diff --git a/target/linux/mediatek/patches-5.4/750-add-mdio-bus-for-gphy-calibration.patch b/target/linux/mediatek/patches-5.4/750-add-mdio-bus-for-gphy-calibration.patch
new file mode 100755
index 0000000..e3efa34
--- /dev/null
+++ b/target/linux/mediatek/patches-5.4/750-add-mdio-bus-for-gphy-calibration.patch
@@ -0,0 +1,133 @@
+Index: linux-5.4.215/drivers/net/dsa/mt7530.c
+===================================================================
+--- linux-5.4.215.orig/drivers/net/dsa/mt7530.c
++++ linux-5.4.215/drivers/net/dsa/mt7530.c
+@@ -847,6 +847,117 @@ mt7531_ind_phy_write(struct dsa_switch *
+ 	return ret;
+ }
+
++static int mt753x_mdio_read(struct mii_bus *bus, int addr, int regnum)
++{
++	struct mt7530_priv *priv = bus->priv;
++	struct mt7530_dummy_poll p;
++	int ret;
++	u32 val;
++
++	INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
++
++	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
++
++	ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val,
++				 !(val & MT7531_PHY_ACS_ST), 20, 100000);
++	if (ret < 0) {
++		dev_err(priv->dev, "poll timeout\n");
++		goto out;
++	}
++
++	val = MT7531_MDIO_CL22_READ | MT7531_MDIO_PHY_ADDR(addr) |
++		  MT7531_MDIO_REG_ADDR(regnum);
++
++	mt7530_mii_write(priv, MT7531_PHY_IAC, val | MT7531_PHY_ACS_ST);
++
++	ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val,
++				 !(val & MT7531_PHY_ACS_ST), 20, 100000);
++	if (ret < 0) {
++		dev_err(priv->dev, "poll timeout\n");
++		goto out;
++	}
++
++	ret = val & MT7531_MDIO_RW_DATA_MASK;
++out:
++	mutex_unlock(&priv->bus->mdio_lock);
++
++	return ret;
++}
++
++static int mt753x_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val)
++{
++	struct mt7530_priv *priv = bus->priv;
++	struct mt7530_dummy_poll p;
++	int ret;
++	u32 reg;
++
++	INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
++
++	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
++
++	ret = readx_poll_timeout(_mt7530_unlocked_read, &p, reg,
++				 !(reg & MT7531_PHY_ACS_ST), 20, 100000);
++	if (ret < 0) {
++		dev_err(priv->dev, "poll timeout\n");
++		goto out;
++	}
++
++	reg = MT7531_MDIO_CL22_WRITE | MT7531_MDIO_PHY_ADDR(addr) |
++		  MT7531_MDIO_REG_ADDR(regnum) | val;
++
++	mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST);
++
++	ret = readx_poll_timeout(_mt7530_unlocked_read, &p, reg,
++				 !(reg & MT7531_PHY_ACS_ST), 20, 100000);
++	if (ret < 0) {
++		dev_err(priv->dev, "poll timeout\n");
++		goto out;
++	}
++
++out:
++	mutex_unlock(&priv->bus->mdio_lock);
++
++	return ret;
++}
++
++static int mt753x_setup_mdio(struct dsa_switch *ds)
++{
++	struct mt7530_priv *priv = ds->priv;
++	struct device_node *mdio_np;
++	int ret;
++
++	mdio_np = of_get_compatible_child(priv->dev->of_node, "mediatek,dsa-slave-mdio");
++	if (!mdio_np) {
++		dev_err(priv->dev, "no MDIO bus node\n");
++		return -ENODEV;
++	}
++
++	priv->ds->slave_mii_bus = devm_mdiobus_alloc(priv->dev);
++	if (!priv->ds->slave_mii_bus) {
++		ret = -ENOMEM;
++		goto err_put_node;
++	}
++	priv->ds->slave_mii_bus->name = "mediatek,dsa-slave-mdio";
++	priv->ds->slave_mii_bus->priv = priv;
++	priv->ds->slave_mii_bus->parent = priv->dev;
++	priv->ds->slave_mii_bus->phy_mask = ~priv->ds->phys_mii_mask;
++	priv->ds->slave_mii_bus->read = mt753x_mdio_read;
++	priv->ds->slave_mii_bus->write = mt753x_mdio_write;
++	snprintf(priv->ds->slave_mii_bus->id, MII_BUS_ID_SIZE, "dsa-%d.%d",
++		 priv->ds->dst->index, priv->ds->index);
++	priv->ds->slave_mii_bus->dev.of_node = mdio_np;
++
++	ret = of_mdiobus_register(priv->ds->slave_mii_bus, mdio_np);
++	if (ret)
++		dev_err(priv->dev, "unable to register MDIO bus %s\n",
++			priv->ds->slave_mii_bus->id);
++
++err_put_node:
++	of_node_put(mdio_np);
++
++	return ret;
++}
++
+ static void
+ mt7530_get_strings(struct dsa_switch *ds, int port, u32 stringset,
+ 		   uint8_t *data)
+@@ -2694,6 +2805,10 @@ mt7988_setup(struct dsa_switch *ds)
+ 	if (ret < 0)
+ 		return ret;
+
++	ret = mt753x_setup_mdio(ds);
++	if (ret < 0)
++		dev_err(priv->dev, "mt753x_setup_mdio failed\n");
++
+ 	return 0;
+ }
+