From dc548fbbd2ecd0fc3b02301d551e5f8e19ae58fd Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 15 Dec 2010 21:53:51 +0000 Subject: [PATCH] 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 Signed-off-by: Russell King --- arch/arm/Kconfig | 1 + 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 58e2fe30715b..726279fe3f53 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 aed301bfa2f9..1b558efbe732 100644 --- a/arch/arm/plat-omap/counter_32k.c +++ b/arch/arm/plat-omap/counter_32k.c @@ -18,6 +18,8 @@ #include #include +#include + #include #include @@ -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; } -- GitLab