1 /* The industrial I/O core, trigger handling functions
3 * Copyright (c) 2008 Jonathan Cameron
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.
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>
18 #include <linux/iio/iio.h>
19 #include <linux/iio/trigger.h>
21 #include "iio_core_trigger.h"
22 #include <linux/iio/trigger_consumer.h>
24 /* RFC - Question of approach
25 * Make the common case (single sensor single trigger)
26 * simple by starting trigger capture from when first sensors
29 * Complex simultaneous start requires use of 'hold' functionality
30 * of the trigger. (not implemented)
32 * Any other suggestions?
35 static DEFINE_IDA(iio_trigger_ida);
37 /* Single list of all available triggers */
38 static LIST_HEAD(iio_trigger_list);
39 static DEFINE_MUTEX(iio_trigger_list_lock);
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
46 * @buf: buffer to print the name into
48 * Return: a negative number on failure or the number of written
49 * characters on success.
51 static ssize_t iio_trigger_read_name(struct device *dev,
52 struct device_attribute *attr,
55 struct iio_trigger *trig = to_iio_trigger(dev);
56 return sprintf(buf, "%s\n", trig->name);
59 static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
61 static struct attribute *iio_trig_dev_attrs[] = {
65 ATTRIBUTE_GROUPS(iio_trig_dev);
67 int iio_trigger_register(struct iio_trigger *trig_info)
71 trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
72 if (trig_info->id < 0)
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);
79 ret = device_add(&trig_info->dev);
81 goto error_unregister_id;
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);
91 ida_simple_remove(&iio_trigger_ida, trig_info->id);
94 EXPORT_SYMBOL(iio_trigger_register);
96 void iio_trigger_unregister(struct iio_trigger *trig_info)
98 mutex_lock(&iio_trigger_list_lock);
99 list_del(&trig_info->list);
100 mutex_unlock(&iio_trigger_list_lock);
102 ida_simple_remove(&iio_trigger_ida, trig_info->id);
103 /* Possible issue in here */
104 device_del(&trig_info->dev);
106 EXPORT_SYMBOL(iio_trigger_unregister);
108 static struct iio_trigger *iio_trigger_find_by_name(const char *name,
111 struct iio_trigger *trig = NULL, *iter;
113 mutex_lock(&iio_trigger_list_lock);
114 list_for_each_entry(iter, &iio_trigger_list, list)
115 if (sysfs_streq(iter->name, name)) {
119 mutex_unlock(&iio_trigger_list_lock);
124 void iio_trigger_poll(struct iio_trigger *trig)
128 if (!atomic_read(&trig->use_count)) {
129 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
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);
135 iio_trigger_notify_done(trig);
139 EXPORT_SYMBOL(iio_trigger_poll);
141 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
143 iio_trigger_poll(private);
146 EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
148 void iio_trigger_poll_chained(struct iio_trigger *trig)
152 if (!atomic_read(&trig->use_count)) {
153 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
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);
159 iio_trigger_notify_done(trig);
163 EXPORT_SYMBOL(iio_trigger_poll_chained);
165 void iio_trigger_notify_done(struct iio_trigger *trig)
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);
173 EXPORT_SYMBOL(iio_trigger_notify_done);
175 /* Trigger Consumer related functions */
176 static int iio_trigger_get_irq(struct iio_trigger *trig)
179 mutex_lock(&trig->pool_lock);
180 ret = bitmap_find_free_region(trig->pool,
181 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
183 mutex_unlock(&trig->pool_lock);
185 ret += trig->subirq_base;
190 static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
192 mutex_lock(&trig->pool_lock);
193 clear_bit(irq - trig->subirq_base, trig->pool);
194 mutex_unlock(&trig->pool_lock);
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
200 * This is not currently handled. Alternative of not enabling trigger unless
201 * the relevant function is in there may be the best option.
