gpiolib-devres.c

  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/device/devres.h>
 10#include <linux/err.h>
 11#include <linux/export.h>
 12#include <linux/gfp.h>
 13#include <linux/types.h>
 14
 15#include <linux/gpio/consumer.h>
 16
 17#include "gpiolib.h"
 18
 19struct fwnode_handle;
 20struct lock_class_key;
 21
 22static void devm_gpiod_release(void *desc)
 23{
 24	gpiod_put(desc);
 25}
 26
 27static void devm_gpiod_release_array(void *descs)
 28{
 29	gpiod_put_array(descs);
 30}
 31
 32/**
 33 * devm_gpiod_get - Resource-managed gpiod_get()
 34 * @dev:	GPIO consumer
 35 * @con_id:	function within the GPIO consumer
 36 * @flags:	optional GPIO initialization flags
 37 *
 38 * Managed gpiod_get(). GPIO descriptors returned from this function are
 39 * automatically disposed on driver detach. See gpiod_get() for detailed
 40 * information about behavior and return values.
 41 *
 42 * Returns:
 43 * The GPIO descriptor corresponding to the function @con_id of device
 44 * dev, %-ENOENT if no GPIO has been assigned to the requested function, or
 45 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
 46 */
 47struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
 48					      const char *con_id,
 49					      enum gpiod_flags flags)
 50{
 51	return devm_gpiod_get_index(dev, con_id, 0, flags);
 52}
 53EXPORT_SYMBOL_GPL(devm_gpiod_get);
 54
 55/**
 56 * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
 57 * @dev: GPIO consumer
 58 * @con_id: function within the GPIO consumer
 59 * @flags: optional GPIO initialization flags
 60 *
 61 * Managed gpiod_get_optional(). GPIO descriptors returned from this function
 62 * are automatically disposed on driver detach. See gpiod_get_optional() for
 63 * detailed information about behavior and return values.
 64 *
 65 * Returns:
 66 * The GPIO descriptor corresponding to the function @con_id of device
 67 * dev, NULL if no GPIO has been assigned to the requested function, or
 68 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
 69 */
 70struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
 71						       const char *con_id,
 72						       enum gpiod_flags flags)
 73{
 74	return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
 75}
 76EXPORT_SYMBOL_GPL(devm_gpiod_get_optional);
 77
 78/**
 79 * devm_gpiod_get_index - Resource-managed gpiod_get_index()
 80 * @dev:	GPIO consumer
 81 * @con_id:	function within the GPIO consumer
 82 * @idx:	index of the GPIO to obtain in the consumer
 83 * @flags:	optional GPIO initialization flags
 84 *
 85 * Managed gpiod_get_index(). GPIO descriptors returned from this function are
 86 * automatically disposed on driver detach. See gpiod_get_index() for detailed
 87 * information about behavior and return values.
 88 *
 89 * Returns:
 90 * The GPIO descriptor corresponding to the function @con_id of device
 91 * dev, %-ENOENT if no GPIO has been assigned to the requested function, or
 92 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
 93 */
 94struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
 95						    const char *con_id,
 96						    unsigned int idx,
 97						    enum gpiod_flags flags)
 98{
 99	struct gpio_desc *desc;
100	int ret;
101
102	desc = gpiod_get_index(dev, con_id, idx, flags);
103	if (IS_ERR(desc))
104		return desc;
105
106	/*
107	 * For non-exclusive GPIO descriptors, check if this descriptor is
108	 * already under resource management by this device.
