drivers: net: cpsw: Add support for fixed-link PHY

Add support for a fixed-link devicetree sub-node in case the the
cpsw MAC is directly connected to a non-mdio PHY/device.
Signed-off-by: Markus Brunner <systemprogrammierung.brunner@gmail.com>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/cpsw.txt

@@ -48,6 +48,11 @@ Optional properties:
 - mac-address		: See ethernet.txt file in the same directory
 - phy-handle		: See ethernet.txt file in the same directory
 
+Slave sub-nodes:
+- fixed-link		: See fixed-link.txt file in the same directory
+			  Either the properties phy_id and phy-mode,
+			  or the sub-node fixed-link can be specified
+
 Note: "ti,hwmods" field is used to fetch the base address and irq
 resources from TI, omap hwmod data base during device registration.
 Future plan is to migrate hwmod data base contents into device tree

drivers/net/ethernet/ti/cpsw.c

@@ -2037,6 +2037,19 @@ static int cpsw_probe_dt(struct cpsw_priv *priv,
 			continue;
 
 		priv->phy_node = of_parse_phandle(slave_node, "phy-handle", 0);
+		if (of_phy_is_fixed_link(slave_node)) {
+			struct phy_device *pd;
+
+			ret = of_phy_register_fixed_link(slave_node);
+			if (ret)
+				return ret;
+			pd = of_phy_find_device(slave_node);
+			if (!pd)
+				return -ENODEV;
+			snprintf(slave_data->phy_id, sizeof(slave_data->phy_id),
+				 PHY_ID_FMT, pd->bus->id, pd->phy_id);
+			goto no_phy_slave;
+		}
 		parp = of_get_property(slave_node, "phy_id", &lenp);
 		if ((parp == NULL) || (lenp != (sizeof(void *) * 2))) {
 			dev_err(&pdev->dev, "Missing slave[%d] phy_id property\n", i);