diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 5d62b85a4024..65f546eca5f4 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -48,6 +48,8 @@
 #define AT803X_INTR_ENABLE_PAGE_RECEIVED	BIT(12)
 #define AT803X_INTR_ENABLE_LINK_FAIL		BIT(11)
 #define AT803X_INTR_ENABLE_LINK_SUCCESS		BIT(10)
+#define AT803X_INTR_ENABLE_LINK_FAIL_BX		BIT(8)
+#define AT803X_INTR_ENABLE_LINK_SUCCESS_BX	BIT(7)
 #define AT803X_INTR_ENABLE_WIRESPEED_DOWNGRADE	BIT(5)
 #define AT803X_INTR_ENABLE_POLARITY_CHANGED	BIT(1)
 #define AT803X_INTR_ENABLE_WOL			BIT(0)
@@ -81,7 +83,17 @@
 #define AT803X_DEBUG_DATA			0x1E
 
 #define AT803X_MODE_CFG_MASK			0x0F
-#define AT803X_MODE_CFG_SGMII			0x01
+#define AT803X_MODE_CFG_BASET_RGMII		0x00
+#define AT803X_MODE_CFG_BASET_SGMII		0x01
+#define AT803X_MODE_CFG_BX1000_RGMII_50		0x02
+#define AT803X_MODE_CFG_BX1000_RGMII_75		0x03
+#define AT803X_MODE_CFG_BX1000_CONV_50		0x04
+#define AT803X_MODE_CFG_BX1000_CONV_75		0x05
+#define AT803X_MODE_CFG_FX100_RGMII_50		0x06
+#define AT803X_MODE_CFG_FX100_CONV_50		0x07
+#define AT803X_MODE_CFG_RGMII_AUTO_MDET		0x0B
+#define AT803X_MODE_CFG_FX100_RGMII_75		0x0E
+#define AT803X_MODE_CFG_FX100_CONV_75		0x0F
 
 #define AT803X_PSSR				0x11	/*PHY-Specific Status Register*/
 #define AT803X_PSSR_MR_AN_COMPLETE		0x0200
@@ -191,6 +203,8 @@ struct at803x_priv {
 	u16 clk_25m_mask;
 	u8 smarteee_lpi_tw_1g;
 	u8 smarteee_lpi_tw_100m;
+	bool is_fiber;
+	bool is_1000basex;
 	struct regulator_dev *vddio_rdev;
 	struct regulator_dev *vddh_rdev;
 	struct regulator *vddio;
@@ -673,12 +687,32 @@ static int at803x_probe(struct phy_device *phydev)
 	}
 
 	/* Some bootloaders leave the fiber page selected.
-	 * Switch to the copper page, as otherwise we read
-	 * the PHY capabilities from the fiber side.
+	 * Switch to the appropriate page (fiber or copper), as otherwise we
+	 * read the PHY capabilities from the wrong page.
 	 */
 	if (at803x_match_phy_id(phydev, ATH8031_PHY_ID)) {
+		int mode_cfg;
+
+		ret = phy_read(phydev, AT803X_REG_CHIP_CONFIG);
+		if (ret < 0)
+			goto err;
+		mode_cfg = ret & AT803X_MODE_CFG_MASK;
+
+		switch (mode_cfg) {
+		case AT803X_MODE_CFG_BX1000_RGMII_50:
+		case AT803X_MODE_CFG_BX1000_RGMII_75:
+			priv->is_1000basex = true;
+			fallthrough;
+		case AT803X_MODE_CFG_FX100_RGMII_50:
+		case AT803X_MODE_CFG_FX100_RGMII_75:
+			priv->is_fiber = true;
+			break;
+		}
+
 		phy_lock_mdio_bus(phydev);
-		ret = at803x_write_page(phydev, AT803X_PAGE_COPPER);
+		ret = at803x_write_page(phydev,
+					priv->is_fiber ? AT803X_PAGE_FIBER :
+							 AT803X_PAGE_COPPER);
 		phy_unlock_mdio_bus(phydev);
 		if (ret)
 			goto err;
@@ -703,6 +737,7 @@ static void at803x_remove(struct phy_device *phydev)
 
 static int at803x_get_features(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int err;
 
 	err = genphy_read_abilities(phydev);
@@ -720,12 +755,13 @@ static int at803x_get_features(struct phy_device *phydev)
 	 * As a result of that, ESTATUS_1000_XFULL is set
 	 * to 1 even when operating in copper TP mode.
 	 *
-	 * Remove this mode from the supported link modes,
-	 * as this driver currently only supports copper
-	 * operation.
+	 * Remove this mode from the supported link modes
+	 * when the device is configured for copper operation.
 	 */
-	linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
-			   phydev->supported);
+	if (!priv->is_1000basex)
+		linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
+				   phydev->supported);
+
 	return 0;
 }
 
@@ -846,6 +882,7 @@ static int at803x_ack_interrupt(struct phy_device *phydev)
 
 static int at803x_config_intr(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int err;
 	int value;
 
@@ -862,6 +899,10 @@ static int at803x_config_intr(struct phy_device *phydev)
 		value |= AT803X_INTR_ENABLE_DUPLEX_CHANGED;
 		value |= AT803X_INTR_ENABLE_LINK_FAIL;
 		value |= AT803X_INTR_ENABLE_LINK_SUCCESS;
+		if (priv->is_fiber) {
+			value |= AT803X_INTR_ENABLE_LINK_FAIL_BX;
+			value |= AT803X_INTR_ENABLE_LINK_SUCCESS_BX;
+		}
 
 		err = phy_write(phydev, AT803X_INTR_ENABLE, value);
 	} else {
@@ -929,8 +970,12 @@ static void at803x_link_change_notify(struct phy_device *phydev)
 
 static int at803x_read_status(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int ss, err, old_link = phydev->link;
 
+	if (priv->is_1000basex)
+		return genphy_c37_read_status(phydev);
+
 	/* Update the link, but return if there was an error */
 	err = genphy_update_link(phydev);
 	if (err)
@@ -1029,6 +1074,7 @@ static int at803x_config_mdix(struct phy_device *phydev, u8 ctrl)
 
 static int at803x_config_aneg(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int ret;
 
 	ret = at803x_config_mdix(phydev, phydev->mdix_ctrl);
@@ -1045,7 +1091,10 @@ static int at803x_config_aneg(struct phy_device *phydev)
 			return ret;
 	}
 
-	return genphy_config_aneg(phydev);
+	if (priv->is_1000basex)
+		return genphy_c37_config_aneg(phydev);
+	else
+		return genphy_config_aneg(phydev);
 }
 
 static int at803x_get_downshift(struct phy_device *phydev, u8 *d)
