Re: [PATCH net-next 12/13] net: dsa: sja1105: expose the SGMII PCS as an mdio_device

+static int sja1105_mdiobus_pcs_register(struct sja1105_private *priv)
+{
+	struct sja1105_mdio_private *mdio_priv;
+	struct dsa_switch *ds = priv->ds;
+	struct mii_bus *bus;
+	int rc = 0;
+	int port;
+
+	if (!priv->info->pcs_mdio_read || !priv->info->pcs_mdio_write)
+		return 0;
+
+	bus = mdiobus_alloc_size(sizeof(*mdio_priv));
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = "SJA1105 PCS MDIO bus";
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-pcs",
+		 dev_name(ds->dev));
+	bus->read = priv->info->pcs_mdio_read;
+	bus->write = priv->info->pcs_mdio_write;
+	bus->parent = ds->dev;
+	mdio_priv = bus->priv;
+	mdio_priv->priv = priv;
+
+	/* We don't register this MDIO bus because there is no PHY on it */

Interesting. If you don't register it, you miss out on the stats in
/sysfs. I wonder if it makes more sense to set phy_mask to stop it
probing for PHYs and register it?

	Andrew