[RFC 1/5] pm, runtime, Add resume notifier

[Huang Ying <ying.huang@intel.com>]

Asynchronous interface is provided for runtime PM, when the requested
action (suspend/resume) is completed, the caller may need to be
notified.

Signed-off-by: Huang Ying <ying.huang@intel.com>
---
 drivers/base/power/runtime.c |    1 +
 include/linux/pm.h           |    2 ++
 2 files changed, 3 insertions(+)

--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -733,6 +733,7 @@ static int rpm_resume(struct device *dev
 			atomic_inc(&parent->power.child_count);
 	}
 	wake_up_all(&dev->power.wait_queue);
+	atomic_notifier_call_chain(&dev->power.notifier, RPM_REQ_RESUME, dev);
 
 	if (!retval)
 		rpm_idle(dev, RPM_ASYNC);
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -27,6 +27,7 @@
 #include <linux/wait.h>
 #include <linux/timer.h>
 #include <linux/completion.h>
+#include <linux/notifier.h>
 
 /*
  * Callbacks for platform drivers to implement.
@@ -488,6 +489,7 @@ struct dev_pm_info {
 	unsigned long		timer_expires;
 	struct work_struct	work;
 	wait_queue_head_t	wait_queue;
+	struct atomic_notifier_head notifier;
 	atomic_t		usage_count;
 	atomic_t		child_count;
 	unsigned int		disable_depth:3;