drivers/of/of_mdio.c - arm/linux - Git at Google

 /*
  * OF helpers for the MDIO (Ethernet PHY) API
  *
  * Copyright (c) 2009 Secret Lab Technologies, Ltd.
  *
  * This file is released under the GPLv2
  *
  * This file provides helper functions for extracting PHY device information
  * out of the OpenFirmware device tree and using it to populate an mii_bus.
  */

 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/netdevice.h>
 #include <linux/err.h>
 #include <linux/phy.h>
 #include <linux/phy_fixed.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/of_irq.h>
 #include <linux/of_mdio.h>
 #include <linux/of_net.h>
 #include <linux/module.h>

 #define DEFAULT_GPIO_RESET_DELAY	10	/* in microseconds */

 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
 MODULE_LICENSE("GPL");

 /* Extract the clause 22 phy ID from the compatible string of the form
  * ethernet-phy-idAAAA.BBBB */
 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
 {
 	struct property *prop;
 	const char *cp;
 	unsigned int upper, lower;

 	of_property_for_each_string(device, "compatible", prop, cp) {
 		if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
 			*phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
 			return 0;
 		}
 	}
 	return -EINVAL;
 }

 static int of_mdiobus_register_phy(struct mii_bus *mdio,
 				    struct device_node *child, u32 addr)
 {
 	struct phy_device *phy;
 	bool is_c45;
 	int rc;
 	u32 phy_id;

 	is_c45 = of_device_is_compatible(child,
 					 "ethernet-phy-ieee802.3-c45");

 	if (!is_c45 && !of_get_phy_id(child, &phy_id))
 		phy = phy_device_create(mdio, addr, phy_id, 0, NULL);
 	else
 		phy = get_phy_device(mdio, addr, is_c45);
 	if (IS_ERR(phy))
 		return PTR_ERR(phy);

 	rc = of_irq_get(child, 0);
 	if (rc == -EPROBE_DEFER) {
 		phy_device_free(phy);
 		return rc;
 	}
 	if (rc > 0) {
 		phy->irq = rc;
 		mdio->irq[addr] = rc;
 	} else {
 		phy->irq = mdio->irq[addr];
 	}

 	if (of_property_read_bool(child, "broken-turn-around"))
 		mdio->phy_ignore_ta_mask |= 1 << addr;

 	/* Associate the OF node with the device structure so it
 	 * can be looked up later */
 	of_node_get(child);
 	phy->mdio.dev.of_node = child;

 	/* All data is now stored in the phy struct;
 	 * register it */
 	rc = phy_device_register(phy);
 	if (rc) {
 		phy_device_free(phy);
 		of_node_put(child);
 		return rc;
 	}

 	dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
 		child->name, addr);
 	return 0;
 }

 static int of_mdiobus_register_device(struct mii_bus *mdio,
 				      struct device_node *child, u32 addr)
 {
 	struct mdio_device *mdiodev;
 	int rc;

 	mdiodev = mdio_device_create(mdio, addr);
 	if (IS_ERR(mdiodev))
 		return PTR_ERR(mdiodev);

 	/* Associate the OF node with the device structure so it
 	 * can be looked up later.
 	 */
 	of_node_get(child);
 	mdiodev->dev.of_node = child;

 	/* All data is now stored in the mdiodev struct; register it. */
 	rc = mdio_device_register(mdiodev);
 	if (rc) {
 		mdio_device_free(mdiodev);
 		of_node_put(child);
 		return rc;
 	}

 	dev_dbg(&mdio->dev, "registered mdio device %s at address %i\n",
 		child->name, addr);
 	return 0;
 }

 /* The following is a list of PHY compatible strings which appear in
  * some DTBs. The compatible string is never matched against a PHY
  * driver, so is pointless. We only expect devices which are not PHYs
  * to have a compatible string, so they can be matched to an MDIO
  * driver.  Encourage users to upgrade their DT blobs to remove these.
  */
 static const struct of_device_id whitelist_phys[] = {
 	{ .compatible = "brcm,40nm-ephy" },
 	{ .compatible = "broadcom,bcm5241" },
 	{ .compatible = "marvell,88E1111", },
 	{ .compatible = "marvell,88e1116", },
 	{ .compatible = "marvell,88e1118", },
 	{ .compatible = "marvell,88e1145", },
 	{ .compatible = "marvell,88e1149r", },
 	{ .compatible = "marvell,88e1310", },
 	{ .compatible = "marvell,88E1510", },
 	{ .compatible = "marvell,88E1514", },
 	{ .compatible = "moxa,moxart-rtl8201cp", },
 	{}
 };

