diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index fc357bc568359ca395351a555714b35fba3f0973..135bf46354ea2245cbf2394e2d3b3162ba78e2ca 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -224,6 +224,9 @@ enum enetc_bdr_type {TX, RX};
 #define ENETC_PM0_MAXFRM	0x8014
 #define ENETC_SET_TX_MTU(val)	((val) << 16)
 #define ENETC_SET_MAXFRM(val)	((val) & 0xffff)
+
+#define ENETC_PM_IMDIO_BASE	0x8030
+
 #define ENETC_PM0_IF_MODE	0x8300
 #define ENETC_PMO_IFM_RG	BIT(2)
 #define ENETC_PM0_IFM_RLP	(BIT(5) | BIT(11))
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
index 4fac57dbb3c8fdfa5ed6bed6f07dadfd5ac4e334..3bf345b84b76995f5ca454f128a1cc1aaefecdb1 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
 /* Copyright 2017-2019 NXP */
 
+#include <linux/mdio.h>
 #include <linux/module.h>
 #include <linux/fsl/enetc_mdio.h>
 #include <linux/of_mdio.h>
@@ -833,6 +834,135 @@ static void enetc_of_put_phy(struct enetc_ndev_priv *priv)
 		of_node_put(priv->phy_node);
 }
 
+static int enetc_imdio_init(struct enetc_pf *pf, bool is_c45)
+{
+	struct device *dev = &pf->si->pdev->dev;
+	struct enetc_mdio_priv *mdio_priv;
+	struct phy_device *pcs;
+	struct mii_bus *bus;
+	int err;
+
+	bus = mdiobus_alloc_size(sizeof(*mdio_priv));
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = "Freescale ENETC internal MDIO Bus";
+	bus->read = enetc_mdio_read;
+	bus->write = enetc_mdio_write;
+	bus->parent = dev;
+	bus->phy_mask = ~0;
+	mdio_priv = bus->priv;
+	mdio_priv->hw = &pf->si->hw;
+	mdio_priv->mdio_base = ENETC_PM_IMDIO_BASE;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-imdio", dev_name(dev));
+
+	err = mdiobus_register(bus);
+	if (err) {
+		dev_err(dev, "cannot register internal MDIO bus (%d)\n", err);
+		goto free_mdio_bus;
+	}
+
+	pcs = get_phy_device(bus, 0, is_c45);
+	if (IS_ERR(pcs)) {
+		err = PTR_ERR(pcs);
+		dev_err(dev, "cannot get internal PCS PHY (%d)\n", err);
+		goto unregister_mdiobus;
+	}
+
+	pf->imdio = bus;
+	pf->pcs = pcs;
+
+	return 0;
+
+unregister_mdiobus:
+	mdiobus_unregister(bus);
+free_mdio_bus:
+	mdiobus_free(bus);
+	return err;
+}
+
+static void enetc_imdio_remove(struct enetc_pf *pf)
+{
+	if (pf->pcs)
+		put_device(&pf->pcs->mdio.dev);
+	if (pf->imdio) {
+		mdiobus_unregister(pf->imdio);
+		mdiobus_free(pf->imdio);
+	}
+}
+
+static void enetc_configure_sgmii(struct phy_device *pcs)
+{
+	/* SGMII spec requires tx_config_Reg[15:0] to be exactly 0x4001
+	 * for the MAC PCS in order to acknowledge the AN.
+	 */
+	phy_write(pcs, MII_ADVERTISE, ADVERTISE_SGMII | ADVERTISE_LPACK);
+
+	phy_write(pcs, ENETC_PCS_IF_MODE,
+		  ENETC_PCS_IF_MODE_SGMII_EN |
+		  ENETC_PCS_IF_MODE_USE_SGMII_AN);
+
+	/* Adjust link timer for SGMII */
+	phy_write(pcs, ENETC_PCS_LINK_TIMER1, ENETC_PCS_LINK_TIMER1_VAL);
