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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/trigger.h>
17#include "iio_core.h"
18#include "iio_core_trigger.h"
19#include <linux/iio/trigger_consumer.h>
20
21/* RFC - Question of approach
22 * Make the common case (single sensor single trigger)
23 * simple by starting trigger capture from when first sensors
24 * is added.
25 *
26 * Complex simultaneous start requires use of 'hold' functionality
27 * of the trigger. (not implemented)
28 *
29 * Any other suggestions?
30 */
31
32static DEFINE_IDA(iio_trigger_ida);
33
34/* Single list of all available triggers */
35static LIST_HEAD(iio_trigger_list);
36static DEFINE_MUTEX(iio_trigger_list_lock);
37
38/**
39 * iio_trigger_read_name() - retrieve useful identifying name
40 * @dev: device associated with the iio_trigger
41 * @attr: pointer to the device_attribute structure that is
42 * being processed
43 * @buf: buffer to print the name into
44 *
45 * Return: a negative number on failure or the number of written
46 * characters on success.
47 */
48static ssize_t iio_trigger_read_name(struct device *dev,
49 struct device_attribute *attr,
50 char *buf)
51{
52 struct iio_trigger *trig = to_iio_trigger(dev);
53 return sprintf(buf, "%s\n", trig->name);
54}
55
56static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
57
58static struct attribute *iio_trig_dev_attrs[] = {
59 &dev_attr_name.attr,
60 NULL,
61};
62ATTRIBUTE_GROUPS(iio_trig_dev);
63
64static struct iio_trigger *__iio_trigger_find_by_name(const char *name);
65
66int __iio_trigger_register(struct iio_trigger *trig_info,
67 struct module *this_mod)
68{
69 int ret;
70
71 trig_info->owner = this_mod;
72
73 trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
74 if (trig_info->id < 0)
75 return trig_info->id;
76
77 /* Set the name used for the sysfs directory etc */
78 dev_set_name(&trig_info->dev, "trigger%ld",
79 (unsigned long) trig_info->id);
80
81 ret = device_add(&trig_info->dev);
82 if (ret)
83 goto error_unregister_id;
84
85 /* Add to list of available triggers held by the IIO core */
86 mutex_lock(&iio_trigger_list_lock);
87 if (__iio_trigger_find_by_name(trig_info->name)) {
88 pr_err("Duplicate trigger name '%s'\n", trig_info->name);
89 ret = -EEXIST;
90 goto error_device_del;
91 }
92 list_add_tail(&trig_info->list, &iio_trigger_list);
93 mutex_unlock(&iio_trigger_list_lock);
94
95 return 0;
96
97error_device_del:
98 mutex_unlock(&iio_trigger_list_lock);
99 device_del(&trig_info->dev);
100error_unregister_id:
101 ida_simple_remove(&iio_trigger_ida, trig_info->id);
102 return ret;
103}
104EXPORT_SYMBOL(__iio_trigger_register);
105
106void iio_trigger_unregister(struct iio_trigger *trig_info)
107{
108 mutex_lock(&iio_trigger_list_lock);
109 list_del(&trig_info->list);
110 mutex_unlock(&iio_trigger_list_lock);
111
112 ida_simple_remove(&iio_trigger_ida, trig_info->id);
113 /* Possible issue in here */
114 device_del(&trig_info->dev);
115}
116EXPORT_SYMBOL(iio_trigger_unregister);
117
118int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)
119{
120 if (!indio_dev || !trig)
121 return -EINVAL;
122
123 mutex_lock(&indio_dev->mlock);
124 WARN_ON(indio_dev->trig_readonly);
125
126 indio_dev->trig = iio_trigger_get(trig);
127 indio_dev->trig_readonly = true;
128 mutex_unlock(&indio_dev->mlock);
129
130 return 0;
131}
132EXPORT_SYMBOL(iio_trigger_set_immutable);
133
134/* Search for trigger by name, assuming iio_trigger_list_lock held */
135static 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
146static 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
162void iio_trigger_poll(struct iio_trigger *trig)
163{
164 int i;
165
166 if (!atomic_read(&trig->use_count)) {
167 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
168
169 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
170 if (trig->subirqs[i].enabled)
171 generic_handle_irq(trig->subirq_base + i);
172 else
173 iio_trigger_notify_done(trig);
174 }
175 }
176}
177EXPORT_SYMBOL(iio_trigger_poll);
178
179irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
180{
181 iio_trigger_poll(private);
182 return IRQ_HANDLED;
183}
184EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
185
186void iio_trigger_poll_chained(struct iio_trigger *trig)
