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>

drivers/net/phy/mdio-mux-bcm-iproc.c

@@ -199,7 +199,7 @@ static int mdio_mux_iproc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, md);
 
-	rc = mdio_mux_init(md->dev, mdio_mux_iproc_switch_fn,
+	rc = mdio_mux_init(md->dev, md->dev->of_node, mdio_mux_iproc_switch_fn,
 			   &md->mux_handle, md, md->mii_bus);
 	if (rc) {
 		dev_info(md->dev, "mdiomux initialization failed\n");

drivers/net/phy/mdio-mux-gpio.c

@@ -54,7 +54,7 @@ static int mdio_mux_gpio_probe(struct platform_device *pdev)
 	if (IS_ERR(s->gpios))
 		return PTR_ERR(s->gpios);
 
-	r = mdio_mux_init(&pdev->dev,
+	r = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
 			  mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL);
 
 	if (r != 0) {

drivers/net/phy/mdio-mux-mmioreg.c

@@ -159,7 +159,8 @@ static int mdio_mux_mmioreg_probe(struct platform_device *pdev)
 		}
 	}
 
-	ret = mdio_mux_init(&pdev->dev, mdio_mux_mmioreg_switch_fn,
+	ret = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
+			    mdio_mux_mmioreg_switch_fn,
 			    &s->mux_handle, s, NULL);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register mdio-mux bus %pOF\n",

drivers/net/phy/mdio-mux.c

@@ -86,6 +86,7 @@ static int mdio_mux_write(struct mii_bus *bus, int phy_id,
 static int parent_count;
 
 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,
@@ -98,11 +99,11 @@ int mdio_mux_init(struct device *dev,
 	struct mdio_mux_parent_bus *pb;
 	struct mdio_mux_child_bus *cb;
 
-	if (!dev->of_node)
+	if (!mux_node)
 		return -ENODEV;
 
 	if (!mux_bus) {
-		parent_bus_node = of_parse_phandle(dev->of_node,
+		parent_bus_node = of_parse_phandle(mux_node,
 						   "mdio-parent-bus", 0);
 
 		if (!parent_bus_node)
@@ -132,7 +133,7 @@ int mdio_mux_init(struct device *dev,
 	pb->mii_bus = parent_bus;
 
 	ret_val = -ENODEV;
-	for_each_available_child_of_node(dev->of_node, child_bus_node) {
+	for_each_available_child_of_node(mux_node, child_bus_node) {
 		int v;
 
 		r = of_property_read_u32(child_bus_node, "reg", &v);

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,