1 // SPDX-License-Identifier: GPL-2.0-only
2 /* The industrial I/O core, trigger handling functions
4 * Copyright (c) 2008 Jonathan Cameron
7 #include <linux/kernel.h>
10 #include <linux/device.h>
11 #include <linux/interrupt.h>
12 #include <linux/list.h>
13 #include <linux/slab.h>
15 #include <linux/iio/iio.h>
16 #include <linux/iio/trigger.h>
18 #include "iio_core_trigger.h"
19 #include <linux/iio/trigger_consumer.h>
21 /* RFC - Question of approach
22 * Make the common case (single sensor single trigger)
23 * simple by starting trigger capture from when first sensors
26 * Complex simultaneous start requires use of 'hold' functionality
27 * of the trigger. (not implemented)
29 * Any other suggestions?
32 static DEFINE_IDA(iio_trigger_ida);
34 /* Single list of all available triggers */
35 static LIST_HEAD(iio_trigger_list);
36 static DEFINE_MUTEX(iio_trigger_list_lock);
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
43 * @buf: buffer to print the name into
45 * Return: a negative number on failure or the number of written
46 * characters on success.
48 static ssize_t iio_trigger_read_name(struct device *dev,
49 struct device_attribute *attr,
52 struct iio_trigger *trig = to_iio_trigger(dev);
53 return sprintf(buf, "%s\n", trig->name);
56 static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
58 static struct attribute *iio_trig_dev_attrs[] = {
62 ATTRIBUTE_GROUPS(iio_trig_dev);
64 static struct iio_trigger *__iio_trigger_find_by_name(const char *name);
66 int __iio_trigger_register(struct iio_trigger *trig_info,
67 struct module *this_mod)
71 trig_info->owner = this_mod;
73 trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
74 if (trig_info->id < 0)
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);
81 ret = device_add(&trig_info->dev);
83 goto error_unregister_id;
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);
90 goto error_device_del;
92 list_add_tail(&trig_info->list, &iio_trigger_list);
93 mutex_unlock(&iio_trigger_list_lock);
98 mutex_unlock(&iio_trigger_list_lock);
99 device_del(&trig_info->dev);
101 ida_simple_remove(&iio_trigger_ida, trig_info->id);
104 EXPORT_SYMBOL(__iio_trigger_register);
106 void iio_trigger_unregister(struct iio_trigger *trig_info)
108 mutex_lock(&iio_trigger_list_lock);
109 list_del(&trig_info->list);
110 mutex_unlock(&iio_trigger_list_lock);
112 ida_simple_remove(&iio_trigger_ida, trig_info->id);
113 /* Possible issue in here */
114 device_del(&trig_info->dev);
116 EXPORT_SYMBOL(iio_trigger_unregister);
118 int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)
120 if (!indio_dev || !trig)
123 mutex_lock(&indio_dev->mlock);
124 WARN_ON(indio_dev->trig_readonly);
126 indio_dev->trig = iio_trigger_get(trig);
127 indio_dev->trig_readonly = true;
128 mutex_unlock(&indio_dev->mlock);
132 EXPORT_SYMBOL(iio_trigger_set_immutable);
134 /* Search for trigger by name, assuming iio_trigger_list_lock held */
135 static struct iio_trigger *__iio_trigger_find_by_name(const char *name)
137 struct iio_trigger *iter;
139 list_for_each_entry(iter, &iio_trigger_list, list)
140 if (!strcmp(iter->name, name))
146 static struct iio_trigger *iio_trigger_acquire_by_name(const char *name)
148 struct iio_trigger *trig = NULL, *iter;
150 mutex_lock(&iio_trigger_list_lock);
151 list_for_each_entry(iter, &iio_trigger_list, list)
152 if (sysfs_streq(iter->name, name)) {
154 iio_trigger_get(trig);
157 mutex_unlock(&iio_trigger_list_lock);
162 void iio_trigger_poll(struct iio_trigger *trig)
166 if (!atomic_read(&trig->use_count)) {
167 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
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);
173 iio_trigger_notify_done(trig);
177 EXPORT_SYMBOL(iio_trigger_poll);
179 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
181 iio_trigger_poll(private);
184 EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
186 void iio_trigger_poll_chained(struct iio_trigger *trig)
190 if (!atomic_read(&trig->use_count)) {
