[PATCH net-next 3/7] net: macb: parse PHY nodes found under an MDIO node

[Codrin Ciubotariu <codrin.ciubotariu@microchip.com>]

The MACB embeds an MDIO bus controller. For this reason, the PHY nodes
were represented as sub-nodes in the MACB node. Generally, the
Ethernet controller is different than the MDIO controller, so the PHYs
are probed by a separate MDIO driver. Since adding the PHY nodes directly
under the ETH node became deprecated, we adjust the MACB driver to look
for an MDIO node and register the subnode MDIO devices.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 89fe7af5e408..66f02c16cc7c 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -740,10 +740,20 @@ static int macb_mii_probe(struct net_device *dev)
 static int macb_mdiobus_register(struct macb *bp)
 {
 	struct device_node *child, *np = bp->pdev->dev.of_node;
+	struct device_node *mdio_node;
+	int ret;
 
 	if (of_phy_is_fixed_link(np))
 		return mdiobus_register(bp->mii_bus);
 
+	/* if an MDIO node is present, it should contain the PHY nodes */
+	mdio_node = of_get_child_by_name(np, "mdio");
+	if (mdio_node) {
+		ret = of_mdiobus_register(bp->mii_bus, mdio_node);
+		of_node_put(mdio_node);
+		return ret;
+	}
+
 	/* Only create the PHY from the device tree if at least one PHY is
 	 * described. Otherwise scan the entire MDIO bus. We do this to support
 	 * old device tree that did not follow the best practices and did not
@@ -755,7 +765,6 @@ static int macb_mdiobus_register(struct macb *bp)
 			 * decrement it before returning.
 			 */
 			of_node_put(child);
-
 			return of_mdiobus_register(bp->mii_bus, np);
 		}
 
-- 
2.25.1