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>
21 #include "iio_core_trigger.h"
22 #include "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
44 static ssize_t iio_trigger_read_name(struct device *dev,
45 struct device_attribute *attr,
48 struct iio_trigger *trig = dev_get_drvdata(dev);
49 return sprintf(buf, "%s\n", trig->name);
52 static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
55 * iio_trigger_register_sysfs() - create a device for this trigger
56 * @trig_info: the trigger
58 * Also adds any control attribute registered by the trigger driver
60 static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
62 return sysfs_add_file_to_group(&trig_info->dev.kobj,
67 static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
69 sysfs_remove_file_from_group(&trig_info->dev.kobj,
74 int iio_trigger_register(struct iio_trigger *trig_info)
78 trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
79 if (trig_info->id < 0) {
83 /* Set the name used for the sysfs directory etc */
84 dev_set_name(&trig_info->dev, "trigger%ld",
85 (unsigned long) trig_info->id);
87 ret = device_add(&trig_info->dev);
89 goto error_unregister_id;
91 ret = iio_trigger_register_sysfs(trig_info);
93 goto error_device_del;
95 /* Add to list of available triggers held by the IIO core */
96 mutex_lock(&iio_trigger_list_lock);
97 list_add_tail(&trig_info->list, &iio_trigger_list);
98 mutex_unlock(&iio_trigger_list_lock);
103 device_del(&trig_info->dev);
105 ida_simple_remove(&iio_trigger_ida, trig_info->id);
109 EXPORT_SYMBOL(iio_trigger_register);
111 void iio_trigger_unregister(struct iio_trigger *trig_info)
113 mutex_lock(&iio_trigger_list_lock);
114 list_del(&trig_info->list);
115 mutex_unlock(&iio_trigger_list_lock);
117 iio_trigger_unregister_sysfs(trig_info);
118 ida_simple_remove(&iio_trigger_ida, trig_info->id);
119 /* Possible issue in here */
120 device_unregister(&trig_info->dev);
122 EXPORT_SYMBOL(iio_trigger_unregister);
124 static struct iio_trigger *iio_trigger_find_by_name(const char *name,
127 struct iio_trigger *trig = NULL, *iter;
129 mutex_lock(&iio_trigger_list_lock);
130 list_for_each_entry(iter, &iio_trigger_list, list)
131 if (sysfs_streq(iter->name, name)) {
135 mutex_unlock(&iio_trigger_list_lock);
140 void iio_trigger_poll(struct iio_trigger *trig, s64 time)
143 if (!trig->use_count)
144 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
145 if (trig->subirqs[i].enabled) {
147 generic_handle_irq(trig->subirq_base + i);
150 EXPORT_SYMBOL(iio_trigger_poll);
152 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
154 iio_trigger_poll(private, iio_get_time_ns());
157 EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
159 void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
162 if (!trig->use_count) {
163 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
164 if (trig->subirqs[i].enabled) {
166 handle_nested_irq(trig->subirq_base + i);
170 EXPORT_SYMBOL(iio_trigger_poll_chained);
172 void iio_trigger_notify_done(struct iio_trigger *trig)
175 if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
176 if (trig->ops->try_reenable(trig)) {
177 /* Missed and interrupt so launch new poll now */
178 iio_trigger_poll(trig, 0);
181 EXPORT_SYMBOL(iio_trigger_notify_done);
183 /* Trigger Consumer related functions */
184 static int iio_trigger_get_irq(struct iio_trigger *trig)
187 mutex_lock(&trig->pool_lock);
188 ret = bitmap_find_free_region(trig->pool,
189 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
191 mutex_unlock(&trig->pool_lock);
193 ret += trig->subirq_base;
198 static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
200 mutex_lock(&trig->pool_lock);
201 clear_bit(irq - trig->subirq_base, trig->pool);
202 mutex_unlock(&trig->pool_lock);
205 /* Complexity in here. With certain triggers (datardy) an acknowledgement
206 * may be needed if the pollfuncs do not include the data read for the
208 * This is not currently handled. Alternative of not enabling trigger unless
209 * the relevant function is in there may be the best option.
211 /* Worth protecting against double additions?*/
212 static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
213 struct iio_poll_func *pf)
217 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
219 /* Prevent the module being removed whilst attached to a trigger */
220 __module_get(pf->indio_dev->info->driver_module);
221 pf->irq = iio_trigger_get_irq(trig);
222 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
225 if (trig->ops && trig->ops->set_trigger_state && notinuse)
226 ret = trig->ops->set_trigger_state(trig, true);
231 static int iio_trigger_dettach_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);
252 irqreturn_t iio_pollfunc_store_time(int irq, void *p)
254 struct iio_poll_func *pf = p;
255 pf->timestamp = iio_get_time_ns();
256 return IRQ_WAKE_THREAD;
258 EXPORT_SYMBOL(iio_pollfunc_store_time);
261 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
262 irqreturn_t (*thread)(int irq, void *p),
264 struct iio_dev *indio_dev,
269 struct iio_poll_func *pf;
271 pf = kmalloc(sizeof *pf, GFP_KERNEL);
274 va_start(vargs, fmt);
275 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
277 if (pf->name == NULL) {
284 pf->indio_dev = indio_dev;
288 EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
290 void iio_dealloc_pollfunc(struct iio_poll_func *pf)
295 EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
298 * iio_trigger_read_currrent() - trigger consumer sysfs query which trigger
300 * For trigger consumers the current_trigger interface allows the trigger
301 * used by the device to be queried.
