1/* The industrial I/O core, trigger handling functions
2 *
3 * Copyright (c) 2008 Jonathan Cameron
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 */
9
10#include <linux/kernel.h>
11#include <linux/idr.h>
12#include <linux/err.h>
13#include <linux/device.h>
14#include <linux/interrupt.h>
15#include <linux/list.h>
16#include <linux/slab.h>
17
18#include <linux/iio/iio.h>
19#include <linux/iio/trigger.h>
20#include "iio_core.h"
21#include "iio_core_trigger.h"
22#include <linux/iio/trigger_consumer.h>
23
24/* RFC - Question of approach
25 * Make the common case (single sensor single trigger)
26 * simple by starting trigger capture from when first sensors
27 * is added.
28 *
29 * Complex simultaneous start requires use of 'hold' functionality
30 * of the trigger. (not implemented)
31 *
32 * Any other suggestions?
33 */
34
35static DEFINE_IDA(iio_trigger_ida);
36
37/* Single list of all available triggers */
38static LIST_HEAD(iio_trigger_list);
39static DEFINE_MUTEX(iio_trigger_list_lock);
40
41/**
42 * iio_trigger_read_name() - retrieve useful identifying name
43 * @dev: device associated with the iio_trigger
44 * @attr: pointer to the device_attribute structure that is
45 * being processed
46 * @buf: buffer to print the name into
47 *
48 * Return: a negative number on failure or the number of written
49 * characters on success.
50 */
51static ssize_t iio_trigger_read_name(struct device *dev,
52 struct device_attribute *attr,
53 char *buf)
54{
55 struct iio_trigger *trig = to_iio_trigger(dev);
56 return sprintf(buf, "%s\n", trig->name);
57}
58
59static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
60
61static struct attribute *iio_trig_dev_attrs[] = {
62 &dev_attr_name.attr,
63 NULL,
64};
65ATTRIBUTE_GROUPS(iio_trig_dev);
66
67static struct iio_trigger *__iio_trigger_find_by_name(const char *name);
68
69int __iio_trigger_register(struct iio_trigger *trig_info,
70 struct module *this_mod)
71{
72 int ret;
73
74 trig_info->owner = this_mod;
75
76 trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
77 if (trig_info->id < 0)
78 return trig_info->id;
79
80 /* Set the name used for the sysfs directory etc */
81 dev_set_name(&trig_info->dev, "trigger%ld",
82 (unsigned long) trig_info->id);
83
84 ret = device_add(&trig_info->dev);
85 if (ret)
86 goto error_unregister_id;
87
88 /* Add to list of available triggers held by the IIO core */
89 mutex_lock(&iio_trigger_list_lock);
90 if (__iio_trigger_find_by_name(trig_info->name)) {
91 pr_err("Duplicate trigger name '%s'\n", trig_info->name);
92 ret = -EEXIST;
93 goto error_device_del;
94 }
95 list_add_tail(&trig_info->list, &iio_trigger_list);
96 mutex_unlock(&iio_trigger_list_lock);
97
98 return 0;
99
100error_device_del:
101 mutex_unlock(&iio_trigger_list_lock);
102 device_del(&trig_info->dev);
103error_unregister_id:
104 ida_simple_remove(&iio_trigger_ida, trig_info->id);
105 return ret;
106}
107EXPORT_SYMBOL(__iio_trigger_register);
108
109void iio_trigger_unregister(struct iio_trigger *trig_info)
110{
111 mutex_lock(&iio_trigger_list_lock);
112 list_del(&trig_info->list);
113 mutex_unlock(&iio_trigger_list_lock);
114
115 ida_simple_remove(&iio_trigger_ida, trig_info->id);
116 /* Possible issue in here */
117 device_del(&trig_info->dev);
118}
119EXPORT_SYMBOL(iio_trigger_unregister);
120
121int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)
122{
123 if (!indio_dev || !trig)
124 return -EINVAL;
125
126 mutex_lock(&indio_dev->mlock);
127 WARN_ON(indio_dev->trig_readonly);
128
129 indio_dev->trig = iio_trigger_get(trig);
130 indio_dev->trig_readonly = true;
131 mutex_unlock(&indio_dev->mlock);
132
133 return 0;
134}
135EXPORT_SYMBOL(iio_trigger_set_immutable);
136
137/* Search for trigger by name, assuming iio_trigger_list_lock held */
138static struct iio_trigger *__iio_trigger_find_by_name(const char *name)
139{
140 struct iio_trigger *iter;
141
142 list_for_each_entry(iter, &iio_trigger_list, list)
143 if (!strcmp(iter->name, name))
144 return iter;
145
146 return NULL;
147}
148
149static struct iio_trigger *iio_trigger_acquire_by_name(const char *name)
150{
151 struct iio_trigger *trig = NULL, *iter;
152
153 mutex_lock(&iio_trigger_list_lock);
154 list_for_each_entry(iter, &iio_trigger_list, list)
155 if (sysfs_streq(iter->name, name)) {
156 trig = iter;
157 iio_trigger_get(trig);
158 break;
159 }
160 mutex_unlock(&iio_trigger_list_lock);
161
162 return trig;
163}
164
165void iio_trigger_poll(struct iio_trigger *trig)
166{
167 int i;
168
169 if (!atomic_read(&trig->use_count)) {