187{
188 int i;
189
190 if (!atomic_read(&trig->use_count)) {
191 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
192
193 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
194 if (trig->subirqs[i].enabled)
195 handle_nested_irq(trig->subirq_base + i);
196 else
197 iio_trigger_notify_done(trig);
198 }
199 }
200}
201EXPORT_SYMBOL(iio_trigger_poll_chained);
202
203void iio_trigger_notify_done(struct iio_trigger *trig)
204{
205 if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
206 trig->ops->try_reenable)
207 if (trig->ops->try_reenable(trig))
208 /* Missed an interrupt so launch new poll now */
209 iio_trigger_poll(trig);
210}
211EXPORT_SYMBOL(iio_trigger_notify_done);
212
213/* Trigger Consumer related functions */
214static int iio_trigger_get_irq(struct iio_trigger *trig)
215{
216 int ret;
217 mutex_lock(&trig->pool_lock);
218 ret = bitmap_find_free_region(trig->pool,
219 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
220 ilog2(1));
221 mutex_unlock(&trig->pool_lock);
222 if (ret >= 0)
223 ret += trig->subirq_base;
224
225 return ret;
226}
227
228static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
229{
230 mutex_lock(&trig->pool_lock);
231 clear_bit(irq - trig->subirq_base, trig->pool);
232 mutex_unlock(&trig->pool_lock);
233}
234
235/* Complexity in here. With certain triggers (datardy) an acknowledgement
236 * may be needed if the pollfuncs do not include the data read for the
237 * triggering device.
238 * This is not currently handled. Alternative of not enabling trigger unless
239 * the relevant function is in there may be the best option.
240 */
241/* Worth protecting against double additions? */
242int iio_trigger_attach_poll_func(struct iio_trigger *trig,
243 struct iio_poll_func *pf)
244{
245 int ret = 0;
246 bool notinuse
247 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
248
249 /* Prevent the module from being removed whilst attached to a trigger */
250 __module_get(pf->indio_dev->driver_module);
251
252 /* Get irq number */
253 pf->irq = iio_trigger_get_irq(trig);
254 if (pf->irq < 0) {
255 pr_err("Could not find an available irq for trigger %s, CONFIG_IIO_CONSUMERS_PER_TRIGGER=%d limit might be exceeded\n",
256 trig->name, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
257 goto out_put_module;
258 }
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
293int 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
588/**
589 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
590 * @dev: Device to allocate iio_trigger for
591 * @fmt: trigger name format. If it includes format
592 * specifiers, the additional arguments following
593 * format are formatted and inserted in the resulting
594 * string replacing their respective specifiers.
595 *
596 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
597 * automatically freed on driver detach.
598 *
599 * RETURNS:
600 * Pointer to allocated iio_trigger on success, NULL on failure.
601 */
602struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
603 const char *fmt, ...)
604{
605 struct iio_trigger **ptr, *trig;
606 va_list vargs;
607
608 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
609 GFP_KERNEL);
610 if (!ptr)
611 return NULL;
612
613 /* use raw alloc_dr for kmalloc caller tracing */
614 va_start(vargs, fmt);
615 trig = viio_trigger_alloc(fmt, vargs);
616 va_end(vargs);
617 if (trig) {
618 *ptr = trig;
619 devres_add(dev, ptr);
620 } else {
621 devres_free(ptr);
622 }
623
624 return trig;
625}
626EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
627
628static void devm_iio_trigger_unreg(struct device *dev, void *res)
629{
630 iio_trigger_unregister(*(struct iio_trigger **)res);
631}
632
633/**
634 * __devm_iio_trigger_register - Resource-managed iio_trigger_register()
635 * @dev: device this trigger was allocated for
636 * @trig_info: trigger to register
637 * @this_mod: module registering the trigger
638 *
639 * Managed iio_trigger_register(). The IIO trigger registered with this
640 * function is automatically unregistered on driver detach. This function
641 * calls iio_trigger_register() internally. Refer to that function for more
642 * information.
643 *
644 * RETURNS:
645 * 0 on success, negative error number on failure.
