alarmtimer: Provide accessor to alarmtimer rtc device

The Android alarm interface provides a settime call that sets both
the alarmtimer RTC device and CLOCK_REALTIME to the same value.

Since there may be multiple rtc devices, provide a hook to access the
one the alarmtimer infrastructure is using.

CC: Colin Cross <ccross@android.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/alarmtimer.h

@@ -76,4 +76,7 @@ static inline int alarmtimer_callback_running(struct alarm *timer)
 }
 
 
+/* Provide way to access the rtc device being used by alarmtimers */
+struct rtc_device *alarmtimer_get_rtcdev(void);
+
 #endif

kernel/time/alarmtimer.c

@@ -59,7 +59,7 @@ static DEFINE_SPINLOCK(rtcdev_lock);
  * If one has not already been chosen, it checks to see if a
  * functional rtc device is available.
  */
-static struct rtc_device *alarmtimer_get_rtcdev(void)
+struct rtc_device *alarmtimer_get_rtcdev(void)
 {
 	unsigned long flags;
 	struct rtc_device *ret;
@@ -115,7 +115,7 @@ static void alarmtimer_rtc_interface_remove(void)
 	class_interface_unregister(&alarmtimer_rtc_interface);
 }
 #else
-static inline struct rtc_device *alarmtimer_get_rtcdev(void)
+struct rtc_device *alarmtimer_get_rtcdev(void)
 {
 	return NULL;
 }