drivers/net/phy/mdio-xgene.c - linux - Git at Google

 /* Applied Micro X-Gene SoC MDIO Driver
  *
  * Copyright (c) 2016, Applied Micro Circuits Corporation
  * Author: Iyappan Subramanian <isubramanian@apm.com>
  *
  * 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.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/acpi.h>
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/efi.h>
 #include <linux/if_vlan.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/of_net.h>
 #include <linux/of_mdio.h>
 #include <linux/prefetch.h>
 #include <linux/phy.h>
 #include <net/ip.h>
 #include "mdio-xgene.h"

 static bool xgene_mdio_status;

 static u32 xgene_enet_rd_mac(void __iomem *base_addr, u32 rd_addr)
 {
 	void __iomem *addr, *rd, *cmd, *cmd_done;
 	u32 done, rd_data = BUSY_MASK;
 	u8 wait = 10;

 	addr = base_addr + MAC_ADDR_REG_OFFSET;
 	rd = base_addr + MAC_READ_REG_OFFSET;
 	cmd = base_addr + MAC_COMMAND_REG_OFFSET;
 	cmd_done = base_addr + MAC_COMMAND_DONE_REG_OFFSET;

 	iowrite32(rd_addr, addr);
 	iowrite32(XGENE_ENET_RD_CMD, cmd);

 	while (wait--) {
 		done = ioread32(cmd_done);
 		if (done)
 			break;
 		udelay(1);
 	}

 	if (!done)
 		return rd_data;

 	rd_data = ioread32(rd);
 	iowrite32(0, cmd);

 	return rd_data;
 }

 static void xgene_enet_wr_mac(void __iomem *base_addr, u32 wr_addr, u32 wr_data)
 {
 	void __iomem *addr, *wr, *cmd, *cmd_done;
 	u8 wait = 10;
 	u32 done;

 	addr = base_addr + MAC_ADDR_REG_OFFSET;
 	wr = base_addr + MAC_WRITE_REG_OFFSET;
 	cmd = base_addr + MAC_COMMAND_REG_OFFSET;
 	cmd_done = base_addr + MAC_COMMAND_DONE_REG_OFFSET;

 	iowrite32(wr_addr, addr);
 	iowrite32(wr_data, wr);
 	iowrite32(XGENE_ENET_WR_CMD, cmd);

 	while (wait--) {
 		done = ioread32(cmd_done);
 		if (done)
 			break;
 		udelay(1);
 	}

 	if (!done)
 		pr_err("MCX mac write failed, addr: 0x%04x\n", wr_addr);

 	iowrite32(0, cmd);
 }

 int xgene_mdio_rgmii_read(struct mii_bus *bus, int phy_id, int reg)
 {
 	void __iomem *addr = (void __iomem *)bus->priv;
 	u32 data, done;
 	u8 wait = 10;

 	data = SET_VAL(PHY_ADDR, phy_id) | SET_VAL(REG_ADDR, reg);
 	xgene_enet_wr_mac(addr, MII_MGMT_ADDRESS_ADDR, data);
 	xgene_enet_wr_mac(addr, MII_MGMT_COMMAND_ADDR, READ_CYCLE_MASK);
 	do {
 		usleep_range(5, 10);
 		done = xgene_enet_rd_mac(addr, MII_MGMT_INDICATORS_ADDR);
 	} while ((done & BUSY_MASK) && wait--);

 	if (done & BUSY_MASK) {
 		dev_err(&bus->dev, "MII_MGMT read failed\n");
 		return -EBUSY;
 	}

 	data = xgene_enet_rd_mac(addr, MII_MGMT_STATUS_ADDR);
 	xgene_enet_wr_mac(addr, MII_MGMT_COMMAND_ADDR, 0);

 	return data;
 }
 EXPORT_SYMBOL(xgene_mdio_rgmii_read);

 int xgene_mdio_rgmii_write(struct mii_bus *bus, int phy_id, int reg, u16 data)
 {
 	void __iomem *addr = (void __iomem *)bus->priv;
 	u32 val, done;
 	u8 wait = 10;

