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
devm_gpiod_release(struct device * dev,void * res)24 static void devm_gpiod_release(struct device *dev, void *res)
25 {
26 struct gpio_desc **desc = res;
27
28 gpiod_put(*desc);
29 }
30
devm_gpiod_match(struct device * dev,void * res,void * data)31 static 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
devm_gpiod_release_array(struct device * dev,void * res)38 static void devm_gpiod_release_array(struct device *dev, void *res)
39 {
40 struct gpio_descs **descs = res;
41
42 gpiod_put_array(*descs);
43 }
44
devm_gpiod_match_array(struct device * dev,void * res,void * data)45 static int devm_gpiod_match_array(struct device *dev, void *res, void *data)
46 {
47 struct gpio_descs **this = res, **gpios = data;
48
49 return *this == *gpios;
50 }
51
52 /**
53 * devm_gpiod_get - Resource-managed gpiod_get()
54 * @dev: GPIO consumer
55 * @con_id: function within the GPIO consumer
56 * @flags: optional GPIO initialization flags
57 *
58 * Managed gpiod_get(). GPIO descriptors returned from this function are
59 * automatically disposed on driver detach. See gpiod_get() for detailed
60 * information about behavior and return values.
61 */
devm_gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)62 struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
63 const char *con_id,
64 enum gpiod_flags flags)
65 {
66 return devm_gpiod_get_index(dev, con_id, 0, flags);
67 }
68 EXPORT_SYMBOL(devm_gpiod_get);
69
70 /**
71 * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
72 * @dev: GPIO consumer
73 * @con_id: function within the GPIO consumer
74 * @flags: optional GPIO initialization flags
75 *
76 * Managed gpiod_get_optional(). GPIO descriptors returned from this function
77 * are automatically disposed on driver detach. See gpiod_get_optional() for
78 * detailed information about behavior and return values.
79 */
devm_gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)80 struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
81 const char *con_id,
82 enum gpiod_flags flags)
83 {
84 return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
85 }
86 EXPORT_SYMBOL(devm_gpiod_get_optional);
87
88 /**
89 * devm_gpiod_get_index - Resource-managed gpiod_get_index()
90 * @dev: GPIO consumer
91 * @con_id: function within the GPIO consumer
92 * @idx: index of the GPIO to obtain in the consumer
93 * @flags: optional GPIO initialization flags
94 *
95 * Managed gpiod_get_index(). GPIO descriptors returned from this function are
96 * automatically disposed on driver detach. See gpiod_get_index() for detailed
97 * information about behavior and return values.
98 */
devm_gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)99 struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
100 const char *con_id,
101 unsigned int idx,
102 enum gpiod_flags flags)
103 {
104 struct gpio_desc **dr;
105 struct gpio_desc *desc;
106
107 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
108 GFP_KERNEL);
109 if (!dr)
110 return ERR_PTR(-ENOMEM);
111
112 desc = gpiod_get_index(dev, con_id, idx, flags);
113 if (IS_ERR(desc)) {
114 devres_free(dr);
115 return desc;
116 }
117
118 *dr = desc;
119 devres_add(dev, dr);
120
121 return desc;
122 }
123 EXPORT_SYMBOL(devm_gpiod_get_index);
124
125 /**
126 * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
127 * @dev: GPIO consumer
128 * @con_id: function within the GPIO consumer
129 * @child: firmware node (child of @dev)
130 *
131 * GPIO descriptors returned from this function are automatically disposed on
132 * driver detach.
133 */
devm_get_gpiod_from_child(struct device * dev,const char * con_id,struct fwnode_handle * child)134 struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
135 const char *con_id,
136 struct fwnode_handle *child)
137 {
138 static const char * const suffixes[] = { "gpios", "gpio" };
139 char prop_name[32]; /* 32 is max size of property name */
140 struct gpio_desc **dr;
141 struct gpio_desc *desc;
142 unsigned int i;
143
144 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
145 GFP_KERNEL);
146 if (!dr)
147 return ERR_PTR(-ENOMEM);
148
149 for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
150 if (con_id)
151 snprintf(prop_name, sizeof(prop_name), "%s-%s",
152 con_id, suffixes[i]);
153 else
154 snprintf(prop_name, sizeof(prop_name), "%s",
155 suffixes[i]);
156
157 desc = fwnode_get_named_gpiod(child, prop_name);
158 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
159 break;
160 }
161 if (IS_ERR(desc)) {
162 devres_free(dr);
163 return desc;
164 }
165
166 *dr = desc;
167 devres_add(dev, dr);
168
169 return desc;
170 }
171 EXPORT_SYMBOL(devm_get_gpiod_from_child);
172
173 /**
174 * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
175 * @dev: GPIO consumer
176 * @con_id: function within the GPIO consumer
177 * @index: index of the GPIO to obtain in the consumer
178 * @flags: optional GPIO initialization flags
179 *
180 * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
181 * function are automatically disposed on driver detach. See
182 * gpiod_get_index_optional() for detailed information about behavior and
183 * return values.
184 */
devm_gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)185 struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
186 const char *con_id,
187 unsigned int index,
188 enum gpiod_flags flags)
189 {
190 struct gpio_desc *desc;
191
192 desc = devm_gpiod_get_index(dev, con_id, index, flags);
193 if (IS_ERR(desc)) {
194 if (PTR_ERR(desc) == -ENOENT)
195 return NULL;
196 }
197
198 return desc;
199 }
200 EXPORT_SYMBOL(devm_gpiod_get_index_optional);
201
202 /**
203 * devm_gpiod_get_array - Resource-managed gpiod_get_array()
204 * @dev: GPIO consumer
205 * @con_id: function within the GPIO consumer
206 * @flags: optional GPIO initialization flags
207 *
208 * Managed gpiod_get_array(). GPIO descriptors returned from this function are
209 * automatically disposed on driver detach. See gpiod_get_array() for detailed
210 * information about behavior and return values.