191 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
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);
197 iio_trigger_notify_done(trig);
201 EXPORT_SYMBOL(iio_trigger_poll_chained);
203 void iio_trigger_notify_done(struct iio_trigger *trig)
205 if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
206 trig->ops->try_reenable)
207 trig->ops->try_reenable(trig);
209 EXPORT_SYMBOL(iio_trigger_notify_done);
211 /* Trigger Consumer related functions */
212 static int iio_trigger_get_irq(struct iio_trigger *trig)
215 mutex_lock(&trig->pool_lock);
216 ret = bitmap_find_free_region(trig->pool,
217 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
219 mutex_unlock(&trig->pool_lock);
221 ret += trig->subirq_base;
226 static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
228 mutex_lock(&trig->pool_lock);
229 clear_bit(irq - trig->subirq_base, trig->pool);
230 mutex_unlock(&trig->pool_lock);
233 /* Complexity in here. With certain triggers (datardy) an acknowledgement
234 * may be needed if the pollfuncs do not include the data read for the
236 * This is not currently handled. Alternative of not enabling trigger unless
237 * the relevant function is in there may be the best option.
239 /* Worth protecting against double additions? */
240 int iio_trigger_attach_poll_func(struct iio_trigger *trig,
241 struct iio_poll_func *pf)
245 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
247 /* Prevent the module from being removed whilst attached to a trigger */
248 __module_get(pf->indio_dev->driver_module);
251 pf->irq = iio_trigger_get_irq(trig);
253 pr_err("Could not find an available irq for trigger %s, CONFIG_IIO_CONSUMERS_PER_TRIGGER=%d limit might be exceeded\n",
254 trig->name, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
259 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
265 /* Enable trigger in driver */
266 if (trig->ops && trig->ops->set_trigger_state && notinuse) {
267 ret = trig->ops->set_trigger_state(trig, true);
273 * Check if we just registered to our own trigger: we determine that
274 * this is the case if the IIO device and the trigger device share the
275 * same parent device.
277 if (pf->indio_dev->dev.parent == trig->dev.parent)
278 trig->attached_own_device = true;
283 free_irq(pf->irq, pf);
285 iio_trigger_put_irq(trig, pf->irq);
287 module_put(pf->indio_dev->driver_module);
291 int iio_trigger_detach_poll_func(struct iio_trigger *trig,
292 struct iio_poll_func *pf)
296 = (bitmap_weight(trig->pool,
297 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
299 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
300 ret = trig->ops->set_trigger_state(trig, false);
304 if (pf->indio_dev->dev.parent == trig->dev.parent)
305 trig->attached_own_device = false;
306 iio_trigger_put_irq(trig, pf->irq);
307 free_irq(pf->irq, pf);
308 module_put(pf->indio_dev->driver_module);
313 irqreturn_t iio_pollfunc_store_time(int irq, void *p)
315 struct iio_poll_func *pf = p;
316 pf->timestamp = iio_get_time_ns(pf->indio_dev);
317 return IRQ_WAKE_THREAD;
319 EXPORT_SYMBOL(iio_pollfunc_store_time);
322 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
323 irqreturn_t (*thread)(int irq, void *p),
325 struct iio_dev *indio_dev,
330 struct iio_poll_func *pf;
332 pf = kmalloc(sizeof *pf, GFP_KERNEL);
335 va_start(vargs, fmt);
336 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
338 if (pf->name == NULL) {
345 pf->indio_dev = indio_dev;
349 EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
351 void iio_dealloc_pollfunc(struct iio_poll_func *pf)
356 EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
359 * iio_trigger_read_current() - trigger consumer sysfs query current trigger
360 * @dev: device associated with an industrial I/O device
361 * @attr: pointer to the device_attribute structure that
363 * @buf: buffer where the current trigger name will be printed into
365 * For trigger consumers the current_trigger interface allows the trigger
366 * used by the device to be queried.