 	val = SET_VAL(PHY_ADDR, phy_id) | SET_VAL(REG_ADDR, reg);
 	xgene_enet_wr_mac(addr, MII_MGMT_ADDRESS_ADDR, val);

 	xgene_enet_wr_mac(addr, MII_MGMT_CONTROL_ADDR, data);
 	do {
 		usleep_range(5, 10);
 		done = xgene_enet_rd_mac(addr, MII_MGMT_INDICATORS_ADDR);
 	} while ((done & BUSY_MASK) && wait--);

 	if (done & BUSY_MASK) {
 		dev_err(&bus->dev, "MII_MGMT write failed\n");
 		return -EBUSY;
 	}

 	return 0;
 }
 EXPORT_SYMBOL(xgene_mdio_rgmii_write);

 static u32 xgene_menet_rd_diag_csr(struct xgene_mdio_pdata *pdata, u32 offset)
 {
 	return ioread32(pdata->diag_csr_addr + offset);
 }

 static void xgene_menet_wr_diag_csr(struct xgene_mdio_pdata *pdata,
 				    u32 offset, u32 val)
 {
 	iowrite32(val, pdata->diag_csr_addr + offset);
 }

 static int xgene_enet_ecc_init(struct xgene_mdio_pdata *pdata)
 {
 	u32 data;
 	u8 wait = 10;

 	xgene_menet_wr_diag_csr(pdata, MENET_CFG_MEM_RAM_SHUTDOWN_ADDR, 0x0);
 	do {
 		usleep_range(100, 110);
 		data = xgene_menet_rd_diag_csr(pdata, MENET_BLOCK_MEM_RDY_ADDR);
 	} while ((data != 0xffffffff) && wait--);

 	if (data != 0xffffffff) {
 		dev_err(pdata->dev, "Failed to release memory from shutdown\n");
 		return -ENODEV;
 	}

 	return 0;
 }

 static void xgene_gmac_reset(struct xgene_mdio_pdata *pdata)
 {
 	xgene_enet_wr_mac(pdata->mac_csr_addr, MAC_CONFIG_1_ADDR, SOFT_RESET);
 	xgene_enet_wr_mac(pdata->mac_csr_addr, MAC_CONFIG_1_ADDR, 0);
 }

 static int xgene_mdio_reset(struct xgene_mdio_pdata *pdata)
 {
 	int ret;

 	if (pdata->dev->of_node) {
 		clk_prepare_enable(pdata->clk);
 		udelay(5);
 		clk_disable_unprepare(pdata->clk);
 		udelay(5);
 		clk_prepare_enable(pdata->clk);
 		udelay(5);
 	} else {
 #ifdef CONFIG_ACPI
 		acpi_evaluate_object(ACPI_HANDLE(pdata->dev),
 				     "_RST", NULL, NULL);
 #endif
 	}

 	ret = xgene_enet_ecc_init(pdata);
 	if (ret)
 		return ret;
 	xgene_gmac_reset(pdata);

 	return 0;
 }

 static void xgene_enet_rd_mdio_csr(void __iomem *base_addr,
 				   u32 offset, u32 *val)
 {
 	void __iomem *addr = base_addr  + offset;

 	*val = ioread32(addr);
 }

 static void xgene_enet_wr_mdio_csr(void __iomem *base_addr,
 				   u32 offset, u32 val)
 {
 	void __iomem *addr = base_addr  + offset;

 	iowrite32(val, addr);
 }

 static int xgene_xfi_mdio_write(struct mii_bus *bus, int phy_id,
 				int reg, u16 data)
 {
 	void __iomem *addr = (void __iomem *)bus->priv;
 	int timeout = 100;
 	u32 status, val;

 	val = SET_VAL(HSTPHYADX, phy_id) | SET_VAL(HSTREGADX, reg) |
 	      SET_VAL(HSTMIIMWRDAT, data);
 	xgene_enet_wr_mdio_csr(addr, MIIM_FIELD_ADDR, data);

 	val = HSTLDCMD | SET_VAL(HSTMIIMCMD, MIIM_CMD_LEGACY_WRITE);
 	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, val);

 	do {
 		usleep_range(5, 10);
 		xgene_enet_rd_mdio_csr(addr, MIIM_INDICATOR_ADDR, &status);
 	} while ((status & BUSY_MASK) && timeout--);

