drivers/usb/otg/otg.c - kernel/msm-4.9 - Gitiles

 /*
  * otg.c -- USB OTG utility code
  *
  * Copyright (C) 2004 Texas Instruments
  *
  * 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/kernel.h>
 #include <linux/export.h>
 #include <linux/err.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/of.h>

 #include <linux/usb/otg.h>

 static LIST_HEAD(phy_list);
 static LIST_HEAD(phy_bind_list);
 static DEFINE_SPINLOCK(phy_lock);

 static struct usb_phy *__usb_find_phy(struct list_head *list,
 	enum usb_phy_type type)
 {
 	struct usb_phy  *phy = NULL;

 	list_for_each_entry(phy, list, head) {
 		if (phy->type != type)
 			continue;

 		return phy;
 	}

 	return ERR_PTR(-ENODEV);
 }

 static struct usb_phy *__usb_find_phy_dev(struct device *dev,
 	struct list_head *list, u8 index)
 {
 	struct usb_phy_bind *phy_bind = NULL;

 	list_for_each_entry(phy_bind, list, list) {
 		if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
 				phy_bind->index == index) {
 			if (phy_bind->phy)
 				return phy_bind->phy;
 			else
 				return ERR_PTR(-EPROBE_DEFER);
 		}
 	}

 	return ERR_PTR(-ENODEV);
 }

 static struct usb_phy *__of_usb_find_phy(struct device_node *node)
 {
 	struct usb_phy  *phy;

 	list_for_each_entry(phy, &phy_list, head) {
 		if (node != phy->dev->of_node)
 			continue;

 		return phy;
 	}

 	return ERR_PTR(-ENODEV);
 }

 static void devm_usb_phy_release(struct device *dev, void *res)
 {
 	struct usb_phy *phy = *(struct usb_phy **)res;

 	usb_put_phy(phy);
 }

 static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
 {
 	return res == match_data;
 }

 /**
  * devm_usb_get_phy - find the USB PHY
  * @dev - device that requests this phy
  * @type - the type of the phy the controller requires
  *
  * Gets the phy using usb_get_phy(), and associates a device with it using
  * devres. On driver detach, release function is invoked on the devres data,
  * then, devres data is freed.
  *
  * For use by USB host and peripheral drivers.
  */
 struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
 {
 	struct usb_phy **ptr, *phy;

 	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 	if (!ptr)
 		return NULL;

 	phy = usb_get_phy(type);
 	if (!IS_ERR(phy)) {
 		*ptr = phy;
 		devres_add(dev, ptr);
 	} else
 		devres_free(ptr);

 	return phy;
 }
 EXPORT_SYMBOL(devm_usb_get_phy);

 /**
  * usb_get_phy - find the USB PHY
  * @type - the type of the phy the controller requires
  *
  * Returns the phy driver, after getting a refcount to it; or
  * -ENODEV if there is no such phy.  The caller is responsible for
  * calling usb_put_phy() to release that count.
  *
  * For use by USB host and peripheral drivers.
  */
 struct usb_phy *usb_get_phy(enum usb_phy_type type)
 {
 	struct usb_phy	*phy = NULL;
 	unsigned long	flags;

 	spin_lock_irqsave(&phy_lock, flags);

 	phy = __usb_find_phy(&phy_list, type);
 	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
 		pr_err("unable to find transceiver of type %s\n",
 			usb_phy_type_string(type));
 		goto err0;
 	}

 	get_device(phy->dev);

 err0:
 	spin_unlock_irqrestore(&phy_lock, flags);

 	return phy;
 }
 EXPORT_SYMBOL(usb_get_phy);

  /**
  * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
  * @dev - device that requests this phy
  * @phandle - name of the property holding the phy phandle value
  * @index - the index of the phy
  *
  * Returns the phy driver associated with the given phandle value,
  * after getting a refcount to it, -ENODEV if there is no such phy or
  * -EPROBE_DEFER if there is a phandle to the phy, but the device is
  * not yet loaded. While at that, it also associates the device with
  * the phy using devres. On driver detach, release function is invoked
  * on the devres data, then, devres data is freed.
  *
  * For use by USB host and peripheral drivers.
  */
 struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
 	const char *phandle, u8 index)
 {
 	struct usb_phy	*phy = ERR_PTR(-ENOMEM), **ptr;
 	unsigned long	flags;
 	struct device_node *node;

 	if (!dev->of_node) {
 		dev_dbg(dev, "device does not have a device node entry\n");
 		return ERR_PTR(-EINVAL);
 	}

 	node = of_parse_phandle(dev->of_node, phandle, index);
 	if (!node) {
 		dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
 			dev->of_node->full_name);
 		return ERR_PTR(-ENODEV);
 	}

