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Code Issues Releases Wiki Activity

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 <tomasz.figa@gmail.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Mark Brown <broonie@linaro.org>
Tested-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This commit is contained in:
Tomasz Figa 2013-06-17 01:11:31 +02:00
parent 6792e636d5
commit 0b96258b42
1 changed files with 28 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/clocksource/samsung_pwm_timer.c
View File

@ -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,
};