 	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, 0);

 	return 0;
 }

 static int xgene_xfi_mdio_read(struct mii_bus *bus, int phy_id, int reg)
 {
 	void __iomem *addr = (void __iomem *)bus->priv;
 	u32 data, status, val;
 	int timeout = 100;

 	val = SET_VAL(HSTPHYADX, phy_id) | SET_VAL(HSTREGADX, reg);
 	xgene_enet_wr_mdio_csr(addr, MIIM_FIELD_ADDR, val);

 	val = HSTLDCMD | SET_VAL(HSTMIIMCMD, MIIM_CMD_LEGACY_READ);
 	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, val);

 	do {
 		usleep_range(5, 10);
 		xgene_enet_rd_mdio_csr(addr, MIIM_INDICATOR_ADDR, &status);
 	} while ((status & BUSY_MASK) && timeout--);

 	if (status & BUSY_MASK) {
 		pr_err("XGENET_MII_MGMT write failed\n");
 		return -EBUSY;
 	}

 	xgene_enet_rd_mdio_csr(addr, MIIMRD_FIELD_ADDR, &data);
 	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, 0);

 	return data;
 }

 struct phy_device *xgene_enet_phy_register(struct mii_bus *bus, int phy_addr)
 {
 	struct phy_device *phy_dev;

 	phy_dev = get_phy_device(bus, phy_addr, false);
 	if (!phy_dev || IS_ERR(phy_dev))
 		return NULL;

 	if (phy_device_register(phy_dev))
 		phy_device_free(phy_dev);

 	return phy_dev;
 }
 EXPORT_SYMBOL(xgene_enet_phy_register);

 #ifdef CONFIG_ACPI
 static acpi_status acpi_register_phy(acpi_handle handle, u32 lvl,
 				     void *context, void **ret)
 {
 	struct mii_bus *mdio = context;
 	struct acpi_device *adev;
 	struct phy_device *phy_dev;
 	const union acpi_object *obj;
 	u32 phy_addr;

 	if (acpi_bus_get_device(handle, &adev))
 		return AE_OK;

 	if (acpi_dev_get_property(adev, "phy-channel", ACPI_TYPE_INTEGER, &obj))
 		return AE_OK;
 	phy_addr = obj->integer.value;

 	phy_dev = xgene_enet_phy_register(mdio, phy_addr);
 	adev->driver_data = phy_dev;

 	return AE_OK;
 }
 #endif

 static const struct of_device_id xgene_mdio_of_match[] = {
 	{
 		.compatible = "apm,xgene-mdio-rgmii",
 		.data = (void *)XGENE_MDIO_RGMII
 	},
 	{
 		.compatible = "apm,xgene-mdio-xfi",
 		.data = (void *)XGENE_MDIO_XFI
 	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, xgene_mdio_of_match);

 #ifdef CONFIG_ACPI
 static const struct acpi_device_id xgene_mdio_acpi_match[] = {
 	{ "APMC0D65", XGENE_MDIO_RGMII },
 	{ "APMC0D66", XGENE_MDIO_XFI },
 	{ }
 };

