net: mdio: realtek-rtl9300: relocate c22/c45 device tree readout

otto_emdio_map_ports() is the central place to lookup the topology and the
properties of the Realtek ethernet MDIO controller from the device tree.
Deviating from this the c22/c45 detection via "ethernet-phy-ieee802.3-c45"
is running separately in otto_emdio_probe_one(). It loops over the same
nodes, just at a later point in time.

There is no benefit to divide this setup and to have a time window where
the data structure is only filled partially. Additionally it uses the
"fwnode" API. Consolidate the setup and convert it to the "of" API.

Remark. This is a subtle change for dangling PHY nodes (not referenced
by ethernet-ports). Before this commit all PHY nodes were evaluated for
c45 setup, now only the referenced ones.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://patch.msgid.link/20260603175924.123019-6-markus.stockhausen@gmx.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 9 insertions, 12 deletions

diff --git a/drivers/net/mdio/mdio-realtek-rtl9300.c b/drivers/net/mdio/mdio-realtek-rtl9300.c
index 58854c54ad99..e626dd7fb4b8 100644
--- a/drivers/net/mdio/mdio-realtek-rtl9300.c
+++ b/drivers/net/mdio/mdio-realtek-rtl9300.c
@@ -405,18 +405,6 @@ static int otto_emdio_probe_one(struct device *dev, struct otto_emdio_priv *priv
 		return dev_err_probe(dev, -EINVAL,
 				     "illegal (dangling) smi bus number %d\n", mdio_bus);
 
-	/* The MDIO accesses from the kernel work with the PHY polling unit in
-	 * the switch. We need to tell the PPU to operate either in GPHY (i.e.
-	 * clause 22) or 10GPHY mode (i.e. clause 45).
-	 *
-	 * We select 10GPHY mode if there is at least one PHY that declares
-	 * compatible = "ethernet-phy-ieee802.3-c45". This does mean we can't
-	 * support both c45 and c22 on the same MDIO bus.
-	 */
-	fwnode_for_each_child_node_scoped(node, child)
-		if (fwnode_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
-			priv->smi_bus_is_c45[mdio_bus] = true;
-
 	bus = devm_mdiobus_alloc_size(dev, sizeof(*chan));
 	if (!bus)
 		return -ENOMEM;
@@ -506,6 +494,15 @@ static int otto_emdio_map_ports(struct device *dev)
 			goto put_nodes;
 		}
 
+		/*
+		 * The MDIO accesses from the kernel work with the PHY polling unit in the
+		 * switch. The PPU either operates in GPHY (i.e. clause 22) or 10GPHY mode
+		 * (i.e. clause 45). Select 10GPHY mode if there is at least one PHY that
+		 * declares compatible = "ethernet-phy-ieee802.3-c45".
+		 */
+		if (of_device_is_compatible(phy_dn, "ethernet-phy-ieee802.3-c45"))
+			priv->smi_bus_is_c45[bus] = true;
+
 		__set_bit(pn, priv->valid_ports);
 		priv->smi_bus[pn] = bus;
 		priv->smi_addr[pn] = addr;