211 */
devm_gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)212 struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
213 const char *con_id,
214 enum gpiod_flags flags)
215 {
216 struct gpio_descs **dr;
217 struct gpio_descs *descs;
218
219 dr = devres_alloc(devm_gpiod_release_array,
220 sizeof(struct gpio_descs *), GFP_KERNEL);
221 if (!dr)
222 return ERR_PTR(-ENOMEM);
223
224 descs = gpiod_get_array(dev, con_id, flags);
225 if (IS_ERR(descs)) {
226 devres_free(dr);
227 return descs;
228 }
229
230 *dr = descs;
231 devres_add(dev, dr);
232
233 return descs;
234 }
235 EXPORT_SYMBOL(devm_gpiod_get_array);
236
237 /**
238 * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
239 * @dev: GPIO consumer
240 * @con_id: function within the GPIO consumer
241 * @flags: optional GPIO initialization flags
242 *
243 * Managed gpiod_get_array_optional(). GPIO descriptors returned from this
244 * function are automatically disposed on driver detach.
245 * See gpiod_get_array_optional() for detailed information about behavior and
246 * return values.
247 */
248 struct gpio_descs *__must_check
devm_gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)249 devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
250 enum gpiod_flags flags)
251 {
252 struct gpio_descs *descs;
253
254 descs = devm_gpiod_get_array(dev, con_id, flags);
255 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
256 return NULL;
257
258 return descs;
259 }
260 EXPORT_SYMBOL(devm_gpiod_get_array_optional);
261
262 /**
263 * devm_gpiod_put - Resource-managed gpiod_put()
264 * @desc: GPIO descriptor to dispose of
265 *
266 * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
267 * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
268 * will be disposed of by the resource management code.
269 */
devm_gpiod_put(struct device * dev,struct gpio_desc * desc)270 void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
271 {
272 WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
273 &desc));
274 }
275 EXPORT_SYMBOL(devm_gpiod_put);
276
277 /**
278 * devm_gpiod_put_array - Resource-managed gpiod_put_array()
279 * @descs: GPIO descriptor array to dispose of
280 *
281 * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
282 * Normally this function will not be called as the GPIOs will be disposed of
283 * by the resource management code.
284 */
devm_gpiod_put_array(struct device * dev,struct gpio_descs * descs)285 void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
286 {
287 WARN_ON(devres_release(dev, devm_gpiod_release_array,
288 devm_gpiod_match_array, &descs));
289 }
290 EXPORT_SYMBOL(devm_gpiod_put_array);
291
292
293
294
devm_gpio_release(struct device * dev,void * res)295 static void devm_gpio_release(struct device *dev, void *res)
296 {
297 unsigned *gpio = res;
298
299 gpio_free(*gpio);
300 }
301
devm_gpio_match(struct device * dev,void * res,void * data)302 static int devm_gpio_match(struct device *dev, void *res, void *data)
303 {
304 unsigned *this = res, *gpio = data;
305
306 return *this == *gpio;
307 }
308
309 /**
310 * devm_gpio_request - request a GPIO for a managed device
311 * @dev: device to request the GPIO for
312 * @gpio: GPIO to allocate
313 * @label: the name of the requested GPIO
314 *
315 * Except for the extra @dev argument, this function takes the
316 * same arguments and performs the same function as
317 * gpio_request(). GPIOs requested with this function will be
318 * automatically freed on driver detach.
319 *
320 * If an GPIO allocated with this function needs to be freed
321 * separately, devm_gpio_free() must be used.
322 */
323
devm_gpio_request(struct device * dev,unsigned gpio,const char * label)324 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
325 {
326 unsigned *dr;
327 int rc;
328
329 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
330 if (!dr)
331 return -ENOMEM;
332
333 rc = gpio_request(gpio, label);
334 if (rc) {
335 devres_free(dr);
336 return rc;
337 }
338
339 *dr = gpio;
340 devres_add(dev, dr);
341
342 return 0;
343 }
344 EXPORT_SYMBOL(devm_gpio_request);
345
346 /**
347 * devm_gpio_request_one - request a single GPIO with initial setup
348 * @dev: device to request for
349 * @gpio: the GPIO number
350 * @flags: GPIO configuration as specified by GPIOF_*
351 * @label: a literal description string of this GPIO
352 */
devm_gpio_request_one(struct device * dev,unsigned gpio,unsigned long flags,const char * label)353 int devm_gpio_request_one(struct device *dev, unsigned gpio,
354 unsigned long flags, const char *label)
355 {
356 unsigned *dr;
357 int rc;
358
359 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
360 if (!dr)
361 return -ENOMEM;
362
363 rc = gpio_request_one(gpio, flags, label);
364 if (rc) {
365 devres_free(dr);
366 return rc;
367 }
368
369 *dr = gpio;
370 devres_add(dev, dr);
371
372 return 0;
373 }
374 EXPORT_SYMBOL(devm_gpio_request_one);
375
376 /**
377 * devm_gpio_free - free a GPIO
378 * @dev: device to free GPIO for
379 * @gpio: GPIO to free
380 *
381 * Except for the extra @dev argument, this function takes the
382 * same arguments and performs the same function as gpio_free().
383 * This function instead of gpio_free() should be used to manually
384 * free GPIOs allocated with devm_gpio_request().
385 */
devm_gpio_free(struct device * dev,unsigned int gpio)386 void devm_gpio_free(struct device *dev, unsigned int gpio)
387 {
388
389 WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
390 &gpio));
391 }
392 EXPORT_SYMBOL(devm_gpio_free);
393