net: add Hisilicon Network Subsystem MDIO support

The MDIO support for Hisilicon Network Subsystem. It is used in Hislicon
hip04, hip05 and Hi1610 SoC to control the external PHY
Signed-off-by: Nhuangdaode <huangdaode@hisilicon.com>
Signed-off-by: NYisen Zhuang <Yisen.Zhuang@huawei.com>
Signed-off-by: NKenneth Lee <liguozhu@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/Kconfig

@@ -5,7 +5,7 @@
 config NET_VENDOR_HISILICON
 	bool "Hisilicon devices"
 	default y
-	depends on ARM
+	depends on ARM || ARM64
 	---help---
 	  If you have a network (Ethernet) card belonging to this class, say Y.
 
@@ -27,8 +27,16 @@ config HIP04_ETH
 	select PHYLIB
 	select MARVELL_PHY
 	select MFD_SYSCON
+	select HNS_MDIO
 	---help---
 	  If you wish to compile a kernel for a hardware with hisilicon p04 SoC and
 	  want to use the internal ethernet then you should answer Y to this.
 
+config HNS_MDIO
+	tristate "Hisilicon HNS MDIO device Support"
+	select MDIO
+	---help---
+	  This selects the HNS MDIO support. It is needed by HNS_DSAF to access
+	  the PHY
+
 endif # NET_VENDOR_HISILICON

drivers/net/ethernet/hisilicon/Makefile

@@ -3,4 +3,5 @@
 #
 
 obj-$(CONFIG_HIX5HD2_GMAC) += hix5hd2_gmac.o
-obj-$(CONFIG_HIP04_ETH) += hip04_mdio.o hip04_eth.o
+obj-$(CONFIG_HIP04_ETH) += hip04_eth.o
+obj-$(CONFIG_HNS_MDIO) += hns_mdio.o

