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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,const 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 					      const 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_gpiod_get_index - get a GPIO descriptor from a given node
189  * @dev:	GPIO consumer
190  * @fwnode:	firmware node containing GPIO reference
191  * @con_id:	function within the GPIO consumer
192  * @index:	index of the GPIO to obtain in the consumer
193  * @flags:	GPIO initialization flags
194  * @label:	label to attach to the requested GPIO
195  *
196  * GPIO descriptors returned from this function are automatically disposed on
197  * driver detach.
198  *
199  * On successful request the GPIO pin is configured in accordance with
200  * provided @flags.
201  */
devm_fwnode_gpiod_get_index(struct device * dev,struct fwnode_handle * fwnode,const char * con_id,int index,enum gpiod_flags flags,const char * label)202 struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
203 					      struct fwnode_handle *fwnode,
204 					      const char *con_id, int index,
205 					      enum gpiod_flags flags,
206 					      const char *label)
207 {
208 	struct gpio_desc **dr;
209 	struct gpio_desc *desc;
210 
211 	dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
212 			  GFP_KERNEL);
213 	if (!dr)
214 		return ERR_PTR(-ENOMEM);
215 
216 	desc = fwnode_gpiod_get_index(fwnode, con_id, index, flags, label);
217 	if (IS_ERR(desc)) {
218 		devres_free(dr);
219 		return desc;
220 	}
221 
222 	*dr = desc;
223 	devres_add(dev, dr);
224 
225 	return desc;
226 }
227 EXPORT_SYMBOL_GPL(devm_fwnode_gpiod_get_index);
228 
229 /**
230  * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
231  * @dev: GPIO consumer
232  * @con_id: function within the GPIO consumer
233  * @index: index of the GPIO to obtain in the consumer
234  * @flags: optional GPIO initialization flags
235  *
236  * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
237  * function are automatically disposed on driver detach. See
238  * gpiod_get_index_optional() for detailed information about behavior and
239  * return values.
240  */
devm_gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)241 struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
242 							     const char *con_id,
243 							     unsigned int index,
244 							     enum gpiod_flags flags)
245 {
246 	struct gpio_desc *desc;
247 
248 	desc = devm_gpiod_get_index(dev, con_id, index, flags);
249 	if (gpiod_not_found(desc))
250 		return NULL;
251 
252 	return desc;
253 }
254 EXPORT_SYMBOL_GPL(devm_gpiod_get_index_optional);
255 
256 /**
257  * devm_gpiod_get_array - Resource-managed gpiod_get_array()
258  * @dev:	GPIO consumer
259  * @con_id:	function within the GPIO consumer
260  * @flags:	optional GPIO initialization flags
261  *
262  * Managed gpiod_get_array(). GPIO descriptors returned from this function are
263  * automatically disposed on driver detach. See gpiod_get_array() for detailed
264  * information about behavior and return values.
265  */
devm_gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)266 struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
267 						     const char *con_id,
268 						     enum gpiod_flags flags)
269 {
270 	struct gpio_descs **dr;
271 	struct gpio_descs *descs;
272 
273 	dr = devres_alloc(devm_gpiod_release_array,
274 			  sizeof(struct gpio_descs *), GFP_KERNEL);
275 	if (!dr)
276 		return ERR_PTR(-ENOMEM);
277 
278 	descs = gpiod_get_array(dev, con_id, flags);
279 	if (IS_ERR(descs)) {
280 		devres_free(dr);
281 		return descs;
282 	}
283 
284 	*dr = descs;
285 	devres_add(dev, dr);
286 
287 	return descs;
288 }
289 EXPORT_SYMBOL_GPL(devm_gpiod_get_array);
290 
291 /**
292  * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
293  * @dev:	GPIO consumer
294  * @con_id:	function within the GPIO consumer
295  * @flags:	optional GPIO initialization flags
296  *
297  * Managed gpiod_get_array_optional(). GPIO descriptors returned from this
298  * function are automatically disposed on driver detach.
299  * See gpiod_get_array_optional() for detailed information about behavior and
300  * return values.
301  */
302 struct gpio_descs *__must_check
devm_gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)303 devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
304 			      enum gpiod_flags flags)
305 {
306 	struct gpio_descs *descs;
307 
308 	descs = devm_gpiod_get_array(dev, con_id, flags);
309 	if (gpiod_not_found(descs))
310 		return NULL;
311 
312 	return descs;
313 }
314 EXPORT_SYMBOL_GPL(devm_gpiod_get_array_optional);
315 
316 /**
317  * devm_gpiod_put - Resource-managed gpiod_put()
318  * @dev:	GPIO consumer
319  * @desc:	GPIO descriptor to dispose of
320  *
321  * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
322  * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
323  * will be disposed of by the resource management code.
324  */
devm_gpiod_put(struct device * dev,struct gpio_desc * desc)325 void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
326 {
327 	WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
328 		&desc));
329 }
330 EXPORT_SYMBOL_GPL(devm_gpiod_put);
331 
332 /**
333  * devm_gpiod_unhinge - Remove resource management from a gpio descriptor
334  * @dev:	GPIO consumer
335  * @desc:	GPIO descriptor to remove resource management from
336  *
337  * Remove resource management from a GPIO descriptor. This is needed when
338  * you want to hand over lifecycle management of a descriptor to another
339  * mechanism.
