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ARM: EXYNOS: fix cycle count for periodic mode of clock event timers

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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>
This commit is contained in:
Changhwan Youn 2012-03-09 15:09:21 -08:00 committed by Kukjin Kim
parent 3dbe6d4cac
commit 4d2e4d7f2c
1 changed files with 13 additions and 8 deletions
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21
arch/arm/mach-exynos/mct.c
View File

@ -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) {