170 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
171
172 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
173 if (trig->subirqs[i].enabled)
174 generic_handle_irq(trig->subirq_base + i);
175 else
176 iio_trigger_notify_done(trig);
177 }
178 }
179}
180EXPORT_SYMBOL(iio_trigger_poll);
181
182irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
183{
184 iio_trigger_poll(private);
185 return IRQ_HANDLED;
186}
187EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
188
189void iio_trigger_poll_chained(struct iio_trigger *trig)
190{
191 int i;
192
193 if (!atomic_read(&trig->use_count)) {
194 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
195
196 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
197 if (trig->subirqs[i].enabled)
198 handle_nested_irq(trig->subirq_base + i);
199 else
200 iio_trigger_notify_done(trig);
201 }
202 }
203}
204EXPORT_SYMBOL(iio_trigger_poll_chained);
205
206void iio_trigger_notify_done(struct iio_trigger *trig)
207{
208 if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
209 trig->ops->try_reenable)
210 if (trig->ops->try_reenable(trig))
211 /* Missed an interrupt so launch new poll now */
212 iio_trigger_poll(trig);
213}
214EXPORT_SYMBOL(iio_trigger_notify_done);
215
216/* Trigger Consumer related functions */
217static int iio_trigger_get_irq(struct iio_trigger *trig)
218{
219 int ret;
220 mutex_lock(&trig->pool_lock);
221 ret = bitmap_find_free_region(trig->pool,
222 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
223 ilog2(1));
224 mutex_unlock(&trig->pool_lock);
225 if (ret >= 0)
226 ret += trig->subirq_base;
227
228 return ret;
229}
230
231static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
232{
233 mutex_lock(&trig->pool_lock);
234 clear_bit(irq - trig->subirq_base, trig->pool);
235 mutex_unlock(&trig->pool_lock);
236}
237
238/* Complexity in here. With certain triggers (datardy) an acknowledgement
239 * may be needed if the pollfuncs do not include the data read for the
240 * triggering device.
241 * This is not currently handled. Alternative of not enabling trigger unless
242 * the relevant function is in there may be the best option.
243 */
244/* Worth protecting against double additions? */
245static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
246 struct iio_poll_func *pf)
247{
248 int ret = 0;
249 bool notinuse
250 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
251
252 /* Prevent the module from being removed whilst attached to a trigger */
253 __module_get(pf->indio_dev->driver_module);
254
255 /* Get irq number */
256 pf->irq = iio_trigger_get_irq(trig);
257 if (pf->irq < 0)
258 goto out_put_module;
259
260 /* Request irq */
261 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
262 pf->type, pf->name,
263 pf);
264 if (ret < 0)
265 goto out_put_irq;
266
267 /* Enable trigger in driver */
268 if (trig->ops && trig->ops->set_trigger_state && notinuse) {
269 ret = trig->ops->set_trigger_state(trig, true);
270 if (ret < 0)
271 goto out_free_irq;
272 }
273
274 /*
275 * Check if we just registered to our own trigger: we determine that
276 * this is the case if the IIO device and the trigger device share the
277 * same parent device.
278 */
279 if (pf->indio_dev->dev.parent == trig->dev.parent)
280 trig->attached_own_device = true;
281
282 return ret;
283
284out_free_irq:
285 free_irq(pf->irq, pf);
286out_put_irq:
287 iio_trigger_put_irq(trig, pf->irq);
288out_put_module:
289 module_put(pf->indio_dev->driver_module);
290 return ret;
291}
292
293static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
294 struct iio_poll_func *pf)
295{
296 int ret = 0;
297 bool no_other_users
298 = (bitmap_weight(trig->pool,
299 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
300 == 1);
301 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
302 ret = trig->ops->set_trigger_state(trig, false);
303 if (ret)
304 return ret;
305 }
306 if (pf->indio_dev->dev.parent == trig->dev.parent)
307 trig->attached_own_device = false;
308 iio_trigger_put_irq(trig, pf->irq);
309 free_irq(pf->irq, pf);
310 module_put(pf->indio_dev->driver_module);
311
312 return ret;
313}
314
315irqreturn_t iio_pollfunc_store_time(int irq, void *p)
316{
317 struct iio_poll_func *pf = p;
318 pf->timestamp = iio_get_time_ns(pf->indio_dev);
319 return IRQ_WAKE_THREAD;
320}
321EXPORT_SYMBOL(iio_pollfunc_store_time);
322
323struct iio_poll_func
324*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
325 irqreturn_t (*thread)(int irq, void *p),
326 int type,
327 struct iio_dev *indio_dev,
328 const char *fmt,
329 ...)
