drivers/net/ethernet/marvell/mvmdio.c - linux - Git at Google

 /*
  * Driver for the MDIO interface of Marvell network interfaces.
  *
  * Since the MDIO interface of Marvell network interfaces is shared
  * between all network interfaces, having a single driver allows to
  * handle concurrent accesses properly (you may have four Ethernet
  * ports, but they in fact share the same SMI interface to access
  * the MDIO bus). This driver is currently used by the mvneta and
  * mv643xx_eth drivers.
  *
  * Copyright (C) 2012 Marvell
  *
  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  *
  * This file is licensed under the terms of the GNU General Public
  * License version 2. This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  */

 #include <linux/acpi.h>
 #include <linux/acpi_mdio.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/of_mdio.h>
 #include <linux/phy.h>
 #include <linux/platform_device.h>
 #include <linux/sched.h>
 #include <linux/wait.h>

 #define MVMDIO_SMI_DATA_SHIFT		0
 #define MVMDIO_SMI_PHY_ADDR_SHIFT	16
 #define MVMDIO_SMI_PHY_REG_SHIFT	21
 #define MVMDIO_SMI_READ_OPERATION	BIT(26)
 #define MVMDIO_SMI_WRITE_OPERATION	0
 #define MVMDIO_SMI_READ_VALID		BIT(27)
 #define MVMDIO_SMI_BUSY			BIT(28)
 #define MVMDIO_ERR_INT_CAUSE		0x007C
 #define  MVMDIO_ERR_INT_SMI_DONE	0x00000010
 #define MVMDIO_ERR_INT_MASK		0x0080

 #define MVMDIO_XSMI_MGNT_REG		0x0
 #define  MVMDIO_XSMI_PHYADDR_SHIFT	16
 #define  MVMDIO_XSMI_DEVADDR_SHIFT	21
 #define  MVMDIO_XSMI_WRITE_OPERATION	(0x5 << 26)
 #define  MVMDIO_XSMI_READ_OPERATION	(0x7 << 26)
 #define  MVMDIO_XSMI_READ_VALID		BIT(29)
 #define  MVMDIO_XSMI_BUSY		BIT(30)
 #define MVMDIO_XSMI_ADDR_REG		0x8

 #define MVMDIO_XSMI_CFG_REG		0xc
 #define  MVMDIO_XSMI_CLKDIV_MASK	0x3
 #define  MVMDIO_XSMI_CLKDIV_256		0x0
 #define  MVMDIO_XSMI_CLKDIV_64		0x1
 #define  MVMDIO_XSMI_CLKDIV_32		0x2
 #define  MVMDIO_XSMI_CLKDIV_8		0x3

 /*
  * SMI Timeout measurements:
  * - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
  * - Armada 370       (Globalscale Mirabox):   41us to 43us (Polled)
  */
 #define MVMDIO_SMI_TIMEOUT		1000 /* 1000us = 1ms */

 struct orion_mdio_dev {
 	void __iomem *regs;
 	struct clk *clk[4];
 	/*
 	 * If we have access to the error interrupt pin (which is
 	 * somewhat misnamed as it not only reflects internal errors
 	 * but also reflects SMI completion), use that to wait for
 	 * SMI access completion instead of polling the SMI busy bit.
 	 */
 	int err_interrupt;
 	wait_queue_head_t smi_busy_wait;
 };

 enum orion_mdio_bus_type {
 	BUS_TYPE_SMI,
 	BUS_TYPE_XSMI
 };

 struct orion_mdio_ops {
 	int (*is_done)(struct orion_mdio_dev *);
 };

 /* Wait for the SMI unit to be ready for another operation
  */
 static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops,
 				 struct mii_bus *bus)
 {
 	struct orion_mdio_dev *dev = bus->priv;
 	unsigned long timeout;
 	int done;

 	if (dev->err_interrupt <= 0) {
 		if (!read_poll_timeout_atomic(ops->is_done, done, done, 2,
 					      MVMDIO_SMI_TIMEOUT, false, dev))
 			return 0;
 	} else {
 		/* wait_event_timeout does not guarantee a delay of at
 		 * least one whole jiffy, so timeout must be no less
 		 * than two.
 		 */
 		timeout = max(usecs_to_jiffies(MVMDIO_SMI_TIMEOUT), 2);

