1 // SPDX-License-Identifier: GPL-2.0-only
2 /* The industrial I/O core, trigger handling functions
3  *
4  * Copyright (c) 2008 Jonathan Cameron
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/idr.h>
9 #include <linux/err.h>
10 #include <linux/device.h>
11 #include <linux/interrupt.h>
12 #include <linux/list.h>
13 #include <linux/slab.h>
14 
15 #include <linux/iio/iio.h>
16 #include <linux/iio/iio-opaque.h>
17 #include <linux/iio/trigger.h>
18 #include "iio_core.h"
19 #include "iio_core_trigger.h"
20 #include <linux/iio/trigger_consumer.h>
21 
22 /* RFC - Question of approach
23  * Make the common case (single sensor single trigger)
24  * simple by starting trigger capture from when first sensors
25  * is added.
26  *
27  * Complex simultaneous start requires use of 'hold' functionality
28  * of the trigger. (not implemented)
29  *
30  * Any other suggestions?
31  */
32 
33 static DEFINE_IDA(iio_trigger_ida);
34 
35 /* Single list of all available triggers */
36 static LIST_HEAD(iio_trigger_list);
37 static DEFINE_MUTEX(iio_trigger_list_lock);
38 
39 /**
40  * name_show() - retrieve useful identifying name
41  * @dev:	device associated with the iio_trigger
42  * @attr:	pointer to the device_attribute structure that is
43  *		being processed
44  * @buf:	buffer to print the name into
45  *
46  * Return: a negative number on failure or the number of written
47  *	   characters on success.
48  */
49 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
50 			 char *buf)
51 {
52 	struct iio_trigger *trig = to_iio_trigger(dev);
53 
54 	return sysfs_emit(buf, "%s\n", trig->name);
55 }
56 
57 static DEVICE_ATTR_RO(name);
58 
59 static struct attribute *iio_trig_dev_attrs[] = {
60 	&dev_attr_name.attr,
61 	NULL,
62 };
63 ATTRIBUTE_GROUPS(iio_trig_dev);
64 
65 static struct iio_trigger *__iio_trigger_find_by_name(const char *name);
66 
67 int iio_trigger_register(struct iio_trigger *trig_info)
68 {
69 	int ret;
70 
71 	trig_info->id = ida_alloc(&iio_trigger_ida, GFP_KERNEL);
72 	if (trig_info->id < 0)
73 		return trig_info->id;
74 
75 	/* Set the name used for the sysfs directory etc */
76 	dev_set_name(&trig_info->dev, "trigger%d", trig_info->id);
77 
78 	ret = device_add(&trig_info->dev);
79 	if (ret)
80 		goto error_unregister_id;
81 
82 	/* Add to list of available triggers held by the IIO core */
83 	mutex_lock(&iio_trigger_list_lock);
84 	if (__iio_trigger_find_by_name(trig_info->name)) {
85 		pr_err("Duplicate trigger name '%s'\n", trig_info->name);
86 		ret = -EEXIST;
87 		goto error_device_del;
88 	}
89 	list_add_tail(&trig_info->list, &iio_trigger_list);
90 	mutex_unlock(&iio_trigger_list_lock);
91 
92 	return 0;
93 
94 error_device_del:
95 	mutex_unlock(&iio_trigger_list_lock);
96 	device_del(&trig_info->dev);
97 error_unregister_id:
98 	ida_free(&iio_trigger_ida, trig_info->id);
99 	return ret;
100 }
101 EXPORT_SYMBOL(iio_trigger_register);
102 
103 void iio_trigger_unregister(struct iio_trigger *trig_info)
104 {
105 	mutex_lock(&iio_trigger_list_lock);
106 	list_del(&trig_info->list);
107 	mutex_unlock(&iio_trigger_list_lock);
108 
109 	ida_free(&iio_trigger_ida, trig_info->id);
110 	/* Possible issue in here */
111 	device_del(&trig_info->dev);
112 }
113 EXPORT_SYMBOL(iio_trigger_unregister);
114 
115 int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)
116 {
117 	struct iio_dev_opaque *iio_dev_opaque;
118 
119 	if (!indio_dev || !trig)
120 		return -EINVAL;
121 
122 	iio_dev_opaque = to_iio_dev_opaque(indio_dev);
123 	mutex_lock(&indio_dev->mlock);
124 	WARN_ON(iio_dev_opaque->trig_readonly);
125 
126 	indio_dev->trig = iio_trigger_get(trig);
127 	iio_dev_opaque->trig_readonly = true;
128 	mutex_unlock(&indio_dev->mlock);
129 
130 	return 0;
131 }
132 EXPORT_SYMBOL(iio_trigger_set_immutable);
133 
134 /* Search for trigger by name, assuming iio_trigger_list_lock held */
135 static struct iio_trigger *__iio_trigger_find_by_name(const char *name)
136 {