drivers/net/ethernet/hisilicon/hip04_mdio.c

-/* Copyright (c) 2014 Linaro Ltd.
- * Copyright (c) 2014 Hisilicon Limited.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- */
-
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/io.h>
-#include <linux/of_mdio.h>
-#include <linux/delay.h>
-
-#define MDIO_CMD_REG		0x0
-#define MDIO_ADDR_REG		0x4
-#define MDIO_WDATA_REG		0x8
-#define MDIO_RDATA_REG		0xc
-#define MDIO_STA_REG		0x10
-
-#define MDIO_START		BIT(14)
-#define MDIO_R_VALID		BIT(1)
-#define MDIO_READ	        (BIT(12) | BIT(11) | MDIO_START)
-#define MDIO_WRITE	        (BIT(12) | BIT(10) | MDIO_START)
-
-struct hip04_mdio_priv {
-	void __iomem *base;
-};
-
-#define WAIT_TIMEOUT 10
-static int hip04_mdio_wait_ready(struct mii_bus *bus)
-{
-	struct hip04_mdio_priv *priv = bus->priv;
-	int i;
-
-	for (i = 0; readl_relaxed(priv->base + MDIO_CMD_REG) & MDIO_START; i++) {
-		if (i == WAIT_TIMEOUT)
-			return -ETIMEDOUT;
-		msleep(20);
-	}
-
-	return 0;
-}
-
-static int hip04_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
-{
-	struct hip04_mdio_priv *priv = bus->priv;
-	u32 val;
-	int ret;
-
-	ret = hip04_mdio_wait_ready(bus);
-	if (ret < 0)
-		goto out;
-
-	val = regnum | (mii_id << 5) | MDIO_READ;
-	writel_relaxed(val, priv->base + MDIO_CMD_REG);
-
-	ret = hip04_mdio_wait_ready(bus);
-	if (ret < 0)
-		goto out;
-
-	val = readl_relaxed(priv->base + MDIO_STA_REG);
-	if (val & MDIO_R_VALID) {
-		dev_err(bus->parent, "SMI bus read not valid\n");
-		ret = -ENODEV;
-		goto out;
-	}
-
-	val = readl_relaxed(priv->base + MDIO_RDATA_REG);
-	ret = val & 0xFFFF;
-out:
-	return ret;
-}
-
-static int hip04_mdio_write(struct mii_bus *bus, int mii_id,
-			    int regnum, u16 value)
-{
-	struct hip04_mdio_priv *priv = bus->priv;
-	u32 val;
-	int ret;
-
-	ret = hip04_mdio_wait_ready(bus);
-	if (ret < 0)
-		goto out;
-
-	writel_relaxed(value, priv->base + MDIO_WDATA_REG);
-	val = regnum | (mii_id << 5) | MDIO_WRITE;
-	writel_relaxed(val, priv->base + MDIO_CMD_REG);
-out:
-	return ret;
-}
-
-static int hip04_mdio_reset(struct mii_bus *bus)
-{
-	int temp, i;
-
-	for (i = 0; i < PHY_MAX_ADDR; i++) {
-		hip04_mdio_write(bus, i, 22, 0);
-		temp = hip04_mdio_read(bus, i, MII_BMCR);
-		if (temp < 0)
-			continue;
-
-		temp |= BMCR_RESET;
-		if (hip04_mdio_write(bus, i, MII_BMCR, temp) < 0)
-			continue;
-	}
-
-	mdelay(500);
-	return 0;
-}
-
-static int hip04_mdio_probe(struct platform_device *pdev)
-{
-	struct resource *r;
-	struct mii_bus *bus;
-	struct hip04_mdio_priv *priv;
-	int ret;
-
-	bus = mdiobus_alloc_size(sizeof(struct hip04_mdio_priv));
-	if (!bus) {
-		dev_err(&pdev->dev, "Cannot allocate MDIO bus\n");
-		return -ENOMEM;
-	}
-
-	bus->name = "hip04_mdio_bus";
-	bus->read = hip04_mdio_read;
-	bus->write = hip04_mdio_write;
-	bus->reset = hip04_mdio_reset;
-	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
-	bus->parent = &pdev->dev;
-	priv = bus->priv;
-
-	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	priv->base = devm_ioremap_resource(&pdev->dev, r);
-	if (IS_ERR(priv->base)) {
-		ret = PTR_ERR(priv->base);
-		goto out_mdio;
-	}
-
-	ret = of_mdiobus_register(bus, pdev->dev.of_node);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
-		goto out_mdio;
-	}
-
-	platform_set_drvdata(pdev, bus);
-
-	return 0;
-
-out_mdio:
-	mdiobus_free(bus);
-	return ret;
-}
-
-static int hip04_mdio_remove(struct platform_device *pdev)
-{
-	struct mii_bus *bus = platform_get_drvdata(pdev);
-
-	mdiobus_unregister(bus);
-	mdiobus_free(bus);
-
-	return 0;
-}
-
-static const struct of_device_id hip04_mdio_match[] = {
-	{ .compatible = "hisilicon,hip04-mdio" },
-	{ }
-};
-MODULE_DEVICE_TABLE(of, hip04_mdio_match);
-
-static struct platform_driver hip04_mdio_driver = {
-	.probe = hip04_mdio_probe,
-	.remove = hip04_mdio_remove,
-	.driver = {
-		.name = "hip04-mdio",
-		.of_match_table = hip04_mdio_match,
-	},
-};
-
-module_platform_driver(hip04_mdio_driver);
-
-MODULE_DESCRIPTION("HISILICON P04 MDIO interface driver");
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("platform:hip04-mdio");