303 static ssize_t iio_trigger_read_current(struct device *dev,
304 struct device_attribute *attr,
307 struct iio_dev *indio_dev = dev_get_drvdata(dev);
310 return sprintf(buf, "%s\n", indio_dev->trig->name);
315 * iio_trigger_write_current() trigger consumer sysfs set current trigger
317 * For trigger consumers the current_trigger interface allows the trigger
318 * used for this device to be specified at run time based on the triggers
321 static ssize_t iio_trigger_write_current(struct device *dev,
322 struct device_attribute *attr,
326 struct iio_dev *indio_dev = dev_get_drvdata(dev);
327 struct iio_trigger *oldtrig = indio_dev->trig;
328 struct iio_trigger *trig;
331 mutex_lock(&indio_dev->mlock);
332 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
333 mutex_unlock(&indio_dev->mlock);
336 mutex_unlock(&indio_dev->mlock);
338 trig = iio_trigger_find_by_name(buf, len);
340 if (trig && indio_dev->info->validate_trigger) {
341 ret = indio_dev->info->validate_trigger(indio_dev, trig);
346 if (trig && trig->ops && trig->ops->validate_device) {
347 ret = trig->ops->validate_device(trig, indio_dev);
352 indio_dev->trig = trig;
354 if (oldtrig && indio_dev->trig != oldtrig)
355 iio_put_trigger(oldtrig);
357 iio_get_trigger(indio_dev->trig);
362 static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
363 iio_trigger_read_current,
364 iio_trigger_write_current);
366 static struct attribute *iio_trigger_consumer_attrs[] = {
367 &dev_attr_current_trigger.attr,
371 static const struct attribute_group iio_trigger_consumer_attr_group = {
373 .attrs = iio_trigger_consumer_attrs,
376 static void iio_trig_release(struct device *device)
378 struct iio_trigger *trig = to_iio_trigger(device);
381 if (trig->subirq_base) {
382 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
383 irq_modify_status(trig->subirq_base + i,
385 IRQ_NOREQUEST | IRQ_NOPROBE);
386 irq_set_chip(trig->subirq_base + i,
388 irq_set_handler(trig->subirq_base + i,
392 irq_free_descs(trig->subirq_base,
393 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
399 static struct device_type iio_trig_type = {
400 .release = iio_trig_release,
403 static void iio_trig_subirqmask(struct irq_data *d)
405 struct irq_chip *chip = irq_data_get_irq_chip(d);
406 struct iio_trigger *trig
408 struct iio_trigger, subirq_chip);
409 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
412 static void iio_trig_subirqunmask(struct irq_data *d)
414 struct irq_chip *chip = irq_data_get_irq_chip(d);
415 struct iio_trigger *trig
417 struct iio_trigger, subirq_chip);
418 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
421 struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
424 struct iio_trigger *trig;
425 trig = kzalloc(sizeof *trig, GFP_KERNEL);
428 trig->dev.type = &iio_trig_type;
429 trig->dev.bus = &iio_bus_type;
430 device_initialize(&trig->dev);
431 dev_set_drvdata(&trig->dev, (void *)trig);
433 mutex_init(&trig->pool_lock);
435 = irq_alloc_descs(-1, 0,
436 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
438 if (trig->subirq_base < 0) {
442 va_start(vargs, fmt);
443 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
445 if (trig->name == NULL) {
446 irq_free_descs(trig->subirq_base,
447 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
451 trig->subirq_chip.name = trig->name;
452 trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
453 trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
454 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
455 irq_set_chip(trig->subirq_base + i,
457 irq_set_handler(trig->subirq_base + i,
459 irq_modify_status(trig->subirq_base + i,
460 IRQ_NOREQUEST | IRQ_NOAUTOEN,
463 get_device(&trig->dev);
467 EXPORT_SYMBOL(iio_allocate_trigger);
469 void iio_free_trigger(struct iio_trigger *trig)
472 put_device(&trig->dev);
474 EXPORT_SYMBOL(iio_free_trigger);
476 int iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
478 indio_dev->groups[indio_dev->groupcounter++] =
479 &iio_trigger_consumer_attr_group;
484 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
486 /* Clean up and associated but not attached triggers references */
488 iio_put_trigger(indio_dev->trig);
491 int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
493 return indio_dev->trig
494 ? iio_trigger_attach_poll_func(indio_dev->trig,
498 EXPORT_SYMBOL(iio_triggered_buffer_postenable);
500 int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
502 return indio_dev->trig
503 ? iio_trigger_dettach_poll_func(indio_dev->trig,
507 EXPORT_SYMBOL(iio_triggered_buffer_predisable);