 MODULE_DEVICE_TABLE(acpi, xgene_mdio_acpi_match);
 #endif


 static int xgene_mdio_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct mii_bus *mdio_bus;
 	const struct of_device_id *of_id;
 	struct resource *res;
 	struct xgene_mdio_pdata *pdata;
 	void __iomem *csr_base;
 	int mdio_id = 0, ret = 0;

 	of_id = of_match_device(xgene_mdio_of_match, &pdev->dev);
 	if (of_id) {
 		mdio_id = (enum xgene_mdio_id)of_id->data;
 	} else {
 #ifdef CONFIG_ACPI
 		const struct acpi_device_id *acpi_id;

 		acpi_id = acpi_match_device(xgene_mdio_acpi_match, &pdev->dev);
 		if (acpi_id)
 			mdio_id = (enum xgene_mdio_id)acpi_id->driver_data;
 #endif
 	}

 	if (!mdio_id)
 		return -ENODEV;

 	pdata = devm_kzalloc(dev, sizeof(struct xgene_mdio_pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
 	pdata->mdio_id = mdio_id;
 	pdata->dev = dev;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	csr_base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(csr_base))
 		return PTR_ERR(csr_base);
 	pdata->mac_csr_addr = csr_base;
 	pdata->mdio_csr_addr = csr_base + BLOCK_XG_MDIO_CSR_OFFSET;
 	pdata->diag_csr_addr = csr_base + BLOCK_DIAG_CSR_OFFSET;

 	if (dev->of_node) {
 		pdata->clk = devm_clk_get(dev, NULL);
 		if (IS_ERR(pdata->clk)) {
 			dev_err(dev, "Unable to retrieve clk\n");
 			return PTR_ERR(pdata->clk);
 		}
 	}

 	ret = xgene_mdio_reset(pdata);
 	if (ret)
 		return ret;

 	mdio_bus = mdiobus_alloc();
 	if (!mdio_bus)
 		return -ENOMEM;

 	mdio_bus->name = "APM X-Gene MDIO bus";

 	if (mdio_id == XGENE_MDIO_RGMII) {
 		mdio_bus->read = xgene_mdio_rgmii_read;
 		mdio_bus->write = xgene_mdio_rgmii_write;
 		mdio_bus->priv = (void __force *)pdata->mac_csr_addr;
 		snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "%s",
 			 "xgene-mii-rgmii");
 	} else {
 		mdio_bus->read = xgene_xfi_mdio_read;
 		mdio_bus->write = xgene_xfi_mdio_write;
 		mdio_bus->priv = (void __force *)pdata->mdio_csr_addr;
 		snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "%s",
 			 "xgene-mii-xfi");
 	}

 	mdio_bus->parent = dev;
 	platform_set_drvdata(pdev, pdata);

 	if (dev->of_node) {
 		ret = of_mdiobus_register(mdio_bus, dev->of_node);
 	} else {
 #ifdef CONFIG_ACPI
 		/* Mask out all PHYs from auto probing. */
 		mdio_bus->phy_mask = ~0;
 		ret = mdiobus_register(mdio_bus);
 		if (ret)
 			goto out;

 		acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_HANDLE(dev), 1,
 				    acpi_register_phy, NULL, mdio_bus, NULL);
 #endif
 	}

 	if (ret)
 		goto out;

 	pdata->mdio_bus = mdio_bus;
 	xgene_mdio_status = true;

 	return 0;

 out:
 	mdiobus_free(mdio_bus);

 	return ret;
 }

 static int xgene_mdio_remove(struct platform_device *pdev)
 {
 	struct xgene_mdio_pdata *pdata = platform_get_drvdata(pdev);
 	struct mii_bus *mdio_bus = pdata->mdio_bus;
 	struct device *dev = &pdev->dev;

 	mdiobus_unregister(mdio_bus);
 	mdiobus_free(mdio_bus);

 	if (dev->of_node)
 		clk_disable_unprepare(pdata->clk);

 	return 0;
 }

 static struct platform_driver xgene_mdio_driver = {
 	.driver = {
 		.name = "xgene-mdio",
 		.of_match_table = of_match_ptr(xgene_mdio_of_match),
 		.acpi_match_table = ACPI_PTR(xgene_mdio_acpi_match),
 	},
 	.probe = xgene_mdio_probe,
 	.remove = xgene_mdio_remove,
 };

 module_platform_driver(xgene_mdio_driver);

