+#define DWMAC_sUN8I_MDIO_MUX_INTERNAL_ID	0
+#define DWMAC_sUN8I_MDIO_MUX_EXTERNAL_ID	1
 
 /* H3/A64 specific bits */
 #define SYSCON_RMII_EN		BIT(13) /* 1: enable RMII (overrides EPIT) */

@@ -634,6 +639,76 @@ static int sun8i_dwmac_reset(struct stmmac_priv *priv)
 	return 0;
 }
 
+/* MDIO multiplexing switch function
+ * This function is called by the mdio-mux layer when it thinks the mdio bus
+ * multiplexer needs to switch.
+ * 'current_child' is the current value of the mux register
+ * 'desired_child' is the value of the 'reg' property of the target child MDIO
+ * node.
+ * The first time this function is called, current_child == -1.
+ * If current_child == desired_child, then the mux is already set to the
+ * correct bus.
+ *
+ * Note that we do not use reg/mask like mdio-mux-mmioreg because we need to
+ * know easily which bus is used (reset must be done only for desired bus).
+ */
+static int mdio_mux_syscon_switch_fn(int current_child, int desired_child,
+				     void *data)
+{
+	struct stmmac_priv *priv = data;
+	struct sunxi_priv_data *gmac = priv->plat->bsp_priv;
+	u32 reg, val;
+	int ret = 0;
+	bool need_reset = false;
+
+	if (current_child ^ desired_child) {
+		regmap_read(gmac->regmap, SYSCON_EMAC_REG, &reg);
+		switch (desired_child) {
+		case DWMAC_sUN8I_MDIO_MUX_INTERNAL_ID:
+			dev_info(priv->device, "Switch mux to internal PHY");
+			val = (reg & ~H3_EPHY_MUX_MASK) | H3_EPHY_SELECT;
+			if (gmac->use_internal_phy)
+				need_reset = true;
+			break;