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.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(struct device *dev, void *res)
 23{
 24	struct gpio_desc **desc = res;
 25
 26	gpiod_put(*desc);
 27}
 28
 29static int devm_gpiod_match(struct device *dev, void *res, void *data)
 30{
 31	struct gpio_desc **this = res, **gpio = data;
 32
 33	return *this == *gpio;
 34}
 35
 36static void devm_gpiod_release_array(struct device *dev, void *res)
 37{
 38	struct gpio_descs **descs = res;
 39
 40	gpiod_put_array(*descs);
 41}
 42
 43static int devm_gpiod_match_array(struct device *dev, void *res, void *data)
 44{
 45	struct gpio_descs **this = res, **gpios = data;
 46
 47	return *this == *gpios;
 48}
 49
 50/**
 51 * devm_gpiod_get - Resource-managed gpiod_get()
 52 * @dev:	GPIO consumer
 53 * @con_id:	function within the GPIO consumer
 54 * @flags:	optional GPIO initialization flags
 55 *
 56 * Managed gpiod_get(). GPIO descriptors returned from this function are
 57 * automatically disposed on driver detach. See gpiod_get() for detailed
 58 * information about behavior and return values.
 59 *
 60 * Returns:
 61 * The GPIO descriptor corresponding to the function @con_id of device
 62 * dev, %-ENOENT if no GPIO has been assigned to the requested function, or
 63 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
 64 */
 65struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
 66					      const char *con_id,
 67					      enum gpiod_flags flags)
 68{
 69	return devm_gpiod_get_index(dev, con_id, 0, flags);
 70}
 71EXPORT_SYMBOL_GPL(devm_gpiod_get);
 72
 73/**
 74 * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
 75 * @dev: GPIO consumer
 76 * @con_id: function within the GPIO consumer
 77 * @flags: optional GPIO initialization flags
 78 *
 79 * Managed gpiod_get_optional(). GPIO descriptors returned from this function
 80 * are automatically disposed on driver detach. See gpiod_get_optional() for
 81 * detailed information about behavior and return values.
 82 *
 83 * Returns:
 84 * The GPIO descriptor corresponding to the function @con_id of device
 85 * dev, NULL if no GPIO has been assigned to the requested function, or
 86 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
 87 */
 88struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
 89						       const char *con_id,
 90						       enum gpiod_flags flags)
 91{
 92	return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
 93}
 94EXPORT_SYMBOL_GPL(devm_gpiod_get_optional);
 95
 96/**
 97 * devm_gpiod_get_index - Resource-managed gpiod_get_index()
 98 * @dev:	GPIO consumer
 99 * @con_id:	function within the GPIO consumer
100 * @idx:	index of the GPIO to obtain in the consumer
101 * @flags:	optional GPIO initialization flags
102 *
103 * Managed gpiod_get_index(). GPIO descriptors returned from this function are
104 * automatically disposed on driver detach. See gpiod_get_index() for detailed
105 * information about behavior and return values.
106 *
107 * Returns:
108 * The GPIO descriptor corresponding to the function @con_id of device
109 * dev, %-ENOENT if no GPIO has been assigned to the requested function, or
110 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
111 */
112struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
113						    const char *con_id,
114						    unsigned int idx,
115						    enum gpiod_flags flags)
116{
117	struct gpio_desc **dr;
118	struct gpio_desc *desc;
119
120	desc = gpiod_get_index(dev, con_id, idx, flags);
121	if (IS_ERR(desc))
122		return desc;
123
124	/*
125	 * For non-exclusive GPIO descriptors, check if this descriptor is
126	 * already under resource management by this device.