+	phy_write(pcs, ENETC_PCS_LINK_TIMER2, ENETC_PCS_LINK_TIMER2_VAL);
+
+	phy_write(pcs, MII_BMCR, BMCR_ANRESTART | BMCR_ANENABLE);
+}
+
+static void enetc_configure_2500basex(struct phy_device *pcs)
+{
+	phy_write(pcs, ENETC_PCS_IF_MODE,
+		  ENETC_PCS_IF_MODE_SGMII_EN |
+		  ENETC_PCS_IF_MODE_SGMII_SPEED(ENETC_PCS_SPEED_2500));
+
+	phy_write(pcs, MII_BMCR, BMCR_SPEED1000 | BMCR_FULLDPLX | BMCR_RESET);
+}
+
+static void enetc_configure_usxgmii(struct phy_device *pcs)
+{
+	/* Configure device ability for the USXGMII Replicator */
+	phy_write_mmd(pcs, MDIO_MMD_VEND2, MII_ADVERTISE,
+		      ADVERTISE_SGMII | ADVERTISE_LPACK |
+		      MDIO_USXGMII_FULL_DUPLEX);
+
+	/* Restart PCS AN */
+	phy_write_mmd(pcs, MDIO_MMD_VEND2, MII_BMCR,
+		      BMCR_RESET | BMCR_ANENABLE | BMCR_ANRESTART);
+}
+
+static int enetc_configure_serdes(struct enetc_ndev_priv *priv)
+{
+	bool is_c45 = priv->if_mode == PHY_INTERFACE_MODE_USXGMII;
+	struct enetc_pf *pf = enetc_si_priv(priv->si);
+	int err;
+
+	if (priv->if_mode != PHY_INTERFACE_MODE_SGMII &&
+	    priv->if_mode != PHY_INTERFACE_MODE_2500BASEX &&
+	    priv->if_mode != PHY_INTERFACE_MODE_USXGMII)
+		return 0;
+
+	err = enetc_imdio_init(pf, is_c45);
+	if (err)
+		return err;
+
+	switch (priv->if_mode) {
+	case PHY_INTERFACE_MODE_SGMII:
+		enetc_configure_sgmii(pf->pcs);
+		break;
+	case PHY_INTERFACE_MODE_2500BASEX:
+		enetc_configure_2500basex(pf->pcs);
+		break;
+	case PHY_INTERFACE_MODE_USXGMII:
+		enetc_configure_usxgmii(pf->pcs);
+		break;
+	default:
+		dev_err(&pf->si->pdev->dev, "Unsupported link mode %s\n",
+			phy_modes(priv->if_mode));
+	}
+
+	return 0;
+}
+
 static int enetc_pf_probe(struct pci_dev *pdev,
 			  const struct pci_device_id *ent)
 {
@@ -897,6 +1027,10 @@ static int enetc_pf_probe(struct pci_dev *pdev,
 	if (err)
 		dev_warn(&pdev->dev, "Fallback to PHY-less operation\n");
 
+	err = enetc_configure_serdes(priv);
+	if (err)
+		dev_warn(&pdev->dev, "Attempted SerDes config but failed\n");
+
 	err = register_netdev(ndev);
 	if (err)
 		goto err_reg_netdev;
@@ -932,6 +1066,7 @@ static void enetc_pf_remove(struct pci_dev *pdev)
 	priv = netdev_priv(si->ndev);
 	unregister_netdev(si->ndev);
 
+	enetc_imdio_remove(pf);
 	enetc_mdio_remove(pf);
 	enetc_of_put_phy(priv);
 
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.h b/drivers/net/ethernet/freescale/enetc/enetc_pf.h
index 59e65a6f6c3e1ced65331cdb53f98365775e5e2c..2cb922b59f4602ee90617b448bf3ee7eb53a5554 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.h
@@ -44,6 +44,8 @@ struct enetc_pf {
 	DECLARE_BITMAP(active_vlans, VLAN_N_VID);
 
 	struct mii_bus *mdio; /* saved for cleanup */
+	struct mii_bus *imdio;
+	struct phy_device *pcs;
 };
 
 int enetc_msg_psi_init(struct enetc_pf *pf);