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| author | Changhwan Youn <chaos.youn@samsung.com> | 2012-03-09 15:09:21 -0800 |
|---|---|---|
| committer | Kukjin Kim <kgene.kim@samsung.com> | 2012-03-10 07:26:59 -0800 |
| commit | 4d2e4d7f2c2b1a4382286821a59fa2f4012cb748 (patch) | |
| tree | 93f3f8631c16c0a7e6784b12a9df05cfb51faf3a | |
| parent | 3dbe6d4cacc76100f3166cd824d3ce7a8cef7cef (diff) | |
| download | linux-4d2e4d7f2c2b1a4382286821a59fa2f4012cb748.tar.gz linux-4d2e4d7f2c2b1a4382286821a59fa2f4012cb748.tar.bz2 linux-4d2e4d7f2c2b1a4382286821a59fa2f4012cb748.zip | |
ARM: EXYNOS: fix cycle count for periodic mode of clock event timers
EXYNOS SOC series use MCT for kernel timer and MCT has two types of
clock event timers, which are mct-comp and mct-tick.
Because the clock rate of each event timer is diffent from the other,
this patch fixes cycles_per_jiffy for each timer's periodic mode.
Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
| -rw-r--r-- | arch/arm/mach-exynos/mct.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/arch/arm/mach-exynos/mct.c b/arch/arm/mach-exynos/mct.c index 85b5527d0918..3e894ba25b01 100644 --- a/arch/arm/mach-exynos/mct.c +++ b/arch/arm/mach-exynos/mct.c @@ -29,12 +29,13 @@ #include <mach/regs-mct.h> #include <asm/mach/time.h> +#define TICK_BASE_CNT 1 + enum { MCT_INT_SPI, MCT_INT_PPI }; -static unsigned long clk_cnt_per_tick; static unsigned long clk_rate; static unsigned int mct_int_type; @@ -205,11 +206,14 @@ static int exynos4_comp_set_next_event(unsigned long cycles, static void exynos4_comp_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) { + unsigned long cycles_per_jiffy; exynos4_mct_comp0_stop(); switch (mode) { case CLOCK_EVT_MODE_PERIODIC: - exynos4_mct_comp0_start(mode, clk_cnt_per_tick); + cycles_per_jiffy = + (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift); + exynos4_mct_comp0_start(mode, cycles_per_jiffy); break; case CLOCK_EVT_MODE_ONESHOT: @@ -248,9 +252,7 @@ static struct irqaction mct_comp_event_irq = { static void exynos4_clockevent_init(void) { - clk_cnt_per_tick = clk_rate / 2 / HZ; - - clockevents_calc_mult_shift(&mct_comp_device, clk_rate / 2, 5); + clockevents_calc_mult_shift(&mct_comp_device, clk_rate, 5); mct_comp_device.max_delta_ns = clockevent_delta2ns(0xffffffff, &mct_comp_device); mct_comp_device.min_delta_ns = @@ -314,12 +316,15 @@ static inline void exynos4_tick_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) { struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick); + unsigned long cycles_per_jiffy; exynos4_mct_tick_stop(mevt); switch (mode) { case CLOCK_EVT_MODE_PERIODIC: - exynos4_mct_tick_start(clk_cnt_per_tick, mevt); + cycles_per_jiffy = + (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift); + exynos4_mct_tick_start(cycles_per_jiffy, mevt); break; case CLOCK_EVT_MODE_ONESHOT: @@ -393,7 +398,7 @@ static void exynos4_mct_tick_init(struct clock_event_device *evt) evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; evt->rating = 450; - clockevents_calc_mult_shift(evt, clk_rate / 2, 5); + clockevents_calc_mult_shift(evt, clk_rate / (TICK_BASE_CNT + 1), 5); evt->max_delta_ns = clockevent_delta2ns(0x7fffffff, evt); evt->min_delta_ns = @@ -401,7 +406,7 @@ static void exynos4_mct_tick_init(struct clock_event_device *evt) clockevents_register_device(evt); - exynos4_mct_write(0x1, mevt->base + MCT_L_TCNTB_OFFSET); + exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET); if (mct_int_type == MCT_INT_SPI) { if (cpu == 0) { |