137 	struct iio_trigger *iter;
138 
139 	list_for_each_entry(iter, &iio_trigger_list, list)
140 		if (!strcmp(iter->name, name))
141 			return iter;
142 
143 	return NULL;
144 }
145 
146 static struct iio_trigger *iio_trigger_acquire_by_name(const char *name)
147 {
148 	struct iio_trigger *trig = NULL, *iter;
149 
150 	mutex_lock(&iio_trigger_list_lock);
151 	list_for_each_entry(iter, &iio_trigger_list, list)
152 		if (sysfs_streq(iter->name, name)) {
153 			trig = iter;
154 			iio_trigger_get(trig);
155 			break;
156 		}
157 	mutex_unlock(&iio_trigger_list_lock);
158 
159 	return trig;
160 }
161 
162 static void iio_reenable_work_fn(struct work_struct *work)
163 {
164 	struct iio_trigger *trig = container_of(work, struct iio_trigger,
165 						reenable_work);
166 
167 	/*
168 	 * This 'might' occur after the trigger state is set to disabled -
169 	 * in that case the driver should skip reenabling.
170 	 */
171 	trig->ops->reenable(trig);
172 }
173 
174 /*
175  * In general, reenable callbacks may need to sleep and this path is
176  * not performance sensitive, so just queue up a work item
177  * to reneable the trigger for us.
178  *
179  * Races that can cause this.
180  * 1) A handler occurs entirely in interrupt context so the counter
181  *    the final decrement is still in this interrupt.
182  * 2) The trigger has been removed, but one last interrupt gets through.
183  *
184  * For (1) we must call reenable, but not in atomic context.
185  * For (2) it should be safe to call reenanble, if drivers never blindly
186  * reenable after state is off.
187  */
188 static void iio_trigger_notify_done_atomic(struct iio_trigger *trig)
189 {
190 	if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
191 	    trig->ops->reenable)
192 		schedule_work(&trig->reenable_work);
193 }
194 
195 void iio_trigger_poll(struct iio_trigger *trig)
196 {
197 	int i;
198 
199 	if (!atomic_read(&trig->use_count)) {
200 		atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
201 
202 		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
203 			if (trig->subirqs[i].enabled)
204 				generic_handle_irq(trig->subirq_base + i);
205 			else
206 				iio_trigger_notify_done_atomic(trig);
207 		}
208 	}
209 }
210 EXPORT_SYMBOL(iio_trigger_poll);
211 
212 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
213 {
214 	iio_trigger_poll(private);
215 	return IRQ_HANDLED;
216 }
217 EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
218 
219 void iio_trigger_poll_chained(struct iio_trigger *trig)
220 {
221 	int i;
222 
223 	if (!atomic_read(&trig->use_count)) {
224 		atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
225 
226 		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
227 			if (trig->subirqs[i].enabled)
228 				handle_nested_irq(trig->subirq_base + i);
229 			else
230 				iio_trigger_notify_done(trig);
231 		}
232 	}
233 }
234 EXPORT_SYMBOL(iio_trigger_poll_chained);
235 
236 void iio_trigger_notify_done(struct iio_trigger *trig)
237 {
238 	if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
239 	    trig->ops->reenable)
240 		trig->ops->reenable(trig);
241 }
242 EXPORT_SYMBOL(iio_trigger_notify_done);
243 
244 /* Trigger Consumer related functions */
245 static int iio_trigger_get_irq(struct iio_trigger *trig)
246 {
247 	int ret;
248 
249 	mutex_lock(&trig->pool_lock);
250 	ret = bitmap_find_free_region(trig->pool,
251 				      CONFIG_IIO_CONSUMERS_PER_TRIGGER,
252 				      ilog2(1));
253 	mutex_unlock(&trig->pool_lock);
254 	if (ret >= 0)
255 		ret += trig->subirq_base;
256 
257 	return ret;
258 }
259 
260 static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
261 {
262 	mutex_lock(&trig->pool_lock);
263 	clear_bit(irq - trig->subirq_base, trig->pool);
264 	mutex_unlock(&trig->pool_lock);
265 }
266 
267 /* Complexity in here.  With certain triggers (datardy) an acknowledgement
268  * may be needed if the pollfuncs do not include the data read for the
269  * triggering device.
