net: ethernet: ti: am65-cpsw: Add support for SERDES configuration

Use PHY framework APIs to initialize the SERDES PHY connected to CPSW MAC.

Define the functions am65_cpsw_disable_phy(), am65_cpsw_enable_phy(),
am65_cpsw_disable_serdes_phy() and am65_cpsw_enable_serdes_phy().

Add new member "serdes_phy" to struct "am65_cpsw_slave_data" to store the
SERDES PHY for each port, if it exists. Use it later while disabling the
SERDES PHY for each port.

Power on and initialize the SerDes PHY in am65_cpsw_nuss_init_slave_ports()
by invoking am65_cpsw_enable_serdes_phy().

Power off the SerDes PHY in am65_cpsw_nuss_remove() by invoking
am65_cpsw_disable_serdes_phy().

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/ti/am65-cpsw-nuss.c

@@ -1416,6 +1416,68 @@ static const struct net_device_ops am65_cpsw_nuss_netdev_ops = {
 	.ndo_setup_tc           = am65_cpsw_qos_ndo_setup_tc,
 };
 
+static void am65_cpsw_disable_phy(struct phy *phy)
+{
+	phy_power_off(phy);
+	phy_exit(phy);
+}
+
+static int am65_cpsw_enable_phy(struct phy *phy)
+{
+	int ret;
+
+	ret = phy_init(phy);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_power_on(phy);
+	if (ret < 0) {
+		phy_exit(phy);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void am65_cpsw_disable_serdes_phy(struct am65_cpsw_common *common)
+{
+	struct am65_cpsw_port *port;
+	struct phy *phy;
+	int i;
+
+	for (i = 0; i < common->port_num; i++) {
+		port = &common->ports[i];
+		phy = port->slave.serdes_phy;
+		if (phy)
+			am65_cpsw_disable_phy(phy);
+	}
+}
+
+static int am65_cpsw_init_serdes_phy(struct device *dev, struct device_node *port_np,
+				     struct am65_cpsw_port *port)
+{
+	const char *name = "serdes-phy";
+	struct phy *phy;
+	int ret;
+
+	phy = devm_of_phy_get(dev, port_np, name);
+	if (PTR_ERR(phy) == -ENODEV)
+		return 0;
+
+	/* Serdes PHY exists. Store it. */
+	port->slave.serdes_phy = phy;
+
+	ret =  am65_cpsw_enable_phy(phy);
+	if (ret < 0)
+		goto err_phy;
+
+	return 0;
+
+err_phy:
+	devm_phy_put(dev, phy);
+	return ret;
+}
+
 static void am65_cpsw_nuss_mac_config(struct phylink_config *config, unsigned int mode,
 				      const struct phylink_link_state *state)
 {
@@ -1959,6 +2021,11 @@ static int am65_cpsw_nuss_init_slave_ports(struct am65_cpsw_common *common)
 			goto of_node_put;
 		}
 
+		/* Initialize the Serdes PHY for the port */
+		ret = am65_cpsw_init_serdes_phy(dev, port_np, port);
+		if (ret)
+			return ret;
+
 		port->slave.mac_only =
 				of_property_read_bool(port_np, "ti,mac-only");
 
@@ -2878,6 +2945,7 @@ static int am65_cpsw_nuss_remove(struct platform_device *pdev)
 	 */
 	am65_cpsw_nuss_cleanup_ndev(common);
 	am65_cpsw_nuss_phylink_cleanup(common);
+	am65_cpsw_disable_serdes_phy(common);
 
 	of_platform_device_destroy(common->mdio_dev, NULL);
 

drivers/net/ethernet/ti/am65-cpsw-nuss.h

@@ -32,6 +32,7 @@ struct am65_cpsw_slave_data {
 	struct device_node		*phy_node;
 	phy_interface_t			phy_if;
 	struct phy			*ifphy;
+	struct phy			*serdes_phy;
 	bool				rx_pause;
 	bool				tx_pause;
 	u8				mac_addr[ETH_ALEN];