WSL2-Linux-Kernel/drivers/extcon/devres.c

217 строки
6.1 KiB
C

/*
* drivers/extcon/devres.c - EXTCON device's resource management
*
* Copyright (C) 2016 Samsung Electronics
* Author: Chanwoo Choi <cw00.choi@samsung.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*/
#include <linux/extcon.h>
static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
{
struct extcon_dev **r = res;
if (WARN_ON(!r || !*r))
return 0;
return *r == data;
}
static void devm_extcon_dev_release(struct device *dev, void *res)
{
extcon_dev_free(*(struct extcon_dev **)res);
}
static void devm_extcon_dev_unreg(struct device *dev, void *res)
{
extcon_dev_unregister(*(struct extcon_dev **)res);
}
struct extcon_dev_notifier_devres {
struct extcon_dev *edev;
unsigned int id;
struct notifier_block *nb;
};
static void devm_extcon_dev_notifier_unreg(struct device *dev, void *res)
{
struct extcon_dev_notifier_devres *this = res;
extcon_unregister_notifier(this->edev, this->id, this->nb);
}
/**
* devm_extcon_dev_allocate - Allocate managed extcon device
* @dev: device owning the extcon device being created
* @supported_cable: Array of supported extcon ending with EXTCON_NONE.
* If supported_cable is NULL, cable name related APIs
* are disabled.
*
* This function manages automatically the memory of extcon device using device
* resource management and simplify the control of freeing the memory of extcon
* device.
*
* Returns the pointer memory of allocated extcon_dev if success
* or ERR_PTR(err) if fail
*/
struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
const unsigned int *supported_cable)
{
struct extcon_dev **ptr, *edev;
ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
edev = extcon_dev_allocate(supported_cable);
if (IS_ERR(edev)) {
devres_free(ptr);
return edev;
}
edev->dev.parent = dev;
*ptr = edev;
devres_add(dev, ptr);
return edev;
}
EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
/**
* devm_extcon_dev_free() - Resource-managed extcon_dev_unregister()
* @dev: device the extcon belongs to
* @edev: the extcon device to unregister
*
* Free the memory that is allocated with devm_extcon_dev_allocate()
* function.
*/
void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
{
WARN_ON(devres_release(dev, devm_extcon_dev_release,
devm_extcon_dev_match, edev));
}
EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
/**
* devm_extcon_dev_register() - Resource-managed extcon_dev_register()
* @dev: device to allocate extcon device
* @edev: the new extcon device to register
*
* Managed extcon_dev_register() function. If extcon device is attached with
* this function, that extcon device is automatically unregistered on driver
* detach. Internally this function calls extcon_dev_register() function.
* To get more information, refer that function.
*
* If extcon device is registered with this function and the device needs to be
* unregistered separately, devm_extcon_dev_unregister() should be used.
*
* Returns 0 if success or negaive error number if failure.
*/
int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
{
struct extcon_dev **ptr;
int ret;
ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return -ENOMEM;
ret = extcon_dev_register(edev);
if (ret) {
devres_free(ptr);
return ret;
}
*ptr = edev;
devres_add(dev, ptr);
return 0;
}
EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
/**
* devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
* @dev: device the extcon belongs to
* @edev: the extcon device to unregister
*
* Unregister extcon device that is registered with devm_extcon_dev_register()
* function.
*/
void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
{
WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
devm_extcon_dev_match, edev));
}
EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
/**
* devm_extcon_register_notifier() - Resource-managed extcon_register_notifier()
* @dev: device to allocate extcon device
* @edev: the extcon device that has the external connecotr.
* @id: the unique id of each external connector in extcon enumeration.
* @nb: a notifier block to be registered.
*
* This function manages automatically the notifier of extcon device using
* device resource management and simplify the control of unregistering
* the notifier of extcon device.
*
* Note that the second parameter given to the callback of nb (val) is
* "old_state", not the current state. The current state can be retrieved
* by looking at the third pameter (edev pointer)'s state value.
*
* Returns 0 if success or negaive error number if failure.
*/
int devm_extcon_register_notifier(struct device *dev, struct extcon_dev *edev,
unsigned int id, struct notifier_block *nb)
{
struct extcon_dev_notifier_devres *ptr;
int ret;
ptr = devres_alloc(devm_extcon_dev_notifier_unreg, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return -ENOMEM;
ret = extcon_register_notifier(edev, id, nb);
if (ret) {
devres_free(ptr);
return ret;
}
ptr->edev = edev;
ptr->id = id;
ptr->nb = nb;
devres_add(dev, ptr);
return 0;
}
EXPORT_SYMBOL(devm_extcon_register_notifier);
/**
* devm_extcon_unregister_notifier()
- Resource-managed extcon_unregister_notifier()
* @dev: device to allocate extcon device
* @edev: the extcon device that has the external connecotr.
* @id: the unique id of each external connector in extcon enumeration.
* @nb: a notifier block to be registered.
*/
void devm_extcon_unregister_notifier(struct device *dev,
struct extcon_dev *edev, unsigned int id,
struct notifier_block *nb)
{
WARN_ON(devres_release(dev, devm_extcon_dev_notifier_unreg,
devm_extcon_dev_match, edev));
}
EXPORT_SYMBOL(devm_extcon_unregister_notifier);