From adc78e6b9946a4b22e22403d961f3b03c469e5d3 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 6 Aug 2012 01:40:41 +0200 Subject: [PATCH] timekeeping: Add suspend and resume of clock event devices Some clock event devices, for example such that belong to PM domains, need to be handled in a spcial way during the timekeeping suspend and resume (which takes place in the system core, or "syscore", stages of system power transitions) in analogy with clock sources. Introduce .suspend() and .resume() callbacks for clock event devices that will be executed by timekeeping_suspend/_resume(), respectively, next the the clock sources' .suspend() and .resume() callbacks. Signed-off-by: Rafael J. Wysocki --- include/linux/clockchips.h | 8 ++++++++ kernel/time/clockevents.c | 24 ++++++++++++++++++++++++ kernel/time/timekeeping.c | 2 ++ 3 files changed, 34 insertions(+) diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index acba894374a1..8a7096fcb01e 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -97,6 +97,8 @@ struct clock_event_device { void (*broadcast)(const struct cpumask *mask); void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); + void (*suspend)(struct clock_event_device *); + void (*resume)(struct clock_event_device *); unsigned long min_delta_ticks; unsigned long max_delta_ticks; @@ -156,6 +158,9 @@ clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) freq, minsec); } +extern void clockevents_suspend(void); +extern void clockevents_resume(void); + #ifdef CONFIG_GENERIC_CLOCKEVENTS extern void clockevents_notify(unsigned long reason, void *arg); #else @@ -164,6 +169,9 @@ extern void clockevents_notify(unsigned long reason, void *arg); #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */ +static inline void clockevents_suspend(void) {} +static inline void clockevents_resume(void) {} + #define clockevents_notify(reason, arg) do { } while (0) #endif diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 7e1ce012a851..30b6de0d977c 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -397,6 +397,30 @@ void clockevents_exchange_device(struct clock_event_device *old, local_irq_restore(flags); } +/** + * clockevents_suspend - suspend clock devices + */ +void clockevents_suspend(void) +{ + struct clock_event_device *dev; + + list_for_each_entry_reverse(dev, &clockevent_devices, list) + if (dev->suspend) + dev->suspend(dev); +} + +/** + * clockevents_resume - resume clock devices + */ +void clockevents_resume(void) +{ + struct clock_event_device *dev; + + list_for_each_entry(dev, &clockevent_devices, list) + if (dev->resume) + dev->resume(dev); +} + #ifdef CONFIG_GENERIC_CLOCKEVENTS /** * clockevents_notify - notification about relevant events diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 34e5eac81424..312a675cb240 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -773,6 +773,7 @@ static void timekeeping_resume(void) read_persistent_clock(&ts); + clockevents_resume(); clocksource_resume(); write_seqlock_irqsave(&tk->lock, flags); @@ -832,6 +833,7 @@ static int timekeeping_suspend(void) clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); clocksource_suspend(); + clockevents_suspend(); return 0; } -- 2.20.1