net: mdio-mux: add mdio_mux parameter to mdio_mux_init()

mdio_mux_init() use the parameter dev for two distinct thing:
1) Have a device for all devm_ functions
2) Get device_node from it

Since it is two distinct purpose, this patch add a parameter mdio_mux
that is linked to task 2.

This will also permit to register an of_node mdio-mux that lacks a direct
owning device.
For example a mdio-mux which is a subnode of a real device.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mdio-mux.h b/include/linux/mdio-mux.h
index 61f5b21..a5d58f2 100644
--- a/include/linux/mdio-mux.h
+++ b/include/linux/mdio-mux.h
@@ -12,7 +12,16 @@
 #include <linux/device.h>
 #include <linux/phy.h>
 
+/* mdio_mux_init() - Initialize a MDIO mux
+ * @dev		The device owning the MDIO mux
+ * @mux_node	The device node of the MDIO mux
+ * @switch_fn	The function called for switching target MDIO child
+ * mux_handle	A pointer to a (void *) used internaly by mdio-mux
+ * @data	Private data used by switch_fn()
+ * @mux_bus	An optional parent bus (Other case are to use parent_bus property)
+ */
 int mdio_mux_init(struct device *dev,
+		  struct device_node *mux_node,
 		  int (*switch_fn) (int cur, int desired, void *data),
 		  void **mux_handle,
 		  void *data,