clk: add clk_set_parent()

Clocks may support multiple parents: this change introduces an
optional operation on the clk-uclass to set a clock's parent.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: David Wu <david.wu@rock-chips.com>

Series-changes: 2
- Fixed David's email address.

2 files changed, 19 insertions, 0 deletions

diff --git a/include/clk-uclass.h b/include/clk-uclass.h
index e7ea334c608..75933eb8841 100644
--- a/include/clk-uclass.h
+++ b/include/clk-uclass.h
@@ -78,6 +78,14 @@ struct clk_ops {
 	 */
 	ulong (*set_rate)(struct clk *clk, ulong rate);
 	/**
+	 * set_parent() - Set current clock parent
+	 *
+	 * @clk:        The clock to manipulate.
+	 * @parent:     New clock parent.
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*set_parent)(struct clk *clk, struct clk *parent);
+	/**
 	 * enable() - Enable a clock.
 	 *
 	 * @clk:	The clock to manipulate.
diff --git a/include/clk.h b/include/clk.h
index e7ce3e85768..e463d8e60dc 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -178,6 +178,17 @@ ulong clk_get_rate(struct clk *clk);
 ulong clk_set_rate(struct clk *clk, ulong rate);
 
 /**
+ * clk_set_parent() - Set current clock parent.
+ *
+ * @clk:	A clock struct that was previously successfully requested by
+ *		clk_request/get_by_*().
+ * @parent:	A clock struct that was previously successfully requested by
+ *		clk_request/get_by_*().
+ * @return new rate, or -ve error code.
+ */
+int clk_set_parent(struct clk *clk, struct clk *parent);
+
+/**
  * clk_enable() - Enable (turn on) a clock.
  *
  * @clk:	A clock struct that was previously successfully requested by