Linux kernel mirror (for testing)
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linux
1/*
2 * drivers/gpio/devres.c - managed gpio resources
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2
6 * as published by the Free Software Foundation.
7 *
8 * You should have received a copy of the GNU General Public License
9 * along with this program; if not, write to the Free Software
10 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
11 *
12 * This file is based on kernel/irq/devres.c
13 *
14 * Copyright (c) 2011 John Crispin <blogic@openwrt.org>
15 */
16
17#include <linux/module.h>
18#include <linux/err.h>
19#include <linux/gpio.h>
20#include <linux/gpio/consumer.h>
21#include <linux/device.h>
22#include <linux/gfp.h>
23
24static void devm_gpiod_release(struct device *dev, void *res)
25{
26 struct gpio_desc **desc = res;
27
28 gpiod_put(*desc);
29}
30
31static int devm_gpiod_match(struct device *dev, void *res, void *data)
32{
33 struct gpio_desc **this = res, **gpio = data;
34
35 return *this == *gpio;
36}
37
38/**
39 * devm_gpiod_get - Resource-managed gpiod_get()
40 * @dev: GPIO consumer
41 * @con_id: function within the GPIO consumer
42 * @flags: optional GPIO initialization flags
43 *
44 * Managed gpiod_get(). GPIO descriptors returned from this function are
45 * automatically disposed on driver detach. See gpiod_get() for detailed
46 * information about behavior and return values.
47 */
48struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev,
49 const char *con_id,
50 enum gpiod_flags flags)
51{
52 return devm_gpiod_get_index(dev, con_id, 0, flags);
53}
54EXPORT_SYMBOL(__devm_gpiod_get);
55
56/**
57 * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
58 * @dev: GPIO consumer
59 * @con_id: function within the GPIO consumer
60 * @flags: optional GPIO initialization flags
61 *
62 * Managed gpiod_get_optional(). GPIO descriptors returned from this function
63 * are automatically disposed on driver detach. See gpiod_get_optional() for
64 * detailed information about behavior and return values.
65 */
66struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev,
67 const char *con_id,
68 enum gpiod_flags flags)
69{
70 return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
71}
72EXPORT_SYMBOL(__devm_gpiod_get_optional);
73
74/**
75 * devm_gpiod_get_index - Resource-managed gpiod_get_index()
76 * @dev: GPIO consumer
77 * @con_id: function within the GPIO consumer
78 * @idx: index of the GPIO to obtain in the consumer
79 * @flags: optional GPIO initialization flags
80 *
81 * Managed gpiod_get_index(). GPIO descriptors returned from this function are
82 * automatically disposed on driver detach. See gpiod_get_index() for detailed
83 * information about behavior and return values.
84 */
85struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev,
86 const char *con_id,
87 unsigned int idx,
88 enum gpiod_flags flags)
89{
90 struct gpio_desc **dr;
91 struct gpio_desc *desc;
92
93 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
94 GFP_KERNEL);
95 if (!dr)
96 return ERR_PTR(-ENOMEM);
97
98 desc = gpiod_get_index(dev, con_id, idx, flags);
99 if (IS_ERR(desc)) {
100 devres_free(dr);
101 return desc;
102 }
103
104 *dr = desc;
105 devres_add(dev, dr);
106
107 return desc;
108}
109EXPORT_SYMBOL(__devm_gpiod_get_index);
110
111/**
112 * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
113 * @dev: GPIO consumer
114 * @child: firmware node (child of @dev)
115 *
116 * GPIO descriptors returned from this function are automatically disposed on
117 * driver detach.