 MODULE_DESCRIPTION("APM X-Gene SoC MDIO driver");
 MODULE_AUTHOR("Iyappan Subramanian <isubramanian@apm.com>");
 MODULE_LICENSE("GPL");
	/* Applied Micro X-Gene SoC MDIO Driver
	*
	* Copyright (c) 2016, Applied Micro Circuits Corporation
	* Author: Iyappan Subramanian <isubramanian@apm.com>
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/acpi.h>
	#include <linux/clk.h>
	#include <linux/device.h>
	#include <linux/efi.h>
	#include <linux/if_vlan.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/of_platform.h>
	#include <linux/of_net.h>
	#include <linux/of_mdio.h>
	#include <linux/prefetch.h>
	#include <linux/phy.h>
	#include <net/ip.h>
	#include "mdio-xgene.h"

	static bool xgene_mdio_status;

	static u32 xgene_enet_rd_mac(void __iomem *base_addr, u32 rd_addr)
	{
	void __iomem addr, rd, cmd, cmd_done;
	u32 done, rd_data = BUSY_MASK;
	u8 wait = 10;

	addr = base_addr + MAC_ADDR_REG_OFFSET;
	rd = base_addr + MAC_READ_REG_OFFSET;
	cmd = base_addr + MAC_COMMAND_REG_OFFSET;
	cmd_done = base_addr + MAC_COMMAND_DONE_REG_OFFSET;

	iowrite32(rd_addr, addr);
	iowrite32(XGENE_ENET_RD_CMD, cmd);

	while (wait--) {
	done = ioread32(cmd_done);
	if (done)
	break;
	udelay(1);
	}

	if (!done)
	return rd_data;

	rd_data = ioread32(rd);
	iowrite32(0, cmd);

	return rd_data;
	}

	static void xgene_enet_wr_mac(void __iomem *base_addr, u32 wr_addr, u32 wr_data)
	{
	void __iomem addr, wr, cmd, cmd_done;
	u8 wait = 10;
	u32 done;

	addr = base_addr + MAC_ADDR_REG_OFFSET;
	wr = base_addr + MAC_WRITE_REG_OFFSET;
	cmd = base_addr + MAC_COMMAND_REG_OFFSET;
	cmd_done = base_addr + MAC_COMMAND_DONE_REG_OFFSET;

	iowrite32(wr_addr, addr);
	iowrite32(wr_data, wr);
	iowrite32(XGENE_ENET_WR_CMD, cmd);

	while (wait--) {
	done = ioread32(cmd_done);
	if (done)
	break;
	udelay(1);
	}

	if (!done)
	pr_err("MCX mac write failed, addr: 0x%04x\n", wr_addr);

	iowrite32(0, cmd);
	}

	int xgene_mdio_rgmii_read(struct mii_bus *bus, int phy_id, int reg)
	{
	void __iomem addr = (void __iomem )bus->priv;
	u32 data, done;
	u8 wait = 10;

	data = SET_VAL(PHY_ADDR, phy_id) \| SET_VAL(REG_ADDR, reg);
	xgene_enet_wr_mac(addr, MII_MGMT_ADDRESS_ADDR, data);
	xgene_enet_wr_mac(addr, MII_MGMT_COMMAND_ADDR, READ_CYCLE_MASK);
	do {
	usleep_range(5, 10);
	done = xgene_enet_rd_mac(addr, MII_MGMT_INDICATORS_ADDR);
	} while ((done & BUSY_MASK) && wait--);

	if (done & BUSY_MASK) {
	dev_err(&bus->dev, "MII_MGMT read failed\n");
	return -EBUSY;
	}

	data = xgene_enet_rd_mac(addr, MII_MGMT_STATUS_ADDR);
	xgene_enet_wr_mac(addr, MII_MGMT_COMMAND_ADDR, 0);

	return data;
	}
	EXPORT_SYMBOL(xgene_mdio_rgmii_read);