127	 */
128	if (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
129		struct devres *dres;
130
131		dres = devres_find(dev, devm_gpiod_release,
132				   devm_gpiod_match, &desc);
133		if (dres)
134			return desc;
135	}
136
137	dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
138			  GFP_KERNEL);
139	if (!dr) {
140		gpiod_put(desc);
141		return ERR_PTR(-ENOMEM);
142	}
143
144	*dr = desc;
145	devres_add(dev, dr);
146
147	return desc;
148}
149EXPORT_SYMBOL_GPL(devm_gpiod_get_index);
150
151/**
152 * devm_fwnode_gpiod_get_index - get a GPIO descriptor from a given node
153 * @dev:	GPIO consumer
154 * @fwnode:	firmware node containing GPIO reference
155 * @con_id:	function within the GPIO consumer
156 * @index:	index of the GPIO to obtain in the consumer
157 * @flags:	GPIO initialization flags
158 * @label:	label to attach to the requested GPIO
159 *
160 * GPIO descriptors returned from this function are automatically disposed on
161 * driver detach.
162 *
163 * Returns:
164 * The GPIO descriptor corresponding to the function @con_id of device
165 * dev, %-ENOENT if no GPIO has been assigned to the requested function, or
166 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
167 */
168struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
169					      struct fwnode_handle *fwnode,
170					      const char *con_id, int index,
171					      enum gpiod_flags flags,
172					      const char *label)
173{
174	struct gpio_desc **dr;
175	struct gpio_desc *desc;
176
177	dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
178			  GFP_KERNEL);
179	if (!dr)
180		return ERR_PTR(-ENOMEM);
181
182	desc = gpiod_find_and_request(dev, fwnode, con_id, index, flags, label, false);
183	if (IS_ERR(desc)) {
184		devres_free(dr);
185		return desc;
186	}
187
188	*dr = desc;
189	devres_add(dev, dr);
190
191	return desc;
192}
193EXPORT_SYMBOL_GPL(devm_fwnode_gpiod_get_index);
194
195/**
196 * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
197 * @dev: GPIO consumer
198 * @con_id: function within the GPIO consumer
199 * @index: index of the GPIO to obtain in the consumer
200 * @flags: optional GPIO initialization flags
201 *
202 * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
203 * function are automatically disposed on driver detach. See
204 * gpiod_get_index_optional() for detailed information about behavior and
205 * return values.
206 *
207 * Returns:
208 * The GPIO descriptor corresponding to the function @con_id of device
209 * dev, %NULL if no GPIO has been assigned to the requested function, or
210 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
211 */
212struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
213							     const char *con_id,
214							     unsigned int index,
215							     enum gpiod_flags flags)
216{
217	struct gpio_desc *desc;
218
219	desc = devm_gpiod_get_index(dev, con_id, index, flags);
220	if (gpiod_not_found(desc))
221		return NULL;
222
223	return desc;
224}
225EXPORT_SYMBOL_GPL(devm_gpiod_get_index_optional);
226
227/**
228 * devm_gpiod_get_array - Resource-managed gpiod_get_array()
229 * @dev:	GPIO consumer
230 * @con_id:	function within the GPIO consumer
231 * @flags:	optional GPIO initialization flags
232 *
233 * Managed gpiod_get_array(). GPIO descriptors returned from this function are
234 * automatically disposed on driver detach. See gpiod_get_array() for detailed
235 * information about behavior and return values.
236 *
237 * Returns:
238 * The GPIO descriptors corresponding to the function @con_id of device
239 * dev, %-ENOENT if no GPIO has been assigned to the requested function,
240 * or another IS_ERR() code if an error occurred while trying to acquire
241 * the GPIOs.
242 */
243struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
244						     const char *con_id,
245						     enum gpiod_flags flags)
246{
247	struct gpio_descs **dr;
248	struct gpio_descs *descs;
249
250	dr = devres_alloc(devm_gpiod_release_array,
251			  sizeof(struct gpio_descs *), GFP_KERNEL);
252	if (!dr)
253		return ERR_PTR(-ENOMEM);
254
255	descs = gpiod_get_array(dev, con_id, flags);
256	if (IS_ERR(descs)) {
257		devres_free(dr);
258		return descs;
259	}
260
261	*dr = descs;
262	devres_add(dev, dr);
263
264	return descs;
265}
266EXPORT_SYMBOL_GPL(devm_gpiod_get_array);
267
268/**
269 * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
270 * @dev:	GPIO consumer
271 * @con_id:	function within the GPIO consumer
272 * @flags:	optional GPIO initialization flags
273 *
274 * Managed gpiod_get_array_optional(). GPIO descriptors returned from this
275 * function are automatically disposed on driver detach.
