1/*
  2 *  drivers/extcon/devres.c - EXTCON device's resource management
  3 *
  4 * Copyright (C) 2016 Samsung Electronics
  5 * Author: Chanwoo Choi <cw00.choi@samsung.com>
  6 *
  7 * This software is licensed under the terms of the GNU General Public
  8 * License version 2, as published by the Free Software Foundation, and
  9 * may be copied, distributed, and modified under those terms.
 10 *
 11 * This program is distributed in the hope that it will be useful,
 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 * GNU General Public License for more details.
 15 */
 16
 17#include <linux/extcon.h>
 18
 19static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 20{
 21	struct extcon_dev **r = res;
 22
 23	if (WARN_ON(!r || !*r))
 24		return 0;
 25
 26	return *r == data;
 27}
 28
 29static void devm_extcon_dev_release(struct device *dev, void *res)
 30{
 31	extcon_dev_free(*(struct extcon_dev **)res);
 32}
 33
 34
 35static void devm_extcon_dev_unreg(struct device *dev, void *res)
 36{
 37	extcon_dev_unregister(*(struct extcon_dev **)res);
 38}
 39
 40struct extcon_dev_notifier_devres {
 41	struct extcon_dev *edev;
 42	unsigned int id;
 43	struct notifier_block *nb;
 44};
 45
 46static void devm_extcon_dev_notifier_unreg(struct device *dev, void *res)
 47{
 48	struct extcon_dev_notifier_devres *this = res;
 49
 50	extcon_unregister_notifier(this->edev, this->id, this->nb);
 51}
 52
 53/**
 54 * devm_extcon_dev_allocate - Allocate managed extcon device
 55 * @dev:		device owning the extcon device being created
 56 * @supported_cable:	Array of supported extcon ending with EXTCON_NONE.
 57 *			If supported_cable is NULL, cable name related APIs
 58 *			are disabled.
 59 *
 60 * This function manages automatically the memory of extcon device using device
 61 * resource management and simplify the control of freeing the memory of extcon
 62 * device.
 63 *
 64 * Returns the pointer memory of allocated extcon_dev if success
 65 * or ERR_PTR(err) if fail
 66 */
 67struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 68					const unsigned int *supported_cable)
 69{
 70	struct extcon_dev **ptr, *edev;
 71
 72	ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 73	if (!ptr)
 74		return ERR_PTR(-ENOMEM);
 75
 76	edev = extcon_dev_allocate(supported_cable);
 77	if (IS_ERR(edev)) {
 78		devres_free(ptr);
 79		return edev;
 80	}
 81
 82	edev->dev.parent = dev;
 83
 84	*ptr = edev;
 85	devres_add(dev, ptr);
 86
 87	return edev;
 88}
 89EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 90
 91/**
 92 * devm_extcon_dev_free() - Resource-managed extcon_dev_unregister()
 93 * @dev:	device the extcon belongs to
 94 * @edev:	the extcon device to unregister
 95 *
 96 * Free the memory that is allocated with devm_extcon_dev_allocate()
 97 * function.
 98 */
 99void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
100{
101	WARN_ON(devres_release(dev, devm_extcon_dev_release,
102			       devm_extcon_dev_match, edev));
103}
104EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
105
106/**
107 * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
108 * @dev:	device to allocate extcon device
109 * @edev:	the new extcon device to register
110 *
111 * Managed extcon_dev_register() function. If extcon device is attached with
112 * this function, that extcon device is automatically unregistered on driver
113 * detach. Internally this function calls extcon_dev_register() function.
114 * To get more information, refer that function.
115 *
116 * If extcon device is registered with this function and the device needs to be
117 * unregistered separately, devm_extcon_dev_unregister() should be used.
118 *
119 * Returns 0 if success or negaive error number if failure.
120 */
121int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
122{
123	struct extcon_dev **ptr;
124	int ret;
125
126	ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
127	if (!ptr)
128		return -ENOMEM;
129
130	ret = extcon_dev_register(edev);
131	if (ret) {
132		devres_free(ptr);
133		return ret;
134	}
135
136	*ptr = edev;
137	devres_add(dev, ptr);
138
139	return 0;
140}
141EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
142
143/**
144 * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
145 * @dev:	device the extcon belongs to
146 * @edev:	the extcon device to unregister
147 *
148 * Unregister extcon device that is registered with devm_extcon_dev_register()
149 * function.
150 */
151void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
152{
153	WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
154			       devm_extcon_dev_match, edev));
155}
156EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
157
158/**
159 * devm_extcon_register_notifier() - Resource-managed extcon_register_notifier()
160 * @dev:	device to allocate extcon device
161 * @edev:	the extcon device that has the external connecotr.
162 * @id:		the unique id of each external connector in extcon enumeration.
163 * @nb:		a notifier block to be registered.
164 *
165 * This function manages automatically the notifier of extcon device using
166 * device resource management and simplify the control of unregistering
167 * the notifier of extcon device.
168 *
169 * Note that the second parameter given to the callback of nb (val) is
170 * "old_state", not the current state. The current state can be retrieved
171 * by looking at the third pameter (edev pointer)'s state value.
172 *
173 * Returns 0 if success or negaive error number if failure.
174 */
175int devm_extcon_register_notifier(struct device *dev, struct extcon_dev *edev,
176				unsigned int id, struct notifier_block *nb)
177{
178	struct extcon_dev_notifier_devres *ptr;
179	int ret;
180
181	ptr = devres_alloc(devm_extcon_dev_notifier_unreg, sizeof(*ptr),
182				GFP_KERNEL);
183	if (!ptr)
184		return -ENOMEM;
185
186	ret = extcon_register_notifier(edev, id, nb);
187	if (ret) {
188		devres_free(ptr);
189		return ret;
190	}
191
192	ptr->edev = edev;
193	ptr->id = id;
194	ptr->nb = nb;
195	devres_add(dev, ptr);
196
197	return 0;
198}
199EXPORT_SYMBOL(devm_extcon_register_notifier);
200
201/**
202 * devm_extcon_unregister_notifier()
203			- Resource-managed extcon_unregister_notifier()
204 * @dev:	device to allocate extcon device
205 * @edev:	the extcon device that has the external connecotr.
206 * @id:		the unique id of each external connector in extcon enumeration.
207 * @nb:		a notifier block to be registered.
208 */
209void devm_extcon_unregister_notifier(struct device *dev,
210				struct extcon_dev *edev, unsigned int id,
211				struct notifier_block *nb)
212{
213	WARN_ON(devres_release(dev, devm_extcon_dev_notifier_unreg,
214			       devm_extcon_dev_match, edev));
215}
216EXPORT_SYMBOL(devm_extcon_unregister_notifier);