 		if (wait_event_timeout(dev->smi_busy_wait,
 				       ops->is_done(dev), timeout))
 			return 0;
 	}

 	dev_err(bus->parent, "Timeout: SMI busy for too long\n");
 	return  -ETIMEDOUT;
 }

 static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
 {
 	return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
 }

 static const struct orion_mdio_ops orion_mdio_smi_ops = {
 	.is_done = orion_mdio_smi_is_done,
 };

 static int orion_mdio_smi_read(struct mii_bus *bus, int mii_id,
 			       int regnum)
 {
 	struct orion_mdio_dev *dev = bus->priv;
 	u32 val;
 	int ret;

 	ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
 	if (ret < 0)
 		return ret;

 	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
 		(regnum << MVMDIO_SMI_PHY_REG_SHIFT)  |
 		MVMDIO_SMI_READ_OPERATION),
 	       dev->regs);

 	ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
 	if (ret < 0)
 		return ret;

 	val = readl(dev->regs);
 	if (!(val & MVMDIO_SMI_READ_VALID)) {
 		dev_err(bus->parent, "SMI bus read not valid\n");
 		return -ENODEV;
 	}

 	return val & GENMASK(15, 0);
 }

 static int orion_mdio_smi_write(struct mii_bus *bus, int mii_id,
 				int regnum, u16 value)
 {
 	struct orion_mdio_dev *dev = bus->priv;
 	int ret;

 	ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
 	if (ret < 0)
 		return ret;

 	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
 		(regnum << MVMDIO_SMI_PHY_REG_SHIFT)  |
 		MVMDIO_SMI_WRITE_OPERATION            |
 		(value << MVMDIO_SMI_DATA_SHIFT)),
 	       dev->regs);

 	return 0;
 }

 static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev)
 {
 	return !(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & MVMDIO_XSMI_BUSY);
 }

 static const struct orion_mdio_ops orion_mdio_xsmi_ops = {
 	.is_done = orion_mdio_xsmi_is_done,
 };

 static int orion_mdio_xsmi_read_c45(struct mii_bus *bus, int mii_id,
 				    int dev_addr, int regnum)
 {
 	struct orion_mdio_dev *dev = bus->priv;
 	int ret;

 	ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
 	if (ret < 0)
 		return ret;

 	writel(regnum, dev->regs + MVMDIO_XSMI_ADDR_REG);
 	writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) |
 	       (dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) |
 	       MVMDIO_XSMI_READ_OPERATION,
 	       dev->regs + MVMDIO_XSMI_MGNT_REG);

 	ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
 	if (ret < 0)
 		return ret;

 	if (!(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) &
 	      MVMDIO_XSMI_READ_VALID)) {
 		dev_err(bus->parent, "XSMI bus read not valid\n");
 		return -ENODEV;
 	}

 	return readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & GENMASK(15, 0);
 }

 static int orion_mdio_xsmi_write_c45(struct mii_bus *bus, int mii_id,
 				     int dev_addr, int regnum, u16 value)
 {
 	struct orion_mdio_dev *dev = bus->priv;
 	int ret;

 	ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
 	if (ret < 0)
 		return ret;

 	writel(regnum, dev->regs + MVMDIO_XSMI_ADDR_REG);
 	writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) |
 	       (dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) |
 	       MVMDIO_XSMI_WRITE_OPERATION | value,
 	       dev->regs + MVMDIO_XSMI_MGNT_REG);

 	return 0;
 }

 static void orion_mdio_xsmi_set_mdc_freq(struct mii_bus *bus)
 {
 	struct orion_mdio_dev *dev = bus->priv;
 	struct clk *mg_core;
 	u32 div, freq, cfg;

 	if (device_property_read_u32(bus->parent, "clock-frequency", &freq))
 		return;

 	mg_core = of_clk_get_by_name(bus->parent->of_node, "mg_core_clk");
 	if (IS_ERR(mg_core)) {
 		dev_err(bus->parent,
 			"MG core clock unknown, not changing MDC frequency");
 		return;
 	}

 	div = clk_get_rate(mg_core) / (freq + 1) + 1;
 	clk_put(mg_core);

