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authorRafael J. Wysocki <rjw@sisk.pl>2012-04-30 00:53:42 +0400
committerRafael J. Wysocki <rjw@sisk.pl>2012-05-01 23:26:05 +0400
commitb86ff9820fd5df69295273b9aa68e58786ffc23f (patch)
treee8af5745652c926b9a82b3b7531dc455564efdfb /kernel/power/power.h
parent55850945e872531644f31fefd217d61dd15dcab8 (diff)
downloadlinux-b86ff9820fd5df69295273b9aa68e58786ffc23f.tar.xz
PM / Sleep: Add user space interface for manipulating wakeup sources, v3
Android allows user space to manipulate wakelocks using two sysfs file located in /sys/power/, wake_lock and wake_unlock. Writing a wakelock name and optionally a timeout to the wake_lock file causes the wakelock whose name was written to be acquired (it is created before is necessary), optionally with the given timeout. Writing the name of a wakelock to wake_unlock causes that wakelock to be released. Implement an analogous interface for user space using wakeup sources. Add the /sys/power/wake_lock and /sys/power/wake_unlock files allowing user space to create, activate and deactivate wakeup sources, such that writing a name and optionally a timeout to wake_lock causes the wakeup source of that name to be activated, optionally with the given timeout. If that wakeup source doesn't exist, it will be created and then activated. Writing a name to wake_unlock causes the wakeup source of that name, if there is one, to be deactivated. Wakeup sources created with the help of wake_lock that haven't been used for more than 5 minutes are garbage collected and destroyed. Moreover, there can be only WL_NUMBER_LIMIT wakeup sources created with the help of wake_lock present at a time. The data type used to track wakeup sources created by user space is called "struct wakelock" to indicate the origins of this feature. This version of the patch includes an rbtree manipulation fix from John Stultz. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'kernel/power/power.h')
-rw-r--r--kernel/power/power.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 4cf80fa115d9..b0bd4beaebfe 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -282,3 +282,12 @@ static inline void pm_autosleep_unlock(void) {}
static inline suspend_state_t pm_autosleep_state(void) { return PM_SUSPEND_ON; }
#endif /* !CONFIG_PM_AUTOSLEEP */
+
+#ifdef CONFIG_PM_WAKELOCKS
+
+/* kernel/power/wakelock.c */
+extern ssize_t pm_show_wakelocks(char *buf, bool show_active);
+extern int pm_wake_lock(const char *buf);
+extern int pm_wake_unlock(const char *buf);
+
+#endif /* !CONFIG_PM_WAKELOCKS */