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);
213 pf->irq = iio_trigger_get_irq(trig);
214 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
218 module_put(pf->indio_dev->info->driver_module);
222 if (trig->ops && trig->ops->set_trigger_state && notinuse) {
223 ret = trig->ops->set_trigger_state(trig, true);
225 module_put(pf->indio_dev->info->driver_module);
231 static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
232 struct iio_poll_func *pf)
236 = (bitmap_weight(trig->pool,
237 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
239 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
240 ret = trig->ops->set_trigger_state(trig, false);
244 iio_trigger_put_irq(trig, pf->irq);
245 free_irq(pf->irq, pf);
246 module_put(pf->indio_dev->info->driver_module);
251 irqreturn_t iio_pollfunc_store_time(int irq, void *p)
253 struct iio_poll_func *pf = p;
254 pf->timestamp = iio_get_time_ns();
255 return IRQ_WAKE_THREAD;
257 EXPORT_SYMBOL(iio_pollfunc_store_time);
260 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
261 irqreturn_t (*thread)(int irq, void *p),
263 struct iio_dev *indio_dev,
268 struct iio_poll_func *pf;
270 pf = kmalloc(sizeof *pf, GFP_KERNEL);
273 va_start(vargs, fmt);
274 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
276 if (pf->name == NULL) {
283 pf->indio_dev = indio_dev;
287 EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
289 void iio_dealloc_pollfunc(struct iio_poll_func *pf)
294 EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
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
301 * @buf: buffer where the current trigger name will be printed into
303 * For trigger consumers the current_trigger interface allows the trigger
304 * used by the device to be queried.
306 * Return: a negative number on failure, the number of characters written
307 * on success or 0 if no trigger is available
309 static ssize_t iio_trigger_read_current(struct device *dev,
310 struct device_attribute *attr,
313 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
316 return sprintf(buf, "%s\n", indio_dev->trig->name);
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
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
331 * Return: negative error code on failure or length of the buffer
334 static ssize_t iio_trigger_write_current(struct device *dev,
335 struct device_attribute *attr,
339 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
340 struct iio_trigger *oldtrig = indio_dev->trig;
341 struct iio_trigger *trig;
344 mutex_lock(&indio_dev->mlock);
345 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
346 mutex_unlock(&indio_dev->mlock);
349 mutex_unlock(&indio_dev->mlock);
351 trig = iio_trigger_find_by_name(buf, len);
355 if (trig && indio_dev->info->validate_trigger) {
356 ret = indio_dev->info->validate_trigger(indio_dev, trig);
361 if (trig && trig->ops && trig->ops->validate_device) {
362 ret = trig->ops->validate_device(trig, indio_dev);
367 indio_dev->trig = trig;
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);
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);
385 static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
386 iio_trigger_read_current,
387 iio_trigger_write_current);
389 static struct attribute *iio_trigger_consumer_attrs[] = {
390 &dev_attr_current_trigger.attr,
394 static const struct attribute_group iio_trigger_consumer_attr_group = {
396 .attrs = iio_trigger_consumer_attrs,
399 static void iio_trig_release(struct device *device)
401 struct iio_trigger *trig = to_iio_trigger(device);
404 if (trig->subirq_base) {
405 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
406 irq_modify_status(trig->subirq_base + i,
408 IRQ_NOREQUEST | IRQ_NOPROBE);
409 irq_set_chip(trig->subirq_base + i,
411 irq_set_handler(trig->subirq_base + i,
415 irq_free_descs(trig->subirq_base,
416 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
422 static struct device_type iio_trig_type = {
423 .release = iio_trig_release,
424 .groups = iio_trig_dev_groups,
427 static void iio_trig_subirqmask(struct irq_data *d)
429 struct irq_chip *chip = irq_data_get_irq_chip(d);
430 struct iio_trigger *trig
432 struct iio_trigger, subirq_chip);
433 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
436 static void iio_trig_subirqunmask(struct irq_data *d)
438 struct irq_chip *chip = irq_data_get_irq_chip(d);
439 struct iio_trigger *trig
441 struct iio_trigger, subirq_chip);
442 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
445 static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
447 struct iio_trigger *trig;
448 trig = kzalloc(sizeof *trig, GFP_KERNEL);
451 trig->dev.type = &iio_trig_type;
452 trig->dev.bus = &iio_bus_type;
453 device_initialize(&trig->dev);
455 mutex_init(&trig->pool_lock);
457 = irq_alloc_descs(-1, 0,
458 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
460 if (trig->subirq_base < 0) {
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);
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,
478 irq_set_handler(trig->subirq_base + i,
480 irq_modify_status(trig->subirq_base + i,
481 IRQ_NOREQUEST | IRQ_NOAUTOEN,
484 get_device(&trig->dev);
490 struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
492 struct iio_trigger *trig;
495 va_start(vargs, fmt);
496 trig = viio_trigger_alloc(fmt, vargs);
501 EXPORT_SYMBOL(iio_trigger_alloc);
503 void iio_trigger_free(struct iio_trigger *trig)
506 put_device(&trig->dev);
508 EXPORT_SYMBOL(iio_trigger_free);
510 static void devm_iio_trigger_release(struct device *dev, void *res)
512 iio_trigger_free(*(struct iio_trigger **)res);
515 static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
517 struct iio_trigger **r = res;
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.
535 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
536 * automatically freed on driver detach.
538 * If an iio_trigger allocated with this function needs to be freed separately,
539 * devm_iio_trigger_free() must be used.
542 * Pointer to allocated iio_trigger on success, NULL on failure.
544 struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
545 const char *fmt, ...)
547 struct iio_trigger **ptr, *trig;
550 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
555 /* use raw alloc_dr for kmalloc caller tracing */
556 va_start(vargs, fmt);
557 trig = viio_trigger_alloc(fmt, vargs);
561 devres_add(dev, ptr);
568 EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
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
575 * Free iio_trigger allocated with devm_iio_trigger_alloc().
577 void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
581 rc = devres_release(dev, devm_iio_trigger_release,
582 devm_iio_trigger_match, iio_trig);
585 EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
587 void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
589 indio_dev->groups[indio_dev->groupcounter++] =
590 &iio_trigger_consumer_attr_group;
593 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
595 /* Clean up an associated but not attached trigger reference */
597 iio_trigger_put(indio_dev->trig);
600 int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
602 return iio_trigger_attach_poll_func(indio_dev->trig,
603 indio_dev->pollfunc);
605 EXPORT_SYMBOL(iio_triggered_buffer_postenable);
607 int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
609 return iio_trigger_detach_poll_func(indio_dev->trig,
610 indio_dev->pollfunc);
612 EXPORT_SYMBOL(iio_triggered_buffer_predisable);