 	if (div <= 8)
 		div = MVMDIO_XSMI_CLKDIV_8;
 	else if (div <= 32)
 		div = MVMDIO_XSMI_CLKDIV_32;
 	else if (div <= 64)
 		div = MVMDIO_XSMI_CLKDIV_64;
 	else
 		div = MVMDIO_XSMI_CLKDIV_256;

 	cfg = readl(dev->regs + MVMDIO_XSMI_CFG_REG);
 	cfg &= ~MVMDIO_XSMI_CLKDIV_MASK;
 	cfg |= div;
 	writel(cfg, dev->regs + MVMDIO_XSMI_CFG_REG);
 }

 static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
 {
 	struct orion_mdio_dev *dev = dev_id;

 	if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
 			MVMDIO_ERR_INT_SMI_DONE) {
 		writel(~MVMDIO_ERR_INT_SMI_DONE,
 				dev->regs + MVMDIO_ERR_INT_CAUSE);
 		wake_up(&dev->smi_busy_wait);
 		return IRQ_HANDLED;
 	}

 	return IRQ_NONE;
 }

 static int orion_mdio_probe(struct platform_device *pdev)
 {
 	enum orion_mdio_bus_type type;
 	struct resource *r;
 	struct mii_bus *bus;
 	struct orion_mdio_dev *dev;
 	int i, ret;

 	type = (uintptr_t)device_get_match_data(&pdev->dev);

 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!r) {
 		dev_err(&pdev->dev, "No SMI register address given\n");
 		return -ENODEV;
 	}

 	bus = devm_mdiobus_alloc_size(&pdev->dev,
 				      sizeof(struct orion_mdio_dev));
 	if (!bus)
 		return -ENOMEM;

 	switch (type) {
 	case BUS_TYPE_SMI:
 		bus->read = orion_mdio_smi_read;
 		bus->write = orion_mdio_smi_write;
 		break;
 	case BUS_TYPE_XSMI:
 		bus->read_c45 = orion_mdio_xsmi_read_c45;
 		bus->write_c45 = orion_mdio_xsmi_write_c45;
 		break;
 	}

 	bus->name = "orion_mdio_bus";
 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
 		 dev_name(&pdev->dev));
 	bus->parent = &pdev->dev;

 	dev = bus->priv;
 	dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 	if (!dev->regs) {
 		dev_err(&pdev->dev, "Unable to remap SMI register\n");
 		return -ENODEV;
 	}

 	init_waitqueue_head(&dev->smi_busy_wait);

 	if (pdev->dev.of_node) {
 		for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
 			dev->clk[i] = of_clk_get(pdev->dev.of_node, i);
 			if (PTR_ERR(dev->clk[i]) == -EPROBE_DEFER) {
 				ret = -EPROBE_DEFER;
 				goto out_clk;
 			}
 			if (IS_ERR(dev->clk[i]))
 				break;
 			clk_prepare_enable(dev->clk[i]);
 		}

 		if (!IS_ERR(of_clk_get(pdev->dev.of_node,
 				       ARRAY_SIZE(dev->clk))))
 			dev_warn(&pdev->dev,
 				 "unsupported number of clocks, limiting to the first "
 				 __stringify(ARRAY_SIZE(dev->clk)) "\n");

 		if (type == BUS_TYPE_XSMI)
 			orion_mdio_xsmi_set_mdc_freq(bus);
 	} else {
 		dev->clk[0] = clk_get(&pdev->dev, NULL);
 		if (PTR_ERR(dev->clk[0]) == -EPROBE_DEFER) {
 			ret = -EPROBE_DEFER;
 			goto out_clk;
 		}
 		if (!IS_ERR(dev->clk[0]))
 			clk_prepare_enable(dev->clk[0]);
 	}


 	dev->err_interrupt = platform_get_irq_optional(pdev, 0);
 	if (dev->err_interrupt > 0 &&
 	    resource_size(r) < MVMDIO_ERR_INT_MASK + 4) {
 		dev_err(&pdev->dev,
 			"disabling interrupt, resource size is too small\n");
 		dev->err_interrupt = 0;
 	}
 	if (dev->err_interrupt > 0) {
 		ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
 					orion_mdio_err_irq,
 					IRQF_SHARED, pdev->name, dev);
 		if (ret)
 			goto out_mdio;

 		writel(MVMDIO_ERR_INT_SMI_DONE,
 			dev->regs + MVMDIO_ERR_INT_MASK);