 	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 	if (!ptr) {
 		dev_dbg(dev, "failed to allocate memory for devres\n");
 		goto err0;
 	}

 	spin_lock_irqsave(&phy_lock, flags);

 	phy = __of_usb_find_phy(node);
 	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
 		phy = ERR_PTR(-EPROBE_DEFER);
 		devres_free(ptr);
 		goto err1;
 	}

 	*ptr = phy;
 	devres_add(dev, ptr);

 	get_device(phy->dev);

 err1:
 	spin_unlock_irqrestore(&phy_lock, flags);

 err0:
 	of_node_put(node);

 	return phy;
 }
 EXPORT_SYMBOL(devm_usb_get_phy_by_phandle);

 /**
  * usb_get_phy_dev - find the USB PHY
  * @dev - device that requests this phy
  * @index - the index of the phy
  *
  * Returns the phy driver, after getting a refcount to it; or
  * -ENODEV if there is no such phy.  The caller is responsible for
  * calling usb_put_phy() to release that count.
  *
  * For use by USB host and peripheral drivers.
  */
 struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
 {
 	struct usb_phy	*phy = NULL;
 	unsigned long	flags;

 	spin_lock_irqsave(&phy_lock, flags);

 	phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
 	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
 		pr_err("unable to find transceiver\n");
 		goto err0;
 	}

 	get_device(phy->dev);

 err0:
 	spin_unlock_irqrestore(&phy_lock, flags);

 	return phy;
 }
 EXPORT_SYMBOL(usb_get_phy_dev);

 /**
  * devm_usb_get_phy_dev - find the USB PHY using device ptr and index
  * @dev - device that requests this phy
  * @index - the index of the phy
  *
  * Gets the phy using usb_get_phy_dev(), and associates a device with it using
  * devres. On driver detach, release function is invoked on the devres data,
  * then, devres data is freed.
  *
  * For use by USB host and peripheral drivers.
  */
 struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
 {
 	struct usb_phy **ptr, *phy;

 	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 	if (!ptr)
 		return NULL;

 	phy = usb_get_phy_dev(dev, index);
 	if (!IS_ERR(phy)) {
 		*ptr = phy;
 		devres_add(dev, ptr);
 	} else
 		devres_free(ptr);

 	return phy;
 }
 EXPORT_SYMBOL(devm_usb_get_phy_dev);

 /**
  * devm_usb_put_phy - release the USB PHY
  * @dev - device that wants to release this phy
  * @phy - the phy returned by devm_usb_get_phy()
  *
  * destroys the devres associated with this phy and invokes usb_put_phy
  * to release the phy.
  *
  * For use by USB host and peripheral drivers.
  */
 void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
 {
 	int r;

 	r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
 	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
 }
 EXPORT_SYMBOL(devm_usb_put_phy);

 /**
  * usb_put_phy - release the USB PHY
  * @x: the phy returned by usb_get_phy()
  *
  * Releases a refcount the caller received from usb_get_phy().
  *
  * For use by USB host and peripheral drivers.
  */
 void usb_put_phy(struct usb_phy *x)
 {
 	if (x) {
 		struct module *owner = x->dev->driver->owner;

 		put_device(x->dev);
 		module_put(owner);
 	}
 }
 EXPORT_SYMBOL(usb_put_phy);

 /**
  * usb_add_phy - declare the USB PHY
  * @x: the USB phy to be used; or NULL
  * @type - the type of this PHY
  *
  * This call is exclusively for use by phy drivers, which
  * coordinate the activities of drivers for host and peripheral
  * controllers, and in some cases for VBUS current regulation.
  */
 int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
 {
 	int		ret = 0;
 	unsigned long	flags;
 	struct usb_phy	*phy;

 	if (x->type != USB_PHY_TYPE_UNDEFINED) {
 		dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
 		return -EINVAL;
 	}

 	spin_lock_irqsave(&phy_lock, flags);

 	list_for_each_entry(phy, &phy_list, head) {
 		if (phy->type == type) {
 			ret = -EBUSY;
 			dev_err(x->dev, "transceiver type %s already exists\n",
 						usb_phy_type_string(type));
 			goto out;
 		}
 	}

 	x->type = type;
 	list_add_tail(&x->head, &phy_list);

 out:
 	spin_unlock_irqrestore(&phy_lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(usb_add_phy);