109	 */
110	if (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
111		bool dres;
112
113		dres = devm_is_action_added(dev, devm_gpiod_release, desc);
114		if (dres)
115			return desc;
116	}
117
118	ret = devm_add_action_or_reset(dev, devm_gpiod_release, desc);
119	if (ret)
120		return ERR_PTR(ret);
121
122	return desc;
123}
124EXPORT_SYMBOL_GPL(devm_gpiod_get_index);
125
126/**
127 * devm_fwnode_gpiod_get_index - get a GPIO descriptor from a given node
128 * @dev:	GPIO consumer
129 * @fwnode:	firmware node containing GPIO reference
130 * @con_id:	function within the GPIO consumer
131 * @index:	index of the GPIO to obtain in the consumer
132 * @flags:	GPIO initialization flags
133 * @label:	label to attach to the requested GPIO
134 *
135 * GPIO descriptors returned from this function are automatically disposed on
136 * driver detach.
137 *
138 * Returns:
139 * The GPIO descriptor corresponding to the function @con_id of device
140 * dev, %-ENOENT if no GPIO has been assigned to the requested function, or
141 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
142 */
143struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
144					      struct fwnode_handle *fwnode,
145					      const char *con_id, int index,
146					      enum gpiod_flags flags,
147					      const char *label)
148{
149	struct gpio_desc *desc;
150	int ret;
151
152	desc = gpiod_find_and_request(dev, fwnode, con_id, index, flags, label, false);
153	if (IS_ERR(desc))
154		return desc;
155
156	ret = devm_add_action_or_reset(dev, devm_gpiod_release, desc);
157	if (ret)
158		return ERR_PTR(ret);
159
160	return desc;
161}
162EXPORT_SYMBOL_GPL(devm_fwnode_gpiod_get_index);
163
164/**
165 * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
166 * @dev: GPIO consumer
167 * @con_id: function within the GPIO consumer
168 * @index: index of the GPIO to obtain in the consumer
169 * @flags: optional GPIO initialization flags
170 *
171 * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
172 * function are automatically disposed on driver detach. See
173 * gpiod_get_index_optional() for detailed information about behavior and
174 * return values.
175 *
176 * Returns:
177 * The GPIO descriptor corresponding to the function @con_id of device
178 * dev, %NULL if no GPIO has been assigned to the requested function, or
179 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
180 */
181struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
182							     const char *con_id,
183							     unsigned int index,
184							     enum gpiod_flags flags)
185{
186	struct gpio_desc *desc;
187
188	desc = devm_gpiod_get_index(dev, con_id, index, flags);
189	if (gpiod_not_found(desc))
190		return NULL;
191
192	return desc;
193}
194EXPORT_SYMBOL_GPL(devm_gpiod_get_index_optional);
195
196/**
197 * devm_gpiod_get_array - Resource-managed gpiod_get_array()
198 * @dev:	GPIO consumer
199 * @con_id:	function within the GPIO consumer
200 * @flags:	optional GPIO initialization flags
201 *
202 * Managed gpiod_get_array(). GPIO descriptors returned from this function are
203 * automatically disposed on driver detach. See gpiod_get_array() for detailed
204 * information about behavior and return values.
205 *
206 * Returns:
207 * The GPIO descriptors corresponding to the function @con_id of device
208 * dev, %-ENOENT if no GPIO has been assigned to the requested function,
209 * or another IS_ERR() code if an error occurred while trying to acquire
210 * the GPIOs.
211 */
212struct 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 *descs;
217	int ret;
218
219	descs = gpiod_get_array(dev, con_id, flags);
220	if (IS_ERR(descs))
221		return descs;
222
223	ret = devm_add_action_or_reset(dev, devm_gpiod_release_array, descs);
224	if (ret)
225		return ERR_PTR(ret);
226
227	return descs;
228}
229EXPORT_SYMBOL_GPL(devm_gpiod_get_array);
230
231/**
232 * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
233 * @dev:	GPIO consumer
234 * @con_id:	function within the GPIO consumer
235 * @flags:	optional GPIO initialization flags
236 *
237 * Managed gpiod_get_array_optional(). GPIO descriptors returned from this
238 * function are automatically disposed on driver detach.
239 * See gpiod_get_array_optional() for detailed information about behavior and
240 * return values.