 /*
  * Return true if the child node is for a phy. It must either:
  * o Compatible string of "ethernet-phy-idX.X"
  * o Compatible string of "ethernet-phy-ieee802.3-c45"
  * o Compatible string of "ethernet-phy-ieee802.3-c22"
  * o In the white list above (and issue a warning)
  * o No compatibility string
  *
  * A device which is not a phy is expected to have a compatible string
  * indicating what sort of device it is.
  */
 static bool of_mdiobus_child_is_phy(struct device_node *child)
 {
 	u32 phy_id;

 	if (of_get_phy_id(child, &phy_id) != -EINVAL)
 		return true;

 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
 		return true;

 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
 		return true;

 	if (of_match_node(whitelist_phys, child)) {
 		pr_warn(FW_WARN
 			"%pOF: Whitelisted compatible string. Please remove\n",
 			child);
 		return true;
 	}

 	if (!of_find_property(child, "compatible", NULL))
 		return true;

 	return false;
 }

 /**
  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
  * @mdio: pointer to mii_bus structure
  * @np: pointer to device_node of MDIO bus.
  *
  * This function registers the mii_bus structure and registers a phy_device
  * for each child node of @np.
  */
 int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 {
 	struct device_node *child;
 	bool scanphys = false;
 	int addr, rc;

 	/* Do not continue if the node is disabled */
 	if (!of_device_is_available(np))
 		return -ENODEV;

 	/* Mask out all PHYs from auto probing.  Instead the PHYs listed in
 	 * the device tree are populated after the bus has been registered */
 	mdio->phy_mask = ~0;

 	mdio->dev.of_node = np;

 	/* Get bus level PHY reset GPIO details */
 	mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
 	of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);

 	/* Register the MDIO bus */
 	rc = mdiobus_register(mdio);
 	if (rc)
 		return rc;

 	/* Loop over the child nodes and register a phy_device for each phy */
 	for_each_available_child_of_node(np, child) {
 		addr = of_mdio_parse_addr(&mdio->dev, child);
 		if (addr < 0) {
 			scanphys = true;
 			continue;
 		}

 		if (of_mdiobus_child_is_phy(child))
 			rc = of_mdiobus_register_phy(mdio, child, addr);
 		else
 			rc = of_mdiobus_register_device(mdio, child, addr);
 		if (rc)
 			goto unregister;
 	}

 	if (!scanphys)
 		return 0;

 	/* auto scan for PHYs with empty reg property */
 	for_each_available_child_of_node(np, child) {
 		/* Skip PHYs with reg property set */
 		if (of_find_property(child, "reg", NULL))
 			continue;

 		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
 			/* skip already registered PHYs */
 			if (mdiobus_is_registered_device(mdio, addr))
 				continue;

 			/* be noisy to encourage people to set reg property */
 			dev_info(&mdio->dev, "scan phy %s at address %i\n",
 				 child->name, addr);

 			if (of_mdiobus_child_is_phy(child)) {
 				rc = of_mdiobus_register_phy(mdio, child, addr);
 				if (rc)
 					goto unregister;
 			}
 		}
 	}

 	return 0;

 unregister:
 	mdiobus_unregister(mdio);
 	return rc;
 }
 EXPORT_SYMBOL(of_mdiobus_register);

 /* Helper function for of_phy_find_device */
 static int of_phy_match(struct device *dev, void *phy_np)
 {
 	return dev->of_node == phy_np;
 }

 /**
  * of_phy_find_device - Give a PHY node, find the phy_device
  * @phy_np: Pointer to the phy's device tree node
  *
  * If successful, returns a pointer to the phy_device with the embedded
  * struct device refcount incremented by one, or NULL on failure.
  */
 struct phy_device *of_phy_find_device(struct device_node *phy_np)
 {
 	struct device *d;
 	struct mdio_device *mdiodev;

 	if (!phy_np)
 		return NULL;

 	d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
 	if (d) {
 		mdiodev = to_mdio_device(d);
 		if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
 			return to_phy_device(d);
 		put_device(d);
 	}

 	return NULL;
 }
 EXPORT_SYMBOL(of_phy_find_device);