 /**
  * usb_add_phy_dev - declare the USB PHY
  * @x: the USB phy to be used; or NULL
  *
  * This call is exclusively for use by phy drivers, which
  * coordinate the activities of drivers for host and peripheral
  * controllers, and in some cases for VBUS current regulation.
  */
 int usb_add_phy_dev(struct usb_phy *x)
 {
 	struct usb_phy_bind *phy_bind;
 	unsigned long flags;

 	if (!x->dev) {
 		dev_err(x->dev, "no device provided for PHY\n");
 		return -EINVAL;
 	}

 	spin_lock_irqsave(&phy_lock, flags);
 	list_for_each_entry(phy_bind, &phy_bind_list, list)
 		if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
 			phy_bind->phy = x;

 	list_add_tail(&x->head, &phy_list);

 	spin_unlock_irqrestore(&phy_lock, flags);
 	return 0;
 }
 EXPORT_SYMBOL(usb_add_phy_dev);

 /**
  * usb_remove_phy - remove the OTG PHY
  * @x: the USB OTG PHY to be removed;
  *
  * This reverts the effects of usb_add_phy
  */
 void usb_remove_phy(struct usb_phy *x)
 {
 	unsigned long	flags;
 	struct usb_phy_bind *phy_bind;

 	spin_lock_irqsave(&phy_lock, flags);
 	if (x) {
 		list_for_each_entry(phy_bind, &phy_bind_list, list)
 			if (phy_bind->phy == x)
 				phy_bind->phy = NULL;
 		list_del(&x->head);
 	}
 	spin_unlock_irqrestore(&phy_lock, flags);
 }
 EXPORT_SYMBOL(usb_remove_phy);

 /**
  * usb_bind_phy - bind the phy and the controller that uses the phy
  * @dev_name: the device name of the device that will bind to the phy
  * @index: index to specify the port number
  * @phy_dev_name: the device name of the phy
  *
  * Fills the phy_bind structure with the dev_name and phy_dev_name. This will
  * be used when the phy driver registers the phy and when the controller
  * requests this phy.
  *
  * To be used by platform specific initialization code.
  */
 int __init usb_bind_phy(const char *dev_name, u8 index,
 				const char *phy_dev_name)
 {
 	struct usb_phy_bind *phy_bind;
 	unsigned long flags;

 	phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
 	if (!phy_bind) {
 		pr_err("phy_bind(): No memory for phy_bind");
 		return -ENOMEM;
 	}

 	phy_bind->dev_name = dev_name;
 	phy_bind->phy_dev_name = phy_dev_name;
 	phy_bind->index = index;

 	spin_lock_irqsave(&phy_lock, flags);
 	list_add_tail(&phy_bind->list, &phy_bind_list);
 	spin_unlock_irqrestore(&phy_lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(usb_bind_phy);

 const char *otg_state_string(enum usb_otg_state state)
 {
 	switch (state) {
 	case OTG_STATE_A_IDLE:
 		return "a_idle";
 	case OTG_STATE_A_WAIT_VRISE:
 		return "a_wait_vrise";
 	case OTG_STATE_A_WAIT_BCON:
 		return "a_wait_bcon";
 	case OTG_STATE_A_HOST:
 		return "a_host";
 	case OTG_STATE_A_SUSPEND:
 		return "a_suspend";
 	case OTG_STATE_A_PERIPHERAL:
 		return "a_peripheral";
 	case OTG_STATE_A_WAIT_VFALL:
 		return "a_wait_vfall";
 	case OTG_STATE_A_VBUS_ERR:
 		return "a_vbus_err";
 	case OTG_STATE_B_IDLE:
 		return "b_idle";
 	case OTG_STATE_B_SRP_INIT:
 		return "b_srp_init";
 	case OTG_STATE_B_PERIPHERAL:
 		return "b_peripheral";
 	case OTG_STATE_B_WAIT_ACON:
 		return "b_wait_acon";
 	case OTG_STATE_B_HOST:
 		return "b_host";
 	default:
 		return "UNDEFINED";
 	}
 }
 EXPORT_SYMBOL(otg_state_string);
	/*
	* otg.c -- USB OTG utility code
	*
	* Copyright (C) 2004 Texas Instruments
	*
	* 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/kernel.h>
	#include <linux/export.h>
	#include <linux/err.h>
	#include <linux/device.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/of.h>

