Implement ndo_get_phys_port_id and ndo_get_phys_port_name callbacks
to provide physical port identification for all stmmac-based devices.

Default implementations use the permanent MAC address for port ID and
bus_id for port name. Glue drivers can override these by setting
get_phys_port_id and get_phys_port_name callbacks in plat_stmmacenet_data.

Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 54 +++++++++++++++++++
 include/linux/stmmac.h                        |  5 ++
 2 files changed, 59 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 15b0c08ebd877..e8f642c9941b6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7151,6 +7151,58 @@ static void stmmac_get_stats64(struct net_device *dev, struct rtnl_link_stats64
 	stats->rx_missed_errors = priv->xstats.rx_missed_cntr;
 }
 
+/**
+ * stmmac_get_phys_port_id - Get physical port identification
+ * @dev: net device structure
+ * @ppid: pointer to physical port id structure
+ *
+ * Returns a unique physical port identifier. If the platform provides
+ * a custom callback, it is used. Otherwise, the permanent MAC address
+ * serves as the default identifier.
+ *
+ * Return: 0 on success, negative error code otherwise
+ */
+static int stmmac_get_phys_port_id(struct net_device *dev,
+				   struct netdev_phys_item_id *ppid)
+{
+	struct stmmac_priv *priv = netdev_priv(dev);
+
+	/* Allow glue driver to override */
+	if (priv->plat->get_phys_port_id)
+		return priv->plat->get_phys_port_id(dev, ppid);
+
+	/* Default: use permanent MAC address as port ID */
+	ppid->id_len = ETH_ALEN;
+	memcpy(ppid->id, dev->perm_addr, ETH_ALEN);
+
+	return 0;
+}
+
+/**
+ * stmmac_get_phys_port_name - Get physical port name
+ * @dev: net device structure
+ * @name: buffer to store the port name
+ * @len: length of the buffer
+ *
+ * Returns a human-readable physical port name. If the platform provides
+ * a custom callback, it is used. Otherwise, a default name based on
+ * the bus_id is generated.
+ *
+ * Return: 0 on success, negative error code otherwise
+ */
+static int stmmac_get_phys_port_name(struct net_device *dev,
+				     char *name, size_t len)
+{
+	struct stmmac_priv *priv = netdev_priv(dev);
+
+	/* Allow glue driver to override */
+	if (priv->plat->get_phys_port_name)
+		return priv->plat->get_phys_port_name(dev, name, len);
+
+	/* Default: use bus_id as port identifier */
+	return snprintf(name, len, "p%d", priv->plat->bus_id) >= len ? -EINVAL : 0;
+}
+
 static const struct net_device_ops stmmac_netdev_ops = {
 	.ndo_open = stmmac_open,
 	.ndo_start_xmit = stmmac_xmit,
@@ -7172,6 +7224,8 @@ static const struct net_device_ops stmmac_netdev_ops = {
 	.ndo_xsk_wakeup = stmmac_xsk_wakeup,
 	.ndo_hwtstamp_get = stmmac_hwtstamp_get,
 	.ndo_hwtstamp_set = stmmac_hwtstamp_set,
+	.ndo_get_phys_port_id = stmmac_get_phys_port_id,
+	.ndo_get_phys_port_name = stmmac_get_phys_port_name,
 };
 
 static void stmmac_reset_subtask(struct stmmac_priv *priv)
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 4f70a6551e68c..2b98c2d354804 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -277,6 +277,11 @@ struct plat_stmmacenet_data {
 	void (*pcs_exit)(struct stmmac_priv *priv);
 	struct phylink_pcs *(*select_pcs)(struct stmmac_priv *priv,
 					  phy_interface_t interface);
+	/* Physical port identification callbacks (optional, for glue driver override) */
+	int (*get_phys_port_id)(struct net_device *ndev,
+				struct netdev_phys_item_id *ppid);
+	int (*get_phys_port_name)(struct net_device *ndev,
+				  char *name, size_t len);
 	void *bsp_priv;
 	struct clk *stmmac_clk;
 	struct clk *pclk;
-- 
2.25.1