1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * devres.c - managed gpio resources
4 * This file is based on kernel/irq/devres.c
5 *
6 * Copyright (c) 2011 John Crispin <john@phrozen.org>
7 */
8
9 #include <linux/module.h>
10 #include <linux/err.h>
11 #include <linux/gpio.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/device.h>
14 #include <linux/gfp.h>
15
16 #include "gpiolib.h"
17
18 static void devm_gpiod_release(struct device *dev, void *res)
19 {
20 struct gpio_desc **desc = res;
21
22 gpiod_put(*desc);
23 }
24
25 static int devm_gpiod_match(struct device *dev, void *res, void *data)
26 {
27 struct gpio_desc **this = res, **gpio = data;
28
29 return *this == *gpio;
30 }
31
32 static void devm_gpiod_release_array(struct device *dev, void *res)
33 {
34 struct gpio_descs **descs = res;
35
36 gpiod_put_array(*descs);
37 }
38
39 static int devm_gpiod_match_array(struct device *dev, void *res, void *data)
40 {
41 struct gpio_descs **this = res, **gpios = data;
42
43 return *this == *gpios;
44 }
45
46 /**
47 * devm_gpiod_get - Resource-managed gpiod_get()
48 * @dev: GPIO consumer
49 * @con_id: function within the GPIO consumer
50 * @flags: optional GPIO initialization flags
51 *
52 * Managed gpiod_get(). GPIO descriptors returned from this function are
53 * automatically disposed on driver detach. See gpiod_get() for detailed
54 * information about behavior and return values.
55 */
56 struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
57 const char *con_id,
58 enum gpiod_flags flags)
59 {
60 return devm_gpiod_get_index(dev, con_id, 0, flags);
61 }
62 EXPORT_SYMBOL_GPL(devm_gpiod_get);
63
64 /**
65 * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
66 * @dev: GPIO consumer
67 * @con_id: function within the GPIO consumer
68 * @flags: optional GPIO initialization flags
69 *
70 * Managed gpiod_get_optional(). GPIO descriptors returned from this function
71 * are automatically disposed on driver detach. See gpiod_get_optional() for
72 * detailed information about behavior and return values.
73 */
74 struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
75 const char *con_id,
76 enum gpiod_flags flags)
77 {
78 return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
79 }
80 EXPORT_SYMBOL_GPL(devm_gpiod_get_optional);
81
82 /**
83 * devm_gpiod_get_index - Resource-managed gpiod_get_index()
84 * @dev: GPIO consumer
85 * @con_id: function within the GPIO consumer
86 * @idx: index of the GPIO to obtain in the consumer
87 * @flags: optional GPIO initialization flags
88 *
89 * Managed gpiod_get_index(). GPIO descriptors returned from this function are
90 * automatically disposed on driver detach. See gpiod_get_index() for detailed
91 * information about behavior and return values.
92 */
93 struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
94 const char *con_id,
95 unsigned int idx,
96 enum gpiod_flags flags)
97 {
98 struct gpio_desc **dr;
99 struct gpio_desc *desc;
100
101 desc = gpiod_get_index(dev, con_id, idx, flags);
102 if (IS_ERR(desc))
103 return desc;
104
105 /*
106 * For non-exclusive GPIO descriptors, check if this descriptor is
107 * already under resource management by this device.
108 */
109 if (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
110 struct devres *dres;
111
112 dres = devres_find(dev, devm_gpiod_release,
113 devm_gpiod_match, &desc);
114 if (dres)
115 return desc;
116 }
117
118 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
119 GFP_KERNEL);
120 if (!dr) {
121 gpiod_put(desc);
122 return ERR_PTR(-ENOMEM);
123 }
124
125 *dr = desc;
126 devres_add(dev, dr);
127
128 return desc;
129 }
130 EXPORT_SYMBOL_GPL(devm_gpiod_get_index);
131
132 /**
133 * devm_gpiod_get_from_of_node() - obtain a GPIO from an OF node
134 * @dev: device for lifecycle management
135 * @node: handle of the OF node
136 * @propname: name of the DT property representing the GPIO
137 * @index: index of the GPIO to obtain for the consumer
138 * @dflags: GPIO initialization flags
139 * @label: label to attach to the requested GPIO
140 *
141 * Returns:
142 * On successful request the GPIO pin is configured in accordance with
143 * provided @dflags.
144 *
145 * In case of error an ERR_PTR() is returned.
146 */
147 struct gpio_desc *devm_gpiod_get_from_of_node(struct device *dev,
148 struct device_node *node,
149 const char *propname, int index,
150 enum gpiod_flags dflags,
151 const char *label)
152 {
153 struct gpio_desc **dr;
154 struct gpio_desc *desc;
155
156 desc = gpiod_get_from_of_node(node, propname, index, dflags, label);
157 if (IS_ERR(desc))
158 return desc;
159
160 /*
161 * For non-exclusive GPIO descriptors, check if this descriptor is
162 * already under resource management by this device.
