ARM: davinci: clk: add set_parent callback for mux clocks

Introduce a set_parent callback that will be used for mux clocks, such as
the USB PHY muxes and the async3 clock domain mux.
Signed-off-by: David Lechner <david@lechnology.com>
[nsekhar@ti.com: checkpatch fixes]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

arch/arm/mach-davinci/clock.c

@@ -195,6 +195,14 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
 		return -EINVAL;
 
 	mutex_lock(&clocks_mutex);
+	if (clk->set_parent) {
+		int ret = clk->set_parent(clk, parent);
+
+		if (ret) {
+			mutex_unlock(&clocks_mutex);
+			return ret;
+		}
+	}
 	clk->parent = parent;
 	list_del_init(&clk->childnode);
 	list_add(&clk->childnode, &clk->parent->children);
@@ -224,8 +232,17 @@ int clk_register(struct clk *clk)
 
 	mutex_lock(&clocks_mutex);
 	list_add_tail(&clk->node, &clocks);
-	if (clk->parent)
+	if (clk->parent) {
+		if (clk->set_parent) {
+			int ret = clk->set_parent(clk, clk->parent);
+
+			if (ret) {
+				mutex_unlock(&clocks_mutex);
+				return ret;
+			}
+		}
 		list_add_tail(&clk->childnode, &clk->parent->children);
+	}
 	mutex_unlock(&clocks_mutex);
 
 	/* If rate is already set, use it */

arch/arm/mach-davinci/clock.h

@@ -106,6 +106,7 @@ struct clk {
 	int (*reset) (struct clk *clk, bool reset);
 	void (*clk_enable) (struct clk *clk);
 	void (*clk_disable) (struct clk *clk);
+	int (*set_parent) (struct clk *clk, struct clk *parent);
 };
 
 /* Clock flags: SoC-specific flags start at BIT(16) */