	#include <linux/usb/otg.h>

	static LIST_HEAD(phy_list);
	static LIST_HEAD(phy_bind_list);
	static DEFINE_SPINLOCK(phy_lock);

	static struct usb_phy __usb_find_phy(struct list_head list,
	enum usb_phy_type type)
	{
	struct usb_phy *phy = NULL;

	list_for_each_entry(phy, list, head) {
	if (phy->type != type)
	continue;

	return phy;
	}

	return ERR_PTR(-ENODEV);
	}

	static struct usb_phy __usb_find_phy_dev(struct device dev,
	struct list_head *list, u8 index)
	{
	struct usb_phy_bind *phy_bind = NULL;

	list_for_each_entry(phy_bind, list, list) {
	if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
	phy_bind->index == index) {
	if (phy_bind->phy)
	return phy_bind->phy;
	else
	return ERR_PTR(-EPROBE_DEFER);
	}
	}

	return ERR_PTR(-ENODEV);
	}

	static struct usb_phy __of_usb_find_phy(struct device_node node)
	{
	struct usb_phy *phy;

	list_for_each_entry(phy, &phy_list, head) {
	if (node != phy->dev->of_node)
	continue;

	return phy;
	}

	return ERR_PTR(-ENODEV);
	}

	static void devm_usb_phy_release(struct device dev, void res)
	{
	struct usb_phy phy = (struct usb_phy **)res;

	usb_put_phy(phy);
	}

	static int devm_usb_phy_match(struct device dev, void res, void *match_data)
	{
	return res == match_data;
	}

	/**
	* devm_usb_get_phy - find the USB PHY
	* @dev - device that requests this phy
	* @type - the type of the phy the controller requires
	*
	* Gets the phy using usb_get_phy(), and associates a device with it using
	* devres. On driver detach, release function is invoked on the devres data,
	* then, devres data is freed.
	*
	* For use by USB host and peripheral drivers.
	*/
	struct usb_phy devm_usb_get_phy(struct device dev, enum usb_phy_type type)
	{
	struct usb_phy *ptr, phy;

	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
	return NULL;

	phy = usb_get_phy(type);
	if (!IS_ERR(phy)) {
	*ptr = phy;
	devres_add(dev, ptr);
	} else
	devres_free(ptr);

	return phy;
	}
	EXPORT_SYMBOL(devm_usb_get_phy);

	/**
	* usb_get_phy - find the USB PHY
	* @type - the type of the phy the controller requires
	*
	* Returns the phy driver, after getting a refcount to it; or
	* -ENODEV if there is no such phy. The caller is responsible for
	* calling usb_put_phy() to release that count.
	*
	* For use by USB host and peripheral drivers.
	*/
	struct usb_phy *usb_get_phy(enum usb_phy_type type)
	{
	struct usb_phy *phy = NULL;
	unsigned long flags;

	spin_lock_irqsave(&phy_lock, flags);

	phy = __usb_find_phy(&phy_list, type);
	if (IS_ERR(phy) \|\| !try_module_get(phy->dev->driver->owner)) {
	pr_err("unable to find transceiver of type %s\n",
	usb_phy_type_string(type));
	goto err0;
	}

	get_device(phy->dev);

	err0:
	spin_unlock_irqrestore(&phy_lock, flags);

	return phy;
	}
	EXPORT_SYMBOL(usb_get_phy);

	/**
	* devm_usb_get_phy_by_phandle - find the USB PHY by phandle
	* @dev - device that requests this phy
	* @phandle - name of the property holding the phy phandle value
	* @index - the index of the phy
	*
	* Returns the phy driver associated with the given phandle value,
	* after getting a refcount to it, -ENODEV if there is no such phy or
	* -EPROBE_DEFER if there is a phandle to the phy, but the device is
	* not yet loaded. While at that, it also associates the device with
	* the phy using devres. On driver detach, release function is invoked
	* on the devres data, then, devres data is freed.
	*
	* For use by USB host and peripheral drivers.
	*/
	struct usb_phy devm_usb_get_phy_by_phandle(struct device dev,
	const char *phandle, u8 index)
	{
	struct usb_phy phy = ERR_PTR(-ENOMEM), *ptr;
	unsigned long flags;
	struct device_node *node;

	if (!dev->of_node) {
	dev_dbg(dev, "device does not have a device node entry\n");
	return ERR_PTR(-EINVAL);
	}

	node = of_parse_phandle(dev->of_node, phandle, index);
	if (!node) {
	dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
	dev->of_node->full_name);
	return ERR_PTR(-ENODEV);
	}