241 *
242 * Returns:
243 * The GPIO descriptors corresponding to the function @con_id of device
244 * dev, %NULL if no GPIO has been assigned to the requested function,
245 * or another IS_ERR() code if an error occurred while trying to acquire
246 * the GPIOs.
247 */
248struct gpio_descs *__must_check
249devm_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 (gpiod_not_found(descs))
256		return NULL;
257
258	return descs;
259}
260EXPORT_SYMBOL_GPL(devm_gpiod_get_array_optional);
261
262/**
263 * devm_gpiod_put - Resource-managed gpiod_put()
264 * @dev:	GPIO consumer
265 * @desc:	GPIO descriptor to dispose of
266 *
267 * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
268 * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
269 * will be disposed of by the resource management code.
270 */
271void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
272{
273	devm_release_action(dev, devm_gpiod_release, desc);
274}
275EXPORT_SYMBOL_GPL(devm_gpiod_put);
276
277/**
278 * devm_gpiod_unhinge - Remove resource management from a gpio descriptor
279 * @dev:	GPIO consumer
280 * @desc:	GPIO descriptor to remove resource management from
281 *
282 * *DEPRECATED*
283 * This function should not be used. It's been provided as a workaround for
284 * resource ownership issues in the regulator framework and should be replaced
285 * with a better solution.
286 *
287 * Remove resource management from a GPIO descriptor. This is needed when
288 * you want to hand over lifecycle management of a descriptor to another
289 * mechanism.
290 */
291void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc)
292{
293	int ret;
294
295	if (IS_ERR_OR_NULL(desc))
296		return;
297
298	/*
299	 * If the GPIO descriptor is requested as nonexclusive, we
300	 * may call this function several times on the same descriptor
301	 * so it is OK if devres_destroy() returns -ENOENT.
302	 */
303	ret = devm_remove_action_nowarn(dev, devm_gpiod_release, desc);
304	if (ret == -ENOENT)
305		return;
306	/* Anything else we should warn about */
307	WARN_ON(ret);
308}
309EXPORT_SYMBOL_GPL(devm_gpiod_unhinge);
310
311/**
312 * devm_gpiod_put_array - Resource-managed gpiod_put_array()
313 * @dev:	GPIO consumer
314 * @descs:	GPIO descriptor array to dispose of
315 *
316 * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
317 * Normally this function will not be called as the GPIOs will be disposed of
318 * by the resource management code.
319 */
320void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
321{
322	devm_release_action(dev, devm_gpiod_release_array, descs);
323}
324EXPORT_SYMBOL_GPL(devm_gpiod_put_array);
325
326static void devm_gpio_chip_release(void *data)
327{
328	struct gpio_chip *gc = data;
329
330	gpiochip_remove(gc);
331}
332
333/**
334 * devm_gpiochip_add_data_with_key() - Resource managed gpiochip_add_data_with_key()
335 * @dev: pointer to the device that gpio_chip belongs to.
336 * @gc: the GPIO chip to register
337 * @data: driver-private data associated with this chip
338 * @lock_key: lockdep class for IRQ lock
339 * @request_key: lockdep class for IRQ request
340 *
341 * Context: potentially before irqs will work
342 *
343 * The gpio chip automatically be released when the device is unbound.
344 *
345 * Returns:
346 * A negative errno if the chip can't be registered, such as because the
347 * gc->base is invalid or already associated with a different chip.
348 * Otherwise it returns zero as a success code.
349 */
350int devm_gpiochip_add_data_with_key(struct device *dev, struct gpio_chip *gc, void *data,
351				    struct lock_class_key *lock_key,
352				    struct lock_class_key *request_key)
353{
354	int ret;
355
356	ret = gpiochip_add_data_with_key(gc, data, lock_key, request_key);
357	if (ret < 0)
358		return ret;
359
360	return devm_add_action_or_reset(dev, devm_gpio_chip_release, gc);
361}
362EXPORT_SYMBOL_GPL(devm_gpiochip_add_data_with_key);