	int xgene_mdio_rgmii_write(struct mii_bus *bus, int phy_id, int reg, u16 data)
	{
	void __iomem addr = (void __iomem )bus->priv;
	u32 val, done;
	u8 wait = 10;

	val = SET_VAL(PHY_ADDR, phy_id) \| SET_VAL(REG_ADDR, reg);
	xgene_enet_wr_mac(addr, MII_MGMT_ADDRESS_ADDR, val);

	xgene_enet_wr_mac(addr, MII_MGMT_CONTROL_ADDR, data);
	do {
	usleep_range(5, 10);
	done = xgene_enet_rd_mac(addr, MII_MGMT_INDICATORS_ADDR);
	} while ((done & BUSY_MASK) && wait--);

	if (done & BUSY_MASK) {
	dev_err(&bus->dev, "MII_MGMT write failed\n");
	return -EBUSY;
	}

	return 0;
	}
	EXPORT_SYMBOL(xgene_mdio_rgmii_write);

	static u32 xgene_menet_rd_diag_csr(struct xgene_mdio_pdata *pdata, u32 offset)
	{
	return ioread32(pdata->diag_csr_addr + offset);
	}

	static void xgene_menet_wr_diag_csr(struct xgene_mdio_pdata *pdata,
	u32 offset, u32 val)
	{
	iowrite32(val, pdata->diag_csr_addr + offset);
	}

	static int xgene_enet_ecc_init(struct xgene_mdio_pdata *pdata)
	{
	u32 data;
	u8 wait = 10;

	xgene_menet_wr_diag_csr(pdata, MENET_CFG_MEM_RAM_SHUTDOWN_ADDR, 0x0);
	do {
	usleep_range(100, 110);
	data = xgene_menet_rd_diag_csr(pdata, MENET_BLOCK_MEM_RDY_ADDR);
	} while ((data != 0xffffffff) && wait--);

	if (data != 0xffffffff) {
	dev_err(pdata->dev, "Failed to release memory from shutdown\n");
	return -ENODEV;
	}

	return 0;
	}

	static void xgene_gmac_reset(struct xgene_mdio_pdata *pdata)
	{
	xgene_enet_wr_mac(pdata->mac_csr_addr, MAC_CONFIG_1_ADDR, SOFT_RESET);
	xgene_enet_wr_mac(pdata->mac_csr_addr, MAC_CONFIG_1_ADDR, 0);
	}

	static int xgene_mdio_reset(struct xgene_mdio_pdata *pdata)
	{
	int ret;

	if (pdata->dev->of_node) {
	clk_prepare_enable(pdata->clk);
	udelay(5);
	clk_disable_unprepare(pdata->clk);
	udelay(5);
	clk_prepare_enable(pdata->clk);
	udelay(5);
	} else {
	#ifdef CONFIG_ACPI
	acpi_evaluate_object(ACPI_HANDLE(pdata->dev),
	"_RST", NULL, NULL);
	#endif
	}

	ret = xgene_enet_ecc_init(pdata);
	if (ret)
	return ret;
	xgene_gmac_reset(pdata);

	return 0;
	}

	static void xgene_enet_rd_mdio_csr(void __iomem *base_addr,
	u32 offset, u32 *val)
	{
	void __iomem *addr = base_addr + offset;

	*val = ioread32(addr);
	}

	static void xgene_enet_wr_mdio_csr(void __iomem *base_addr,
	u32 offset, u32 val)
	{
	void __iomem *addr = base_addr + offset;

	iowrite32(val, addr);
	}

	static int xgene_xfi_mdio_write(struct mii_bus *bus, int phy_id,
	int reg, u16 data)
	{
	void __iomem addr = (void __iomem )bus->priv;
	int timeout = 100;
	u32 status, val;

	val = SET_VAL(HSTPHYADX, phy_id) \| SET_VAL(HSTREGADX, reg) \|
	SET_VAL(HSTMIIMWRDAT, data);
	xgene_enet_wr_mdio_csr(addr, MIIM_FIELD_ADDR, data);

	val = HSTLDCMD \| SET_VAL(HSTMIIMCMD, MIIM_CMD_LEGACY_WRITE);
	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, val);

	do {
	usleep_range(5, 10);
	xgene_enet_rd_mdio_csr(addr, MIIM_INDICATOR_ADDR, &status);
	} while ((status & BUSY_MASK) && timeout--);