340  */
341 
devm_gpiod_unhinge(struct device * dev,struct gpio_desc * desc)342 void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc)
343 {
344 	int ret;
345 
346 	if (IS_ERR_OR_NULL(desc))
347 		return;
348 	ret = devres_destroy(dev, devm_gpiod_release,
349 			     devm_gpiod_match, &desc);
350 	/*
351 	 * If the GPIO descriptor is requested as nonexclusive, we
352 	 * may call this function several times on the same descriptor
353 	 * so it is OK if devres_destroy() returns -ENOENT.
354 	 */
355 	if (ret == -ENOENT)
356 		return;
357 	/* Anything else we should warn about */
358 	WARN_ON(ret);
359 }
360 EXPORT_SYMBOL_GPL(devm_gpiod_unhinge);
361 
362 /**
363  * devm_gpiod_put_array - Resource-managed gpiod_put_array()
364  * @dev:	GPIO consumer
365  * @descs:	GPIO descriptor array to dispose of
366  *
367  * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
368  * Normally this function will not be called as the GPIOs will be disposed of
369  * by the resource management code.
370  */
devm_gpiod_put_array(struct device * dev,struct gpio_descs * descs)371 void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
372 {
373 	WARN_ON(devres_release(dev, devm_gpiod_release_array,
374 			       devm_gpiod_match_array, &descs));
375 }
376 EXPORT_SYMBOL_GPL(devm_gpiod_put_array);
377 
devm_gpio_release(struct device * dev,void * res)378 static void devm_gpio_release(struct device *dev, void *res)
379 {
380 	unsigned *gpio = res;
381 
382 	gpio_free(*gpio);
383 }
384 
385 /**
386  *      devm_gpio_request - request a GPIO for a managed device
387  *      @dev: device to request the GPIO for
388  *      @gpio: GPIO to allocate
389  *      @label: the name of the requested GPIO
390  *
391  *      Except for the extra @dev argument, this function takes the
392  *      same arguments and performs the same function as
393  *      gpio_request().  GPIOs requested with this function will be
394  *      automatically freed on driver detach.
395  */
devm_gpio_request(struct device * dev,unsigned gpio,const char * label)396 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
397 {
398 	unsigned *dr;
399 	int rc;
400 
401 	dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
402 	if (!dr)
403 		return -ENOMEM;
404 
405 	rc = gpio_request(gpio, label);
406 	if (rc) {
407 		devres_free(dr);
408 		return rc;
409 	}
410 
411 	*dr = gpio;
412 	devres_add(dev, dr);
413 
414 	return 0;
415 }
416 EXPORT_SYMBOL_GPL(devm_gpio_request);
417 
418 /**
419  *	devm_gpio_request_one - request a single GPIO with initial setup
420  *	@dev:   device to request for
421  *	@gpio:	the GPIO number
422  *	@flags:	GPIO configuration as specified by GPIOF_*
423  *	@label:	a literal description string of this GPIO
424  */
devm_gpio_request_one(struct device * dev,unsigned gpio,unsigned long flags,const char * label)425 int devm_gpio_request_one(struct device *dev, unsigned gpio,
426 			  unsigned long flags, const char *label)
427 {
428 	unsigned *dr;
429 	int rc;
430 
431 	dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
432 	if (!dr)
433 		return -ENOMEM;
434 
435 	rc = gpio_request_one(gpio, flags, label);
436 	if (rc) {
437 		devres_free(dr);
438 		return rc;
439 	}
440 
441 	*dr = gpio;
442 	devres_add(dev, dr);
443 
444 	return 0;
445 }
446 EXPORT_SYMBOL_GPL(devm_gpio_request_one);
447 
devm_gpio_chip_release(void * data)448 static void devm_gpio_chip_release(void *data)
449 {
450 	struct gpio_chip *gc = data;
451 
452 	gpiochip_remove(gc);
453 }
454 
455 /**
456  * devm_gpiochip_add_data_with_key() - Resource managed gpiochip_add_data_with_key()
457  * @dev: pointer to the device that gpio_chip belongs to.
458  * @gc: the GPIO chip to register
459  * @data: driver-private data associated with this chip
460  * @lock_key: lockdep class for IRQ lock
461  * @request_key: lockdep class for IRQ request
462  *
463  * Context: potentially before irqs will work
464  *
465  * The gpio chip automatically be released when the device is unbound.
466  *
467  * Returns:
468  * A negative errno if the chip can't be registered, such as because the
469  * gc->base is invalid or already associated with a different chip.
470  * Otherwise it returns zero as a success code.
471  */
devm_gpiochip_add_data_with_key(struct device * dev,struct gpio_chip * gc,void * data,struct lock_class_key * lock_key,struct lock_class_key * request_key)472 int devm_gpiochip_add_data_with_key(struct device *dev, struct gpio_chip *gc, void *data,
473 				    struct lock_class_key *lock_key,
474 				    struct lock_class_key *request_key)
475 {
476 	int ret;
477 
478 	ret = gpiochip_add_data_with_key(gc, data, lock_key, request_key);
479 	if (ret < 0)
480 		return ret;
481 
482 	return devm_add_action_or_reset(dev, devm_gpio_chip_release, gc);
483 }
484 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data_with_key);
485