 /**
  * of_phy_connect - Connect to the phy described in the device tree
  * @dev: pointer to net_device claiming the phy
  * @phy_np: Pointer to device tree node for the PHY
  * @hndlr: Link state callback for the network device
  * @flags: flags to pass to the PHY
  * @iface: PHY data interface type
  *
  * If successful, returns a pointer to the phy_device with the embedded
  * struct device refcount incremented by one, or NULL on failure. The
  * refcount must be dropped by calling phy_disconnect() or phy_detach().
  */
 struct phy_device *of_phy_connect(struct net_device *dev,
 				  struct device_node *phy_np,
 				  void (*hndlr)(struct net_device *), u32 flags,
 				  phy_interface_t iface)
 {
 	struct phy_device *phy = of_phy_find_device(phy_np);
 	int ret;

 	if (!phy)
 		return NULL;

 	phy->dev_flags = flags;

 	ret = phy_connect_direct(dev, phy, hndlr, iface);

 	/* refcount is held by phy_connect_direct() on success */
 	put_device(&phy->mdio.dev);

 	return ret ? NULL : phy;
 }
 EXPORT_SYMBOL(of_phy_connect);

 /**
  * of_phy_get_and_connect
  * - Get phy node and connect to the phy described in the device tree
  * @dev: pointer to net_device claiming the phy
  * @np: Pointer to device tree node for the net_device claiming the phy
  * @hndlr: Link state callback for the network device
  *
  * If successful, returns a pointer to the phy_device with the embedded
  * struct device refcount incremented by one, or NULL on failure. The
  * refcount must be dropped by calling phy_disconnect() or phy_detach().
  */
 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
 					  struct device_node *np,
 					  void (*hndlr)(struct net_device *))
 {
 	phy_interface_t iface;
 	struct device_node *phy_np;
 	struct phy_device *phy;

 	iface = of_get_phy_mode(np);
 	if (iface < 0)
 		return NULL;

 	phy_np = of_parse_phandle(np, "phy-handle", 0);
 	if (!phy_np)
 		return NULL;

 	phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);

 	of_node_put(phy_np);

 	return phy;
 }
 EXPORT_SYMBOL(of_phy_get_and_connect);

 /**
  * of_phy_attach - Attach to a PHY without starting the state machine
  * @dev: pointer to net_device claiming the phy
  * @phy_np: Node pointer for the PHY
  * @flags: flags to pass to the PHY
  * @iface: PHY data interface type
  *
  * If successful, returns a pointer to the phy_device with the embedded
  * struct device refcount incremented by one, or NULL on failure. The
  * refcount must be dropped by calling phy_disconnect() or phy_detach().
  */
 struct phy_device *of_phy_attach(struct net_device *dev,
 				 struct device_node *phy_np, u32 flags,
 				 phy_interface_t iface)
 {
 	struct phy_device *phy = of_phy_find_device(phy_np);
 	int ret;

 	if (!phy)
 		return NULL;

 	ret = phy_attach_direct(dev, phy, flags, iface);

 	/* refcount is held by phy_attach_direct() on success */
 	put_device(&phy->mdio.dev);

 	return ret ? NULL : phy;
 }
 EXPORT_SYMBOL(of_phy_attach);

 /*
  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
  * support two DT bindings:
  * - the old DT binding, where 'fixed-link' was a property with 5
  *   cells encoding various informations about the fixed PHY
  * - the new DT binding, where 'fixed-link' is a sub-node of the
  *   Ethernet device.
  */
 bool of_phy_is_fixed_link(struct device_node *np)
 {
 	struct device_node *dn;
 	int len, err;
 	const char *managed;

 	/* New binding */
 	dn = of_get_child_by_name(np, "fixed-link");
 	if (dn) {
 		of_node_put(dn);
 		return true;
 	}

 	err = of_property_read_string(np, "managed", &managed);
 	if (err == 0 && strcmp(managed, "auto") != 0)
 		return true;

