From 0b96258b420208ebaacc0ef4b21b67dba262badf Mon Sep 17 00:00:00 2001 From: Tomasz Figa Date: Mon, 17 Jun 2013 01:11:31 +0200 Subject: [PATCH] clocksource: samsung_pwm_timer: Handle suspend/resume correctly Current suspend/resume handling of the driver was broken, because: - periodic timer was being enabled in CLOCK_EVT_MODE_RESUME mode, which does not seem to be correct behavior looking at other platforms, - PWM divisors need to be restored, but they were not, - clockevent interrupt mask needs to be restored, but it was not, - clocksource was being restored in clockevent resume callback. This patch fixes issues mentioned above, making suspend/resume handling in the driver correct. Signed-off-by: Tomasz Figa Reviewed-by: Sylwester Nawrocki Tested-by: Heiko Stuebner Tested-by: Mark Brown Tested-by: Sylwester Nawrocki Acked-by: Arnd Bergmann Acked-by: Daniel Lezcano --- drivers/clocksource/samsung_pwm_timer.c | 42 ++++++++++++++++--------- 1 file changed, 28 insertions(+), 14 deletions(-) diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c index b3112dc293ba..ac60f8b8a5f7 100644 --- a/drivers/clocksource/samsung_pwm_timer.c +++ b/drivers/clocksource/samsung_pwm_timer.c @@ -207,17 +207,6 @@ static int samsung_set_next_event(unsigned long cycles, return 0; } -static void samsung_timer_resume(void) -{ - /* event timer restart */ - samsung_time_setup(pwm.event_id, pwm.clock_count_per_tick - 1); - samsung_time_start(pwm.event_id, true); - - /* source timer restart */ - samsung_time_setup(pwm.source_id, pwm.tcnt_max); - samsung_time_start(pwm.source_id, true); -} - static void samsung_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) { @@ -234,20 +223,29 @@ static void samsung_set_mode(enum clock_event_mode mode, case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: - break; - case CLOCK_EVT_MODE_RESUME: - samsung_timer_resume(); break; } } +static void samsung_clockevent_resume(struct clock_event_device *cev) +{ + samsung_timer_set_prescale(pwm.event_id, pwm.tscaler_div); + samsung_timer_set_divisor(pwm.event_id, pwm.tdiv); + + if (pwm.variant.has_tint_cstat) { + u32 mask = (1 << pwm.event_id); + writel(mask | (mask << 5), pwm.base + REG_TINT_CSTAT); + } +} + static struct clock_event_device time_event_device = { .name = "samsung_event_timer", .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, .rating = 200, .set_next_event = samsung_set_next_event, .set_mode = samsung_set_mode, + .resume = samsung_clockevent_resume, }; static irqreturn_t samsung_clock_event_isr(int irq, void *dev_id) @@ -298,6 +296,20 @@ static void __init samsung_clockevent_init(void) } } +static void samsung_clocksource_suspend(struct clocksource *cs) +{ + samsung_time_stop(pwm.source_id); +} + +static void samsung_clocksource_resume(struct clocksource *cs) +{ + samsung_timer_set_prescale(pwm.source_id, pwm.tscaler_div); + samsung_timer_set_divisor(pwm.source_id, pwm.tdiv); + + samsung_time_setup(pwm.source_id, pwm.tcnt_max); + samsung_time_start(pwm.source_id, true); +} + static cycle_t samsung_clocksource_read(struct clocksource *c) { return ~readl_relaxed(pwm.source_reg); @@ -307,6 +319,8 @@ static struct clocksource samsung_clocksource = { .name = "samsung_clocksource_timer", .rating = 250, .read = samsung_clocksource_read, + .suspend = samsung_clocksource_suspend, + .resume = samsung_clocksource_resume, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; -- 2.34.1