276 * See gpiod_get_array_optional() for detailed information about behavior and
277 * return values.
278 *
279 * Returns:
280 * The GPIO descriptors corresponding to the function @con_id of device
281 * dev, %NULL if no GPIO has been assigned to the requested function,
282 * or another IS_ERR() code if an error occurred while trying to acquire
283 * the GPIOs.
284 */
285struct gpio_descs *__must_check
286devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
287			      enum gpiod_flags flags)
288{
289	struct gpio_descs *descs;
290
291	descs = devm_gpiod_get_array(dev, con_id, flags);
292	if (gpiod_not_found(descs))
293		return NULL;
294
295	return descs;
296}
297EXPORT_SYMBOL_GPL(devm_gpiod_get_array_optional);
298
299/**
300 * devm_gpiod_put - Resource-managed gpiod_put()
301 * @dev:	GPIO consumer
302 * @desc:	GPIO descriptor to dispose of
303 *
304 * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
305 * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
306 * will be disposed of by the resource management code.
307 */
308void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
309{
310	WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
311		&desc));
312}
313EXPORT_SYMBOL_GPL(devm_gpiod_put);
314
315/**
316 * devm_gpiod_unhinge - Remove resource management from a gpio descriptor
317 * @dev:	GPIO consumer
318 * @desc:	GPIO descriptor to remove resource management from
319 *
320 * Remove resource management from a GPIO descriptor. This is needed when
321 * you want to hand over lifecycle management of a descriptor to another
322 * mechanism.
323 */
324
325void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc)
326{
327	int ret;
328
329	if (IS_ERR_OR_NULL(desc))
330		return;
331	ret = devres_destroy(dev, devm_gpiod_release,
332			     devm_gpiod_match, &desc);
333	/*
334	 * If the GPIO descriptor is requested as nonexclusive, we
335	 * may call this function several times on the same descriptor
336	 * so it is OK if devres_destroy() returns -ENOENT.
337	 */
338	if (ret == -ENOENT)
339		return;
340	/* Anything else we should warn about */
341	WARN_ON(ret);
342}
343EXPORT_SYMBOL_GPL(devm_gpiod_unhinge);
344
345/**
346 * devm_gpiod_put_array - Resource-managed gpiod_put_array()
347 * @dev:	GPIO consumer
348 * @descs:	GPIO descriptor array to dispose of
349 *
350 * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
351 * Normally this function will not be called as the GPIOs will be disposed of
352 * by the resource management code.
353 */
354void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
355{
356	WARN_ON(devres_release(dev, devm_gpiod_release_array,
357			       devm_gpiod_match_array, &descs));
358}
359EXPORT_SYMBOL_GPL(devm_gpiod_put_array);
360
361static void devm_gpio_chip_release(void *data)
362{
363	struct gpio_chip *gc = data;
364
365	gpiochip_remove(gc);
366}
367
368/**
369 * devm_gpiochip_add_data_with_key() - Resource managed gpiochip_add_data_with_key()
370 * @dev: pointer to the device that gpio_chip belongs to.
371 * @gc: the GPIO chip to register
372 * @data: driver-private data associated with this chip
373 * @lock_key: lockdep class for IRQ lock
374 * @request_key: lockdep class for IRQ request
375 *
376 * Context: potentially before irqs will work
377 *
378 * The gpio chip automatically be released when the device is unbound.
379 *
380 * Returns:
381 * A negative errno if the chip can't be registered, such as because the
382 * gc->base is invalid or already associated with a different chip.
383 * Otherwise it returns zero as a success code.
384 */
385int devm_gpiochip_add_data_with_key(struct device *dev, struct gpio_chip *gc, void *data,
386				    struct lock_class_key *lock_key,
387				    struct lock_class_key *request_key)
388{
389	int ret;
390
391	ret = gpiochip_add_data_with_key(gc, data, lock_key, request_key);
392	if (ret < 0)
393		return ret;
394
395	return devm_add_action_or_reset(dev, devm_gpio_chip_release, gc);
396}
397EXPORT_SYMBOL_GPL(devm_gpiochip_add_data_with_key);