diff options
Diffstat (limited to 'drivers/extcon/devres.c')
-rw-r--r-- | drivers/extcon/devres.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/extcon/devres.c b/drivers/extcon/devres.c new file mode 100644 index 000000000000..e686acd1c459 --- /dev/null +++ b/drivers/extcon/devres.c @@ -0,0 +1,216 @@ +/* + * 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); |