330{
331 va_list vargs;
332 struct iio_poll_func *pf;
333
334 pf = kmalloc(sizeof *pf, GFP_KERNEL);
335 if (pf == NULL)
336 return NULL;
337 va_start(vargs, fmt);
338 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
339 va_end(vargs);
340 if (pf->name == NULL) {
341 kfree(pf);
342 return NULL;
343 }
344 pf->h = h;
345 pf->thread = thread;
346 pf->type = type;
347 pf->indio_dev = indio_dev;
348
349 return pf;
350}
351EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
352
353void iio_dealloc_pollfunc(struct iio_poll_func *pf)
354{
355 kfree(pf->name);
356 kfree(pf);
357}
358EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
359
360/**
361 * iio_trigger_read_current() - trigger consumer sysfs query current trigger
362 * @dev: device associated with an industrial I/O device
363 * @attr: pointer to the device_attribute structure that
364 * is being processed
365 * @buf: buffer where the current trigger name will be printed into
366 *
367 * For trigger consumers the current_trigger interface allows the trigger
368 * used by the device to be queried.
369 *
370 * Return: a negative number on failure, the number of characters written
371 * on success or 0 if no trigger is available
372 */
373static ssize_t iio_trigger_read_current(struct device *dev,
374 struct device_attribute *attr,
375 char *buf)
376{
377 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
378
379 if (indio_dev->trig)
380 return sprintf(buf, "%s\n", indio_dev->trig->name);
381 return 0;
382}
383
384/**
385 * iio_trigger_write_current() - trigger consumer sysfs set current trigger
386 * @dev: device associated with an industrial I/O device
387 * @attr: device attribute that is being processed
388 * @buf: string buffer that holds the name of the trigger
389 * @len: length of the trigger name held by buf
390 *
391 * For trigger consumers the current_trigger interface allows the trigger
392 * used for this device to be specified at run time based on the trigger's
393 * name.
394 *
395 * Return: negative error code on failure or length of the buffer
396 * on success
397 */
398static ssize_t iio_trigger_write_current(struct device *dev,
399 struct device_attribute *attr,
400 const char *buf,
401 size_t len)
402{
403 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
404 struct iio_trigger *oldtrig = indio_dev->trig;
405 struct iio_trigger *trig;
406 int ret;
407
408 mutex_lock(&indio_dev->mlock);
409 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
410 mutex_unlock(&indio_dev->mlock);
411 return -EBUSY;
412 }
413 if (indio_dev->trig_readonly) {
414 mutex_unlock(&indio_dev->mlock);
415 return -EPERM;
416 }
417 mutex_unlock(&indio_dev->mlock);
418
419 trig = iio_trigger_acquire_by_name(buf);
420 if (oldtrig == trig) {
421 ret = len;
422 goto out_trigger_put;
423 }
424
425 if (trig && indio_dev->info->validate_trigger) {
426 ret = indio_dev->info->validate_trigger(indio_dev, trig);
427 if (ret)
428 goto out_trigger_put;
429 }
430
431 if (trig && trig->ops && trig->ops->validate_device) {
432 ret = trig->ops->validate_device(trig, indio_dev);
433 if (ret)
434 goto out_trigger_put;
435 }
436
437 indio_dev->trig = trig;
438
439 if (oldtrig) {
440 if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
441 iio_trigger_detach_poll_func(oldtrig,
442 indio_dev->pollfunc_event);
443 iio_trigger_put(oldtrig);
444 }
445 if (indio_dev->trig) {
446 if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
447 iio_trigger_attach_poll_func(indio_dev->trig,
448 indio_dev->pollfunc_event);
449 }
450
451 return len;
452
453out_trigger_put:
454 if (trig)
455 iio_trigger_put(trig);
456 return ret;
457}
458
459static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
460 iio_trigger_read_current,
461 iio_trigger_write_current);
462
463static struct attribute *iio_trigger_consumer_attrs[] = {
464 &dev_attr_current_trigger.attr,
465 NULL,
466};
467
468static const struct attribute_group iio_trigger_consumer_attr_group = {
469 .name = "trigger",
470 .attrs = iio_trigger_consumer_attrs,
471};
472
