Commit 0b96258b authored by Tomasz Figa's avatar Tomasz Figa
Browse files

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: default avatarTomasz Figa <tomasz.figa@gmail.com>
Reviewed-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: default avatarHeiko Stuebner <heiko@sntech.de>
Tested-by: default avatarMark Brown <broonie@linaro.org>
Tested-by: default avatarSylwester Nawrocki <sylvester.nawrocki@gmail.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
parent 6792e636

drivers/clocksource/samsung_pwm_timer.c

+28 −14
Original line number Diff line number Diff line
@@ -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,

};

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