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| author | Stanislav Meduna <stano@meduna.org> | 2012-11-09 02:39:14 +0400 |
|---|---|---|
| committer | Shawn Guo <shawn.guo@linaro.org> | 2012-11-12 05:27:30 +0400 |
| commit | 67948adad178a041cd545c3f9b2bd077b1c5d7a1 (patch) | |
| tree | 6511c3bd9c432b40d2b398b1a72663fced360cbf /arch/arm/mach-mxs | |
| parent | 24196d5c597272b1e5c57903f2e3c7996e607117 (diff) | |
| download | linux-67948adad178a041cd545c3f9b2bd077b1c5d7a1.tar.xz | |
ARM: mxs: Setup scheduler clock
Setup scheduler clock on ARM MXS platforms with a 32-bit timrot
such as i.MX28. This allows the scheduler to use sub-jiffy resolution.
The corresponding change for 16-bit v1 timrots is not possible
at the moment due to rounding issues with clock values wrapping
faster than once per several seconds in the common ARM platform code.
Signed-off-by: Stanislav Meduna <stano@meduna.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Diffstat (limited to 'arch/arm/mach-mxs')
| -rw-r--r-- | arch/arm/mach-mxs/timer.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/arm/mach-mxs/timer.c b/arch/arm/mach-mxs/timer.c index 7c3792613392..856f4c796061 100644 --- a/arch/arm/mach-mxs/timer.c +++ b/arch/arm/mach-mxs/timer.c @@ -29,6 +29,7 @@ #include <linux/of_irq.h> #include <asm/mach/time.h> +#include <asm/sched_clock.h> #include <mach/mxs.h> #include <mach/common.h> @@ -233,15 +234,22 @@ static struct clocksource clocksource_mxs = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +static u32 notrace mxs_read_sched_clock_v2(void) +{ + return ~readl_relaxed(mxs_timrot_base + HW_TIMROT_RUNNING_COUNTn(1)); +} + static int __init mxs_clocksource_init(struct clk *timer_clk) { unsigned int c = clk_get_rate(timer_clk); if (timrot_is_v1()) clocksource_register_hz(&clocksource_mxs, c); - else + else { clocksource_mmio_init(mxs_timrot_base + HW_TIMROT_RUNNING_COUNTn(1), "mxs_timer", c, 200, 32, clocksource_mmio_readl_down); + setup_sched_clock(mxs_read_sched_clock_v2, 32, c); + } return 0; } |