473static void iio_trig_release(struct device *device)
474{
475 struct iio_trigger *trig = to_iio_trigger(device);
476 int i;
477
478 if (trig->subirq_base) {
479 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
480 irq_modify_status(trig->subirq_base + i,
481 IRQ_NOAUTOEN,
482 IRQ_NOREQUEST | IRQ_NOPROBE);
483 irq_set_chip(trig->subirq_base + i,
484 NULL);
485 irq_set_handler(trig->subirq_base + i,
486 NULL);
487 }
488
489 irq_free_descs(trig->subirq_base,
490 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
491 }
492 kfree(trig->name);
493 kfree(trig);
494}
495
496static const struct device_type iio_trig_type = {
497 .release = iio_trig_release,
498 .groups = iio_trig_dev_groups,
499};
500
501static void iio_trig_subirqmask(struct irq_data *d)
502{
503 struct irq_chip *chip = irq_data_get_irq_chip(d);
504 struct iio_trigger *trig
505 = container_of(chip,
506 struct iio_trigger, subirq_chip);
507 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
508}
509
510static void iio_trig_subirqunmask(struct irq_data *d)
511{
512 struct irq_chip *chip = irq_data_get_irq_chip(d);
513 struct iio_trigger *trig
514 = container_of(chip,
515 struct iio_trigger, subirq_chip);
516 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
517}
518
519static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
520{
521 struct iio_trigger *trig;
522 int i;
523
524 trig = kzalloc(sizeof *trig, GFP_KERNEL);
525 if (!trig)
526 return NULL;
527
528 trig->dev.type = &iio_trig_type;
529 trig->dev.bus = &iio_bus_type;
530 device_initialize(&trig->dev);
531
532 mutex_init(&trig->pool_lock);
533 trig->subirq_base = irq_alloc_descs(-1, 0,
534 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
535 0);
536 if (trig->subirq_base < 0)
537 goto free_trig;
538
539 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
540 if (trig->name == NULL)
541 goto free_descs;
542
543 trig->subirq_chip.name = trig->name;
544 trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
545 trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
546 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
547 irq_set_chip(trig->subirq_base + i, &trig->subirq_chip);
548 irq_set_handler(trig->subirq_base + i, &handle_simple_irq);
549 irq_modify_status(trig->subirq_base + i,
550 IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
551 }
552 get_device(&trig->dev);
553
554 return trig;
555
556free_descs:
557 irq_free_descs(trig->subirq_base, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
558free_trig:
559 kfree(trig);
560 return NULL;
561}
562
563struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
564{
565 struct iio_trigger *trig;
566 va_list vargs;
567
568 va_start(vargs, fmt);
569 trig = viio_trigger_alloc(fmt, vargs);
570 va_end(vargs);
571
572 return trig;
573}
574EXPORT_SYMBOL(iio_trigger_alloc);
575
576void iio_trigger_free(struct iio_trigger *trig)
577{
578 if (trig)
579 put_device(&trig->dev);
580}
581EXPORT_SYMBOL(iio_trigger_free);
582
583static void devm_iio_trigger_release(struct device *dev, void *res)
584{
585 iio_trigger_free(*(struct iio_trigger **)res);
586}
587
588static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
589{
590 struct iio_trigger **r = res;
591
592 if (!r || !*r) {
593 WARN_ON(!r || !*r);
594 return 0;
595 }
596
597 return *r == data;
598}
599
600/**
601 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
602 * @dev: Device to allocate iio_trigger for
603 * @fmt: trigger name format. If it includes format
604 * specifiers, the additional arguments following
605 * format are formatted and inserted in the resulting
606 * string replacing their respective specifiers.
607 *
608 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
609 * automatically freed on driver detach.
610 *
611 * If an iio_trigger allocated with this function needs to be freed separately,
612 * devm_iio_trigger_free() must be used.
613 *
614 * RETURNS:
615 * Pointer to allocated iio_trigger on success, NULL on failure.
616 */
617struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
618 const char *fmt, ...)
