Commit 4d2e4d7f authored by Changhwan Youn's avatar Changhwan Youn Committed by Kukjin Kim
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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: default avatarChanghwan Youn <chaos.youn@samsung.com>
Signed-off-by: default avatarKukjin Kim <kgene.kim@samsung.com>
parent 3dbe6d4c

arch/arm/mach-exynos/mct.c

+13 −8
Original line number Diff line number Diff line
@@ -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) {

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