drivers/net/ethernet/hisilicon/hns_mdio.c

+/*
+ * Copyright (c) 2014-2015 Hisilicon Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+#include <linux/of_mdio.h>
+#include <linux/of_platform.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock_types.h>
+
+#define MDIO_DRV_NAME "Hi-HNS_MDIO"
+#define MDIO_BUS_NAME "Hisilicon MII Bus"
+#define MDIO_DRV_VERSION "1.3.0"
+#define MDIO_COPYRIGHT "Copyright(c) 2015 Huawei Corporation."
+#define MDIO_DRV_STRING MDIO_BUS_NAME
+#define MDIO_DEFAULT_DEVICE_DESCR MDIO_BUS_NAME
+
+#define MDIO_CTL_DEV_ADDR(x)	(x & 0x1f)
+#define MDIO_CTL_PORT_ADDR(x)	((x & 0x1f) << 5)
+
+#define MDIO_TIMEOUT			1000000
+
+struct hns_mdio_device {
+	void *vbase;		/* mdio reg base address */
+	void *sys_vbase;
+};
+
+/* mdio reg */
+#define MDIO_COMMAND_REG		0x0
+#define MDIO_ADDR_REG			0x4
+#define MDIO_WDATA_REG			0x8
+#define MDIO_RDATA_REG			0xc
+#define MDIO_STA_REG			0x10
+
+/* cfg phy bit map */
+#define MDIO_CMD_DEVAD_M	0x1f
+#define MDIO_CMD_DEVAD_S	0
+#define MDIO_CMD_PRTAD_M	0x1f
+#define MDIO_CMD_PRTAD_S	5
+#define MDIO_CMD_OP_M		0x3
+#define MDIO_CMD_OP_S		10
+#define MDIO_CMD_ST_M		0x3
+#define MDIO_CMD_ST_S		12
+#define MDIO_CMD_START_B	14
+
+#define MDIO_ADDR_DATA_M	0xffff
+#define MDIO_ADDR_DATA_S	0
+
+#define MDIO_WDATA_DATA_M	0xffff
+#define MDIO_WDATA_DATA_S	0
+
+#define MDIO_RDATA_DATA_M	0xffff
+#define MDIO_RDATA_DATA_S	0
+
+#define MDIO_STATE_STA_B	0
+
+enum mdio_st_clause {
+	MDIO_ST_CLAUSE_45 = 0,
+	MDIO_ST_CLAUSE_22
+};
+
+enum mdio_c22_op_seq {
+	MDIO_C22_WRITE = 1,
+	MDIO_C22_READ = 2
+};
+
+enum mdio_c45_op_seq {
+	MDIO_C45_WRITE_ADDR = 0,
+	MDIO_C45_WRITE_DATA,
+	MDIO_C45_READ_INCREMENT,
+	MDIO_C45_READ
+};
+
+/* peri subctrl reg */
+#define MDIO_SC_CLK_EN		0x338
+#define MDIO_SC_CLK_DIS		0x33C
+#define MDIO_SC_RESET_REQ	0xA38
+#define MDIO_SC_RESET_DREQ	0xA3C
+#define MDIO_SC_CTRL		0x2010
+#define MDIO_SC_CLK_ST		0x531C
+#define MDIO_SC_RESET_ST	0x5A1C
+
+static void mdio_write_reg(void *base, u32 reg, u32 value)
+{
+	u8 __iomem *reg_addr = (u8 __iomem *)base;
+
+	writel_relaxed(value, reg_addr + reg);
+}
+
+#define MDIO_WRITE_REG(a, reg, value) \
+	mdio_write_reg((a)->vbase, (reg), (value))
+
+static u32 mdio_read_reg(void *base, u32 reg)
+{
+	u8 __iomem *reg_addr = (u8 __iomem *)base;
+
+	return readl_relaxed(reg_addr + reg);
+}
+
+#define mdio_set_field(origin, mask, shift, val) \
+	do { \
+		(origin) &= (~((mask) << (shift))); \
+		(origin) |= (((val) & (mask)) << (shift)); \
+	} while (0)
+
+#define mdio_get_field(origin, mask, shift) (((origin) >> (shift)) & (mask))
+
+static void mdio_set_reg_field(void *base, u32 reg, u32 mask, u32 shift,
+			       u32 val)
+{
+	u32 origin = mdio_read_reg(base, reg);
+
+	mdio_set_field(origin, mask, shift, val);
+	mdio_write_reg(base, reg, origin);
+}
+
+#define MDIO_SET_REG_FIELD(dev, reg, mask, shift, val) \
+	mdio_set_reg_field((dev)->vbase, (reg), (mask), (shift), (val))
+
+static u32 mdio_get_reg_field(void *base, u32 reg, u32 mask, u32 shift)
+{
+	u32 origin;
+
+	origin = mdio_read_reg(base, reg);
+	return mdio_get_field(origin, mask, shift);
+}
+
+#define MDIO_GET_REG_FIELD(dev, reg, mask, shift) \