203 /* Worth protecting against double additions? */
204 static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
205 struct iio_poll_func *pf)
209 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
211 /* Prevent the module from being removed whilst attached to a trigger */
212 __module_get(pf->indio_dev->info->driver_module);
215 pf->irq = iio_trigger_get_irq(trig);
220 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
226 /* Enable trigger in driver */
227 if (trig->ops && trig->ops->set_trigger_state && notinuse) {
228 ret = trig->ops->set_trigger_state(trig, true);
236 free_irq(pf->irq, pf);
238 iio_trigger_put_irq(trig, pf->irq);
240 module_put(pf->indio_dev->info->driver_module);
244 static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
245 struct iio_poll_func *pf)
249 = (bitmap_weight(trig->pool,
250 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
252 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
253 ret = trig->ops->set_trigger_state(trig, false);
257 iio_trigger_put_irq(trig, pf->irq);
258 free_irq(pf->irq, pf);
259 module_put(pf->indio_dev->info->driver_module);
264 irqreturn_t iio_pollfunc_store_time(int irq, void *p)
266 struct iio_poll_func *pf = p;
267 pf->timestamp = iio_get_time_ns();
268 return IRQ_WAKE_THREAD;
270 EXPORT_SYMBOL(iio_pollfunc_store_time);
273 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
274 irqreturn_t (*thread)(int irq, void *p),
276 struct iio_dev *indio_dev,
281 struct iio_poll_func *pf;
283 pf = kmalloc(sizeof *pf, GFP_KERNEL);
286 va_start(vargs, fmt);
287 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
289 if (pf->name == NULL) {
296 pf->indio_dev = indio_dev;
300 EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
302 void iio_dealloc_pollfunc(struct iio_poll_func *pf)
307 EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
310 * iio_trigger_read_current() - trigger consumer sysfs query current trigger
311 * @dev: device associated with an industrial I/O device
312 * @attr: pointer to the device_attribute structure that
314 * @buf: buffer where the current trigger name will be printed into
316 * For trigger consumers the current_trigger interface allows the trigger
317 * used by the device to be queried.
319 * Return: a negative number on failure, the number of characters written
320 * on success or 0 if no trigger is available
322 static ssize_t iio_trigger_read_current(struct device *dev,
323 struct device_attribute *attr,
326 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
329 return sprintf(buf, "%s\n", indio_dev->trig->name);
334 * iio_trigger_write_current() - trigger consumer sysfs set current trigger
335 * @dev: device associated with an industrial I/O device
336 * @attr: device attribute that is being processed
337 * @buf: string buffer that holds the name of the trigger
338 * @len: length of the trigger name held by buf
340 * For trigger consumers the current_trigger interface allows the trigger
341 * used for this device to be specified at run time based on the trigger's
344 * Return: negative error code on failure or length of the buffer
347 static ssize_t iio_trigger_write_current(struct device *dev,
348 struct device_attribute *attr,
352 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
353 struct iio_trigger *oldtrig = indio_dev->trig;
354 struct iio_trigger *trig;
357 mutex_lock(&indio_dev->mlock);
358 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
359 mutex_unlock(&indio_dev->mlock);
362 mutex_unlock(&indio_dev->mlock);
364 trig = iio_trigger_find_by_name(buf, len);
368 if (trig && indio_dev->info->validate_trigger) {
369 ret = indio_dev->info->validate_trigger(indio_dev, trig);
374 if (trig && trig->ops && trig->ops->validate_device) {
375 ret = trig->ops->validate_device(trig, indio_dev);
380 indio_dev->trig = trig;
383 if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
384 iio_trigger_detach_poll_func(oldtrig,
385 indio_dev->pollfunc_event);
386 iio_trigger_put(oldtrig);
388 if (indio_dev->trig) {
389 iio_trigger_get(indio_dev->trig);
390 if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
391 iio_trigger_attach_poll_func(indio_dev->trig,
392 indio_dev->pollfunc_event);
398 static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
399 iio_trigger_read_current,
400 iio_trigger_write_current);
402 static struct attribute *iio_trigger_consumer_attrs[] = {
403 &dev_attr_current_trigger.attr,
407 static const struct attribute_group iio_trigger_consumer_attr_group = {
409 .attrs = iio_trigger_consumer_attrs,
412 static void iio_trig_release(struct device *device)
414 struct iio_trigger *trig = to_iio_trigger(device);
