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| author | Sascha Hauer <sascha@saschahauer.de> | 2006-12-12 09:21:50 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-12-13 14:37:26 +0000 |
| commit | c80204e5d67d1452ac0b761d980f1651dc2c66dc (patch) | |
| tree | 78ca0812db8fe4729c804efd6e1c5acb18ca3031 | |
| parent | da2c12a279ae225f3d4696f76cb3b32a5bec5bfb (diff) | |
| download | linux-c80204e5d67d1452ac0b761d980f1651dc2c66dc.tar.gz linux-c80204e5d67d1452ac0b761d980f1651dc2c66dc.tar.bz2 linux-c80204e5d67d1452ac0b761d980f1651dc2c66dc.zip | |
[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>
| -rw-r--r-- | arch/arm/mach-pxa/time.c | 45 |
1 files changed, 23 insertions, 22 deletions
diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c index b91466861029..3775b8f38429 100644 --- a/arch/arm/mach-pxa/time.c +++ b/arch/arm/mach-pxa/time.c @@ -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 |