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);
169 EXPORT_SYMBOL(iio_trigger_poll_chained);
171 void iio_trigger_notify_done(struct iio_trigger *trig)
174 if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
175 if (trig->ops->try_reenable(trig))
176 /* Missed and interrupt so launch new poll now */
177 iio_trigger_poll(trig, 0);
179 EXPORT_SYMBOL(iio_trigger_notify_done);
181 /* Trigger Consumer related functions */
182 static int iio_trigger_get_irq(struct iio_trigger *trig)
185 mutex_lock(&trig->pool_lock);
186 ret = bitmap_find_free_region(trig->pool,
187 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
189 mutex_unlock(&trig->pool_lock);
191 ret += trig->subirq_base;
196 static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
198 mutex_lock(&trig->pool_lock);
199 clear_bit(irq - trig->subirq_base, trig->pool);
200 mutex_unlock(&trig->pool_lock);
203 /* Complexity in here. With certain triggers (datardy) an acknowledgement
204 * may be needed if the pollfuncs do not include the data read for the
206 * This is not currently handled. Alternative of not enabling trigger unless
207 * the relevant function is in there may be the best option.
209 /* Worth protecting against double additions?*/
210 static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
211 struct iio_poll_func *pf)
215 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
217 /* Prevent the module being removed whilst attached to a trigger */
218 __module_get(pf->indio_dev->info->driver_module);
219 pf->irq = iio_trigger_get_irq(trig);
220 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
224 module_put(pf->indio_dev->info->driver_module);
228 if (trig->ops && trig->ops->set_trigger_state && notinuse) {
229 ret = trig->ops->set_trigger_state(trig, true);
231 module_put(pf->indio_dev->info->driver_module);
237 static int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
238 struct iio_poll_func *pf)
242 = (bitmap_weight(trig->pool,
243 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
245 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
246 ret = trig->ops->set_trigger_state(trig, false);
250 iio_trigger_put_irq(trig, pf->irq);
251 free_irq(pf->irq, pf);
252 module_put(pf->indio_dev->info->driver_module);
258 irqreturn_t iio_pollfunc_store_time(int irq, void *p)
260 struct iio_poll_func *pf = p;
261 pf->timestamp = iio_get_time_ns();
262 return IRQ_WAKE_THREAD;
264 EXPORT_SYMBOL(iio_pollfunc_store_time);
267 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
268 irqreturn_t (*thread)(int irq, void *p),
270 struct iio_dev *indio_dev,
275 struct iio_poll_func *pf;
277 pf = kmalloc(sizeof *pf, GFP_KERNEL);
280 va_start(vargs, fmt);
281 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
283 if (pf->name == NULL) {
290 pf->indio_dev = indio_dev;
294 EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
296 void iio_dealloc_pollfunc(struct iio_poll_func *pf)
301 EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
304 * iio_trigger_read_current() - trigger consumer sysfs query which trigger
306 * For trigger consumers the current_trigger interface allows the trigger
307 * used by the device to be queried.
309 static ssize_t iio_trigger_read_current(struct device *dev,
310 struct device_attribute *attr,
313 struct iio_dev *indio_dev = dev_get_drvdata(dev);
316 return sprintf(buf, "%s\n", indio_dev->trig->name);
321 * iio_trigger_write_current() trigger consumer sysfs set current trigger
323 * For trigger consumers the current_trigger interface allows the trigger
324 * used for this device to be specified at run time based on the triggers
327 static ssize_t iio_trigger_write_current(struct device *dev,
328 struct device_attribute *attr,
332 struct iio_dev *indio_dev = dev_get_drvdata(dev);
333 struct iio_trigger *oldtrig = indio_dev->trig;
334 struct iio_trigger *trig;
337 mutex_lock(&indio_dev->mlock);
338 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
339 mutex_unlock(&indio_dev->mlock);
342 mutex_unlock(&indio_dev->mlock);
344 trig = iio_trigger_find_by_name(buf, len);
348 if (trig && indio_dev->info->validate_trigger) {
349 ret = indio_dev->info->validate_trigger(indio_dev, trig);
354 if (trig && trig->ops && trig->ops->validate_device) {
355 ret = trig->ops->validate_device(trig, indio_dev);
360 indio_dev->trig = trig;
362 if (oldtrig && indio_dev->trig != oldtrig)
363 iio_put_trigger(oldtrig);
365 iio_get_trigger(indio_dev->trig);
370 static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
371 iio_trigger_read_current,
372 iio_trigger_write_current);
374 static struct attribute *iio_trigger_consumer_attrs[] = {
375 &dev_attr_current_trigger.attr,
379 static const struct attribute_group iio_trigger_consumer_attr_group = {
381 .attrs = iio_trigger_consumer_attrs,
384 static void iio_trig_release(struct device *device)
386 struct iio_trigger *trig = to_iio_trigger(device);
389 if (trig->subirq_base) {
390 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
391 irq_modify_status(trig->subirq_base + i,
393 IRQ_NOREQUEST | IRQ_NOPROBE);
394 irq_set_chip(trig->subirq_base + i,
396 irq_set_handler(trig->subirq_base + i,
400 irq_free_descs(trig->subirq_base,
401 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
407 static struct device_type iio_trig_type = {
408 .release = iio_trig_release,
411 static void iio_trig_subirqmask(struct irq_data *d)
413 struct irq_chip *chip = irq_data_get_irq_chip(d);
414 struct iio_trigger *trig
416 struct iio_trigger, subirq_chip);
417 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
420 static void iio_trig_subirqunmask(struct irq_data *d)
422 struct irq_chip *chip = irq_data_get_irq_chip(d);
423 struct iio_trigger *trig
425 struct iio_trigger, subirq_chip);
426 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
429 struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
432 struct iio_trigger *trig;
433 trig = kzalloc(sizeof *trig, GFP_KERNEL);
436 trig->dev.type = &iio_trig_type;
437 trig->dev.bus = &iio_bus_type;
438 device_initialize(&trig->dev);
439 dev_set_drvdata(&trig->dev, (void *)trig);
441 mutex_init(&trig->pool_lock);
443 = irq_alloc_descs(-1, 0,
444 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
446 if (trig->subirq_base < 0) {
450 va_start(vargs, fmt);
451 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
453 if (trig->name == NULL) {
454 irq_free_descs(trig->subirq_base,
455 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
459 trig->subirq_chip.name = trig->name;
460 trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
461 trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
462 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
463 irq_set_chip(trig->subirq_base + i,
465 irq_set_handler(trig->subirq_base + i,
467 irq_modify_status(trig->subirq_base + i,
468 IRQ_NOREQUEST | IRQ_NOAUTOEN,
471 get_device(&trig->dev);
475 EXPORT_SYMBOL(iio_allocate_trigger);
477 void iio_free_trigger(struct iio_trigger *trig)
480 put_device(&trig->dev);
482 EXPORT_SYMBOL(iio_free_trigger);
484 void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
486 indio_dev->groups[indio_dev->groupcounter++] =
487 &iio_trigger_consumer_attr_group;
490 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
492 /* Clean up and associated but not attached triggers references */
494 iio_put_trigger(indio_dev->trig);
497 int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
499 return iio_trigger_attach_poll_func(indio_dev->trig,
500 indio_dev->pollfunc);
502 EXPORT_SYMBOL(iio_triggered_buffer_postenable);
504 int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
506 return iio_trigger_dettach_poll_func(indio_dev->trig,
507 indio_dev->pollfunc);
509 EXPORT_SYMBOL(iio_triggered_buffer_predisable);