[PATCH 6/8] net: fec_mxc: fix usage of DM_MDIO and DM_ETH_PHY

[Alexander Feilke]

From: Markus Niebel <Markus.Niebel at ew.tq-group.com>

If DM_ETH_PHY is used and the FEC instance owns the shared MDIO bus,
eth_phy_get_mdio_bus returns NULL. If DM_MDIO bus is used, the
mdio_register API is called from dm_mdio_post_probe. Therefore the
bus should must be queried by name in this case.

For DM_MDIO case fec_mii_setspeed has already being called in
dm_fec_mdio_probe(), so skip setting this again.

Fixes: 3b8f99a3e762 ("net: fec: add support for DM_MDIO")
Fixes: e75d08821574 ("net: fec-mxc: prevent crash if no MAC address is set")

Signed-off-by: Markus Niebel <Markus.Niebel at ew.tq-group.com>
Signed-off-by: Alexander Stein <alexander.stein at ew.tq-group.com>
Signed-off-by: Alexander Feilke <alexander.feilke at ew.tq-group.com>
---
 drivers/net/fec_mxc.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
index 7d1567fd88d..6789bfe2500 100644
--- a/drivers/net/fec_mxc.c
+++ b/drivers/net/fec_mxc.c
@@ -581,7 +581,7 @@ static int fecmxc_init(struct udevice *dev)
 
 	fec_reg_setup(fec);
 
-	if (fec->xcv_type != SEVENWIRE)
+	if (fec->xcv_type != SEVENWIRE && !IS_ENABLED(CONFIG_DM_MDIO))
 		fec_mii_setspeed(dev, fec->bus->priv);
 
 	/* Set Opcode/Pause Duration Register */
@@ -1363,16 +1363,26 @@ static int fecmxc_probe(struct udevice *dev)
 	priv->dev_id = dev_seq(dev);
 
 #ifdef CONFIG_DM_MDIO
+	/* If our instance manages the mdio bus, dm_fec_bind_mdio will bind, probe
+	 * and register the MDIO bus driver. To get access to the mii_dev structure
+	 * query it from the global mii_devs list.
+	 */
 	ret = dm_fec_bind_mdio(dev);
-	if (ret && ret != -ENODEV)
+	if (!ret)
+		bus = miiphy_get_dev_by_name("mdio");
+	else if (ret != -ENODEV)
 		return ret;
 #endif
 
 #ifdef CONFIG_DM_ETH_PHY
-	bus = eth_phy_get_mdio_bus(dev);
+	/* if our PHY is not on our mdio bus, this call queries the bus in case
+	 * we using the DM abstraction for shared MDIO busses.
+	 */
 	if (!bus)
-		bus = fec_get_miibus(dev, (ulong)priv->eth, dev_seq(dev));
-#else
+		bus = eth_phy_get_mdio_bus(dev);
+#endif
+
+#ifndef CONFIG_DM_MDIO
 	if (!bus) {
 		ulong regs = (ulong)priv->eth;
 
@@ -1384,8 +1394,8 @@ static int fecmxc_probe(struct udevice *dev)
 
 		bus = fec_get_miibus(dev, regs, dev_seq(dev));
 	}
+#endif /* !CONFIG_DM_MDIO */
 
-#endif /* CONFIG_DM_ETH_PHY */
 	if (!bus) {
 		ret = -ENOMEM;
 		goto err_mii;
-- 
2.34.1