646 */
647int __devm_iio_trigger_register(struct device *dev,
648 struct iio_trigger *trig_info,
649 struct module *this_mod)
650{
651 struct iio_trigger **ptr;
652 int ret;
653
654 ptr = devres_alloc(devm_iio_trigger_unreg, sizeof(*ptr), GFP_KERNEL);
655 if (!ptr)
656 return -ENOMEM;
657
658 *ptr = trig_info;
659 ret = __iio_trigger_register(trig_info, this_mod);
660 if (!ret)
661 devres_add(dev, ptr);
662 else
663 devres_free(ptr);
664
665 return ret;
666}
667EXPORT_SYMBOL_GPL(__devm_iio_trigger_register);
668
669bool iio_trigger_using_own(struct iio_dev *indio_dev)
670{
671 return indio_dev->trig->attached_own_device;
672}
673EXPORT_SYMBOL(iio_trigger_using_own);
674
675/**
676 * iio_trigger_validate_own_device - Check if a trigger and IIO device belong to
677 * the same device
678 * @trig: The IIO trigger to check
679 * @indio_dev: the IIO device to check
680 *
681 * This function can be used as the validate_device callback for triggers that
682 * can only be attached to their own device.
683 *
684 * Return: 0 if both the trigger and the IIO device belong to the same
685 * device, -EINVAL otherwise.
686 */
687int iio_trigger_validate_own_device(struct iio_trigger *trig,
688 struct iio_dev *indio_dev)
689{
690 if (indio_dev->dev.parent != trig->dev.parent)
691 return -EINVAL;
692 return 0;
693}
694EXPORT_SYMBOL(iio_trigger_validate_own_device);
695
696void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
697{
698 indio_dev->groups[indio_dev->groupcounter++] =
699 &iio_trigger_consumer_attr_group;
700}
701
702void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
703{
704 /* Clean up an associated but not attached trigger reference */
705 if (indio_dev->trig)
706 iio_trigger_put(indio_dev->trig);
707}
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 **/
44static ssize_t iio_trigger_read_name(struct device *dev,
45 struct device_attribute *attr,
46 char *buf)
47{
48 struct iio_trigger *trig = to_iio_trigger(dev);
49 return sprintf(buf, "%s\n", trig->name);
50}
51
52static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
53
54static struct attribute *iio_trig_dev_attrs[] = {
55 &dev_attr_name.attr,
56 NULL,
57};
58ATTRIBUTE_GROUPS(iio_trig_dev);
59
60int iio_trigger_register(struct iio_trigger *trig_info)
61{
62 int ret;
63
64 trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
65 if (trig_info->id < 0)
66 return trig_info->id;
67
68 /* Set the name used for the sysfs directory etc */
69 dev_set_name(&trig_info->dev, "trigger%ld",
70 (unsigned long) trig_info->id);
71
72 ret = device_add(&trig_info->dev);
73 if (ret)
74 goto error_unregister_id;
75
76 /* Add to list of available triggers held by the IIO core */
77 mutex_lock(&iio_trigger_list_lock);
78 list_add_tail(&trig_info->list, &iio_trigger_list);
79 mutex_unlock(&iio_trigger_list_lock);
80
81 return 0;
82
83error_unregister_id:
84 ida_simple_remove(&iio_trigger_ida, trig_info->id);
85 return ret;
86}
87EXPORT_SYMBOL(iio_trigger_register);
88
89void iio_trigger_unregister(struct iio_trigger *trig_info)
90{
91 mutex_lock(&iio_trigger_list_lock);
92 list_del(&trig_info->list);
93 mutex_unlock(&iio_trigger_list_lock);
94
95 ida_simple_remove(&iio_trigger_ida, trig_info->id);
96 /* Possible issue in here */
97 device_del(&trig_info->dev);
98}
99EXPORT_SYMBOL(iio_trigger_unregister);
100
101static struct iio_trigger *iio_trigger_find_by_name(const char *name,
102 size_t len)
103{
104 struct iio_trigger *trig = NULL, *iter;
105
106 mutex_lock(&iio_trigger_list_lock);
107 list_for_each_entry(iter, &iio_trigger_list, list)
108 if (sysfs_streq(iter->name, name)) {
109 trig = iter;
110 break;
111 }
112 mutex_unlock(&iio_trigger_list_lock);
113
114 return trig;
115}
116
117void iio_trigger_poll(struct iio_trigger *trig, s64 time)
118{
119 int i;
120
121 if (!atomic_read(&trig->use_count)) {
122 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
123