+		mdio_get_reg_field((dev)->vbase, (reg), (mask), (shift))
+
+#define MDIO_GET_REG_BIT(dev, reg, bit) \
+		mdio_get_reg_field((dev)->vbase, (reg), 0x1ull, (bit))
+
+#define MDIO_CHECK_SET_ST	1
+#define MDIO_CHECK_CLR_ST	0
+
+static int mdio_sc_cfg_reg_write(struct hns_mdio_device *mdio_dev,
+				 u32 cfg_reg, u32 set_val,
+				 u32 st_reg, u32 st_msk, u8 check_st)
+{
+	u32 time_cnt;
+	u32 reg_value;
+
+	mdio_write_reg((void *)mdio_dev->sys_vbase, cfg_reg, set_val);
+
+	for (time_cnt = MDIO_TIMEOUT; time_cnt; time_cnt--) {
+		reg_value = mdio_read_reg((void *)mdio_dev->sys_vbase, st_reg);
+		reg_value &= st_msk;
+		if ((!!check_st) == (!!reg_value))
+			break;
+	}
+
+	if ((!!check_st) != (!!reg_value))
+		return -EBUSY;
+
+	return 0;
+}
+
+static int hns_mdio_wait_ready(struct mii_bus *bus)
+{
+	struct hns_mdio_device *mdio_dev = bus->priv;
+	int i;
+	u32 cmd_reg_value = 1;
+
+	/* waitting for MDIO_COMMAND_REG 's mdio_start==0 */
+	/* after that can do read or write*/
+	for (i = 0; cmd_reg_value; i++) {
+		cmd_reg_value = MDIO_GET_REG_BIT(mdio_dev,
+						 MDIO_COMMAND_REG,
+						 MDIO_CMD_START_B);
+		if (i == MDIO_TIMEOUT)
+			return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void hns_mdio_cmd_write(struct hns_mdio_device *mdio_dev,
+			       u8 is_c45, u8 op, u8 phy_id, u16 cmd)
+{
+	u32 cmd_reg_value;
+	u8 st = is_c45 ? MDIO_ST_CLAUSE_45 : MDIO_ST_CLAUSE_22;
+
+	cmd_reg_value = st << MDIO_CMD_ST_S;
+	cmd_reg_value |= op << MDIO_CMD_OP_S;
+	cmd_reg_value |=
+		(phy_id & MDIO_CMD_PRTAD_M) << MDIO_CMD_PRTAD_S;
+	cmd_reg_value |= (cmd & MDIO_CMD_DEVAD_M) << MDIO_CMD_DEVAD_S;
+	cmd_reg_value |= 1 << MDIO_CMD_START_B;
+
+	MDIO_WRITE_REG(mdio_dev, MDIO_COMMAND_REG, cmd_reg_value);
+}
+
+/**
+ * hns_mdio_write - access phy register
+ * @bus: mdio bus
+ * @phy_id: phy id
+ * @regnum: register num
+ * @value: register value
+ *
+ * Return 0 on success, negative on failure
+ */
+static int hns_mdio_write(struct mii_bus *bus,
+			  int phy_id, int regnum, u16 data)
+{
+	int ret;
+	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
+	u8 devad = ((regnum >> 16) & 0x1f);
+	u8 is_c45 = !!(regnum & MII_ADDR_C45);
+	u16 reg = (u16)(regnum & 0xffff);
+	u8 op;
+	u16 cmd_reg_cfg;
+
+	dev_dbg(&bus->dev, "mdio write %s,base is %p\n",
+		bus->id, mdio_dev->vbase);
+	dev_dbg(&bus->dev, "phy id=%d, is_c45=%d, devad=%d, reg=%#x, write data=%d\n",
+		phy_id, is_c45, devad, reg, data);
+
+	/* wait for ready */
+	ret = hns_mdio_wait_ready(bus);
+	if (ret) {
+		dev_err(&bus->dev, "MDIO bus is busy\n");
+		return ret;
+	}
+
+	if (!is_c45) {
+		cmd_reg_cfg = reg;
+		op = MDIO_C22_WRITE;
+	} else {
+		/* config the cmd-reg to write addr*/
+		MDIO_SET_REG_FIELD(mdio_dev, MDIO_ADDR_REG, MDIO_ADDR_DATA_M,
+				   MDIO_ADDR_DATA_S, reg);
+
+		hns_mdio_cmd_write(mdio_dev, is_c45,
+				   MDIO_C45_WRITE_ADDR, phy_id, devad);
+
+		/* check for read or write opt is finished */
+		ret = hns_mdio_wait_ready(bus);
+		if (ret) {
+			dev_err(&bus->dev, "MDIO bus is busy\n");
+			return ret;
+		}
+
+		/* config the data needed writing */
+		cmd_reg_cfg = devad;
+		op = MDIO_C45_WRITE_ADDR;
+	}
+
+	MDIO_SET_REG_FIELD(mdio_dev, MDIO_WDATA_REG, MDIO_WDATA_DATA_M,