	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr) {
	dev_dbg(dev, "failed to allocate memory for devres\n");
	goto err0;
	}

	spin_lock_irqsave(&phy_lock, flags);

	phy = __of_usb_find_phy(node);
	if (IS_ERR(phy) \|\| !try_module_get(phy->dev->driver->owner)) {
	phy = ERR_PTR(-EPROBE_DEFER);
	devres_free(ptr);
	goto err1;
	}

	*ptr = phy;
	devres_add(dev, ptr);

	get_device(phy->dev);

	err1:
	spin_unlock_irqrestore(&phy_lock, flags);

	err0:
	of_node_put(node);

	return phy;
	}
	EXPORT_SYMBOL(devm_usb_get_phy_by_phandle);

	/**
	* usb_get_phy_dev - find the USB PHY
	* @dev - device that requests this phy
	* @index - the index of the phy
	*
	* Returns the phy driver, after getting a refcount to it; or
	* -ENODEV if there is no such phy. The caller is responsible for
	* calling usb_put_phy() to release that count.
	*
	* For use by USB host and peripheral drivers.
	*/
	struct usb_phy usb_get_phy_dev(struct device dev, u8 index)
	{
	struct usb_phy *phy = NULL;
	unsigned long flags;

	spin_lock_irqsave(&phy_lock, flags);

	phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
	if (IS_ERR(phy) \|\| !try_module_get(phy->dev->driver->owner)) {
	pr_err("unable to find transceiver\n");
	goto err0;
	}

	get_device(phy->dev);

	err0:
	spin_unlock_irqrestore(&phy_lock, flags);

	return phy;
	}
	EXPORT_SYMBOL(usb_get_phy_dev);

	/**
	* devm_usb_get_phy_dev - find the USB PHY using device ptr and index
	* @dev - device that requests this phy
	* @index - the index of the phy
	*
	* Gets the phy using usb_get_phy_dev(), and associates a device with it using
	* devres. On driver detach, release function is invoked on the devres data,
	* then, devres data is freed.
	*
	* For use by USB host and peripheral drivers.
	*/
	struct usb_phy devm_usb_get_phy_dev(struct device dev, u8 index)
	{
	struct usb_phy *ptr, phy;

	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
	return NULL;

	phy = usb_get_phy_dev(dev, index);
	if (!IS_ERR(phy)) {
	*ptr = phy;
	devres_add(dev, ptr);
	} else
	devres_free(ptr);

	return phy;
	}
	EXPORT_SYMBOL(devm_usb_get_phy_dev);

	/**
	* devm_usb_put_phy - release the USB PHY
	* @dev - device that wants to release this phy
	* @phy - the phy returned by devm_usb_get_phy()
	*
	* destroys the devres associated with this phy and invokes usb_put_phy
	* to release the phy.
	*
	* For use by USB host and peripheral drivers.
	*/
	void devm_usb_put_phy(struct device dev, struct usb_phy phy)
	{
	int r;

	r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
	}
	EXPORT_SYMBOL(devm_usb_put_phy);

	/**
	* usb_put_phy - release the USB PHY
	* @x: the phy returned by usb_get_phy()
	*
	* Releases a refcount the caller received from usb_get_phy().
	*
	* For use by USB host and peripheral drivers.
	*/
	void usb_put_phy(struct usb_phy *x)
	{
	if (x) {
	struct module *owner = x->dev->driver->owner;

	put_device(x->dev);
	module_put(owner);
	}
	}
	EXPORT_SYMBOL(usb_put_phy);

	/**
	* usb_add_phy - declare the USB PHY
	* @x: the USB phy to be used; or NULL
	* @type - the type of this PHY
	*
	* This call is exclusively for use by phy drivers, which
	* coordinate the activities of drivers for host and peripheral
	* controllers, and in some cases for VBUS current regulation.
	*/
	int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
	{
	int ret = 0;
	unsigned long flags;
	struct usb_phy *phy;

	if (x->type != USB_PHY_TYPE_UNDEFINED) {
	dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
	return -EINVAL;
	}

	spin_lock_irqsave(&phy_lock, flags);

	list_for_each_entry(phy, &phy_list, head) {
	if (phy->type == type) {
	ret = -EBUSY;
	dev_err(x->dev, "transceiver type %s already exists\n",
	usb_phy_type_string(type));
	goto out;
	}
	}

	x->type = type;
	list_add_tail(&x->head, &phy_list);

	out:
	spin_unlock_irqrestore(&phy_lock, flags);
	return ret;
	}
	EXPORT_SYMBOL(usb_add_phy);

