler = pxa_timer_interrupt,
};
cycle_t pxa_get_cycles(void)
{
return OSCR;
}
static struct clocksource clocksource_pxa = {
.name = "pxa_timer",
.rating = 200,
.read = pxa_get_cycles,
.mask = CLOCKSOURCE_MASK(32),
.shift = 20,
.is_continuous = 1,
};
static void __init pxa_timer_init(void)
{
struct timespec tv;
@ -139,6 +133,14 @@ static void __init pxa_timer_init(void)
OIER = OIER_E0; /* enable match on timer 0 to cause interrupts */
OSMR0 = OSCR + LATCH; /* set initial match */
local_irq_restore(flags);
/* on PXA OSCR runs continiously and is not written to, so we can use it
* as clock source directly.
*/
clocksource_pxa.mult =
clocksource_hz2mult(CLOCK_TICK_RATE, clocksource_pxa.shift);
clocksource_register(&clocksource_pxa);
}
#ifdef CONFIG_NO_IDLE_HZ
@ -211,7 +213,6 @@ struct sys_timer pxa_timer = {
.init = pxa_timer_init,
.suspend = pxa_timer_suspend,
.resume = pxa_timer_resume,
.offset = pxa_gettimeoffset,
#ifdef CONFIG_NO_IDLE_HZ
.dyn_tick = &pxa_dyn_tick,
#endif