+			   MDIO_WDATA_DATA_S, data);
+
+	hns_mdio_cmd_write(mdio_dev, is_c45, op, phy_id, cmd_reg_cfg);
+
+	return 0;
+}
+
+/**
+ * hns_mdio_read - access phy register
+ * @bus: mdio bus
+ * @phy_id: phy id
+ * @regnum: register num
+ * @value: register value
+ *
+ * Return phy register value
+ */
+static int hns_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
+{
+	int ret;
+	u16 reg_val = 0;
+	u8 devad = ((regnum >> 16) & 0x1f);
+	u8 is_c45 = !!(regnum & MII_ADDR_C45);
+	u16 reg = (u16)(regnum & 0xffff);
+	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
+
+	dev_dbg(&bus->dev, "mdio read %s,base is %p\n",
+		bus->id, mdio_dev->vbase);
+	dev_dbg(&bus->dev, "phy id=%d, is_c45=%d, devad=%d, reg=%#x!\n",
+		phy_id, is_c45, devad, reg);
+
+	/* Step 1: wait for ready */
+	ret = hns_mdio_wait_ready(bus);
+	if (ret) {
+		dev_err(&bus->dev, "MDIO bus is busy\n");
+		return ret;
+	}
+
+	if (!is_c45) {
+		hns_mdio_cmd_write(mdio_dev, is_c45,
+				   MDIO_C22_READ, phy_id, reg);
+	} else {
+		MDIO_SET_REG_FIELD(mdio_dev, MDIO_ADDR_REG, MDIO_ADDR_DATA_M,
+				   MDIO_ADDR_DATA_S, reg);
+
+		/* Step 2; config the cmd-reg to write addr*/
+		hns_mdio_cmd_write(mdio_dev, is_c45,
+				   MDIO_C45_WRITE_ADDR, phy_id, devad);
+
+		/* Step 3: check for read or write opt is finished */
+		ret = hns_mdio_wait_ready(bus);
+		if (ret) {
+			dev_err(&bus->dev, "MDIO bus is busy\n");
+			return ret;
+		}
+
+		hns_mdio_cmd_write(mdio_dev, is_c45,
+				   MDIO_C45_WRITE_ADDR, phy_id, devad);
+	}
+
+	/* Step 5: waitting for MDIO_COMMAND_REG 's mdio_start==0,*/
+	/* check for read or write opt is finished */
+	ret = hns_mdio_wait_ready(bus);
+	if (ret) {
+		dev_err(&bus->dev, "MDIO bus is busy\n");
+		return ret;
+	}
+
+	reg_val = MDIO_GET_REG_BIT(mdio_dev, MDIO_STA_REG, MDIO_STATE_STA_B);
+	if (reg_val) {
+		dev_err(&bus->dev, " ERROR! MDIO Read failed!\n");
+		return -EBUSY;
+	}
+
+	/* Step 6; get out data*/
+	reg_val = (u16)MDIO_GET_REG_FIELD(mdio_dev, MDIO_RDATA_REG,
+					  MDIO_RDATA_DATA_M, MDIO_RDATA_DATA_S);
+
+	return reg_val;
+}
+
+/**
+ * hns_mdio_reset - reset mdio bus
+ * @bus: mdio bus
+ *
+ * Return 0 on success, negative on failure
+ */
+static int hns_mdio_reset(struct mii_bus *bus)
+{
+	struct hns_mdio_device *mdio_dev = (struct hns_mdio_device *)bus->priv;
+	int ret;
+
+	if (!mdio_dev->sys_vbase) {
+		dev_err(&bus->dev, "mdio sys ctl reg has not maped\n");
+		return -ENODEV;
+	}
+
+	/*1. reset req, and read reset st check*/
+	ret = mdio_sc_cfg_reg_write(mdio_dev, MDIO_SC_RESET_REQ, 0x1,
+				    MDIO_SC_RESET_ST, 0x1,
+				    MDIO_CHECK_SET_ST);
+	if (ret) {
+		dev_err(&bus->dev, "MDIO reset fail\n");
+		return ret;
+	}
+
+	/*2. dis clk, and read clk st check*/
+	ret = mdio_sc_cfg_reg_write(mdio_dev, MDIO_SC_CLK_DIS,
+				    0x1, MDIO_SC_CLK_ST, 0x1,
+				    MDIO_CHECK_CLR_ST);
+	if (ret) {
+		dev_err(&bus->dev, "MDIO dis clk fail\n");
+		return ret;
+	}
+
+	/*3. reset dreq, and read reset st check*/
+	ret = mdio_sc_cfg_reg_write(mdio_dev, MDIO_SC_RESET_DREQ, 0x1,
+				    MDIO_SC_RESET_ST, 0x1,
+				    MDIO_CHECK_CLR_ST);
+	if (ret) {
+		dev_err(&bus->dev, "MDIO dis clk fail\n");
+		return ret;
+	}
+
+	/*4. en clk, and read clk st check*/