270  * This is not currently handled.  Alternative of not enabling trigger unless
271  * the relevant function is in there may be the best option.
272  */
273 /* Worth protecting against double additions? */
274 int iio_trigger_attach_poll_func(struct iio_trigger *trig,
275 				 struct iio_poll_func *pf)
276 {
277 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(pf->indio_dev);
278 	bool notinuse =
279 		bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
280 	int ret = 0;
281 
282 	/* Prevent the module from being removed whilst attached to a trigger */
283 	__module_get(iio_dev_opaque->driver_module);
284 
285 	/* Get irq number */
286 	pf->irq = iio_trigger_get_irq(trig);
287 	if (pf->irq < 0) {
288 		pr_err("Could not find an available irq for trigger %s, CONFIG_IIO_CONSUMERS_PER_TRIGGER=%d limit might be exceeded\n",
289 			trig->name, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
290 		goto out_put_module;
291 	}
292 
293 	/* Request irq */
294 	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
295 				   pf->type, pf->name,
296 				   pf);
297 	if (ret < 0)
298 		goto out_put_irq;
299 
300 	/* Enable trigger in driver */
301 	if (trig->ops && trig->ops->set_trigger_state && notinuse) {
302 		ret = trig->ops->set_trigger_state(trig, true);
303 		if (ret < 0)
304 			goto out_free_irq;
305 	}
306 
307 	/*
308 	 * Check if we just registered to our own trigger: we determine that
309 	 * this is the case if the IIO device and the trigger device share the
310 	 * same parent device.
311 	 */
312 	if (pf->indio_dev->dev.parent == trig->dev.parent)
313 		trig->attached_own_device = true;
314 
315 	return ret;
316 
317 out_free_irq:
318 	free_irq(pf->irq, pf);
319 out_put_irq:
320 	iio_trigger_put_irq(trig, pf->irq);
321 out_put_module:
322 	module_put(iio_dev_opaque->driver_module);
323 	return ret;
324 }
325 
326 int iio_trigger_detach_poll_func(struct iio_trigger *trig,
327 				 struct iio_poll_func *pf)
328 {
329 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(pf->indio_dev);
330 	bool no_other_users =
331 		bitmap_weight(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER) == 1;
332 	int ret = 0;
333 
334 	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
335 		ret = trig->ops->set_trigger_state(trig, false);
336 		if (ret)
337 			return ret;
338 	}
339 	if (pf->indio_dev->dev.parent == trig->dev.parent)
340 		trig->attached_own_device = false;
341 	iio_trigger_put_irq(trig, pf->irq);
342 	free_irq(pf->irq, pf);
343 	module_put(iio_dev_opaque->driver_module);
344 
345 	return ret;
346 }
347 
348 irqreturn_t iio_pollfunc_store_time(int irq, void *p)
349 {
350 	struct iio_poll_func *pf = p;
351 
352 	pf->timestamp = iio_get_time_ns(pf->indio_dev);
353 	return IRQ_WAKE_THREAD;
354 }
355 EXPORT_SYMBOL(iio_pollfunc_store_time);
356 
357 struct iio_poll_func
358 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
359 		    irqreturn_t (*thread)(int irq, void *p),
360 		    int type,
361 		    struct iio_dev *indio_dev,
362 		    const char *fmt,
363 		    ...)
