diff --git a/drivers/net/ethernet/tehuti/Makefile b/drivers/net/ethernet/tehuti/Makefile
index 1c468d99e476..7a0fe586a243 100644
--- a/drivers/net/ethernet/tehuti/Makefile
+++ b/drivers/net/ethernet/tehuti/Makefile
@@ -5,5 +5,5 @@
 
 obj-$(CONFIG_TEHUTI) += tehuti.o
 
-tn40xx-y := tn40.o
+tn40xx-y := tn40.o tn40_mdio.o
 obj-$(CONFIG_TEHUTI_TN40) += tn40xx.o
diff --git a/drivers/net/ethernet/tehuti/tn40.c b/drivers/net/ethernet/tehuti/tn40.c
index f676fc6e1d3a..0b8a063adb8c 100644
--- a/drivers/net/ethernet/tehuti/tn40.c
+++ b/drivers/net/ethernet/tehuti/tn40.c
@@ -1760,8 +1760,13 @@ static int tn40_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_unset_drvdata;
 	}
 
-	priv->stats_flag = ((read_reg(priv, FPGA_VER) & 0xFFF) != 308);
+	ret = tn40_mdiobus_init(priv);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to initialize mdio bus.\n");
+		goto err_free_irq;
+	}
 
+	priv->stats_flag = ((read_reg(priv, FPGA_VER) & 0xFFF) != 308);
 	priv->isr_mask =
 	    IR_RX_FREE_0 | IR_LNKCHG0 | IR_PSE | IR_TMR0 | IR_RX_DESC_0 |
 	    IR_TX_FREE_0 | IR_TMR1;
diff --git a/drivers/net/ethernet/tehuti/tn40.h b/drivers/net/ethernet/tehuti/tn40.h
index 2c24f75cab03..0f39dc70f37c 100644
--- a/drivers/net/ethernet/tehuti/tn40.h
+++ b/drivers/net/ethernet/tehuti/tn40.h
@@ -11,6 +11,7 @@
 #include <linux/if_vlan.h>
 #include <linux/in.h>
 #include <linux/interrupt.h>
+#include <linux/iopoll.h>
 #include <linux/ip.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
@@ -176,6 +177,7 @@ struct tn40_priv {
 	char *b0_va; /* Virtual address of buffer */
 
 	struct rx_page_table rx_page_table;
+	struct mii_bus *mdio;
 };
 
 /* RX FREE descriptor - 64bit */
@@ -262,4 +264,6 @@ static inline void write_reg(struct tn40_priv *priv, u32 reg, u32 val)
 	writel(val, priv->regs + reg);
 }
 
+int tn40_mdiobus_init(struct tn40_priv *priv);
+
 #endif /* _TN40XX_H */
diff --git a/drivers/net/ethernet/tehuti/tn40_mdio.c b/drivers/net/ethernet/tehuti/tn40_mdio.c
new file mode 100644
index 000000000000..c00421427f20
--- /dev/null
+++ b/drivers/net/ethernet/tehuti/tn40_mdio.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (c) Tehuti Networks Ltd. */
+
+#include "tn40.h"
+
+static void mdio_set_speed(struct tn40_priv *priv, u32 speed)
+{
+	void __iomem *regs = priv->regs;
+	int mdio_cfg;
+
+	mdio_cfg = readl(regs + REG_MDIO_CMD_STAT);
+	if (speed == 1)
+		mdio_cfg = (0x7d << 7) | 0x08;	/* 1MHz */
+	else
+		mdio_cfg = 0xA08;	/* 6MHz */
+	mdio_cfg |= (1 << 6);
+	writel(mdio_cfg, regs + REG_MDIO_CMD_STAT);
+	msleep(100);
+}
+
+static u32 mdio_stat(struct tn40_priv *priv)
+{
+	void __iomem *regs = priv->regs;
+
+	return readl(regs + REG_MDIO_CMD_STAT);
+}
+
+static int mdio_get(struct tn40_priv *priv, u32 *val)
+{
+	u32 stat;
+	int ret;
+
+	ret = readx_poll_timeout_atomic(mdio_stat, priv, stat,
+					GET_MDIO_BUSY(stat) == 0, 10, 10000);
+	return ret;
+}
+
+static int tn40_mdio_read(struct tn40_priv *priv, int port, int device,
+			  u16 regnum)
+{
+	void __iomem *regs = priv->regs;
+	u32 tmp_reg, i;
+
+	/* wait until MDIO is not busy */
+	if (mdio_get(priv, NULL))
+		return -EIO;
+
+	i = ((device & 0x1F) | ((port & 0x1F) << 5));
+	writel(i, regs + REG_MDIO_CMD);
+	writel((u32)regnum, regs + REG_MDIO_ADDR);
+	if (mdio_get(priv, NULL))
+		return -EIO;
+
+	writel(((1 << 15) | i), regs + REG_MDIO_CMD);
+	/* read CMD_STAT until not busy */
+	if (mdio_get(priv, NULL))
+		return -EIO;
+
+	tmp_reg = readl(regs + REG_MDIO_DATA);
+	return lower_16_bits(tmp_reg);
+}
+
+static int tn40_mdio_write(struct tn40_priv *priv, int port, int device,
+			   u16 regnum, u16 data)
+{
+	void __iomem *regs = priv->regs;
+	u32 tmp_reg = 0;
+	int ret;
+
+	/* wait until MDIO is not busy */
+	if (mdio_get(priv, NULL))
+		return -EIO;
+	writel(((device & 0x1F) | ((port & 0x1F) << 5)), regs + REG_MDIO_CMD);
+	writel((u32)regnum, regs + REG_MDIO_ADDR);
+	if (mdio_get(priv, NULL))
+		return -EIO;
+	writel((u32)data, regs + REG_MDIO_DATA);
+	/* read CMD_STAT until not busy */
+	ret = mdio_get(priv, &tmp_reg);
+	if (ret)
+		return -EIO;
+
+	if (GET_MDIO_RD_ERR(tmp_reg)) {
+		dev_err(&priv->pdev->dev, "MDIO error after write command\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+static int mdio_read(struct mii_bus *mii_bus, int addr, int devnum, int regnum)
+{
+	return tn40_mdio_read(mii_bus->priv, addr, devnum, regnum);
+}
+
+static int mdio_write(struct mii_bus *mii_bus, int addr, int devnum,
+		      int regnum, u16 val)
+{
+	return  tn40_mdio_write(mii_bus->priv, addr, devnum, regnum, val);
+}
+
+int tn40_mdiobus_init(struct tn40_priv *priv)
+{
+	struct pci_dev *pdev = priv->pdev;
+	struct mii_bus *bus;
+	int ret;
+
+	bus = devm_mdiobus_alloc(&pdev->dev);
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = TN40_DRV_NAME;
+	bus->parent = &pdev->dev;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "tn40xx-%x-%x",
+		 pci_domain_nr(pdev->bus), pci_dev_id(pdev));
+	bus->priv = priv;
+
+	bus->read_c45 = mdio_read;
+	bus->write_c45 = mdio_write;
+
+	ret = devm_mdiobus_register(&pdev->dev, bus);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register mdiobus %d %u %u\n",
+			ret, bus->state, MDIOBUS_UNREGISTERED);
+		return ret;
+	}
+	mdio_set_speed(priv, MDIO_SPEED_6MHZ);
+	priv->mdio = bus;
+	return 0;
+}