368 * Return: a negative number on failure, the number of characters written
369 * on success or 0 if no trigger is available
371 static ssize_t iio_trigger_read_current(struct device *dev,
372 struct device_attribute *attr,
375 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
378 return sprintf(buf, "%s\n", indio_dev->trig->name);
383 * iio_trigger_write_current() - trigger consumer sysfs set current trigger
384 * @dev: device associated with an industrial I/O device
385 * @attr: device attribute that is being processed
386 * @buf: string buffer that holds the name of the trigger
387 * @len: length of the trigger name held by buf
389 * For trigger consumers the current_trigger interface allows the trigger
390 * used for this device to be specified at run time based on the trigger's
393 * Return: negative error code on failure or length of the buffer
396 static ssize_t iio_trigger_write_current(struct device *dev,
397 struct device_attribute *attr,
401 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
402 struct iio_trigger *oldtrig = indio_dev->trig;
403 struct iio_trigger *trig;
406 mutex_lock(&indio_dev->mlock);
407 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
408 mutex_unlock(&indio_dev->mlock);
411 if (indio_dev->trig_readonly) {
412 mutex_unlock(&indio_dev->mlock);
415 mutex_unlock(&indio_dev->mlock);
417 trig = iio_trigger_acquire_by_name(buf);
418 if (oldtrig == trig) {
420 goto out_trigger_put;
423 if (trig && indio_dev->info->validate_trigger) {
424 ret = indio_dev->info->validate_trigger(indio_dev, trig);
426 goto out_trigger_put;
429 if (trig && trig->ops && trig->ops->validate_device) {
430 ret = trig->ops->validate_device(trig, indio_dev);
432 goto out_trigger_put;
435 indio_dev->trig = trig;
438 if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
439 iio_trigger_detach_poll_func(oldtrig,
440 indio_dev->pollfunc_event);
441 iio_trigger_put(oldtrig);
443 if (indio_dev->trig) {
444 if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
445 iio_trigger_attach_poll_func(indio_dev->trig,
446 indio_dev->pollfunc_event);
453 iio_trigger_put(trig);
457 static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
458 iio_trigger_read_current,
459 iio_trigger_write_current);
461 static struct attribute *iio_trigger_consumer_attrs[] = {
462 &dev_attr_current_trigger.attr,
466 static const struct attribute_group iio_trigger_consumer_attr_group = {
468 .attrs = iio_trigger_consumer_attrs,
471 static void iio_trig_release(struct device *device)
473 struct iio_trigger *trig = to_iio_trigger(device);
476 if (trig->subirq_base) {
477 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
478 irq_modify_status(trig->subirq_base + i,
480 IRQ_NOREQUEST | IRQ_NOPROBE);
481 irq_set_chip(trig->subirq_base + i,
483 irq_set_handler(trig->subirq_base + i,
487 irq_free_descs(trig->subirq_base,
488 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
494 static const struct device_type iio_trig_type = {
495 .release = iio_trig_release,
496 .groups = iio_trig_dev_groups,
499 static void iio_trig_subirqmask(struct irq_data *d)
501 struct irq_chip *chip = irq_data_get_irq_chip(d);
502 struct iio_trigger *trig
504 struct iio_trigger, subirq_chip);
505 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
508 static void iio_trig_subirqunmask(struct irq_data *d)
510 struct irq_chip *chip = irq_data_get_irq_chip(d);
511 struct iio_trigger *trig
513 struct iio_trigger, subirq_chip);
514 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
517 static __printf(1, 0)
518 struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
520 struct iio_trigger *trig;
523 trig = kzalloc(sizeof *trig, GFP_KERNEL);
527 trig->dev.type = &iio_trig_type;
528 trig->dev.bus = &iio_bus_type;
529 device_initialize(&trig->dev);
531 mutex_init(&trig->pool_lock);
532 trig->subirq_base = irq_alloc_descs(-1, 0,
533 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
535 if (trig->subirq_base < 0)
538 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
