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/*
* 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/slab.h>
#include <linux/usb/otg.h>
static LIST_HEAD(phy_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 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 (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
* null 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)) {
pr_err("unable to find transceiver of type %s\n",
usb_phy_type_string(type));
return phy;
}
get_device(phy->dev);
spin_unlock_irqrestore(&phy_lock, flags);
return phy;
}
EXPORT_SYMBOL(usb_get_phy);
/**
* 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)
put_device(x->dev);
}
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 && 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_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;
spin_lock_irqsave(&phy_lock, flags);
if (x)
list_del(&x->head);
spin_unlock_irqrestore(&phy_lock, flags);
}
EXPORT_SYMBOL(usb_remove_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);
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