124 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
125 if (trig->subirqs[i].enabled)
126 generic_handle_irq(trig->subirq_base + i);
127 else
128 iio_trigger_notify_done(trig);
129 }
130 }
131}
132EXPORT_SYMBOL(iio_trigger_poll);
133
134irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
135{
136 iio_trigger_poll(private, iio_get_time_ns());
137 return IRQ_HANDLED;
138}
139EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
140
141void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
142{
143 int i;
144
145 if (!atomic_read(&trig->use_count)) {
146 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
147
148 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
149 if (trig->subirqs[i].enabled)
150 handle_nested_irq(trig->subirq_base + i);
151 else
152 iio_trigger_notify_done(trig);
153 }
154 }
155}
156EXPORT_SYMBOL(iio_trigger_poll_chained);
157
158void iio_trigger_notify_done(struct iio_trigger *trig)
159{
160 if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
161 trig->ops->try_reenable)
162 if (trig->ops->try_reenable(trig))
163 /* Missed an interrupt so launch new poll now */
164 iio_trigger_poll(trig, 0);
165}
166EXPORT_SYMBOL(iio_trigger_notify_done);
167
168/* Trigger Consumer related functions */
169static int iio_trigger_get_irq(struct iio_trigger *trig)
170{
171 int ret;
172 mutex_lock(&trig->pool_lock);
173 ret = bitmap_find_free_region(trig->pool,
174 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
175 ilog2(1));
176 mutex_unlock(&trig->pool_lock);
177 if (ret >= 0)
178 ret += trig->subirq_base;
179
180 return ret;
181}
182
183static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
184{
185 mutex_lock(&trig->pool_lock);
186 clear_bit(irq - trig->subirq_base, trig->pool);
187 mutex_unlock(&trig->pool_lock);
188}
189
190/* Complexity in here. With certain triggers (datardy) an acknowledgement
191 * may be needed if the pollfuncs do not include the data read for the
192 * triggering device.
193 * This is not currently handled. Alternative of not enabling trigger unless
194 * the relevant function is in there may be the best option.
195 */
196/* Worth protecting against double additions? */
197static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
198 struct iio_poll_func *pf)
199{
200 int ret = 0;
201 bool notinuse
202 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
203
204 /* Prevent the module from being removed whilst attached to a trigger */
205 __module_get(pf->indio_dev->info->driver_module);
206 pf->irq = iio_trigger_get_irq(trig);
207 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
208 pf->type, pf->name,
209 pf);
210 if (ret < 0) {
211 module_put(pf->indio_dev->info->driver_module);
212 return ret;
213 }
214
215 if (trig->ops && trig->ops->set_trigger_state && notinuse) {
216 ret = trig->ops->set_trigger_state(trig, true);
217 if (ret < 0)
218 module_put(pf->indio_dev->info->driver_module);
219 }
220
221 return ret;
222}
223
224static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
225 struct iio_poll_func *pf)
226{
227 int ret = 0;
228 bool no_other_users
229 = (bitmap_weight(trig->pool,
230 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
231 == 1);
232 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
233 ret = trig->ops->set_trigger_state(trig, false);
234 if (ret)
235 return ret;
236 }
237 iio_trigger_put_irq(trig, pf->irq);
238 free_irq(pf->irq, pf);
239 module_put(pf->indio_dev->info->driver_module);
240
241 return ret;
242}
243
244irqreturn_t iio_pollfunc_store_time(int irq, void *p)
245{
246 struct iio_poll_func *pf = p;
247 pf->timestamp = iio_get_time_ns();
248 return IRQ_WAKE_THREAD;
249}
250EXPORT_SYMBOL(iio_pollfunc_store_time);
251
252struct iio_poll_func
253*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
254 irqreturn_t (*thread)(int irq, void *p),
255 int type,
256 struct iio_dev *indio_dev,
257 const char *fmt,
258 ...)
