Commit c80204e5 authored by Sascha Hauer's avatar Sascha Hauer Committed by Russell King
Browse files

[ARM] 4012/1: Clocksource for pxa 



Add a clocksource driver for pxa2xx systems

Signed-off-by: default avatarLuotao Fu <lfu@pengutronix.de>
Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: default avatarNicolas Pitre <nico@cam.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent da2c12a2

arch/arm/mach-pxa/time.c

+23 −22
Original line number Diff line number Diff line
@@ -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