364 {
365 	va_list vargs;
366 	struct iio_poll_func *pf;
367 
368 	pf = kmalloc(sizeof(*pf), GFP_KERNEL);
369 	if (!pf)
370 		return NULL;
371 	va_start(vargs, fmt);
372 	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
373 	va_end(vargs);
374 	if (pf->name == NULL) {
375 		kfree(pf);
376 		return NULL;
377 	}
378 	pf->h = h;
379 	pf->thread = thread;
380 	pf->type = type;
381 	pf->indio_dev = indio_dev;
382 
383 	return pf;
384 }
385 EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
386 
387 void iio_dealloc_pollfunc(struct iio_poll_func *pf)
388 {
389 	kfree(pf->name);
390 	kfree(pf);
391 }
392 EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
393 
394 /**
395  * current_trigger_show() - trigger consumer sysfs query current trigger
396  * @dev:	device associated with an industrial I/O device
397  * @attr:	pointer to the device_attribute structure that
398  *		is being processed
399  * @buf:	buffer where the current trigger name will be printed into
400  *
401  * For trigger consumers the current_trigger interface allows the trigger
402  * used by the device to be queried.
403  *
404  * Return: a negative number on failure, the number of characters written
405  *	   on success or 0 if no trigger is available
406  */
407 static ssize_t current_trigger_show(struct device *dev,
408 				    struct device_attribute *attr, char *buf)
409 {
410 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
411 
412 	if (indio_dev->trig)
413 		return sysfs_emit(buf, "%s\n", indio_dev->trig->name);
414 	return 0;
415 }
416 
417 /**
418  * current_trigger_store() - trigger consumer sysfs set current trigger
419  * @dev:	device associated with an industrial I/O device
420  * @attr:	device attribute that is being processed
421  * @buf:	string buffer that holds the name of the trigger
422  * @len:	length of the trigger name held by buf
423  *
424  * For trigger consumers the current_trigger interface allows the trigger
425  * used for this device to be specified at run time based on the trigger's
426  * name.
427  *
428  * Return: negative error code on failure or length of the buffer
429  *	   on success
430  */
431 static ssize_t current_trigger_store(struct device *dev,
432 				     struct device_attribute *attr,
433 				     const char *buf, size_t len)
434 {
435 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
436 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
437 	struct iio_trigger *oldtrig = indio_dev->trig;
438 	struct iio_trigger *trig;
439 	int ret;
440 
441 	mutex_lock(&indio_dev->mlock);
442 	if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
443 		mutex_unlock(&indio_dev->mlock);
444 		return -EBUSY;
445 	}
446 	if (iio_dev_opaque->trig_readonly) {
447 		mutex_unlock(&indio_dev->mlock);
448 		return -EPERM;
449 	}
450 	mutex_unlock(&indio_dev->mlock);
451 
452 	trig = iio_trigger_acquire_by_name(buf);
453 	if (oldtrig == trig) {
454 		ret = len;
455 		goto out_trigger_put;
456 	}
457 
458 	if (trig && indio_dev->info->validate_trigger) {
459 		ret = indio_dev->info->validate_trigger(indio_dev, trig);
460 		if (ret)
461 			goto out_trigger_put;
462 	}
463 
464 	if (trig && trig->ops && trig->ops->validate_device) {
465 		ret = trig->ops->validate_device(trig, indio_dev);
466 		if (ret)
467 			goto out_trigger_put;
468 	}
469 
470 	indio_dev->trig = trig;
471 
472 	if (oldtrig) {
473 		if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
474 			iio_trigger_detach_poll_func(oldtrig,
475 						     indio_dev->pollfunc_event);
476 		iio_trigger_put(oldtrig);
477 	}
478 	if (indio_dev->trig) {
479 		if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
480 			iio_trigger_attach_poll_func(indio_dev->trig,
481 						     indio_dev->pollfunc_event);
482 	}
483 
484 	return len;
485 
486 out_trigger_put:
487 	if (trig)
488 		iio_trigger_put(trig);
489 	return ret;
490 }