	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, 0);

	return 0;
	}

	static int xgene_xfi_mdio_read(struct mii_bus *bus, int phy_id, int reg)
	{
	void __iomem addr = (void __iomem )bus->priv;
	u32 data, status, val;
	int timeout = 100;

	val = SET_VAL(HSTPHYADX, phy_id) \| SET_VAL(HSTREGADX, reg);
	xgene_enet_wr_mdio_csr(addr, MIIM_FIELD_ADDR, val);

	val = HSTLDCMD \| SET_VAL(HSTMIIMCMD, MIIM_CMD_LEGACY_READ);
	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, val);

	do {
	usleep_range(5, 10);
	xgene_enet_rd_mdio_csr(addr, MIIM_INDICATOR_ADDR, &status);
	} while ((status & BUSY_MASK) && timeout--);

	if (status & BUSY_MASK) {
	pr_err("XGENET_MII_MGMT write failed\n");
	return -EBUSY;
	}

	xgene_enet_rd_mdio_csr(addr, MIIMRD_FIELD_ADDR, &data);
	xgene_enet_wr_mdio_csr(addr, MIIM_COMMAND_ADDR, 0);

	return data;
	}

	struct phy_device xgene_enet_phy_register(struct mii_bus bus, int phy_addr)
	{
	struct phy_device *phy_dev;

	phy_dev = get_phy_device(bus, phy_addr, false);
	if (!phy_dev \|\| IS_ERR(phy_dev))
	return NULL;

	if (phy_device_register(phy_dev))
	phy_device_free(phy_dev);

	return phy_dev;
	}
	EXPORT_SYMBOL(xgene_enet_phy_register);

	#ifdef CONFIG_ACPI
	static acpi_status acpi_register_phy(acpi_handle handle, u32 lvl,
	void context, void *ret)
	{
	struct mii_bus *mdio = context;
	struct acpi_device *adev;
	struct phy_device *phy_dev;
	const union acpi_object *obj;
	u32 phy_addr;

	if (acpi_bus_get_device(handle, &adev))
	return AE_OK;

	if (acpi_dev_get_property(adev, "phy-channel", ACPI_TYPE_INTEGER, &obj))
	return AE_OK;
	phy_addr = obj->integer.value;

	phy_dev = xgene_enet_phy_register(mdio, phy_addr);
	adev->driver_data = phy_dev;

	return AE_OK;
	}
	#endif

	static const struct of_device_id xgene_mdio_of_match[] = {
	{
	.compatible = "apm,xgene-mdio-rgmii",
	.data = (void *)XGENE_MDIO_RGMII
	},
	{
	.compatible = "apm,xgene-mdio-xfi",
	.data = (void *)XGENE_MDIO_XFI
	},
	{},
	};
	MODULE_DEVICE_TABLE(of, xgene_mdio_of_match);

	#ifdef CONFIG_ACPI
	static const struct acpi_device_id xgene_mdio_acpi_match[] = {
	{ "APMC0D65", XGENE_MDIO_RGMII },
	{ "APMC0D66", XGENE_MDIO_XFI },
	{ }
	};