 	} else if (dev->err_interrupt == -EPROBE_DEFER) {
 		ret = -EPROBE_DEFER;
 		goto out_mdio;
 	}

 	/* For the platforms not supporting DT/ACPI fall-back
 	 * to mdiobus_register via of_mdiobus_register.
 	 */
 	if (is_acpi_node(pdev->dev.fwnode))
 		ret = acpi_mdiobus_register(bus, pdev->dev.fwnode);
 	else
 		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:
 	if (dev->err_interrupt > 0)
 		writel(0, dev->regs + MVMDIO_ERR_INT_MASK);

 out_clk:
 	for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
 		if (IS_ERR(dev->clk[i]))
 			break;
 		clk_disable_unprepare(dev->clk[i]);
 		clk_put(dev->clk[i]);
 	}

 	return ret;
 }

 static void orion_mdio_remove(struct platform_device *pdev)
 {
 	struct mii_bus *bus = platform_get_drvdata(pdev);
 	struct orion_mdio_dev *dev = bus->priv;
 	int i;

 	if (dev->err_interrupt > 0)
 		writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
 	mdiobus_unregister(bus);

 	for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
 		if (IS_ERR(dev->clk[i]))
 			break;
 		clk_disable_unprepare(dev->clk[i]);
 		clk_put(dev->clk[i]);
 	}
 }

 static const struct of_device_id orion_mdio_match[] = {
 	{ .compatible = "marvell,orion-mdio", .data = (void *)BUS_TYPE_SMI },
 	{ .compatible = "marvell,xmdio", .data = (void *)BUS_TYPE_XSMI },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, orion_mdio_match);

 #ifdef CONFIG_ACPI
 static const struct acpi_device_id orion_mdio_acpi_match[] = {
 	{ "MRVL0100", BUS_TYPE_SMI },
 	{ "MRVL0101", BUS_TYPE_XSMI },
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, orion_mdio_acpi_match);
 #endif

 static struct platform_driver orion_mdio_driver = {
 	.probe = orion_mdio_probe,
 	.remove_new = orion_mdio_remove,
 	.driver = {
 		.name = "orion-mdio",
 		.of_match_table = orion_mdio_match,
 		.acpi_match_table = ACPI_PTR(orion_mdio_acpi_match),
 	},
 };

 module_platform_driver(orion_mdio_driver);

 MODULE_DESCRIPTION("Marvell MDIO interface driver");
 MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:orion-mdio");
	/*
	* Driver for the MDIO interface of Marvell network interfaces.
	*
	* Since the MDIO interface of Marvell network interfaces is shared
	* between all network interfaces, having a single driver allows to
	* handle concurrent accesses properly (you may have four Ethernet
	* ports, but they in fact share the same SMI interface to access
	* the MDIO bus). This driver is currently used by the mvneta and
	* mv643xx_eth drivers.
	*
	* Copyright (C) 2012 Marvell
	*
	* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
	*
	* This file is licensed under the terms of the GNU General Public
	* License version 2. This program is licensed "as is" without any
	* warranty of any kind, whether express or implied.
	*/

	#include <linux/acpi.h>
	#include <linux/acpi_mdio.h>
	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/iopoll.h>
	#include <linux/kernel.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/of_mdio.h>
	#include <linux/phy.h>
	#include <linux/platform_device.h>
	#include <linux/sched.h>
	#include <linux/wait.h>

	#define MVMDIO_SMI_DATA_SHIFT 0
	#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
	#define MVMDIO_SMI_PHY_REG_SHIFT 21
	#define MVMDIO_SMI_READ_OPERATION BIT(26)
	#define MVMDIO_SMI_WRITE_OPERATION 0
	#define MVMDIO_SMI_READ_VALID BIT(27)
	#define MVMDIO_SMI_BUSY BIT(28)
	#define MVMDIO_ERR_INT_CAUSE 0x007C
	#define MVMDIO_ERR_INT_SMI_DONE 0x00000010
	#define MVMDIO_ERR_INT_MASK 0x0080