491 
492 static DEVICE_ATTR_RW(current_trigger);
493 
494 static struct attribute *iio_trigger_consumer_attrs[] = {
495 	&dev_attr_current_trigger.attr,
496 	NULL,
497 };
498 
499 static const struct attribute_group iio_trigger_consumer_attr_group = {
500 	.name = "trigger",
501 	.attrs = iio_trigger_consumer_attrs,
502 };
503 
504 static void iio_trig_release(struct device *device)
505 {
506 	struct iio_trigger *trig = to_iio_trigger(device);
507 	int i;
508 
509 	if (trig->subirq_base) {
510 		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
511 			irq_modify_status(trig->subirq_base + i,
512 					  IRQ_NOAUTOEN,
513 					  IRQ_NOREQUEST | IRQ_NOPROBE);
514 			irq_set_chip(trig->subirq_base + i,
515 				     NULL);
516 			irq_set_handler(trig->subirq_base + i,
517 					NULL);
518 		}
519 
520 		irq_free_descs(trig->subirq_base,
521 			       CONFIG_IIO_CONSUMERS_PER_TRIGGER);
522 	}
523 	kfree(trig->name);
524 	kfree(trig);
525 }
526 
527 static const struct device_type iio_trig_type = {
528 	.release = iio_trig_release,
529 	.groups = iio_trig_dev_groups,
530 };
531 
532 static void iio_trig_subirqmask(struct irq_data *d)
533 {
534 	struct irq_chip *chip = irq_data_get_irq_chip(d);
535 	struct iio_trigger *trig = container_of(chip, struct iio_trigger, subirq_chip);
536 
537 	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
538 }
539 
540 static void iio_trig_subirqunmask(struct irq_data *d)
541 {
542 	struct irq_chip *chip = irq_data_get_irq_chip(d);
543 	struct iio_trigger *trig = container_of(chip, struct iio_trigger, subirq_chip);
544 
545 	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
546 }
547 
548 static __printf(3, 0)
549 struct iio_trigger *viio_trigger_alloc(struct device *parent,
550 				       struct module *this_mod,
551 				       const char *fmt,
552 				       va_list vargs)
553 {
554 	struct iio_trigger *trig;
555 	int i;
556 
557 	trig = kzalloc(sizeof(*trig), GFP_KERNEL);
558 	if (!trig)
559 		return NULL;
560 
561 	trig->dev.parent = parent;
562 	trig->dev.type = &iio_trig_type;
563 	trig->dev.bus = &iio_bus_type;
564 	device_initialize(&trig->dev);
565 	INIT_WORK(&trig->reenable_work, iio_reenable_work_fn);
566 
567 	mutex_init(&trig->pool_lock);
568 	trig->subirq_base = irq_alloc_descs(-1, 0,
569 					    CONFIG_IIO_CONSUMERS_PER_TRIGGER,
570 					    0);
571 	if (trig->subirq_base < 0)
572 		goto free_trig;
573 
574 	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
575 	if (trig->name == NULL)
576 		goto free_descs;
577 
578 	INIT_LIST_HEAD(&trig->list);
579 
580 	trig->owner = this_mod;
581 
582 	trig->subirq_chip.name = trig->name;
583 	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
584 	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
585 	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
586 		irq_set_chip(trig->subirq_base + i, &trig->subirq_chip);
587 		irq_set_handler(trig->subirq_base + i, &handle_simple_irq);
588 		irq_modify_status(trig->subirq_base + i,
589 				  IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
590 	}
591 
592 	return trig;
593 
594 free_descs:
595 	irq_free_descs(trig->subirq_base, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
596 free_trig:
597 	kfree(trig);
598 	return NULL;
599 }
600 
601 /**
602  * __iio_trigger_alloc - Allocate a trigger
603  * @parent:		Device to allocate iio_trigger for
604  * @this_mod:		module allocating the trigger
605  * @fmt:		trigger name format. If it includes format
606  *			specifiers, the additional arguments following
607  *			format are formatted and inserted in the resulting
608  *			string replacing their respective specifiers.
609  * RETURNS:
610  * Pointer to allocated iio_trigger on success, NULL on failure.
611  */
612 struct iio_trigger *__iio_trigger_alloc(struct device *parent,
613 					struct module *this_mod,
614 					const char *fmt, ...)
