From c54a42b19fbaae4e9f212322ecca25a6bc95c1ba Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Tue, 2 Feb 2010 14:41:41 -0800 Subject: [PATCH] clocksource: add suspend callback Add a clocksource suspend callback. This callback can be used by the clocksource driver to shutdown and perform any kind of late suspend activities even though the clocksource driver itself is a non-sysdev driver. One example where this is useful is to fix the sh_cmt.c platform driver that today suspends using the platform bus and shuts down the clocksource too early. With this callback in place the sh_cmt driver will suspend using the clocksource and clockevent hooks and leave the platform device pm callbacks unused. Signed-off-by: Magnus Damm Cc: Paul Mundt Cc: john stultz Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- include/linux/clocksource.h | 3 +++ kernel/time/clocksource.c | 12 ++++++++++++ kernel/time/timekeeping.c | 1 + 3 files changed, 16 insertions(+) diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 0de7e72..4bca8b6 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -154,6 +154,7 @@ extern u64 timecounter_cyc2time(struct timecounter *tc, * @max_idle_ns: max idle time permitted by the clocksource (nsecs) * @flags: flags describing special properties * @vread: vsyscall based read + * @suspend: suspend function for the clocksource, if necessary * @resume: resume function for the clocksource, if necessary */ struct clocksource { @@ -172,6 +173,7 @@ struct clocksource { u64 max_idle_ns; unsigned long flags; cycle_t (*vread)(void); + void (*suspend)(struct clocksource *cs); void (*resume)(struct clocksource *cs); #ifdef CONFIG_IA64 void *fsys_mmio; /* used by fsyscall asm code */ @@ -277,6 +279,7 @@ extern void clocksource_unregister(struct clocksource*); extern void clocksource_touch_watchdog(void); extern struct clocksource* clocksource_get_next(void); extern void clocksource_change_rating(struct clocksource *cs, int rating); +extern void clocksource_suspend(void); extern void clocksource_resume(void); extern struct clocksource * __init __weak clocksource_default_clock(void); extern void clocksource_mark_unstable(struct clocksource *cs); diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 08adacb..bd24666 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -441,6 +441,18 @@ static inline int clocksource_watchdog_kthread(void *data) { return 0; } #endif /* CONFIG_CLOCKSOURCE_WATCHDOG */ /** + * clocksource_suspend - suspend the clocksource(s) + */ +void clocksource_suspend(void) +{ + struct clocksource *cs; + + list_for_each_entry_reverse(cs, &clocksource_list, list) + if (cs->suspend) + cs->suspend(cs); +} + +/** * clocksource_resume - resume the clocksource(s) */ void clocksource_resume(void) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 7faaa32..843d8a7 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -622,6 +622,7 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) write_sequnlock_irqrestore(&xtime_lock, flags); clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); + clocksource_suspend(); return 0; } -- 1.8.2.3