diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index bdfbabb86ee0..c67a72d23157 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -123,6 +123,13 @@ config MDIO_MOXART
 	  This driver supports the MDIO interface found in the network
 	  interface units of the MOXA ART SoC
 
+config MDIO_MSCC_MIIM
+	tristate "Microsemi MIIM interface support"
+	depends on HAS_IOMEM
+	help
+	  This driver supports the MIIM (MDIO) interface found in the network
+	  switches of the Microsemi SoCs
+
 config MDIO_OCTEON
 	tristate "Octeon and some ThunderX SOCs MDIO buses"
 	depends on 64BIT
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 01acbcb2c798..7c0ef479ffc4 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_MDIO_GPIO)		+= mdio-gpio.o
 obj-$(CONFIG_MDIO_HISI_FEMAC)	+= mdio-hisi-femac.o
 obj-$(CONFIG_MDIO_I2C)		+= mdio-i2c.o
 obj-$(CONFIG_MDIO_MOXART)	+= mdio-moxart.o
+obj-$(CONFIG_MDIO_MSCC_MIIM)	+= mdio-mscc-miim.o
 obj-$(CONFIG_MDIO_OCTEON)	+= mdio-octeon.o
 obj-$(CONFIG_MDIO_SUN4I)	+= mdio-sun4i.o
 obj-$(CONFIG_MDIO_THUNDER)	+= mdio-thunder.o
diff --git a/drivers/net/phy/mdio-mscc-miim.c b/drivers/net/phy/mdio-mscc-miim.c
new file mode 100644
index 000000000000..8c689ccfdbca
--- /dev/null
+++ b/drivers/net/phy/mdio-mscc-miim.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Driver for the MDIO interface of Microsemi network switches.
+ *
+ * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
+ * Copyright (c) 2017 Microsemi Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/of_mdio.h>
+
+#define MSCC_MIIM_REG_STATUS		0x0
+#define		MSCC_MIIM_STATUS_STAT_BUSY	BIT(3)
+#define MSCC_MIIM_REG_CMD		0x8
+#define		MSCC_MIIM_CMD_OPR_WRITE		BIT(1)
+#define		MSCC_MIIM_CMD_OPR_READ		BIT(2)
+#define		MSCC_MIIM_CMD_WRDATA_SHIFT	4
+#define		MSCC_MIIM_CMD_REGAD_SHIFT	20
+#define		MSCC_MIIM_CMD_PHYAD_SHIFT	25
+#define		MSCC_MIIM_CMD_VLD		BIT(31)
+#define MSCC_MIIM_REG_DATA		0xC
+#define		MSCC_MIIM_DATA_ERROR		(BIT(16) | BIT(17))
+
+#define MSCC_PHY_REG_PHY_CFG	0x0
+#define		PHY_CFG_PHY_ENA		(BIT(0) | BIT(1) | BIT(2) | BIT(3))
+#define		PHY_CFG_PHY_COMMON_RESET BIT(4)
+#define		PHY_CFG_PHY_RESET	(BIT(5) | BIT(6) | BIT(7) | BIT(8))
+#define MSCC_PHY_REG_PHY_STATUS	0x4
+
+struct mscc_miim_dev {
+	void __iomem *regs;
+	void __iomem *phy_regs;
+};
+
+static int mscc_miim_wait_ready(struct mii_bus *bus)
+{
+	struct mscc_miim_dev *miim = bus->priv;
+	u32 val;
+
+	readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
+			   !(val & MSCC_MIIM_STATUS_STAT_BUSY), 100, 250000);
+	if (val & MSCC_MIIM_STATUS_STAT_BUSY)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+	struct mscc_miim_dev *miim = bus->priv;
+	u32 val;
+	int ret;
+
+	ret = mscc_miim_wait_ready(bus);
+	if (ret)
+		goto out;
+
+	writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
+	       (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | MSCC_MIIM_CMD_OPR_READ,
+	       miim->regs + MSCC_MIIM_REG_CMD);
+
+	ret = mscc_miim_wait_ready(bus);
+	if (ret)
+		goto out;
+
+	val = readl(miim->regs + MSCC_MIIM_REG_DATA);
+	if (val & MSCC_MIIM_DATA_ERROR) {
+		ret = -EIO;
+		goto out;
+	}
+
+	ret = val & 0xFFFF;
+out:
+	return ret;
+}
+
+static int mscc_miim_write(struct mii_bus *bus, int mii_id,
+			   int regnum, u16 value)
+{
+	struct mscc_miim_dev *miim = bus->priv;
+	int ret;
+
+	ret = mscc_miim_wait_ready(bus);
+	if (ret < 0)
+		goto out;
+
+	writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
+	       (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
+	       (value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
+	       MSCC_MIIM_CMD_OPR_WRITE,
+	       miim->regs + MSCC_MIIM_REG_CMD);
+
+out:
+	return ret;
+}
+
+static int mscc_miim_reset(struct mii_bus *bus)
+{
+	struct mscc_miim_dev *miim = bus->priv;
+
+	if (miim->phy_regs) {
+		writel(0, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
+		writel(0x1ff, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
+		mdelay(500);
+	}
+
+	return 0;
+}
+
+static int mscc_miim_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct mii_bus *bus;
+	struct mscc_miim_dev *dev;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*dev));
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = "mscc_miim";
+	bus->read = mscc_miim_read;
+	bus->write = mscc_miim_write;
+	bus->reset = mscc_miim_reset;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
+	bus->parent = &pdev->dev;
+
+	dev = bus->priv;
+	dev->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(dev->regs)) {
+		dev_err(&pdev->dev, "Unable to map MIIM registers\n");
+		return PTR_ERR(dev->regs);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (res) {
+		dev->phy_regs = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(dev->phy_regs)) {
+			dev_err(&pdev->dev, "Unable to map internal phy registers\n");
+			return PTR_ERR(dev->phy_regs);
+		}
+	}
+
+	if (pdev->dev.of_node)
+		ret = of_mdiobus_register(bus, pdev->dev.of_node);
+	else
+		ret = mdiobus_register(bus);
+
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, bus);
+
+	return 0;
+}
+
+static int mscc_miim_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus = platform_get_drvdata(pdev);
+
+	mdiobus_unregister(bus);
+
+	return 0;
+}
+
+static const struct of_device_id mscc_miim_match[] = {
+	{ .compatible = "mscc,ocelot-miim" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mscc_miim_match);
+
+static struct platform_driver mscc_miim_driver = {
+	.probe = mscc_miim_probe,
+	.remove = mscc_miim_remove,
+	.driver = {
+		.name = "mscc-miim",
+		.of_match_table = mscc_miim_match,
+	},
+};
+
+module_platform_driver(mscc_miim_driver);
+
+MODULE_DESCRIPTION("Microsemi MIIM driver");
+MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
+MODULE_LICENSE("Dual MIT/GPL");