 	/* Old binding */
 	if (of_get_property(np, "fixed-link", &len) &&
 	    len == (5 * sizeof(__be32)))
 		return true;

 	return false;
 }
 EXPORT_SYMBOL(of_phy_is_fixed_link);

 int of_phy_register_fixed_link(struct device_node *np)
 {
 	struct fixed_phy_status status = {};
 	struct device_node *fixed_link_node;
 	u32 fixed_link_prop[5];
 	const char *managed;
 	int link_gpio = -1;

 	if (of_property_read_string(np, "managed", &managed) == 0 &&
 	    strcmp(managed, "in-band-status") == 0) {
 		/* status is zeroed, namely its .link member */
 		goto register_phy;
 	}

 	/* New binding */
 	fixed_link_node = of_get_child_by_name(np, "fixed-link");
 	if (fixed_link_node) {
 		status.link = 1;
 		status.duplex = of_property_read_bool(fixed_link_node,
 						      "full-duplex");
 		if (of_property_read_u32(fixed_link_node, "speed",
 					 &status.speed)) {
 			of_node_put(fixed_link_node);
 			return -EINVAL;
 		}
 		status.pause = of_property_read_bool(fixed_link_node, "pause");
 		status.asym_pause = of_property_read_bool(fixed_link_node,
 							  "asym-pause");
 		link_gpio = of_get_named_gpio_flags(fixed_link_node,
 						    "link-gpios", 0, NULL);
 		of_node_put(fixed_link_node);
 		if (link_gpio == -EPROBE_DEFER)
 			return -EPROBE_DEFER;

 		goto register_phy;
 	}

 	/* Old binding */
 	if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
 				       ARRAY_SIZE(fixed_link_prop)) == 0) {
 		status.link = 1;
 		status.duplex = fixed_link_prop[1];
 		status.speed  = fixed_link_prop[2];
 		status.pause  = fixed_link_prop[3];
 		status.asym_pause = fixed_link_prop[4];
 		goto register_phy;
 	}

 	return -ENODEV;

 register_phy:
 	return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, link_gpio,
 						  np));
 }
 EXPORT_SYMBOL(of_phy_register_fixed_link);

 void of_phy_deregister_fixed_link(struct device_node *np)
 {
 	struct phy_device *phydev;

 	phydev = of_phy_find_device(np);
 	if (!phydev)
 		return;

 	fixed_phy_unregister(phydev);

 	put_device(&phydev->mdio.dev);	/* of_phy_find_device() */
 	phy_device_free(phydev);	/* fixed_phy_register() */
 }
 EXPORT_SYMBOL(of_phy_deregister_fixed_link);
	/*
	* OF helpers for the MDIO (Ethernet PHY) API
	*
	* Copyright (c) 2009 Secret Lab Technologies, Ltd.
	*
	* This file is released under the GPLv2
	*
	* This file provides helper functions for extracting PHY device information
	* out of the OpenFirmware device tree and using it to populate an mii_bus.
	*/

	#include <linux/kernel.h>
	#include <linux/device.h>
	#include <linux/netdevice.h>
	#include <linux/err.h>
	#include <linux/phy.h>
	#include <linux/phy_fixed.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>
	#include <linux/of_irq.h>
	#include <linux/of_mdio.h>
	#include <linux/of_net.h>
	#include <linux/module.h>

	#define DEFAULT_GPIO_RESET_DELAY 10 /* in microseconds */

	MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
	MODULE_LICENSE("GPL");

	/* Extract the clause 22 phy ID from the compatible string of the form
	* ethernet-phy-idAAAA.BBBB */
	static int of_get_phy_id(struct device_node device, u32 phy_id)
	{
	struct property *prop;
	const char *cp;
	unsigned int upper, lower;

	of_property_for_each_string(device, "compatible", prop, cp) {
	if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
	*phy_id = ((upper & 0xFFFF) << 16) \| (lower & 0xFFFF);
	return 0;
	}
	}
	return -EINVAL;
	}

	static int of_mdiobus_register_phy(struct mii_bus *mdio,
	struct device_node *child, u32 addr)
	{
	struct phy_device *phy;
	bool is_c45;
	int rc;
	u32 phy_id;

	is_c45 = of_device_is_compatible(child,
	"ethernet-phy-ieee802.3-c45");

	if (!is_c45 && !of_get_phy_id(child, &phy_id))
	phy = phy_device_create(mdio, addr, phy_id, 0, NULL);
	else
	phy = get_phy_device(mdio, addr, is_c45);
	if (IS_ERR(phy))
	return PTR_ERR(phy);

	rc = of_irq_get(child, 0);
	if (rc == -EPROBE_DEFER) {
	phy_device_free(phy);
	return rc;
	}
	if (rc > 0) {
	phy->irq = rc;
	mdio->irq[addr] = rc;
	} else {
	phy->irq = mdio->irq[addr];
	}

	if (of_property_read_bool(child, "broken-turn-around"))
	mdio->phy_ignore_ta_mask \|= 1 << addr;