	#define MVMDIO_XSMI_MGNT_REG 0x0
	#define MVMDIO_XSMI_PHYADDR_SHIFT 16
	#define MVMDIO_XSMI_DEVADDR_SHIFT 21
	#define MVMDIO_XSMI_WRITE_OPERATION (0x5 << 26)
	#define MVMDIO_XSMI_READ_OPERATION (0x7 << 26)
	#define MVMDIO_XSMI_READ_VALID BIT(29)
	#define MVMDIO_XSMI_BUSY BIT(30)
	#define MVMDIO_XSMI_ADDR_REG 0x8

	#define MVMDIO_XSMI_CFG_REG 0xc
	#define MVMDIO_XSMI_CLKDIV_MASK 0x3
	#define MVMDIO_XSMI_CLKDIV_256 0x0
	#define MVMDIO_XSMI_CLKDIV_64 0x1
	#define MVMDIO_XSMI_CLKDIV_32 0x2
	#define MVMDIO_XSMI_CLKDIV_8 0x3

	/*
	* SMI Timeout measurements:
	* - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
	* - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled)
	*/
	#define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */

	struct orion_mdio_dev {
	void __iomem *regs;
	struct clk *clk[4];
	/*
	* If we have access to the error interrupt pin (which is
	* somewhat misnamed as it not only reflects internal errors
	* but also reflects SMI completion), use that to wait for
	* SMI access completion instead of polling the SMI busy bit.
	*/
	int err_interrupt;
	wait_queue_head_t smi_busy_wait;
	};

	enum orion_mdio_bus_type {
	BUS_TYPE_SMI,
	BUS_TYPE_XSMI
	};

	struct orion_mdio_ops {
	int (is_done)(struct orion_mdio_dev );
	};

	/* Wait for the SMI unit to be ready for another operation
	*/
	static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops,
	struct mii_bus *bus)
	{
	struct orion_mdio_dev *dev = bus->priv;
	unsigned long timeout;
	int done;

	if (dev->err_interrupt <= 0) {
	if (!read_poll_timeout_atomic(ops->is_done, done, done, 2,
	MVMDIO_SMI_TIMEOUT, false, dev))
	return 0;
	} else {
	/* wait_event_timeout does not guarantee a delay of at
	* least one whole jiffy, so timeout must be no less
	* than two.
	*/
	timeout = max(usecs_to_jiffies(MVMDIO_SMI_TIMEOUT), 2);

	if (wait_event_timeout(dev->smi_busy_wait,
	ops->is_done(dev), timeout))
	return 0;
	}

	dev_err(bus->parent, "Timeout: SMI busy for too long\n");
	return -ETIMEDOUT;
	}

	static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
	{
	return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
	}

	static const struct orion_mdio_ops orion_mdio_smi_ops = {
	.is_done = orion_mdio_smi_is_done,
	};

	static int orion_mdio_smi_read(struct mii_bus *bus, int mii_id,
	int regnum)
	{
	struct orion_mdio_dev *dev = bus->priv;
	u32 val;
	int ret;

	ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
	if (ret < 0)
	return ret;

	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) \|
	(regnum << MVMDIO_SMI_PHY_REG_SHIFT) \|
	MVMDIO_SMI_READ_OPERATION),
	dev->regs);

	ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
	if (ret < 0)
	return ret;

	val = readl(dev->regs);
	if (!(val & MVMDIO_SMI_READ_VALID)) {
	dev_err(bus->parent, "SMI bus read not valid\n");
	return -ENODEV;
	}

	return val & GENMASK(15, 0);
	}

	static int orion_mdio_smi_write(struct mii_bus *bus, int mii_id,
	int regnum, u16 value)
	{
	struct orion_mdio_dev *dev = bus->priv;
	int ret;

	ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
	if (ret < 0)
	return ret;

	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) \|
	(regnum << MVMDIO_SMI_PHY_REG_SHIFT) \|
	MVMDIO_SMI_WRITE_OPERATION \|
	(value << MVMDIO_SMI_DATA_SHIFT)),
	dev->regs);

	return 0;
	}

	static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev)
	{
	return !(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & MVMDIO_XSMI_BUSY);
	}

	static const struct orion_mdio_ops orion_mdio_xsmi_ops = {
	.is_done = orion_mdio_xsmi_is_done,
	};

	static int orion_mdio_xsmi_read_c45(struct mii_bus *bus, int mii_id,
	int dev_addr, int regnum)
	{
	struct orion_mdio_dev *dev = bus->priv;
	int ret;

	ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
	if (ret < 0)
	return ret;

	writel(regnum, dev->regs + MVMDIO_XSMI_ADDR_REG);
	writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) \|
	(dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) \|
	MVMDIO_XSMI_READ_OPERATION,
	dev->regs + MVMDIO_XSMI_MGNT_REG);

	ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
	if (ret < 0)
	return ret;

	if (!(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) &
	MVMDIO_XSMI_READ_VALID)) {
	dev_err(bus->parent, "XSMI bus read not valid\n");
	return -ENODEV;
	}

	return readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & GENMASK(15, 0);
	}

	static int orion_mdio_xsmi_write_c45(struct mii_bus *bus, int mii_id,
	int dev_addr, int regnum, u16 value)
	{
	struct orion_mdio_dev *dev = bus->priv;
	int ret;

	ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
	if (ret < 0)
	return ret;

	writel(regnum, dev->regs + MVMDIO_XSMI_ADDR_REG);
	writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) \|
	(dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) \|
	MVMDIO_XSMI_WRITE_OPERATION \| value,
	dev->regs + MVMDIO_XSMI_MGNT_REG);

	return 0;
	}

	static void orion_mdio_xsmi_set_mdc_freq(struct mii_bus *bus)
	{
	struct orion_mdio_dev *dev = bus->priv;
	struct clk *mg_core;
	u32 div, freq, cfg;

	if (device_property_read_u32(bus->parent, "clock-frequency", &freq))
	return;

	mg_core = of_clk_get_by_name(bus->parent->of_node, "mg_core_clk");
	if (IS_ERR(mg_core)) {
	dev_err(bus->parent,
	"MG core clock unknown, not changing MDC frequency");
	return;
	}

	div = clk_get_rate(mg_core) / (freq + 1) + 1;
	clk_put(mg_core);

	if (div <= 8)
	div = MVMDIO_XSMI_CLKDIV_8;
	else if (div <= 32)
	div = MVMDIO_XSMI_CLKDIV_32;
	else if (div <= 64)
	div = MVMDIO_XSMI_CLKDIV_64;
	else
	div = MVMDIO_XSMI_CLKDIV_256;

	cfg = readl(dev->regs + MVMDIO_XSMI_CFG_REG);
	cfg &= ~MVMDIO_XSMI_CLKDIV_MASK;
	cfg \|= div;
	writel(cfg, dev->regs + MVMDIO_XSMI_CFG_REG);
	}

	static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
	{
	struct orion_mdio_dev *dev = dev_id;

	if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
	MVMDIO_ERR_INT_SMI_DONE) {
	writel(~MVMDIO_ERR_INT_SMI_DONE,
	dev->regs + MVMDIO_ERR_INT_CAUSE);
	wake_up(&dev->smi_busy_wait);
	return IRQ_HANDLED;
	}

	return IRQ_NONE;
	}

	static int orion_mdio_probe(struct platform_device *pdev)
	{
	enum orion_mdio_bus_type type;
	struct resource *r;
	struct mii_bus *bus;
	struct orion_mdio_dev *dev;
	int i, ret;

	type = (uintptr_t)device_get_match_data(&pdev->dev);

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r) {
	dev_err(&pdev->dev, "No SMI register address given\n");
	return -ENODEV;
	}

	bus = devm_mdiobus_alloc_size(&pdev->dev,
	sizeof(struct orion_mdio_dev));
	if (!bus)
	return -ENOMEM;

	switch (type) {
	case BUS_TYPE_SMI:
	bus->read = orion_mdio_smi_read;
	bus->write = orion_mdio_smi_write;
	break;
	case BUS_TYPE_XSMI:
	bus->read_c45 = orion_mdio_xsmi_read_c45;
	bus->write_c45 = orion_mdio_xsmi_write_c45;
	break;
	}

	bus->name = "orion_mdio_bus";
	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
	dev_name(&pdev->dev));
	bus->parent = &pdev->dev;

	dev = bus->priv;
	dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
	if (!dev->regs) {
	dev_err(&pdev->dev, "Unable to remap SMI register\n");
	return -ENODEV;
	}