615 {
616 	struct iio_trigger *trig;
617 	va_list vargs;
618 
619 	va_start(vargs, fmt);
620 	trig = viio_trigger_alloc(parent, this_mod, fmt, vargs);
621 	va_end(vargs);
622 
623 	return trig;
624 }
625 EXPORT_SYMBOL(__iio_trigger_alloc);
626 
627 void iio_trigger_free(struct iio_trigger *trig)
628 {
629 	if (trig)
630 		put_device(&trig->dev);
631 }
632 EXPORT_SYMBOL(iio_trigger_free);
633 
634 static void devm_iio_trigger_release(struct device *dev, void *res)
635 {
636 	iio_trigger_free(*(struct iio_trigger **)res);
637 }
638 
639 /**
640  * __devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
641  * Managed iio_trigger_alloc.  iio_trigger allocated with this function is
642  * automatically freed on driver detach.
643  * @parent:		Device to allocate iio_trigger for
644  * @this_mod:		module allocating the trigger
645  * @fmt:		trigger name format. If it includes format
646  *			specifiers, the additional arguments following
647  *			format are formatted and inserted in the resulting
648  *			string replacing their respective specifiers.
649  *
650  *
651  * RETURNS:
652  * Pointer to allocated iio_trigger on success, NULL on failure.
653  */
654 struct iio_trigger *__devm_iio_trigger_alloc(struct device *parent,
655 					     struct module *this_mod,
656 					     const char *fmt, ...)
657 {
658 	struct iio_trigger **ptr, *trig;
659 	va_list vargs;
660 
661 	ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
662 			   GFP_KERNEL);
663 	if (!ptr)
664 		return NULL;
665 
666 	/* use raw alloc_dr for kmalloc caller tracing */
667 	va_start(vargs, fmt);
668 	trig = viio_trigger_alloc(parent, this_mod, fmt, vargs);
669 	va_end(vargs);
670 	if (trig) {
671 		*ptr = trig;
672 		devres_add(parent, ptr);
673 	} else {
674 		devres_free(ptr);
675 	}
676 
677 	return trig;
678 }
679 EXPORT_SYMBOL_GPL(__devm_iio_trigger_alloc);
680 
681 static void devm_iio_trigger_unreg(void *trigger_info)
682 {
683 	iio_trigger_unregister(trigger_info);
684 }
685 
686 /**
687  * devm_iio_trigger_register - Resource-managed iio_trigger_register()
688  * @dev:	device this trigger was allocated for
689  * @trig_info:	trigger to register
690  *
691  * Managed iio_trigger_register().  The IIO trigger registered with this
692  * function is automatically unregistered on driver detach. This function
693  * calls iio_trigger_register() internally. Refer to that function for more
694  * information.
695  *
696  * RETURNS:
697  * 0 on success, negative error number on failure.
698  */
699 int devm_iio_trigger_register(struct device *dev,
700 			      struct iio_trigger *trig_info)
701 {
702 	int ret;
703 
704 	ret = iio_trigger_register(trig_info);
705 	if (ret)
706 		return ret;
707 
708 	return devm_add_action_or_reset(dev, devm_iio_trigger_unreg, trig_info);
709 }
710 EXPORT_SYMBOL_GPL(devm_iio_trigger_register);
711 
712 bool iio_trigger_using_own(struct iio_dev *indio_dev)
713 {
714 	return indio_dev->trig->attached_own_device;
715 }
716 EXPORT_SYMBOL(iio_trigger_using_own);
717 
718 /**
719  * iio_trigger_validate_own_device - Check if a trigger and IIO device belong to
720  *  the same device
721  * @trig: The IIO trigger to check
722  * @indio_dev: the IIO device to check
723  *
724  * This function can be used as the validate_device callback for triggers that
725  * can only be attached to their own device.
726  *
727  * Return: 0 if both the trigger and the IIO device belong to the same
728  * device, -EINVAL otherwise.
729  */
730 int iio_trigger_validate_own_device(struct iio_trigger *trig,
731 				    struct iio_dev *indio_dev)
732 {
733 	if (indio_dev->dev.parent != trig->dev.parent)
734 		return -EINVAL;
735 	return 0;
736 }
737 EXPORT_SYMBOL(iio_trigger_validate_own_device);
738 
739 int iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
740 {
741 	return iio_device_register_sysfs_group(indio_dev,
742 					       &iio_trigger_consumer_attr_group);
743 }
744 
745 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
746 {
747 	/* Clean up an associated but not attached trigger reference */
748 	if (indio_dev->trig)
749 		iio_trigger_put(indio_dev->trig);
750 }
751