417 if (trig->subirq_base) {
418 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
419 irq_modify_status(trig->subirq_base + i,
421 IRQ_NOREQUEST | IRQ_NOPROBE);
422 irq_set_chip(trig->subirq_base + i,
424 irq_set_handler(trig->subirq_base + i,
428 irq_free_descs(trig->subirq_base,
429 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
435 static struct device_type iio_trig_type = {
436 .release = iio_trig_release,
437 .groups = iio_trig_dev_groups,
440 static void iio_trig_subirqmask(struct irq_data *d)
442 struct irq_chip *chip = irq_data_get_irq_chip(d);
443 struct iio_trigger *trig
445 struct iio_trigger, subirq_chip);
446 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
449 static void iio_trig_subirqunmask(struct irq_data *d)
451 struct irq_chip *chip = irq_data_get_irq_chip(d);
452 struct iio_trigger *trig
454 struct iio_trigger, subirq_chip);
455 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
458 static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
460 struct iio_trigger *trig;
461 trig = kzalloc(sizeof *trig, GFP_KERNEL);
464 trig->dev.type = &iio_trig_type;
465 trig->dev.bus = &iio_bus_type;
466 device_initialize(&trig->dev);
468 mutex_init(&trig->pool_lock);
470 = irq_alloc_descs(-1, 0,
471 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
473 if (trig->subirq_base < 0) {
478 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
479 if (trig->name == NULL) {
480 irq_free_descs(trig->subirq_base,
481 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
485 trig->subirq_chip.name = trig->name;
486 trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
487 trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
488 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
489 irq_set_chip(trig->subirq_base + i,
491 irq_set_handler(trig->subirq_base + i,
493 irq_modify_status(trig->subirq_base + i,
494 IRQ_NOREQUEST | IRQ_NOAUTOEN,
497 get_device(&trig->dev);
503 struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
505 struct iio_trigger *trig;
508 va_start(vargs, fmt);
509 trig = viio_trigger_alloc(fmt, vargs);
514 EXPORT_SYMBOL(iio_trigger_alloc);
516 void iio_trigger_free(struct iio_trigger *trig)
519 put_device(&trig->dev);
521 EXPORT_SYMBOL(iio_trigger_free);
523 static void devm_iio_trigger_release(struct device *dev, void *res)
525 iio_trigger_free(*(struct iio_trigger **)res);
528 static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
530 struct iio_trigger **r = res;
541 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
542 * @dev: Device to allocate iio_trigger for
543 * @fmt: trigger name format. If it includes format
544 * specifiers, the additional arguments following
545 * format are formatted and inserted in the resulting
546 * string replacing their respective specifiers.
548 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
549 * automatically freed on driver detach.
551 * If an iio_trigger allocated with this function needs to be freed separately,
552 * devm_iio_trigger_free() must be used.
555 * Pointer to allocated iio_trigger on success, NULL on failure.
557 struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
558 const char *fmt, ...)
560 struct iio_trigger **ptr, *trig;
563 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
568 /* use raw alloc_dr for kmalloc caller tracing */
569 va_start(vargs, fmt);
570 trig = viio_trigger_alloc(fmt, vargs);
574 devres_add(dev, ptr);
581 EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
584 * devm_iio_trigger_free - Resource-managed iio_trigger_free()
585 * @dev: Device this iio_dev belongs to
586 * @iio_trig: the iio_trigger associated with the device
588 * Free iio_trigger allocated with devm_iio_trigger_alloc().
590 void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
594 rc = devres_release(dev, devm_iio_trigger_release,
595 devm_iio_trigger_match, iio_trig);
598 EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
600 void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
602 indio_dev->groups[indio_dev->groupcounter++] =
603 &iio_trigger_consumer_attr_group;
606 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
608 /* Clean up an associated but not attached trigger reference */
610 iio_trigger_put(indio_dev->trig);
613 int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
615 return iio_trigger_attach_poll_func(indio_dev->trig,
616 indio_dev->pollfunc);
618 EXPORT_SYMBOL(iio_triggered_buffer_postenable);
620 int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
622 return iio_trigger_detach_poll_func(indio_dev->trig,
623 indio_dev->pollfunc);
625 EXPORT_SYMBOL(iio_triggered_buffer_predisable);