From: Magnus Damm <damm@xxxxxxxxxxxxx>
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 <damm@xxxxxxxxxxxxx>
---
Applies to linux-next
include/linux/clocksource.h | 3 +++
kernel/time/clocksource.c | 12 ++++++++++++
kernel/time/timekeeping.c | 1 +
3 files changed, 16 insertions(+)
--- 0002/include/linux/clocksource.h
+++ work/include/linux/clocksource.h 2009-11-30 13:31:40.000000000 +0900
@@ -154,6 +154,7 @@ extern u64 timecounter_cyc2time(struct t
* @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(struc
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);
--- 0002/kernel/time/clocksource.c
+++ work/kernel/time/clocksource.c 2009-11-30 13:30:52.000000000 +0900
@@ -441,6 +441,18 @@ static inline int clocksource_watchdog_k
#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)
--- 0001/kernel/time/timekeeping.c
+++ work/kernel/time/timekeeping.c 2009-11-30 13:42:56.000000000 +0900
@@ -611,6 +611,7 @@ static int timekeeping_suspend(struct sy
write_sequnlock_irqrestore(&xtime_lock, flags);
clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
+ clocksource_suspend();
return 0;
}
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