	/**
	* usb_add_phy_dev - declare the USB PHY
	* @x: the USB phy to be used; or NULL
	*
	* This call is exclusively for use by phy drivers, which
	* coordinate the activities of drivers for host and peripheral
	* controllers, and in some cases for VBUS current regulation.
	*/
	int usb_add_phy_dev(struct usb_phy *x)
	{
	struct usb_phy_bind *phy_bind;
	unsigned long flags;

	if (!x->dev) {
	dev_err(x->dev, "no device provided for PHY\n");
	return -EINVAL;
	}

	spin_lock_irqsave(&phy_lock, flags);
	list_for_each_entry(phy_bind, &phy_bind_list, list)
	if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
	phy_bind->phy = x;

	list_add_tail(&x->head, &phy_list);

	spin_unlock_irqrestore(&phy_lock, flags);
	return 0;
	}
	EXPORT_SYMBOL(usb_add_phy_dev);

	/**
	* usb_remove_phy - remove the OTG PHY
	* @x: the USB OTG PHY to be removed;
	*
	* This reverts the effects of usb_add_phy
	*/
	void usb_remove_phy(struct usb_phy *x)
	{
	unsigned long flags;
	struct usb_phy_bind *phy_bind;

	spin_lock_irqsave(&phy_lock, flags);
	if (x) {
	list_for_each_entry(phy_bind, &phy_bind_list, list)
	if (phy_bind->phy == x)
	phy_bind->phy = NULL;
	list_del(&x->head);
	}
	spin_unlock_irqrestore(&phy_lock, flags);
	}
	EXPORT_SYMBOL(usb_remove_phy);

	/**
	* usb_bind_phy - bind the phy and the controller that uses the phy
	* @dev_name: the device name of the device that will bind to the phy
	* @index: index to specify the port number
	* @phy_dev_name: the device name of the phy
	*
	* Fills the phy_bind structure with the dev_name and phy_dev_name. This will
	* be used when the phy driver registers the phy and when the controller
	* requests this phy.
	*
	* To be used by platform specific initialization code.
	*/
	int __init usb_bind_phy(const char *dev_name, u8 index,
	const char *phy_dev_name)
	{
	struct usb_phy_bind *phy_bind;
	unsigned long flags;

	phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
	if (!phy_bind) {
	pr_err("phy_bind(): No memory for phy_bind");
	return -ENOMEM;
	}

	phy_bind->dev_name = dev_name;
	phy_bind->phy_dev_name = phy_dev_name;
	phy_bind->index = index;

	spin_lock_irqsave(&phy_lock, flags);
	list_add_tail(&phy_bind->list, &phy_bind_list);
	spin_unlock_irqrestore(&phy_lock, flags);

	return 0;
	}
	EXPORT_SYMBOL_GPL(usb_bind_phy);

	const char *otg_state_string(enum usb_otg_state state)
	{
	switch (state) {
	case OTG_STATE_A_IDLE:
	return "a_idle";
	case OTG_STATE_A_WAIT_VRISE:
	return "a_wait_vrise";
	case OTG_STATE_A_WAIT_BCON:
	return "a_wait_bcon";
	case OTG_STATE_A_HOST:
	return "a_host";
	case OTG_STATE_A_SUSPEND:
	return "a_suspend";
	case OTG_STATE_A_PERIPHERAL:
	return "a_peripheral";
	case OTG_STATE_A_WAIT_VFALL:
	return "a_wait_vfall";
	case OTG_STATE_A_VBUS_ERR:
	return "a_vbus_err";
	case OTG_STATE_B_IDLE:
	return "b_idle";
	case OTG_STATE_B_SRP_INIT:
	return "b_srp_init";
	case OTG_STATE_B_PERIPHERAL:
	return "b_peripheral";
	case OTG_STATE_B_WAIT_ACON:
	return "b_wait_acon";
	case OTG_STATE_B_HOST:
	return "b_host";
	default:
	return "UNDEFINED";
	}
	}
	EXPORT_SYMBOL(otg_state_string);