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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 
devm_gpiod_release(struct device * dev,void * res)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 
devm_gpiod_match(struct device * dev,void * res,void * data)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 
devm_gpiod_release_array(struct device * dev,void * res)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 
devm_gpiod_match_array(struct device * dev,void * res,void * data)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  */
devm_gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)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  */
devm_gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)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  */
devm_gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)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  */
devm_gpiod_get_from_of_node(struct device * dev,struct device_node * node,const char * propname,int index,enum gpiod_flags dflags,const char * label)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  */
devm_fwnode_get_index_gpiod_from_child(struct device * dev,const char * con_id,int index,struct fwnode_handle * child,enum gpiod_flags flags,const char * label)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  */
devm_gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)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  */
devm_gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)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
devm_gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)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  */
devm_gpiod_put(struct device * dev,struct gpio_desc * desc)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 
devm_gpiod_unhinge(struct device * dev,struct gpio_desc * desc)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  */
devm_gpiod_put_array(struct device * dev,struct gpio_descs * descs)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 
devm_gpio_release(struct device * dev,void * res)398 static void devm_gpio_release(struct device *dev, void *res)
399 {
400 	unsigned *gpio = res;
401 
402 	gpio_free(*gpio);
403 }
404 
devm_gpio_match(struct device * dev,void * res,void * data)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 
devm_gpio_request(struct device * dev,unsigned gpio,const char * label)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  */
devm_gpio_request_one(struct device * dev,unsigned gpio,unsigned long flags,const char * label)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  */
devm_gpio_free(struct device * dev,unsigned int gpio)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);
496