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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
67int iio_trigger_register(struct iio_trigger *trig_info)
68{
69 int ret;
70
71 trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, 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%ld",
77 (unsigned long) trig_info->id);
78
79 ret = device_add(&trig_info->dev);
80 if (ret)
81 goto error_unregister_id;
82
83 /* Add to list of available triggers held by the IIO core */
84 mutex_lock(&iio_trigger_list_lock);
85 list_add_tail(&trig_info->list, &iio_trigger_list);
86 mutex_unlock(&iio_trigger_list_lock);
87
88 return 0;
89
90error_unregister_id:
91 ida_simple_remove(&iio_trigger_ida, trig_info->id);
92 return ret;
93}
94EXPORT_SYMBOL(iio_trigger_register);
95
96void iio_trigger_unregister(struct iio_trigger *trig_info)
97{
98 mutex_lock(&iio_trigger_list_lock);
99 list_del(&trig_info->list);
100 mutex_unlock(&iio_trigger_list_lock);
101
102 ida_simple_remove(&iio_trigger_ida, trig_info->id);
103 /* Possible issue in here */
104 device_del(&trig_info->dev);
105}
106EXPORT_SYMBOL(iio_trigger_unregister);
107
108static struct iio_trigger *iio_trigger_find_by_name(const char *name,
109 size_t len)
110{
111 struct iio_trigger *trig = NULL, *iter;
112
113 mutex_lock(&iio_trigger_list_lock);
114 list_for_each_entry(iter, &iio_trigger_list, list)
115 if (sysfs_streq(iter->name, name)) {
116 trig = iter;
117 break;
118 }
119 mutex_unlock(&iio_trigger_list_lock);
120
121 return trig;
122}
123
124void iio_trigger_poll(struct iio_trigger *trig)
125{
126 int i;
127
128 if (!atomic_read(&trig->use_count)) {
129 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
130
131 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
132 if (trig->subirqs[i].enabled)
133 generic_handle_irq(trig->subirq_base + i);
134 else
135 iio_trigger_notify_done(trig);
136 }
137 }
138}
139EXPORT_SYMBOL(iio_trigger_poll);
140
141irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
142{
143 iio_trigger_poll(private);
144 return IRQ_HANDLED;
145}
146EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
147
148void iio_trigger_poll_chained(struct iio_trigger *trig)
149{
150 int i;
151
152 if (!atomic_read(&trig->use_count)) {
153 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
154
155 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
156 if (trig->subirqs[i].enabled)
157 handle_nested_irq(trig->subirq_base + i);
158 else
159 iio_trigger_notify_done(trig);
160 }
161 }
162}
163EXPORT_SYMBOL(iio_trigger_poll_chained);
164
165void iio_trigger_notify_done(struct iio_trigger *trig)
166{
167 if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
168 trig->ops->try_reenable)
169 if (trig->ops->try_reenable(trig))
170 /* Missed an interrupt so launch new poll now */
171 iio_trigger_poll(trig);
172}
173EXPORT_SYMBOL(iio_trigger_notify_done);
174
175/* Trigger Consumer related functions */
176static int iio_trigger_get_irq(struct iio_trigger *trig)
177{
178 int ret;
179 mutex_lock(&trig->pool_lock);
180 ret = bitmap_find_free_region(trig->pool,
181 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
182 ilog2(1));
183 mutex_unlock(&trig->pool_lock);
184 if (ret >= 0)
185 ret += trig->subirq_base;
186
187 return ret;
188}
189
190static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
191{
192 mutex_lock(&trig->pool_lock);
193 clear_bit(irq - trig->subirq_base, trig->pool);
194 mutex_unlock(&trig->pool_lock);
195}
196
197/* Complexity in here. With certain triggers (datardy) an acknowledgement
198 * may be needed if the pollfuncs do not include the data read for the
199 * triggering device.
200 * This is not currently handled. Alternative of not enabling trigger unless
201 * the relevant function is in there may be the best option.