118 */
119struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
120 struct fwnode_handle *child)
121{
122 struct gpio_desc **dr;
123 struct gpio_desc *desc;
124
125 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
126 GFP_KERNEL);
127 if (!dr)
128 return ERR_PTR(-ENOMEM);
129
130 desc = fwnode_get_named_gpiod(child, "gpios");
131 if (IS_ERR(desc)) {
132 devres_free(dr);
133 return desc;
134 }
135
136 *dr = desc;
137 devres_add(dev, dr);
138
139 return desc;
140}
141EXPORT_SYMBOL(devm_get_gpiod_from_child);
142
143/**
144 * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
145 * @dev: GPIO consumer
146 * @con_id: function within the GPIO consumer
147 * @index: index of the GPIO to obtain in the consumer
148 * @flags: optional GPIO initialization flags
149 *
150 * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
151 * function are automatically disposed on driver detach. See
152 * gpiod_get_index_optional() for detailed information about behavior and
153 * return values.
154 */
155struct gpio_desc *__must_check __devm_gpiod_get_index_optional(struct device *dev,
156 const char *con_id,
157 unsigned int index,
158 enum gpiod_flags flags)
159{
160 struct gpio_desc *desc;
161
162 desc = devm_gpiod_get_index(dev, con_id, index, flags);
163 if (IS_ERR(desc)) {
164 if (PTR_ERR(desc) == -ENOENT)
165 return NULL;
166 }
167
168 return desc;
169}
170EXPORT_SYMBOL(__devm_gpiod_get_index_optional);
171
172/**
173 * devm_gpiod_put - Resource-managed gpiod_put()
174 * @desc: GPIO descriptor to dispose of
175 *
176 * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
177 * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
178 * will be disposed of by the resource management code.
179 */
180void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
181{
182 WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
183 &desc));
184}
185EXPORT_SYMBOL(devm_gpiod_put);
186
187
188
189
190static void devm_gpio_release(struct device *dev, void *res)
191{
192 unsigned *gpio = res;
193
194 gpio_free(*gpio);
195}
196
197static int devm_gpio_match(struct device *dev, void *res, void *data)
198{
199 unsigned *this = res, *gpio = data;
200
201 return *this == *gpio;
202}
203
204/**
205 * devm_gpio_request - request a GPIO for a managed device
206 * @dev: device to request the GPIO for
207 * @gpio: GPIO to allocate
208 * @label: the name of the requested GPIO
209 *
210 * Except for the extra @dev argument, this function takes the
211 * same arguments and performs the same function as
212 * gpio_request(). GPIOs requested with this function will be
213 * automatically freed on driver detach.
214 *
215 * If an GPIO allocated with this function needs to be freed
216 * separately, devm_gpio_free() must be used.
217 */
218
219int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
220{
221 unsigned *dr;
222 int rc;
223
224 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
225 if (!dr)
226 return -ENOMEM;
227
228 rc = gpio_request(gpio, label);
229 if (rc) {
230 devres_free(dr);
231 return rc;
232 }
233
234 *dr = gpio;
235 devres_add(dev, dr);
236
237 return 0;
238}
239EXPORT_SYMBOL(devm_gpio_request);
240
241/**
242 * devm_gpio_request_one - request a single GPIO with initial setup
243 * @dev: device to request for
244 * @gpio: the GPIO number
245 * @flags: GPIO configuration as specified by GPIOF_*
246 * @label: a literal description string of this GPIO
247 */
248int devm_gpio_request_one(struct device *dev, unsigned gpio,
249 unsigned long flags, const char *label)
250{
251 unsigned *dr;
252 int rc;
253
254 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
255 if (!dr)
256 return -ENOMEM;
257
258 rc = gpio_request_one(gpio, flags, label);
259 if (rc) {
260 devres_free(dr);
261 return rc;
262 }
263
264 *dr = gpio;
265 devres_add(dev, dr);
266
267 return 0;
268}
269EXPORT_SYMBOL(devm_gpio_request_one);
270
271/**
272 * devm_gpio_free - free a GPIO
273 * @dev: device to free GPIO for
274 * @gpio: GPIO to free
275 *
276 * Except for the extra @dev argument, this function takes the
277 * same arguments and performs the same function as gpio_free().
278 * This function instead of gpio_free() should be used to manually
279 * free GPIOs allocated with devm_gpio_request().
280 */
281void devm_gpio_free(struct device *dev, unsigned int gpio)
282{
283
284 WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
285 &gpio));
286}
287EXPORT_SYMBOL(devm_gpio_free);