259{
260 va_list vargs;
261 struct iio_poll_func *pf;
262
263 pf = kmalloc(sizeof *pf, GFP_KERNEL);
264 if (pf == NULL)
265 return NULL;
266 va_start(vargs, fmt);
267 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
268 va_end(vargs);
269 if (pf->name == NULL) {
270 kfree(pf);
271 return NULL;
272 }
273 pf->h = h;
274 pf->thread = thread;
275 pf->type = type;
276 pf->indio_dev = indio_dev;
277
278 return pf;
279}
280EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
281
282void iio_dealloc_pollfunc(struct iio_poll_func *pf)
283{
284 kfree(pf->name);
285 kfree(pf);
286}
287EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
288
289/**
290 * iio_trigger_read_current() - trigger consumer sysfs query current trigger
291 *
292 * For trigger consumers the current_trigger interface allows the trigger
293 * used by the device to be queried.
294 **/
295static ssize_t iio_trigger_read_current(struct device *dev,
296 struct device_attribute *attr,
297 char *buf)
298{
299 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
300
301 if (indio_dev->trig)
302 return sprintf(buf, "%s\n", indio_dev->trig->name);
303 return 0;
304}
305
306/**
307 * iio_trigger_write_current() - trigger consumer sysfs set current trigger
308 *
309 * For trigger consumers the current_trigger interface allows the trigger
310 * used for this device to be specified at run time based on the trigger's
311 * name.
312 **/
313static ssize_t iio_trigger_write_current(struct device *dev,
314 struct device_attribute *attr,
315 const char *buf,
316 size_t len)
317{
318 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
319 struct iio_trigger *oldtrig = indio_dev->trig;
320 struct iio_trigger *trig;
321 int ret;
322
323 mutex_lock(&indio_dev->mlock);
324 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
325 mutex_unlock(&indio_dev->mlock);
326 return -EBUSY;
327 }
328 mutex_unlock(&indio_dev->mlock);
329
330 trig = iio_trigger_find_by_name(buf, len);
331 if (oldtrig == trig)
332 return len;
333
334 if (trig && indio_dev->info->validate_trigger) {
335 ret = indio_dev->info->validate_trigger(indio_dev, trig);
336 if (ret)
337 return ret;
338 }
339
340 if (trig && trig->ops && trig->ops->validate_device) {
341 ret = trig->ops->validate_device(trig, indio_dev);
342 if (ret)
343 return ret;
344 }
345
346 indio_dev->trig = trig;
347
348 if (oldtrig)
349 iio_trigger_put(oldtrig);
350 if (indio_dev->trig)
351 iio_trigger_get(indio_dev->trig);
352
353 return len;
354}
355
356static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
357 iio_trigger_read_current,
358 iio_trigger_write_current);
359
360static struct attribute *iio_trigger_consumer_attrs[] = {
361 &dev_attr_current_trigger.attr,
362 NULL,
363};
364
365static const struct attribute_group iio_trigger_consumer_attr_group = {
366 .name = "trigger",
367 .attrs = iio_trigger_consumer_attrs,
368};
369
370static void iio_trig_release(struct device *device)
371{
372 struct iio_trigger *trig = to_iio_trigger(device);
373 int i;
374
375 if (trig->subirq_base) {
376 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
377 irq_modify_status(trig->subirq_base + i,
378 IRQ_NOAUTOEN,
379 IRQ_NOREQUEST | IRQ_NOPROBE);
380 irq_set_chip(trig->subirq_base + i,
381 NULL);
382 irq_set_handler(trig->subirq_base + i,
383 NULL);
384 }
385
386 irq_free_descs(trig->subirq_base,
387 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
388 }
389 kfree(trig->name);
390 kfree(trig);
391}
392
393static struct device_type iio_trig_type = {
394 .release = iio_trig_release,
395 .groups = iio_trig_dev_groups,
396};
397
398static void iio_trig_subirqmask(struct irq_data *d)
399{
400 struct irq_chip *chip = irq_data_get_irq_chip(d);
401 struct iio_trigger *trig
402 = container_of(chip,
403 struct iio_trigger, subirq_chip);
404 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
405}
406
407static void iio_trig_subirqunmask(struct irq_data *d)
408{
409 struct irq_chip *chip = irq_data_get_irq_chip(d);
410 struct iio_trigger *trig
411 = container_of(chip,
412 struct iio_trigger, subirq_chip);
413 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
414}
415
416static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
417{
418 struct iio_trigger *trig;
419 trig = kzalloc(sizeof *trig, GFP_KERNEL);
420 if (trig) {
421 int i;
422 trig->dev.type = &iio_trig_type;
