reset: add reset_control_status helper function

There are cases where a system will want to read a reset status bit before
doing any other toggling. Add a reset_control_status helper function to the
reset controller API.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
index 41a4695f..ce6b962 100644
--- a/include/linux/reset-controller.h
+++ b/include/linux/reset-controller.h
@@ -12,11 +12,13 @@
  *         things to reset the device
  * @assert: manually assert the reset line, if supported
  * @deassert: manually deassert the reset line, if supported
+ * @status: return the status of the reset line, if supported
  */
 struct reset_control_ops {
 	int (*reset)(struct reset_controller_dev *rcdev, unsigned long id);
 	int (*assert)(struct reset_controller_dev *rcdev, unsigned long id);
 	int (*deassert)(struct reset_controller_dev *rcdev, unsigned long id);
+	int (*status)(struct reset_controller_dev *rcdev, unsigned long id);
 };
 
 struct module;
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 349f150..da5602b 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -10,6 +10,7 @@
 int reset_control_reset(struct reset_control *rstc);
 int reset_control_assert(struct reset_control *rstc);
 int reset_control_deassert(struct reset_control *rstc);
+int reset_control_status(struct reset_control *rstc);
 
 struct reset_control *reset_control_get(struct device *dev, const char *id);
 void reset_control_put(struct reset_control *rstc);
@@ -57,6 +58,12 @@
 	return 0;
 }
 
+static inline int reset_control_status(struct reset_control *rstc)
+{
+	WARN_ON(1);
+	return 0;
+}
+
 static inline void reset_control_put(struct reset_control *rstc)
 {
 	WARN_ON(1);