ANDROID: power: wakeup_reason: add an API to log wakeup reasons

Add API log_wakeup_reason() and expose it to userspace via sysfs path
/sys/kernel/wakeup_reasons/last_resume_reason

Change-Id: I81addaf420f1338255c5d0638b0d244a99d777d1
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>

[AmitP: Folded following android-4.9 commit changes into this patch
        1135122a192a ("ANDROID: POWER: fix compile warnings in log_wakeup_reason")
        b4e6247778b0 ("ANDROID: Power: Changes the permission to read only for sysfs file /sys/kernel/wakeup_reasons/last_resume_reason")
        e13dbc7c69cd ("ANDROID: power: wakeup_reason: rename irq_count to irqcount")]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
3 files changed