539 if (trig->name == NULL)
542 trig->subirq_chip.name = trig->name;
543 trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
544 trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
545 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
546 irq_set_chip(trig->subirq_base + i, &trig->subirq_chip);
547 irq_set_handler(trig->subirq_base + i, &handle_simple_irq);
548 irq_modify_status(trig->subirq_base + i,
549 IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
551 get_device(&trig->dev);
556 irq_free_descs(trig->subirq_base, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
562 struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
564 struct iio_trigger *trig;
567 va_start(vargs, fmt);
568 trig = viio_trigger_alloc(fmt, vargs);
573 EXPORT_SYMBOL(iio_trigger_alloc);
575 void iio_trigger_free(struct iio_trigger *trig)
578 put_device(&trig->dev);
580 EXPORT_SYMBOL(iio_trigger_free);
582 static void devm_iio_trigger_release(struct device *dev, void *res)
584 iio_trigger_free(*(struct iio_trigger **)res);
588 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
589 * @dev: Device to allocate iio_trigger for
590 * @fmt: trigger name format. If it includes format
591 * specifiers, the additional arguments following
592 * format are formatted and inserted in the resulting
593 * string replacing their respective specifiers.
595 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
596 * automatically freed on driver detach.
599 * Pointer to allocated iio_trigger on success, NULL on failure.
601 struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
602 const char *fmt, ...)
604 struct iio_trigger **ptr, *trig;
607 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
612 /* use raw alloc_dr for kmalloc caller tracing */
613 va_start(vargs, fmt);
614 trig = viio_trigger_alloc(fmt, vargs);
618 devres_add(dev, ptr);
625 EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
627 static void devm_iio_trigger_unreg(struct device *dev, void *res)
629 iio_trigger_unregister(*(struct iio_trigger **)res);
633 * __devm_iio_trigger_register - Resource-managed iio_trigger_register()
634 * @dev: device this trigger was allocated for
635 * @trig_info: trigger to register
636 * @this_mod: module registering the trigger
638 * Managed iio_trigger_register(). The IIO trigger registered with this
639 * function is automatically unregistered on driver detach. This function
640 * calls iio_trigger_register() internally. Refer to that function for more
644 * 0 on success, negative error number on failure.
646 int __devm_iio_trigger_register(struct device *dev,
647 struct iio_trigger *trig_info,
648 struct module *this_mod)
650 struct iio_trigger **ptr;
653 ptr = devres_alloc(devm_iio_trigger_unreg, sizeof(*ptr), GFP_KERNEL);
658 ret = __iio_trigger_register(trig_info, this_mod);
660 devres_add(dev, ptr);
666 EXPORT_SYMBOL_GPL(__devm_iio_trigger_register);
668 bool iio_trigger_using_own(struct iio_dev *indio_dev)
670 return indio_dev->trig->attached_own_device;
672 EXPORT_SYMBOL(iio_trigger_using_own);
675 * iio_trigger_validate_own_device - Check if a trigger and IIO device belong to
677 * @trig: The IIO trigger to check
678 * @indio_dev: the IIO device to check
680 * This function can be used as the validate_device callback for triggers that
681 * can only be attached to their own device.
683 * Return: 0 if both the trigger and the IIO device belong to the same
684 * device, -EINVAL otherwise.
686 int iio_trigger_validate_own_device(struct iio_trigger *trig,
687 struct iio_dev *indio_dev)
689 if (indio_dev->dev.parent != trig->dev.parent)
693 EXPORT_SYMBOL(iio_trigger_validate_own_device);
695 void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
697 indio_dev->groups[indio_dev->groupcounter++] =
698 &iio_trigger_consumer_attr_group;
701 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
703 /* Clean up an associated but not attached trigger reference */
705 iio_trigger_put(indio_dev->trig);