423 trig->dev.bus = &iio_bus_type;
424 device_initialize(&trig->dev);
425
426 mutex_init(&trig->pool_lock);
427 trig->subirq_base
428 = irq_alloc_descs(-1, 0,
429 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
430 0);
431 if (trig->subirq_base < 0) {
432 kfree(trig);
433 return NULL;
434 }
435
436 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
437 if (trig->name == NULL) {
438 irq_free_descs(trig->subirq_base,
439 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
440 kfree(trig);
441 return NULL;
442 }
443 trig->subirq_chip.name = trig->name;
444 trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
445 trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
446 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
447 irq_set_chip(trig->subirq_base + i,
448 &trig->subirq_chip);
449 irq_set_handler(trig->subirq_base + i,
450 &handle_simple_irq);
451 irq_modify_status(trig->subirq_base + i,
452 IRQ_NOREQUEST | IRQ_NOAUTOEN,
453 IRQ_NOPROBE);
454 }
455 get_device(&trig->dev);
456 }
457
458 return trig;
459}
460
461struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
462{
463 struct iio_trigger *trig;
464 va_list vargs;
465
466 va_start(vargs, fmt);
467 trig = viio_trigger_alloc(fmt, vargs);
468 va_end(vargs);
469
470 return trig;
471}
472EXPORT_SYMBOL(iio_trigger_alloc);
473
474void iio_trigger_free(struct iio_trigger *trig)
475{
476 if (trig)
477 put_device(&trig->dev);
478}
479EXPORT_SYMBOL(iio_trigger_free);
480
481static void devm_iio_trigger_release(struct device *dev, void *res)
482{
483 iio_trigger_free(*(struct iio_trigger **)res);
484}
485
486static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
487{
488 struct iio_trigger **r = res;
489
490 if (!r || !*r) {
491 WARN_ON(!r || !*r);
492 return 0;
493 }
494
495 return *r == data;
496}
497
498/**
499 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
500 * @dev: Device to allocate iio_trigger for
501 * @fmt: trigger name format. If it includes format
502 * specifiers, the additional arguments following
503 * format are formatted and inserted in the resulting
504 * string replacing their respective specifiers.
505 *
506 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
507 * automatically freed on driver detach.
508 *
509 * If an iio_trigger allocated with this function needs to be freed separately,
510 * devm_iio_trigger_free() must be used.
511 *
512 * RETURNS:
513 * Pointer to allocated iio_trigger on success, NULL on failure.
514 */
515struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
516 const char *fmt, ...)
517{
518 struct iio_trigger **ptr, *trig;
519 va_list vargs;
520
521 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
522 GFP_KERNEL);
523 if (!ptr)
524 return NULL;
525
526 /* use raw alloc_dr for kmalloc caller tracing */
527 va_start(vargs, fmt);
528 trig = viio_trigger_alloc(fmt, vargs);
529 va_end(vargs);
530 if (trig) {
531 *ptr = trig;
532 devres_add(dev, ptr);
533 } else {
534 devres_free(ptr);
535 }
536
537 return trig;
538}
539EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
540
541/**
542 * devm_iio_trigger_free - Resource-managed iio_trigger_free()
543 * @dev: Device this iio_dev belongs to
544 * @iio_trig: the iio_trigger associated with the device
545 *
546 * Free iio_trigger allocated with devm_iio_trigger_alloc().
547 */
548void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
549{
550 int rc;
551
552 rc = devres_release(dev, devm_iio_trigger_release,
553 devm_iio_trigger_match, iio_trig);
554 WARN_ON(rc);
555}
556EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
557
558void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
559{
560 indio_dev->groups[indio_dev->groupcounter++] =
561 &iio_trigger_consumer_attr_group;
562}
563
564void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
565{
566 /* Clean up an associated but not attached trigger reference */
567 if (indio_dev->trig)
568 iio_trigger_put(indio_dev->trig);
569}
570
571int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
572{
573 return iio_trigger_attach_poll_func(indio_dev->trig,
574 indio_dev->pollfunc);
575}
576EXPORT_SYMBOL(iio_triggered_buffer_postenable);
577
578int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
579{
580 return iio_trigger_detach_poll_func(indio_dev->trig,
581 indio_dev->pollfunc);
582}
583EXPORT_SYMBOL(iio_triggered_buffer_predisable);