linux/drivers/extcon/devres.c
Chanwoo Choi 815429b39d extcon: Add new extcon_register_notifier_all() to monitor all external connectors
The extcon core already provides the extcon_register_notifier() function
in order to register the notifier block which is used to monitor
the state change for the specific external connector such as EXTCON_USB,
EXTCON_USB_HOST and so on. The extcon consumer uses the this function.

The extcon consumer might need to monitor the all supported external
connectors from the extcon device. In this case, The extcon consumer
should have each notifier_block structure for each external connector.

This patch adds the new extcon_register_notifier_all() function
that extcon consumer is able to monitor the state change of all
supported external connectors by using only one notifier_block structure.

- List of new added functions:
int extcon_register_notifier_all(struct extcon_dev *edev,
			struct notifier_block *nb);
int extcon_unregister_notifier_all(struct extcon_dev *edev,
			struct notifier_block *nb);
int devm_extcon_register_notifier_all(struct device *dev,
			struct extcon_dev *edev, struct notifier_block *nb);
void devm_extcon_unregister_notifier_all(struct device *dev,
			struct extcon_dev *edev, struct notifier_block *nb);

Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
2017-04-04 11:22:42 +09:00

278 lines
7.9 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 "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);
}
static void devm_extcon_dev_notifier_all_unreg(struct device *dev, void *res)
{
struct extcon_dev_notifier_devres *this = res;
extcon_unregister_notifier_all(this->edev, 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);
/**
* devm_extcon_register_notifier_all()
* - Resource-managed extcon_register_notifier_all()
* @dev: device to allocate extcon device
* @edev: the extcon device that has the external connecotr.
* @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. To get more information, refer that function.
*
* Returns 0 if success or negaive error number if failure.
*/
int devm_extcon_register_notifier_all(struct device *dev, struct extcon_dev *edev,
struct notifier_block *nb)
{
struct extcon_dev_notifier_devres *ptr;
int ret;
ptr = devres_alloc(devm_extcon_dev_notifier_all_unreg, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return -ENOMEM;
ret = extcon_register_notifier_all(edev, nb);
if (ret) {
devres_free(ptr);
return ret;
}
ptr->edev = edev;
ptr->nb = nb;
devres_add(dev, ptr);
return 0;
}
EXPORT_SYMBOL(devm_extcon_register_notifier_all);
/**
* devm_extcon_unregister_notifier_all()
* - Resource-managed extcon_unregister_notifier_all()
* @dev: device to allocate extcon device
* @edev: the extcon device that has the external connecotr.
* @nb: a notifier block to be registered.
*/
void devm_extcon_unregister_notifier_all(struct device *dev,
struct extcon_dev *edev,
struct notifier_block *nb)
{
WARN_ON(devres_release(dev, devm_extcon_dev_notifier_all_unreg,
devm_extcon_dev_match, edev));
}
EXPORT_SYMBOL(devm_extcon_unregister_notifier_all);