diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-12-15 21:53:51 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-12-22 22:44:49 +0000 |
| commit | dc548fbbd2ecd0fc3b02301d551e5f8e19ae58fd (patch) | |
| tree | b96dc2b070c8f3b1835c2ee1fd6bf0e2b13b67f9 | |
| parent | ec05aa139939d9c7b790041a379f0e752b2f1a4d (diff) | |
ARM: omap: convert sched_clock() to use new infrastructure
Convert omap to use the new sched_clock() infrastructure for extending
32bit counters to full 64-bit nanoseconds.
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/plat-omap/counter_32k.c | 24 |
2 files changed, 23 insertions, 2 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 58e2fe30715..726279fe3f5 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -839,6 +839,7 @@ config ARCH_OMAP select ARCH_REQUIRE_GPIOLIB select ARCH_HAS_CPUFREQ select GENERIC_CLOCKEVENTS + select HAVE_SCHED_CLOCK select ARCH_HAS_HOLES_MEMORYMODEL help Support for TI's OMAP platform (OMAP1/2/3/4). diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c index aed301bfa2f..1b558efbe73 100644 --- a/arch/arm/plat-omap/counter_32k.c +++ b/arch/arm/plat-omap/counter_32k.c @@ -18,6 +18,8 @@ #include <linux/io.h> #include <linux/sched.h> +#include <asm/sched_clock.h> + #include <plat/common.h> #include <plat/board.h> @@ -110,10 +112,25 @@ static struct clocksource clocksource_32k = { * Returns current time from boot in nsecs. It's OK for this to wrap * around for now, as it's just a relative time stamp. */ +static DEFINE_CLOCK_DATA(cd); + +/* + * Constants generated by clocks_calc_mult_shift(m, s, 32768, NSEC_PER_SEC, 60). + * This gives a resolution of about 30us and a wrap period of about 36hrs. + */ +#define SC_MULT 4000000000u +#define SC_SHIFT 17 + unsigned long long notrace sched_clock(void) { - return clocksource_cyc2ns(clocksource_32k.read(&clocksource_32k), - clocksource_32k.mult, clocksource_32k.shift); + u32 cyc = clocksource_32k.read(&clocksource_32k); + return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0, SC_MULT, SC_SHIFT); +} + +static void notrace omap_update_sched_clock(void) +{ + u32 cyc = clocksource_32k.read(&clocksource_32k); + update_sched_clock(&cd, cyc, (u32)~0); } /** @@ -171,6 +188,9 @@ static int __init omap_init_clocksource_32k(void) if (clocksource_register_hz(&clocksource_32k, 32768)) printk(err, clocksource_32k.name); + + init_fixed_sched_clock(&cd, omap_update_sched_clock, 32, + 32768, SC_MULT, SC_SHIFT); } return 0; } |