net: phy: Add swnode support to mdiobus_scan

This patch will allow to use a swnode/fwnode defined for a phy_device. The
MDIO bus (mii_bus) needs to contain nodes for the PHY devices, named
"ethernet-phy@i", with i being the MDIO address (0 .. PHY_MAX_ADDR - 1).

The fwnode is only attached to the phy_device if there isn't already an
fwnode attached.

fwnode_get_named_child_node will increase the usage counter of the fwnode.
However, no new code is needed to decrease the counter again, since this is
already implemented in the phy_device_release function.

Signed-off-by: Hans-Frieder Vogt <hfdevel@gmx.net>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250322-tn9510-v3a-v7-1-672a9a3d8628@gmx.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 7e2f10182c0cf37bef4cea1820863f047b5cb466..ede596c1a69d1b2b986e9eef51c3beb4a5fbc805 100644 (file)
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -551,6 +551,8 @@ static int mdiobus_create_device(struct mii_bus *bus,
 static struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr, bool c45)
 {
        struct phy_device *phydev = ERR_PTR(-ENODEV);
+       struct fwnode_handle *fwnode;
+       char node_name[16];
        int err;
 
        phydev = get_phy_device(bus, addr, c45);
@@ -562,6 +564,18 @@ static struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr, bool c45)
         */
        of_mdiobus_link_mdiodev(bus, &phydev->mdio);
 
+       /* Search for a swnode for the phy in the swnode hierarchy of the bus.
+        * If there is no swnode for the phy provided, just ignore it.
+        */
+       if (dev_fwnode(&bus->dev) && !dev_fwnode(&phydev->mdio.dev)) {
+               snprintf(node_name, sizeof(node_name), "ethernet-phy@%d",
+                        addr);
+               fwnode = fwnode_get_named_child_node(dev_fwnode(&bus->dev),
+                                                    node_name);
+               if (fwnode)
+                       device_set_node(&phydev->mdio.dev, fwnode);
+       }
+
        err = phy_device_register(phydev);
        if (err) {
                phy_device_free(phydev);