202 */
203/* Worth protecting against double additions? */
204static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
205 struct iio_poll_func *pf)
206{
207 int ret = 0;
208 bool notinuse
209 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
210
211 /* Prevent the module from being removed whilst attached to a trigger */
212 __module_get(pf->indio_dev->info->driver_module);
213 pf->irq = iio_trigger_get_irq(trig);
214 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
215 pf->type, pf->name,
216 pf);
217 if (ret < 0) {
218 module_put(pf->indio_dev->info->driver_module);
219 return ret;
220 }
221
222 if (trig->ops && trig->ops->set_trigger_state && notinuse) {
223 ret = trig->ops->set_trigger_state(trig, true);
224 if (ret < 0)
225 module_put(pf->indio_dev->info->driver_module);
226 }
227
228 return ret;
229}
230
231static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
232 struct iio_poll_func *pf)
233{
234 int ret = 0;
235 bool no_other_users
236 = (bitmap_weight(trig->pool,
237 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
238 == 1);
239 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
240 ret = trig->ops->set_trigger_state(trig, false);
241 if (ret)
242 return ret;
243 }
244 iio_trigger_put_irq(trig, pf->irq);
245 free_irq(pf->irq, pf);
246 module_put(pf->indio_dev->info->driver_module);
247
248 return ret;
249}
250
251irqreturn_t iio_pollfunc_store_time(int irq, void *p)
252{
253 struct iio_poll_func *pf = p;
254 pf->timestamp = iio_get_time_ns();
255 return IRQ_WAKE_THREAD;
256}
257EXPORT_SYMBOL(iio_pollfunc_store_time);
258
259struct iio_poll_func
260*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
261 irqreturn_t (*thread)(int irq, void *p),
262 int type,
263 struct iio_dev *indio_dev,
264 const char *fmt,
265 ...)
266{
267 va_list vargs;
268 struct iio_poll_func *pf;
269
270 pf = kmalloc(sizeof *pf, GFP_KERNEL);
271 if (pf == NULL)
272 return NULL;
273 va_start(vargs, fmt);
274 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
275 va_end(vargs);
276 if (pf->name == NULL) {
277 kfree(pf);
278 return NULL;
279 }
280 pf->h = h;
281 pf->thread = thread;
282 pf->type = type;
283 pf->indio_dev = indio_dev;
284
285 return pf;
286}
287EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
288
289void iio_dealloc_pollfunc(struct iio_poll_func *pf)
290{
291 kfree(pf->name);
292 kfree(pf);
293}
294EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
295
296/**
297 * iio_trigger_read_current() - trigger consumer sysfs query current trigger
298 * @dev: device associated with an industrial I/O device
299 * @attr: pointer to the device_attribute structure that
300 * is being processed
301 * @buf: buffer where the current trigger name will be printed into
302 *
303 * For trigger consumers the current_trigger interface allows the trigger
304 * used by the device to be queried.
305 *
306 * Return: a negative number on failure, the number of characters written
307 * on success or 0 if no trigger is available
308 */
309static ssize_t iio_trigger_read_current(struct device *dev,
310 struct device_attribute *attr,
311 char *buf)
312{
313 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
314
315 if (indio_dev->trig)
316 return sprintf(buf, "%s\n", indio_dev->trig->name);
317 return 0;
318}
319
320/**
321 * iio_trigger_write_current() - trigger consumer sysfs set current trigger
322 * @dev: device associated with an industrial I/O device
323 * @attr: device attribute that is being processed
324 * @buf: string buffer that holds the name of the trigger
325 * @len: length of the trigger name held by buf
326 *
327 * For trigger consumers the current_trigger interface allows the trigger
328 * used for this device to be specified at run time based on the trigger's
329 * name.