163 */
164 if (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
165 struct devres *dres;
166
167 dres = devres_find(dev, devm_gpiod_release,
168 devm_gpiod_match, &desc);
169 if (dres)
170 return desc;
171 }
172
173 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
174 GFP_KERNEL);
175 if (!dr) {
176 gpiod_put(desc);
177 return ERR_PTR(-ENOMEM);
178 }
179
180 *dr = desc;
181 devres_add(dev, dr);
182
183 return desc;
184 }
185 EXPORT_SYMBOL_GPL(devm_gpiod_get_from_of_node);
186
187 /**
188 * devm_fwnode_get_index_gpiod_from_child - get a GPIO descriptor from a
189 * device's child node
190 * @dev: GPIO consumer
191 * @con_id: function within the GPIO consumer
192 * @index: index of the GPIO to obtain in the consumer
193 * @child: firmware node (child of @dev)
194 * @flags: GPIO initialization flags
195 * @label: label to attach to the requested GPIO
196 *
197 * GPIO descriptors returned from this function are automatically disposed on
198 * driver detach.
199 *
200 * On successful request the GPIO pin is configured in accordance with
201 * provided @flags.
202 */
203 struct gpio_desc *devm_fwnode_get_index_gpiod_from_child(struct device *dev,
204 const char *con_id, int index,
205 struct fwnode_handle *child,
206 enum gpiod_flags flags,
207 const char *label)
208 {
209 char prop_name[32]; /* 32 is max size of property name */
210 struct gpio_desc **dr;
211 struct gpio_desc *desc;
212 unsigned int i;
213
214 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
215 GFP_KERNEL);
216 if (!dr)
217 return ERR_PTR(-ENOMEM);
218
219 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
220 if (con_id)
221 snprintf(prop_name, sizeof(prop_name), "%s-%s",
222 con_id, gpio_suffixes[i]);
223 else
224 snprintf(prop_name, sizeof(prop_name), "%s",
225 gpio_suffixes[i]);
226
227 desc = fwnode_get_named_gpiod(child, prop_name, index, flags,
228 label);
229 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
230 break;
231 }
232 if (IS_ERR(desc)) {
233 devres_free(dr);
234 return desc;
235 }
236
237 *dr = desc;
238 devres_add(dev, dr);
239
240 return desc;
241 }
242 EXPORT_SYMBOL_GPL(devm_fwnode_get_index_gpiod_from_child);
243
244 /**
245 * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
246 * @dev: GPIO consumer
247 * @con_id: function within the GPIO consumer
248 * @index: index of the GPIO to obtain in the consumer
249 * @flags: optional GPIO initialization flags
250 *
251 * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
252 * function are automatically disposed on driver detach. See
253 * gpiod_get_index_optional() for detailed information about behavior and
254 * return values.
255 */
256 struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
257 const char *con_id,
258 unsigned int index,
259 enum gpiod_flags flags)
260 {
261 struct gpio_desc *desc;
262
263 desc = devm_gpiod_get_index(dev, con_id, index, flags);
264 if (IS_ERR(desc)) {
265 if (PTR_ERR(desc) == -ENOENT)
266 return NULL;
267 }
268
269 return desc;
270 }
271 EXPORT_SYMBOL_GPL(devm_gpiod_get_index_optional);
272
273 /**
274 * devm_gpiod_get_array - Resource-managed gpiod_get_array()
275 * @dev: GPIO consumer
276 * @con_id: function within the GPIO consumer
277 * @flags: optional GPIO initialization flags
278 *
279 * Managed gpiod_get_array(). GPIO descriptors returned from this function are
280 * automatically disposed on driver detach. See gpiod_get_array() for detailed
281 * information about behavior and return values.
282 */
283 struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
284 const char *con_id,
285 enum gpiod_flags flags)
286 {
287 struct gpio_descs **dr;
288 struct gpio_descs *descs;
289
290 dr = devres_alloc(devm_gpiod_release_array,
291 sizeof(struct gpio_descs *), GFP_KERNEL);
292 if (!dr)
293 return ERR_PTR(-ENOMEM);
294
295 descs = gpiod_get_array(dev, con_id, flags);
296 if (IS_ERR(descs)) {
297 devres_free(dr);
298 return descs;
299 }
300
301 *dr = descs;
302 devres_add(dev, dr);
303
304 return descs;
305 }
306 EXPORT_SYMBOL_GPL(devm_gpiod_get_array);
307
308 /**
309 * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
310 * @dev: GPIO consumer
311 * @con_id: function within the GPIO consumer
312 * @flags: optional GPIO initialization flags
313 *
314 * Managed gpiod_get_array_optional(). GPIO descriptors returned from this
315 * function are automatically disposed on driver detach.
316 * See gpiod_get_array_optional() for detailed information about behavior and
317 * return values.
