[PATCH 1/2] power: add new interface to return pm_transition state

[Shuah Khan]

Add a new interface get_pm_transition() to return pm_transition state.
This interface is intended to be used from dev_pm_ops class and type
suspend interfaces that call legacy pm ops driver suspend interfaces.
Legacy suspend pm_ops take pm_message_t as a parameter.

e.g: drm_class_suspend() calls into driver suspend routines
via drm_dev->driver->suspend(drm_dev, state).

Once drm_class_suspend() is converted to dev_pm_ops, it will no longer
have access to pm_transition which it has to pass into driver legacy
suspend calls. get_pm_transition() interface addresses this need.

Signed-off-by: Shuah Khan <shuah.kh at samsung.com>
---
 drivers/base/power/main.c |   17 +++++++++++++++++
 include/linux/pm.h        |    3 +++
 2 files changed, 20 insertions(+)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index c2132b8..3e2e09d 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -57,6 +57,23 @@ static pm_message_t pm_transition;
 static int async_error;

 /**
+ * get_pm_transition - return pm_transition state.
+ * This interface is intended to be used from dev_pm_ops class and type
+ * suspend interfaces that call legacy pm ops driver suspend interfaces.
+ * Legacy suspend pm_ops take pm_message_t as a parameter.
+ * e.g: drm_class_suspend() calls into driver suspend routines
+ * via drm_dev->driver->suspend(drm_dev, state).
+ * Once drm_class_suspend() is converted to dev_pm_ops, it will no longer
+ * have access to pm_transition which it has to pass into driver legacy
+ * suspend calls. get_pm_transition() interface addresses this need.
+*/
+pm_message_t get_pm_transition()
+{
+       return pm_transition;
+}
+EXPORT_SYMBOL_GPL(get_pm_transition);
+
+/**
  * device_pm_sleep_init - Initialize system suspend-related device fields.
  * @dev: Device object being initialized.
  */
diff --git a/include/linux/pm.h b/include/linux/pm.h
index a224c7f..46f3252 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -63,6 +63,9 @@ typedef struct pm_message {
        int event;
 } pm_message_t;

+/* drivers/base/power/main.c */
+extern pm_message_t get_pm_transition(void);
+
 /**
  * struct dev_pm_ops - device PM callbacks
  *
-- 
1.7.10.4