+	ret = mdio_sc_cfg_reg_write(mdio_dev, MDIO_SC_CLK_EN,
+				    0x1, MDIO_SC_CLK_ST, 0x1,
+				    MDIO_CHECK_SET_ST);
+	if (ret)
+		dev_err(&bus->dev, "MDIO en clk fail\n");
+
+	return ret;
+}
+
+/**
+ * hns_mdio_bus_name - get mdio bus name
+ * @name: mdio bus name
+ * @np: mdio device node pointer
+ */
+static void hns_mdio_bus_name(char *name, struct device_node *np)
+{
+	const u32 *addr;
+	u64 taddr = OF_BAD_ADDR;
+
+	addr = of_get_address(np, 0, NULL, NULL);
+	if (addr)
+		taddr = of_translate_address(np, addr);
+
+	snprintf(name, MII_BUS_ID_SIZE, "%s@%llx", np->name,
+		 (unsigned long long)taddr);
+}
+
+/**
+ * hns_mdio_probe - probe mdio device
+ * @pdev: mdio platform device
+ *
+ * Return 0 on success, negative on failure
+ */
+static int hns_mdio_probe(struct platform_device *pdev)
+{
+	struct device_node *np;
+	struct hns_mdio_device *mdio_dev;
+	struct mii_bus *new_bus;
+	struct resource *res;
+	int ret;
+
+	if (!pdev) {
+		dev_err(NULL, "pdev is NULL!\r\n");
+		return -ENODEV;
+	}
+	np = pdev->dev.of_node;
+	mdio_dev = devm_kzalloc(&pdev->dev, sizeof(*mdio_dev), GFP_KERNEL);
+	if (!mdio_dev)
+		return -ENOMEM;
+
+	new_bus = devm_mdiobus_alloc(&pdev->dev);
+	if (!new_bus) {
+		dev_err(&pdev->dev, "mdiobus_alloc fail!\n");
+		return -ENOMEM;
+	}
+
+	new_bus->name = MDIO_BUS_NAME;
+	new_bus->read = hns_mdio_read;
+	new_bus->write = hns_mdio_write;
+	new_bus->reset = hns_mdio_reset;
+	new_bus->priv = mdio_dev;
+	hns_mdio_bus_name(new_bus->id, np);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mdio_dev->vbase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(mdio_dev->vbase)) {
+		ret = PTR_ERR(mdio_dev->vbase);
+		return ret;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	mdio_dev->sys_vbase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(mdio_dev->sys_vbase)) {
+		ret = PTR_ERR(mdio_dev->sys_vbase);
+		return ret;
+	}
+
+	new_bus->irq = devm_kcalloc(&pdev->dev, PHY_MAX_ADDR,
+				    sizeof(int), GFP_KERNEL);
+	if (!new_bus->irq)
+		return -ENOMEM;
+
+	new_bus->parent = &pdev->dev;
+	platform_set_drvdata(pdev, new_bus);
+
+	ret = of_mdiobus_register(new_bus, np);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot register as MDIO bus!\n");
+		platform_set_drvdata(pdev, NULL);
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * hns_mdio_remove - remove mdio device
+ * @pdev: mdio platform device
+ *
+ * Return 0 on success, negative on failure
+ */
+static int hns_mdio_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus;
+
+	bus = platform_get_drvdata(pdev);
+
+	mdiobus_unregister(bus);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static const struct of_device_id hns_mdio_match[] = {
+	{.compatible = "hisilicon,mdio"},
+	{.compatible = "hisilicon,hns-mdio"},
+	{}
+};
+
+static struct platform_driver hns_mdio_driver = {
+	.probe = hns_mdio_probe,
+	.remove = hns_mdio_remove,
+	.driver = {
+		   .name = MDIO_DRV_NAME,
+		   .of_match_table = hns_mdio_match,
+		   },
+};
+
+module_platform_driver(hns_mdio_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Huawei Tech. Co., Ltd.");
+MODULE_DESCRIPTION("Hisilicon HNS MDIO driver");
+MODULE_ALIAS("platform:" MDIO_DRV_NAME);