	/* Associate the OF node with the device structure so it
	* can be looked up later */
	of_node_get(child);
	phy->mdio.dev.of_node = child;

	/* All data is now stored in the phy struct;
	* register it */
	rc = phy_device_register(phy);
	if (rc) {
	phy_device_free(phy);
	of_node_put(child);
	return rc;
	}

	dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
	child->name, addr);
	return 0;
	}

	static int of_mdiobus_register_device(struct mii_bus *mdio,
	struct device_node *child, u32 addr)
	{
	struct mdio_device *mdiodev;
	int rc;

	mdiodev = mdio_device_create(mdio, addr);
	if (IS_ERR(mdiodev))
	return PTR_ERR(mdiodev);

	/* Associate the OF node with the device structure so it
	* can be looked up later.
	*/
	of_node_get(child);
	mdiodev->dev.of_node = child;

	/* All data is now stored in the mdiodev struct; register it. */
	rc = mdio_device_register(mdiodev);
	if (rc) {
	mdio_device_free(mdiodev);
	of_node_put(child);
	return rc;
	}

	dev_dbg(&mdio->dev, "registered mdio device %s at address %i\n",
	child->name, addr);
	return 0;
	}

	/* The following is a list of PHY compatible strings which appear in
	* some DTBs. The compatible string is never matched against a PHY
	* driver, so is pointless. We only expect devices which are not PHYs
	* to have a compatible string, so they can be matched to an MDIO
	* driver. Encourage users to upgrade their DT blobs to remove these.
	*/
	static const struct of_device_id whitelist_phys[] = {
	{ .compatible = "brcm,40nm-ephy" },
	{ .compatible = "broadcom,bcm5241" },
	{ .compatible = "marvell,88E1111", },
	{ .compatible = "marvell,88e1116", },
	{ .compatible = "marvell,88e1118", },
	{ .compatible = "marvell,88e1145", },
	{ .compatible = "marvell,88e1149r", },
	{ .compatible = "marvell,88e1310", },
	{ .compatible = "marvell,88E1510", },
	{ .compatible = "marvell,88E1514", },
	{ .compatible = "moxa,moxart-rtl8201cp", },
	{}
	};

	/*
	* Return true if the child node is for a phy. It must either:
	* o Compatible string of "ethernet-phy-idX.X"
	* o Compatible string of "ethernet-phy-ieee802.3-c45"
	* o Compatible string of "ethernet-phy-ieee802.3-c22"
	* o In the white list above (and issue a warning)
	* o No compatibility string
	*
	* A device which is not a phy is expected to have a compatible string
	* indicating what sort of device it is.
	*/
	static bool of_mdiobus_child_is_phy(struct device_node *child)
	{
	u32 phy_id;

	if (of_get_phy_id(child, &phy_id) != -EINVAL)
	return true;

	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
	return true;

	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
	return true;

	if (of_match_node(whitelist_phys, child)) {
	pr_warn(FW_WARN
	"%pOF: Whitelisted compatible string. Please remove\n",
	child);
	return true;
	}

	if (!of_find_property(child, "compatible", NULL))
	return true;

	return false;
	}

	/**
	* of_mdiobus_register - Register mii_bus and create PHYs from the device tree
	* @mdio: pointer to mii_bus structure
	* @np: pointer to device_node of MDIO bus.
	*
	* This function registers the mii_bus structure and registers a phy_device
	* for each child node of @np.
	*/
	int of_mdiobus_register(struct mii_bus mdio, struct device_node np)
	{
	struct device_node *child;
	bool scanphys = false;
	int addr, rc;

	/* Do not continue if the node is disabled */
	if (!of_device_is_available(np))
	return -ENODEV;

	/* Mask out all PHYs from auto probing. Instead the PHYs listed in
	* the device tree are populated after the bus has been registered */
	mdio->phy_mask = ~0;

	mdio->dev.of_node = np;

	/* Get bus level PHY reset GPIO details */
	mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
	of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);