330 *
331 * Return: negative error code on failure or length of the buffer
332 * on success
333 */
334static ssize_t iio_trigger_write_current(struct device *dev,
335 struct device_attribute *attr,
336 const char *buf,
337 size_t len)
338{
339 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
340 struct iio_trigger *oldtrig = indio_dev->trig;
341 struct iio_trigger *trig;
342 int ret;
343
344 mutex_lock(&indio_dev->mlock);
345 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
346 mutex_unlock(&indio_dev->mlock);
347 return -EBUSY;
348 }
349 mutex_unlock(&indio_dev->mlock);
350
351 trig = iio_trigger_find_by_name(buf, len);
352 if (oldtrig == trig)
353 return len;
354
355 if (trig && indio_dev->info->validate_trigger) {
356 ret = indio_dev->info->validate_trigger(indio_dev, trig);
357 if (ret)
358 return ret;
359 }
360
361 if (trig && trig->ops && trig->ops->validate_device) {
362 ret = trig->ops->validate_device(trig, indio_dev);
363 if (ret)
364 return ret;
365 }
366
367 indio_dev->trig = trig;
368
369 if (oldtrig) {
370 if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
371 iio_trigger_detach_poll_func(oldtrig,
372 indio_dev->pollfunc_event);
373 iio_trigger_put(oldtrig);
374 }
375 if (indio_dev->trig) {
376 iio_trigger_get(indio_dev->trig);
377 if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
378 iio_trigger_attach_poll_func(indio_dev->trig,
379 indio_dev->pollfunc_event);
380 }
381
382 return len;
383}
384
385static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
386 iio_trigger_read_current,
387 iio_trigger_write_current);
388
389static struct attribute *iio_trigger_consumer_attrs[] = {
390 &dev_attr_current_trigger.attr,
391 NULL,
392};
393
394static const struct attribute_group iio_trigger_consumer_attr_group = {
395 .name = "trigger",
396 .attrs = iio_trigger_consumer_attrs,
397};
398
399static void iio_trig_release(struct device *device)
400{
401 struct iio_trigger *trig = to_iio_trigger(device);
402 int i;
403
404 if (trig->subirq_base) {
405 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
406 irq_modify_status(trig->subirq_base + i,
407 IRQ_NOAUTOEN,
408 IRQ_NOREQUEST | IRQ_NOPROBE);
409 irq_set_chip(trig->subirq_base + i,
410 NULL);
411 irq_set_handler(trig->subirq_base + i,
412 NULL);
413 }
414
415 irq_free_descs(trig->subirq_base,
416 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
417 }
418 kfree(trig->name);
419 kfree(trig);
420}
421
422static struct device_type iio_trig_type = {
423 .release = iio_trig_release,
424 .groups = iio_trig_dev_groups,
425};
426
427static void iio_trig_subirqmask(struct irq_data *d)
428{
429 struct irq_chip *chip = irq_data_get_irq_chip(d);
430 struct iio_trigger *trig
431 = container_of(chip,
432 struct iio_trigger, subirq_chip);
433 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
434}
435
436static void iio_trig_subirqunmask(struct irq_data *d)
437{
438 struct irq_chip *chip = irq_data_get_irq_chip(d);
439 struct iio_trigger *trig
440 = container_of(chip,
441 struct iio_trigger, subirq_chip);
442 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
443}
444
445static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
446{
447 struct iio_trigger *trig;
448 trig = kzalloc(sizeof *trig, GFP_KERNEL);
449 if (trig) {
450 int i;
451 trig->dev.type = &iio_trig_type;