318 */
319 struct gpio_descs *__must_check
320 devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
321 enum gpiod_flags flags)
322 {
323 struct gpio_descs *descs;
324
325 descs = devm_gpiod_get_array(dev, con_id, flags);
326 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
327 return NULL;
328
329 return descs;
330 }
331 EXPORT_SYMBOL_GPL(devm_gpiod_get_array_optional);
332
333 /**
334 * devm_gpiod_put - Resource-managed gpiod_put()
335 * @dev: GPIO consumer
336 * @desc: GPIO descriptor to dispose of
337 *
338 * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
339 * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
340 * will be disposed of by the resource management code.
341 */
342 void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
343 {
344 WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
345 &desc));
346 }
347 EXPORT_SYMBOL_GPL(devm_gpiod_put);
348
349 /**
350 * devm_gpiod_unhinge - Remove resource management from a gpio descriptor
351 * @dev: GPIO consumer
352 * @desc: GPIO descriptor to remove resource management from
353 *
354 * Remove resource management from a GPIO descriptor. This is needed when
355 * you want to hand over lifecycle management of a descriptor to another
356 * mechanism.
357 */
358
359 void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc)
360 {
361 int ret;
362
363 if (IS_ERR_OR_NULL(desc))
364 return;
365 ret = devres_destroy(dev, devm_gpiod_release,
366 devm_gpiod_match, &desc);
367 /*
368 * If the GPIO descriptor is requested as nonexclusive, we
369 * may call this function several times on the same descriptor
370 * so it is OK if devres_destroy() returns -ENOENT.
371 */
372 if (ret == -ENOENT)
373 return;
374 /* Anything else we should warn about */
375 WARN_ON(ret);
376 }
377 EXPORT_SYMBOL_GPL(devm_gpiod_unhinge);
378
379 /**
380 * devm_gpiod_put_array - Resource-managed gpiod_put_array()
381 * @dev: GPIO consumer
382 * @descs: GPIO descriptor array to dispose of
383 *
384 * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
385 * Normally this function will not be called as the GPIOs will be disposed of
386 * by the resource management code.
387 */
388 void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
389 {
390 WARN_ON(devres_release(dev, devm_gpiod_release_array,
391 devm_gpiod_match_array, &descs));
392 }
393 EXPORT_SYMBOL_GPL(devm_gpiod_put_array);
394
395
396
397
398 static void devm_gpio_release(struct device *dev, void *res)
399 {
400 unsigned *gpio = res;
401
402 gpio_free(*gpio);
403 }
404
405 static int devm_gpio_match(struct device *dev, void *res, void *data)
406 {
407 unsigned *this = res, *gpio = data;
408
409 return *this == *gpio;
410 }
411
412 /**
413 * devm_gpio_request - request a GPIO for a managed device
414 * @dev: device to request the GPIO for
415 * @gpio: GPIO to allocate
416 * @label: the name of the requested GPIO
417 *
418 * Except for the extra @dev argument, this function takes the
419 * same arguments and performs the same function as
420 * gpio_request(). GPIOs requested with this function will be
421 * automatically freed on driver detach.
422 *
423 * If an GPIO allocated with this function needs to be freed
424 * separately, devm_gpio_free() must be used.
425 */
426
427 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
428 {
429 unsigned *dr;
430 int rc;
431
432 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
433 if (!dr)
434 return -ENOMEM;
435
436 rc = gpio_request(gpio, label);
437 if (rc) {
438 devres_free(dr);
439 return rc;
440 }
441
442 *dr = gpio;
443 devres_add(dev, dr);
444
445 return 0;
446 }
447 EXPORT_SYMBOL_GPL(devm_gpio_request);
448
449 /**
450 * devm_gpio_request_one - request a single GPIO with initial setup
451 * @dev: device to request for
452 * @gpio: the GPIO number
453 * @flags: GPIO configuration as specified by GPIOF_*
454 * @label: a literal description string of this GPIO
455 */
456 int devm_gpio_request_one(struct device *dev, unsigned gpio,
457 unsigned long flags, const char *label)
458 {
459 unsigned *dr;
460 int rc;
461
462 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
463 if (!dr)
464 return -ENOMEM;
465
466 rc = gpio_request_one(gpio, flags, label);
467 if (rc) {
468 devres_free(dr);
469 return rc;
470 }
471
472 *dr = gpio;
473 devres_add(dev, dr);
474
475 return 0;
476 }
477 EXPORT_SYMBOL_GPL(devm_gpio_request_one);
478
479 /**
480 * devm_gpio_free - free a GPIO
481 * @dev: device to free GPIO for
482 * @gpio: GPIO to free
483 *
484 * Except for the extra @dev argument, this function takes the
485 * same arguments and performs the same function as gpio_free().
486 * This function instead of gpio_free() should be used to manually
487 * free GPIOs allocated with devm_gpio_request().
488 */
489 void devm_gpio_free(struct device *dev, unsigned int gpio)
490 {
491
492 WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
493 &gpio));
494 }
495 EXPORT_SYMBOL_GPL(devm_gpio_free);