From 67948adad178a041cd545c3f9b2bd077b1c5d7a1 Mon Sep 17 00:00:00 2001 From: Stanislav Meduna Date: Thu, 8 Nov 2012 23:39:14 +0100 Subject: [PATCH] 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 Signed-off-by: Shawn Guo --- arch/arm/mach-mxs/timer.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) 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 #include +#include #include #include @@ -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; } -- 2.11.0