619{
620 struct iio_trigger **ptr, *trig;
621 va_list vargs;
622
623 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
624 GFP_KERNEL);
625 if (!ptr)
626 return NULL;
627
628 /* use raw alloc_dr for kmalloc caller tracing */
629 va_start(vargs, fmt);
630 trig = viio_trigger_alloc(fmt, vargs);
631 va_end(vargs);
632 if (trig) {
633 *ptr = trig;
634 devres_add(dev, ptr);
635 } else {
636 devres_free(ptr);
637 }
638
639 return trig;
640}
641EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
642
643/**
644 * devm_iio_trigger_free - Resource-managed iio_trigger_free()
645 * @dev: Device this iio_dev belongs to
646 * @iio_trig: the iio_trigger associated with the device
647 *
648 * Free iio_trigger allocated with devm_iio_trigger_alloc().
649 */
650void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
651{
652 int rc;
653
654 rc = devres_release(dev, devm_iio_trigger_release,
655 devm_iio_trigger_match, iio_trig);
656 WARN_ON(rc);
657}
658EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
659
660static void devm_iio_trigger_unreg(struct device *dev, void *res)
661{
662 iio_trigger_unregister(*(struct iio_trigger **)res);
663}
664
665/**
666 * __devm_iio_trigger_register - Resource-managed iio_trigger_register()
667 * @dev: device this trigger was allocated for
668 * @trig_info: trigger to register
669 * @this_mod: module registering the trigger
670 *
671 * Managed iio_trigger_register(). The IIO trigger registered with this
672 * function is automatically unregistered on driver detach. This function
673 * calls iio_trigger_register() internally. Refer to that function for more
674 * information.
675 *
676 * If an iio_trigger registered with this function needs to be unregistered
677 * separately, devm_iio_trigger_unregister() must be used.
678 *
679 * RETURNS:
680 * 0 on success, negative error number on failure.
681 */
682int __devm_iio_trigger_register(struct device *dev,
683 struct iio_trigger *trig_info,
684 struct module *this_mod)
685{
686 struct iio_trigger **ptr;
687 int ret;
688
689 ptr = devres_alloc(devm_iio_trigger_unreg, sizeof(*ptr), GFP_KERNEL);
690 if (!ptr)
691 return -ENOMEM;
692
693 *ptr = trig_info;
694 ret = __iio_trigger_register(trig_info, this_mod);
695 if (!ret)
696 devres_add(dev, ptr);
697 else
698 devres_free(ptr);
699
700 return ret;
701}
702EXPORT_SYMBOL_GPL(__devm_iio_trigger_register);
703
704/**
705 * devm_iio_trigger_unregister - Resource-managed iio_trigger_unregister()
706 * @dev: device this iio_trigger belongs to
707 * @trig_info: the trigger associated with the device
708 *
709 * Unregister trigger registered with devm_iio_trigger_register().
710 */
711void devm_iio_trigger_unregister(struct device *dev,
712 struct iio_trigger *trig_info)
713{
714 int rc;
715
716 rc = devres_release(dev, devm_iio_trigger_unreg, devm_iio_trigger_match,
717 trig_info);
718 WARN_ON(rc);
719}
720EXPORT_SYMBOL_GPL(devm_iio_trigger_unregister);
721
722bool iio_trigger_using_own(struct iio_dev *indio_dev)
723{
724 return indio_dev->trig->attached_own_device;
725}
726EXPORT_SYMBOL(iio_trigger_using_own);
727
728/**
729 * iio_trigger_validate_own_device - Check if a trigger and IIO device belong to
730 * the same device
731 * @trig: The IIO trigger to check
732 * @indio_dev: the IIO device to check
733 *
734 * This function can be used as the validate_device callback for triggers that
735 * can only be attached to their own device.
736 *
737 * Return: 0 if both the trigger and the IIO device belong to the same
738 * device, -EINVAL otherwise.
739 */
740int iio_trigger_validate_own_device(struct iio_trigger *trig,
741 struct iio_dev *indio_dev)
742{
743 if (indio_dev->dev.parent != trig->dev.parent)
744 return -EINVAL;
745 return 0;
746}
747EXPORT_SYMBOL(iio_trigger_validate_own_device);
748
749void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
750{
751 indio_dev->groups[indio_dev->groupcounter++] =
752 &iio_trigger_consumer_attr_group;
753}
754
755void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
756{
757 /* Clean up an associated but not attached trigger reference */
758 if (indio_dev->trig)
759 iio_trigger_put(indio_dev->trig);
760}
761
762int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
763{
764 return iio_trigger_attach_poll_func(indio_dev->trig,
765 indio_dev->pollfunc);
766}
767EXPORT_SYMBOL(iio_triggered_buffer_postenable);
768
769int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
770{
771 return iio_trigger_detach_poll_func(indio_dev->trig,
772 indio_dev->pollfunc);
773}
774EXPORT_SYMBOL(iio_triggered_buffer_predisable);
775