	/* Register the MDIO bus */
	rc = mdiobus_register(mdio);
	if (rc)
	return rc;

	/* Loop over the child nodes and register a phy_device for each phy */
	for_each_available_child_of_node(np, child) {
	addr = of_mdio_parse_addr(&mdio->dev, child);
	if (addr < 0) {
	scanphys = true;
	continue;
	}

	if (of_mdiobus_child_is_phy(child))
	rc = of_mdiobus_register_phy(mdio, child, addr);
	else
	rc = of_mdiobus_register_device(mdio, child, addr);
	if (rc)
	goto unregister;
	}

	if (!scanphys)
	return 0;

	/* auto scan for PHYs with empty reg property */
	for_each_available_child_of_node(np, child) {
	/* Skip PHYs with reg property set */
	if (of_find_property(child, "reg", NULL))
	continue;

	for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
	/* skip already registered PHYs */
	if (mdiobus_is_registered_device(mdio, addr))
	continue;

	/* be noisy to encourage people to set reg property */
	dev_info(&mdio->dev, "scan phy %s at address %i\n",
	child->name, addr);

	if (of_mdiobus_child_is_phy(child)) {
	rc = of_mdiobus_register_phy(mdio, child, addr);
	if (rc)
	goto unregister;
	}
	}
	}

	return 0;

	unregister:
	mdiobus_unregister(mdio);
	return rc;
	}
	EXPORT_SYMBOL(of_mdiobus_register);

	/* Helper function for of_phy_find_device */
	static int of_phy_match(struct device dev, void phy_np)
	{
	return dev->of_node == phy_np;
	}

	/**
	* of_phy_find_device - Give a PHY node, find the phy_device
	* @phy_np: Pointer to the phy's device tree node
	*
	* If successful, returns a pointer to the phy_device with the embedded
	* struct device refcount incremented by one, or NULL on failure.
	*/
	struct phy_device of_phy_find_device(struct device_node phy_np)
	{
	struct device *d;
	struct mdio_device *mdiodev;

	if (!phy_np)
	return NULL;

	d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
	if (d) {
	mdiodev = to_mdio_device(d);
	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
	return to_phy_device(d);
	put_device(d);
	}

	return NULL;
	}
	EXPORT_SYMBOL(of_phy_find_device);

	/**
	* of_phy_connect - Connect to the phy described in the device tree
	* @dev: pointer to net_device claiming the phy
	* @phy_np: Pointer to device tree node for the PHY
	* @hndlr: Link state callback for the network device
	* @flags: flags to pass to the PHY
	* @iface: PHY data interface type
	*
	* If successful, returns a pointer to the phy_device with the embedded
	* struct device refcount incremented by one, or NULL on failure. The
	* refcount must be dropped by calling phy_disconnect() or phy_detach().
	*/
	struct phy_device of_phy_connect(struct net_device dev,
	struct device_node *phy_np,
	void (hndlr)(struct net_device ), u32 flags,
	phy_interface_t iface)
	{
	struct phy_device *phy = of_phy_find_device(phy_np);
	int ret;

	if (!phy)
	return NULL;

	phy->dev_flags = flags;

	ret = phy_connect_direct(dev, phy, hndlr, iface);

	/* refcount is held by phy_connect_direct() on success */
	put_device(&phy->mdio.dev);

	return ret ? NULL : phy;
	}
	EXPORT_SYMBOL(of_phy_connect);

	/**
	* of_phy_get_and_connect
	* - Get phy node and connect to the phy described in the device tree
	* @dev: pointer to net_device claiming the phy
	* @np: Pointer to device tree node for the net_device claiming the phy
	* @hndlr: Link state callback for the network device
	*
	* If successful, returns a pointer to the phy_device with the embedded
	* struct device refcount incremented by one, or NULL on failure. The
	* refcount must be dropped by calling phy_disconnect() or phy_detach().
	*/
	struct phy_device of_phy_get_and_connect(struct net_device dev,
	struct device_node *np,
	void (hndlr)(struct net_device ))
	{
	phy_interface_t iface;
	struct device_node *phy_np;
	struct phy_device *phy;

	iface = of_get_phy_mode(np);
	if (iface < 0)
	return NULL;

	phy_np = of_parse_phandle(np, "phy-handle", 0);
	if (!phy_np)
	return NULL;

	phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);

	of_node_put(phy_np);

	return phy;
	}
	EXPORT_SYMBOL(of_phy_get_and_connect);

