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 sysfs_emit(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%d", trig_info->id);
80 ret = device_add(&trig_info->dev);
82 goto error_unregister_id;
84 /* Add to list of available triggers held by the IIO core */
85 mutex_lock(&iio_trigger_list_lock);
86 if (__iio_trigger_find_by_name(trig_info->name)) {
87 pr_err("Duplicate trigger name '%s'\n", trig_info->name);
89 goto error_device_del;
91 list_add_tail(&trig_info->list, &iio_trigger_list);
92 mutex_unlock(&iio_trigger_list_lock);
97 mutex_unlock(&iio_trigger_list_lock);
98 device_del(&trig_info->dev);
100 ida_simple_remove(&iio_trigger_ida, trig_info->id);
103 EXPORT_SYMBOL(__iio_trigger_register);
105 void iio_trigger_unregister(struct iio_trigger *trig_info)
107 mutex_lock(&iio_trigger_list_lock);
108 list_del(&trig_info->list);
109 mutex_unlock(&iio_trigger_list_lock);
111 ida_simple_remove(&iio_trigger_ida, trig_info->id);
112 /* Possible issue in here */
113 device_del(&trig_info->dev);
115 EXPORT_SYMBOL(iio_trigger_unregister);
117 int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)
119 if (!indio_dev || !trig)
122 mutex_lock(&indio_dev->mlock);
123 WARN_ON(indio_dev->trig_readonly);
125 indio_dev->trig = iio_trigger_get(trig);
126 indio_dev->trig_readonly = true;
127 mutex_unlock(&indio_dev->mlock);
131 EXPORT_SYMBOL(iio_trigger_set_immutable);
133 /* Search for trigger by name, assuming iio_trigger_list_lock held */
134 static struct iio_trigger *__iio_trigger_find_by_name(const char *name)
136 struct iio_trigger *iter;
138 list_for_each_entry(iter, &iio_trigger_list, list)
139 if (!strcmp(iter->name, name))
145 static struct iio_trigger *iio_trigger_acquire_by_name(const char *name)
147 struct iio_trigger *trig = NULL, *iter;
149 mutex_lock(&iio_trigger_list_lock);
150 list_for_each_entry(iter, &iio_trigger_list, list)
151 if (sysfs_streq(iter->name, name)) {
153 iio_trigger_get(trig);
156 mutex_unlock(&iio_trigger_list_lock);
161 void iio_trigger_poll(struct iio_trigger *trig)
165 if (!atomic_read(&trig->use_count)) {
166 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
168 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
169 if (trig->subirqs[i].enabled)
170 generic_handle_irq(trig->subirq_base + i);
172 iio_trigger_notify_done(trig);
176 EXPORT_SYMBOL(iio_trigger_poll);
178 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
180 iio_trigger_poll(private);
183 EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
185 void iio_trigger_poll_chained(struct iio_trigger *trig)
189 if (!atomic_read(&trig->use_count)) {
190 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
192 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
193 if (trig->subirqs[i].enabled)
194 handle_nested_irq(trig->subirq_base + i);
196 iio_trigger_notify_done(trig);
200 EXPORT_SYMBOL(iio_trigger_poll_chained);
202 void iio_trigger_notify_done(struct iio_trigger *trig)
204 if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
206 trig->ops->reenable(trig);
208 EXPORT_SYMBOL(iio_trigger_notify_done);
210 /* Trigger Consumer related functions */
211 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)
244 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)
294 bool no_other_users =
295 bitmap_weight(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER) == 1;
298 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
299 ret = trig->ops->set_trigger_state(trig, false);
303 if (pf->indio_dev->dev.parent == trig->dev.parent)
304 trig->attached_own_device = false;
305 iio_trigger_put_irq(trig, pf->irq);
306 free_irq(pf->irq, pf);
307 module_put(pf->indio_dev->driver_module);
312 irqreturn_t iio_pollfunc_store_time(int irq, void *p)
314 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 sysfs_emit(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 = container_of(chip, struct iio_trigger, subirq_chip);
504 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
507 static void iio_trig_subirqunmask(struct irq_data *d)
509 struct irq_chip *chip = irq_data_get_irq_chip(d);
510 struct iio_trigger *trig = container_of(chip, struct iio_trigger, subirq_chip);
512 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
515 static __printf(2, 0)
516 struct iio_trigger *viio_trigger_alloc(struct device *parent,
520 struct iio_trigger *trig;
523 trig = kzalloc(sizeof *trig, GFP_KERNEL);
527 trig->dev.parent = parent;
528 trig->dev.type = &iio_trig_type;
529 trig->dev.bus = &iio_bus_type;
530 device_initialize(&trig->dev);
532 mutex_init(&trig->pool_lock);
533 trig->subirq_base = irq_alloc_descs(-1, 0,
534 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
536 if (trig->subirq_base < 0)
539 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
540 if (trig->name == NULL)
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);
552 get_device(&trig->dev);
557 irq_free_descs(trig->subirq_base, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
564 * iio_trigger_alloc - Allocate a trigger
565 * @parent: Device to allocate iio_trigger for
566 * @fmt: trigger name format. If it includes format
567 * specifiers, the additional arguments following
568 * format are formatted and inserted in the resulting
569 * string replacing their respective specifiers.