	init_waitqueue_head(&dev->smi_busy_wait);

	if (pdev->dev.of_node) {
	for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
	dev->clk[i] = of_clk_get(pdev->dev.of_node, i);
	if (PTR_ERR(dev->clk[i]) == -EPROBE_DEFER) {
	ret = -EPROBE_DEFER;
	goto out_clk;
	}
	if (IS_ERR(dev->clk[i]))
	break;
	clk_prepare_enable(dev->clk[i]);
	}

	if (!IS_ERR(of_clk_get(pdev->dev.of_node,
	ARRAY_SIZE(dev->clk))))
	dev_warn(&pdev->dev,
	"unsupported number of clocks, limiting to the first "
	__stringify(ARRAY_SIZE(dev->clk)) "\n");

	if (type == BUS_TYPE_XSMI)
	orion_mdio_xsmi_set_mdc_freq(bus);
	} else {
	dev->clk[0] = clk_get(&pdev->dev, NULL);
	if (PTR_ERR(dev->clk[0]) == -EPROBE_DEFER) {
	ret = -EPROBE_DEFER;
	goto out_clk;
	}
	if (!IS_ERR(dev->clk[0]))
	clk_prepare_enable(dev->clk[0]);
	}


	dev->err_interrupt = platform_get_irq_optional(pdev, 0);
	if (dev->err_interrupt > 0 &&
	resource_size(r) < MVMDIO_ERR_INT_MASK + 4) {
	dev_err(&pdev->dev,
	"disabling interrupt, resource size is too small\n");
	dev->err_interrupt = 0;
	}
	if (dev->err_interrupt > 0) {
	ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
	orion_mdio_err_irq,
	IRQF_SHARED, pdev->name, dev);
	if (ret)
	goto out_mdio;

	writel(MVMDIO_ERR_INT_SMI_DONE,
	dev->regs + MVMDIO_ERR_INT_MASK);

	} else if (dev->err_interrupt == -EPROBE_DEFER) {
	ret = -EPROBE_DEFER;
	goto out_mdio;
	}

	/* For the platforms not supporting DT/ACPI fall-back
	* to mdiobus_register via of_mdiobus_register.
	*/
	if (is_acpi_node(pdev->dev.fwnode))
	ret = acpi_mdiobus_register(bus, pdev->dev.fwnode);
	else
	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:
	if (dev->err_interrupt > 0)
	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);

	out_clk:
	for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
	if (IS_ERR(dev->clk[i]))
	break;
	clk_disable_unprepare(dev->clk[i]);
	clk_put(dev->clk[i]);
	}

	return ret;
	}

	static void orion_mdio_remove(struct platform_device *pdev)
	{
	struct mii_bus *bus = platform_get_drvdata(pdev);
	struct orion_mdio_dev *dev = bus->priv;
	int i;

	if (dev->err_interrupt > 0)
	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
	mdiobus_unregister(bus);

	for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
	if (IS_ERR(dev->clk[i]))
	break;
	clk_disable_unprepare(dev->clk[i]);
	clk_put(dev->clk[i]);
	}
	}

	static const struct of_device_id orion_mdio_match[] = {
	{ .compatible = "marvell,orion-mdio", .data = (void *)BUS_TYPE_SMI },
	{ .compatible = "marvell,xmdio", .data = (void *)BUS_TYPE_XSMI },
	{ }
	};
	MODULE_DEVICE_TABLE(of, orion_mdio_match);

	#ifdef CONFIG_ACPI
	static const struct acpi_device_id orion_mdio_acpi_match[] = {
	{ "MRVL0100", BUS_TYPE_SMI },
	{ "MRVL0101", BUS_TYPE_XSMI },
	{ },
	};
	MODULE_DEVICE_TABLE(acpi, orion_mdio_acpi_match);
	#endif

	static struct platform_driver orion_mdio_driver = {
	.probe = orion_mdio_probe,
	.remove_new = orion_mdio_remove,
	.driver = {
	.name = "orion-mdio",
	.of_match_table = orion_mdio_match,
	.acpi_match_table = ACPI_PTR(orion_mdio_acpi_match),
	},
	};

	module_platform_driver(orion_mdio_driver);

	MODULE_DESCRIPTION("Marvell MDIO interface driver");
	MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:orion-mdio");