2 files changed, 46 insertions, 4 deletions

diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index 8f571548870f..3a218c3a06ae 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -53,3 +53,24 @@ void devm_clk_put(struct device *dev, struct clk *clk)
         WARN_ON(ret);
 }
 EXPORT_SYMBOL(devm_clk_put);
+
+struct clk *devm_get_clk_from_child(struct device *dev,
+                                    struct device_node *np, const char *con_id)
+{
+        struct clk **ptr, *clk;
+
+        ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
+        if (!ptr)
+                return ERR_PTR(-ENOMEM);
+
+        clk = of_clk_get_by_name(np, con_id);
+        if (!IS_ERR(clk)) {
+                *ptr = clk;
+                devres_add(dev, ptr);
+        } else {
+                devres_free(ptr);
+        }
+
+        return clk;
+}
+EXPORT_SYMBOL(devm_get_clk_from_child);
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 123c02788807..e9d36b3e49de 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -17,8 +17,9 @@
 #include <linux/notifier.h>
 
 struct device;
-
 struct clk;
+struct device_node;
+struct of_phandle_args;
 
 /**
  * DOC: clk notifier callback types
@@ -249,6 +250,23 @@ struct clk *clk_get(struct device *dev, const char *id);
 struct clk *devm_clk_get(struct device *dev, const char *id);
 
 /**
+ * devm_get_clk_from_child - lookup and obtain a managed reference to a
+ *                           clock producer from child node.
+ * @dev: device for clock "consumer"
+ * @np: pointer to clock consumer node
+ * @con_id: clock consumer ID
+ *
+ * This function parses the clocks, and uses them to look up the
+ * struct clk from the registered list of clock providers by using
+ * @np and @con_id
+ *
+ * The clock will automatically be freed when the device is unbound
+ * from the bus.
+ */
+struct clk *devm_get_clk_from_child(struct device *dev,
+                                    struct device_node *np, const char *con_id);
+
+/**
  * clk_enable - inform the system when the clock source should be running.
  * @clk: clock source
  *
@@ -432,6 +450,12 @@ static inline struct clk *devm_clk_get(struct device *dev, const char *id)
         return NULL;
 }
 
+static inline struct clk *devm_get_clk_from_child(struct device *dev,
+                                struct device_node *np, const char *con_id)
+{
+        return NULL;
+}
+
 static inline void clk_put(struct clk *clk) {}
 
 static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
@@ -501,9 +525,6 @@ static inline void clk_disable_unprepare(struct clk *clk)
         clk_unprepare(clk);
 }
 
-struct device_node;
-struct of_phandle_args;
-
 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
 struct clk *of_clk_get(struct device_node *np, int index);
 struct clk *of_clk_get_by_name(struct device_node *np, const char *name);