571 * Pointer to allocated iio_trigger on success, NULL on failure.
573 struct iio_trigger *iio_trigger_alloc(struct device *parent, const char *fmt, ...)
575 struct iio_trigger *trig;
578 va_start(vargs, fmt);
579 trig = viio_trigger_alloc(parent, fmt, vargs);
584 EXPORT_SYMBOL(iio_trigger_alloc);
586 void iio_trigger_free(struct iio_trigger *trig)
589 put_device(&trig->dev);
591 EXPORT_SYMBOL(iio_trigger_free);
593 static void devm_iio_trigger_release(struct device *dev, void *res)
595 iio_trigger_free(*(struct iio_trigger **)res);
599 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
600 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
601 * automatically freed on driver detach.
602 * @parent: 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.
610 * Pointer to allocated iio_trigger on success, NULL on failure.
612 struct iio_trigger *devm_iio_trigger_alloc(struct device *parent, const char *fmt, ...)
614 struct iio_trigger **ptr, *trig;
617 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
622 /* use raw alloc_dr for kmalloc caller tracing */
623 va_start(vargs, fmt);
624 trig = viio_trigger_alloc(parent, fmt, vargs);
628 devres_add(parent, ptr);
635 EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
637 static void devm_iio_trigger_unreg(struct device *dev, void *res)
639 iio_trigger_unregister(*(struct iio_trigger **)res);
643 * __devm_iio_trigger_register - Resource-managed iio_trigger_register()
644 * @dev: device this trigger was allocated for
645 * @trig_info: trigger to register
646 * @this_mod: module registering the trigger
648 * Managed iio_trigger_register(). The IIO trigger registered with this
649 * function is automatically unregistered on driver detach. This function
650 * calls iio_trigger_register() internally. Refer to that function for more
654 * 0 on success, negative error number on failure.
656 int __devm_iio_trigger_register(struct device *dev,
657 struct iio_trigger *trig_info,
658 struct module *this_mod)
660 struct iio_trigger **ptr;
663 ptr = devres_alloc(devm_iio_trigger_unreg, sizeof(*ptr), GFP_KERNEL);
668 ret = __iio_trigger_register(trig_info, this_mod);
670 devres_add(dev, ptr);
676 EXPORT_SYMBOL_GPL(__devm_iio_trigger_register);
678 bool iio_trigger_using_own(struct iio_dev *indio_dev)
680 return indio_dev->trig->attached_own_device;
682 EXPORT_SYMBOL(iio_trigger_using_own);
685 * iio_trigger_validate_own_device - Check if a trigger and IIO device belong to
687 * @trig: The IIO trigger to check
688 * @indio_dev: the IIO device to check
690 * This function can be used as the validate_device callback for triggers that
691 * can only be attached to their own device.
693 * Return: 0 if both the trigger and the IIO device belong to the same
694 * device, -EINVAL otherwise.
696 int iio_trigger_validate_own_device(struct iio_trigger *trig,
697 struct iio_dev *indio_dev)
699 if (indio_dev->dev.parent != trig->dev.parent)
703 EXPORT_SYMBOL(iio_trigger_validate_own_device);
705 int iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
707 return iio_device_register_sysfs_group(indio_dev,
708 &iio_trigger_consumer_attr_group);
711 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
713 /* Clean up an associated but not attached trigger reference */
715 iio_trigger_put(indio_dev->trig);