	MODULE_DEVICE_TABLE(acpi, xgene_mdio_acpi_match);
	#endif


	static int xgene_mdio_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct mii_bus *mdio_bus;
	const struct of_device_id *of_id;
	struct resource *res;
	struct xgene_mdio_pdata *pdata;
	void __iomem *csr_base;
	int mdio_id = 0, ret = 0;

	of_id = of_match_device(xgene_mdio_of_match, &pdev->dev);
	if (of_id) {
	mdio_id = (enum xgene_mdio_id)of_id->data;
	} else {
	#ifdef CONFIG_ACPI
	const struct acpi_device_id *acpi_id;

	acpi_id = acpi_match_device(xgene_mdio_acpi_match, &pdev->dev);
	if (acpi_id)
	mdio_id = (enum xgene_mdio_id)acpi_id->driver_data;
	#endif
	}

	if (!mdio_id)
	return -ENODEV;

	pdata = devm_kzalloc(dev, sizeof(struct xgene_mdio_pdata), GFP_KERNEL);
	if (!pdata)
	return -ENOMEM;
	pdata->mdio_id = mdio_id;
	pdata->dev = dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	csr_base = devm_ioremap_resource(dev, res);
	if (IS_ERR(csr_base))
	return PTR_ERR(csr_base);
	pdata->mac_csr_addr = csr_base;
	pdata->mdio_csr_addr = csr_base + BLOCK_XG_MDIO_CSR_OFFSET;
	pdata->diag_csr_addr = csr_base + BLOCK_DIAG_CSR_OFFSET;

	if (dev->of_node) {
	pdata->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(pdata->clk)) {
	dev_err(dev, "Unable to retrieve clk\n");
	return PTR_ERR(pdata->clk);
	}
	}

	ret = xgene_mdio_reset(pdata);
	if (ret)
	return ret;

	mdio_bus = mdiobus_alloc();
	if (!mdio_bus)
	return -ENOMEM;

	mdio_bus->name = "APM X-Gene MDIO bus";

	if (mdio_id == XGENE_MDIO_RGMII) {
	mdio_bus->read = xgene_mdio_rgmii_read;
	mdio_bus->write = xgene_mdio_rgmii_write;
	mdio_bus->priv = (void __force *)pdata->mac_csr_addr;
	snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "%s",
	"xgene-mii-rgmii");
	} else {
	mdio_bus->read = xgene_xfi_mdio_read;
	mdio_bus->write = xgene_xfi_mdio_write;
	mdio_bus->priv = (void __force *)pdata->mdio_csr_addr;
	snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "%s",
	"xgene-mii-xfi");
	}

	mdio_bus->parent = dev;
	platform_set_drvdata(pdev, pdata);

	if (dev->of_node) {
	ret = of_mdiobus_register(mdio_bus, dev->of_node);
	} else {
	#ifdef CONFIG_ACPI
	/* Mask out all PHYs from auto probing. */
	mdio_bus->phy_mask = ~0;
	ret = mdiobus_register(mdio_bus);
	if (ret)
	goto out;

	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_HANDLE(dev), 1,
	acpi_register_phy, NULL, mdio_bus, NULL);
	#endif
	}

	if (ret)
	goto out;

	pdata->mdio_bus = mdio_bus;
	xgene_mdio_status = true;

	return 0;

	out:
	mdiobus_free(mdio_bus);

	return ret;
	}

	static int xgene_mdio_remove(struct platform_device *pdev)
	{
	struct xgene_mdio_pdata *pdata = platform_get_drvdata(pdev);
	struct mii_bus *mdio_bus = pdata->mdio_bus;
	struct device *dev = &pdev->dev;

	mdiobus_unregister(mdio_bus);
	mdiobus_free(mdio_bus);

	if (dev->of_node)
	clk_disable_unprepare(pdata->clk);

	return 0;
	}

	static struct platform_driver xgene_mdio_driver = {
	.driver = {
	.name = "xgene-mdio",
	.of_match_table = of_match_ptr(xgene_mdio_of_match),
	.acpi_match_table = ACPI_PTR(xgene_mdio_acpi_match),
	},
	.probe = xgene_mdio_probe,
	.remove = xgene_mdio_remove,
	};

	module_platform_driver(xgene_mdio_driver);

	MODULE_DESCRIPTION("APM X-Gene SoC MDIO driver");
	MODULE_AUTHOR("Iyappan Subramanian <isubramanian@apm.com>");
	MODULE_LICENSE("GPL");