452 trig->dev.bus = &iio_bus_type;
453 device_initialize(&trig->dev);
454
455 mutex_init(&trig->pool_lock);
456 trig->subirq_base
457 = irq_alloc_descs(-1, 0,
458 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
459 0);
460 if (trig->subirq_base < 0) {
461 kfree(trig);
462 return NULL;
463 }
464
465 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
466 if (trig->name == NULL) {
467 irq_free_descs(trig->subirq_base,
468 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
469 kfree(trig);
470 return NULL;
471 }
472 trig->subirq_chip.name = trig->name;
473 trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
474 trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
475 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
476 irq_set_chip(trig->subirq_base + i,
477 &trig->subirq_chip);
478 irq_set_handler(trig->subirq_base + i,
479 &handle_simple_irq);
480 irq_modify_status(trig->subirq_base + i,
481 IRQ_NOREQUEST | IRQ_NOAUTOEN,
482 IRQ_NOPROBE);
483 }
484 get_device(&trig->dev);
485 }
486
487 return trig;
488}
489
490struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
491{
492 struct iio_trigger *trig;
493 va_list vargs;
494
495 va_start(vargs, fmt);
496 trig = viio_trigger_alloc(fmt, vargs);
497 va_end(vargs);
498
499 return trig;
500}
501EXPORT_SYMBOL(iio_trigger_alloc);
502
503void iio_trigger_free(struct iio_trigger *trig)
504{
505 if (trig)
506 put_device(&trig->dev);
507}
508EXPORT_SYMBOL(iio_trigger_free);
509
510static void devm_iio_trigger_release(struct device *dev, void *res)
511{
512 iio_trigger_free(*(struct iio_trigger **)res);
513}
514
515static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
516{
517 struct iio_trigger **r = res;
518
519 if (!r || !*r) {
520 WARN_ON(!r || !*r);
521 return 0;
522 }
523
524 return *r == data;
525}
526
527/**
528 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
529 * @dev: Device to allocate iio_trigger for
530 * @fmt: trigger name format. If it includes format
531 * specifiers, the additional arguments following
532 * format are formatted and inserted in the resulting
533 * string replacing their respective specifiers.
534 *
535 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
536 * automatically freed on driver detach.
537 *
538 * If an iio_trigger allocated with this function needs to be freed separately,
539 * devm_iio_trigger_free() must be used.
540 *
541 * RETURNS:
542 * Pointer to allocated iio_trigger on success, NULL on failure.
543 */
544struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
545 const char *fmt, ...)
546{
547 struct iio_trigger **ptr, *trig;
548 va_list vargs;
549
550 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
551 GFP_KERNEL);
552 if (!ptr)
553 return NULL;
554
555 /* use raw alloc_dr for kmalloc caller tracing */
556 va_start(vargs, fmt);
557 trig = viio_trigger_alloc(fmt, vargs);
558 va_end(vargs);
559 if (trig) {
560 *ptr = trig;
561 devres_add(dev, ptr);
562 } else {
563 devres_free(ptr);
564 }
565
566 return trig;
567}
568EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
569
570/**
571 * devm_iio_trigger_free - Resource-managed iio_trigger_free()
572 * @dev: Device this iio_dev belongs to
573 * @iio_trig: the iio_trigger associated with the device
574 *
575 * Free iio_trigger allocated with devm_iio_trigger_alloc().