	/**
	* of_phy_attach - Attach to a PHY without starting the state machine
	* @dev: pointer to net_device claiming the phy
	* @phy_np: Node pointer for the PHY
	* @flags: flags to pass to the PHY
	* @iface: PHY data interface type
	*
	* If successful, returns a pointer to the phy_device with the embedded
	* struct device refcount incremented by one, or NULL on failure. The
	* refcount must be dropped by calling phy_disconnect() or phy_detach().
	*/
	struct phy_device of_phy_attach(struct net_device dev,
	struct device_node *phy_np, u32 flags,
	phy_interface_t iface)
	{
	struct phy_device *phy = of_phy_find_device(phy_np);
	int ret;

	if (!phy)
	return NULL;

	ret = phy_attach_direct(dev, phy, flags, iface);

	/* refcount is held by phy_attach_direct() on success */
	put_device(&phy->mdio.dev);

	return ret ? NULL : phy;
	}
	EXPORT_SYMBOL(of_phy_attach);

	/*
	* of_phy_is_fixed_link() and of_phy_register_fixed_link() must
	* support two DT bindings:
	* - the old DT binding, where 'fixed-link' was a property with 5
	* cells encoding various informations about the fixed PHY
	* - the new DT binding, where 'fixed-link' is a sub-node of the
	* Ethernet device.
	*/
	bool of_phy_is_fixed_link(struct device_node *np)
	{
	struct device_node *dn;
	int len, err;
	const char *managed;

	/* New binding */
	dn = of_get_child_by_name(np, "fixed-link");
	if (dn) {
	of_node_put(dn);
	return true;
	}

	err = of_property_read_string(np, "managed", &managed);
	if (err == 0 && strcmp(managed, "auto") != 0)
	return true;

	/* Old binding */
	if (of_get_property(np, "fixed-link", &len) &&
	len == (5 * sizeof(__be32)))
	return true;

	return false;
	}
	EXPORT_SYMBOL(of_phy_is_fixed_link);

	int of_phy_register_fixed_link(struct device_node *np)
	{
	struct fixed_phy_status status = {};
	struct device_node *fixed_link_node;
	u32 fixed_link_prop[5];
	const char *managed;
	int link_gpio = -1;

	if (of_property_read_string(np, "managed", &managed) == 0 &&
	strcmp(managed, "in-band-status") == 0) {
	/* status is zeroed, namely its .link member */
	goto register_phy;
	}

	/* New binding */
	fixed_link_node = of_get_child_by_name(np, "fixed-link");
	if (fixed_link_node) {
	status.link = 1;
	status.duplex = of_property_read_bool(fixed_link_node,
	"full-duplex");
	if (of_property_read_u32(fixed_link_node, "speed",
	&status.speed)) {
	of_node_put(fixed_link_node);
	return -EINVAL;
	}
	status.pause = of_property_read_bool(fixed_link_node, "pause");
	status.asym_pause = of_property_read_bool(fixed_link_node,
	"asym-pause");
	link_gpio = of_get_named_gpio_flags(fixed_link_node,
	"link-gpios", 0, NULL);
	of_node_put(fixed_link_node);
	if (link_gpio == -EPROBE_DEFER)
	return -EPROBE_DEFER;

	goto register_phy;
	}

	/* Old binding */
	if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
	ARRAY_SIZE(fixed_link_prop)) == 0) {
	status.link = 1;
	status.duplex = fixed_link_prop[1];
	status.speed = fixed_link_prop[2];
	status.pause = fixed_link_prop[3];
	status.asym_pause = fixed_link_prop[4];
	goto register_phy;
	}

	return -ENODEV;

	register_phy:
	return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, link_gpio,
	np));
	}
	EXPORT_SYMBOL(of_phy_register_fixed_link);

	void of_phy_deregister_fixed_link(struct device_node *np)
	{
	struct phy_device *phydev;

	phydev = of_phy_find_device(np);
	if (!phydev)
	return;

	fixed_phy_unregister(phydev);

	put_device(&phydev->mdio.dev); /* of_phy_find_device() */
	phy_device_free(phydev); /* fixed_phy_register() */
	}
	EXPORT_SYMBOL(of_phy_deregister_fixed_link);