576 */
577void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
578{
579 int rc;
580
581 rc = devres_release(dev, devm_iio_trigger_release,
582 devm_iio_trigger_match, iio_trig);
583 WARN_ON(rc);
584}
585EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
586
587void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
588{
589 indio_dev->groups[indio_dev->groupcounter++] =
590 &iio_trigger_consumer_attr_group;
591}
592
593void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
594{
595 /* Clean up an associated but not attached trigger reference */
596 if (indio_dev->trig)
597 iio_trigger_put(indio_dev->trig);
598}
599
600int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
601{
602 return iio_trigger_attach_poll_func(indio_dev->trig,
603 indio_dev->pollfunc);
604}
605EXPORT_SYMBOL(iio_triggered_buffer_postenable);
606
607int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
608{
609 return iio_trigger_detach_poll_func(indio_dev->trig,
610 indio_dev->pollfunc);
611}
612EXPORT_SYMBOL(iio_triggered_buffer_predisable);
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
33static DEFINE_IDA(iio_trigger_ida);
34
35/* Single list of all available triggers */
36static LIST_HEAD(iio_trigger_list);
37static 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 */
49static 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
57static DEVICE_ATTR_RO(name);
58
59static struct attribute *iio_trig_dev_attrs[] = {
60 &dev_attr_name.attr,
61 NULL,
62};
63ATTRIBUTE_GROUPS(iio_trig_dev);
64
65static struct iio_trigger *__iio_trigger_find_by_name(const char *name);
66
67int 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
94error_device_del:
95 mutex_unlock(&iio_trigger_list_lock);
96 device_del(&trig_info->dev);
97error_unregister_id:
98 ida_free(&iio_trigger_ida, trig_info->id);
99 return ret;
100}
101EXPORT_SYMBOL(iio_trigger_register);
102
103void 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}
113EXPORT_SYMBOL(iio_trigger_unregister);
114
115int 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(&iio_dev_opaque->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(&iio_dev_opaque->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
162static 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 */
188static 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
195void 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}
210EXPORT_SYMBOL(iio_trigger_poll);
211
212irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
213{
214 iio_trigger_poll(private);
215 return IRQ_HANDLED;
216}
217EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
218
219void 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}
234EXPORT_SYMBOL(iio_trigger_poll_chained);
235
236void 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}
242EXPORT_SYMBOL(iio_trigger_notify_done);
243
244/* Trigger Consumer related functions */
245static 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
260static 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? */
274int 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
317out_free_irq:
318 free_irq(pf->irq, pf);
319out_put_irq:
320 iio_trigger_put_irq(trig, pf->irq);
321out_put_module:
322 module_put(iio_dev_opaque->driver_module);
323 return ret;
324}
325
326int 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
348irqreturn_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}
355EXPORT_SYMBOL(iio_pollfunc_store_time);
356
357struct 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}
385EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
386
387void iio_dealloc_pollfunc(struct iio_poll_func *pf)
388{
389 kfree(pf->name);
390 kfree(pf);
391}
392EXPORT_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 */
407static 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 */
431static 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(&iio_dev_opaque->mlock);
442 if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
443 mutex_unlock(&iio_dev_opaque->mlock);
444 return -EBUSY;
445 }
446 if (iio_dev_opaque->trig_readonly) {
447 mutex_unlock(&iio_dev_opaque->mlock);
448 return -EPERM;
449 }
450 mutex_unlock(&iio_dev_opaque->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
486out_trigger_put:
487 if (trig)
488 iio_trigger_put(trig);
489 return ret;
490}
491
492static DEVICE_ATTR_RW(current_trigger);
493
494static struct attribute *iio_trigger_consumer_attrs[] = {
495 &dev_attr_current_trigger.attr,
496 NULL,
497};
498
499static const struct attribute_group iio_trigger_consumer_attr_group = {
500 .name = "trigger",
501 .attrs = iio_trigger_consumer_attrs,
502};
503
504static 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
527static const struct device_type iio_trig_type = {
528 .release = iio_trig_release,
529 .groups = iio_trig_dev_groups,
530};
531
532static 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
540static 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
548static __printf(3, 0)
549struct 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
594free_descs:
595 irq_free_descs(trig->subirq_base, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
596free_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 */
612struct 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}
625EXPORT_SYMBOL(__iio_trigger_alloc);
626
627void iio_trigger_free(struct iio_trigger *trig)
628{
629 if (trig)
630 put_device(&trig->dev);
631}
632EXPORT_SYMBOL(iio_trigger_free);
633
634static 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 */
654struct 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}
679EXPORT_SYMBOL_GPL(__devm_iio_trigger_alloc);
680
681static 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 */
699int 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}
710EXPORT_SYMBOL_GPL(devm_iio_trigger_register);
711
712bool iio_trigger_using_own(struct iio_dev *indio_dev)
713{
714 return indio_dev->trig->attached_own_device;
715}
716EXPORT_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 */
730int 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}
737EXPORT_SYMBOL(iio_trigger_validate_own_device);
738
739int 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
745void 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}