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
44 static ssize_t iio_trigger_read_name(struct device *dev,
45 struct device_attribute *attr,
48 struct iio_trigger *trig = to_iio_trigger(dev);
49 return sprintf(buf, "%s\n", trig->name);
52 static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
54 static struct attribute *iio_trig_dev_attrs[] = {
58 ATTRIBUTE_GROUPS(iio_trig_dev);
60 int iio_trigger_register(struct iio_trigger *trig_info)
64 trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
65 if (trig_info->id < 0)
68 /* Set the name used for the sysfs directory etc */
69 dev_set_name(&trig_info->dev, "trigger%ld",
70 (unsigned long) trig_info->id);
72 ret = device_add(&trig_info->dev);
74 goto error_unregister_id;
76 /* Add to list of available triggers held by the IIO core */
77 mutex_lock(&iio_trigger_list_lock);
78 list_add_tail(&trig_info->list, &iio_trigger_list);
79 mutex_unlock(&iio_trigger_list_lock);
84 ida_simple_remove(&iio_trigger_ida, trig_info->id);
87 EXPORT_SYMBOL(iio_trigger_register);
89 void iio_trigger_unregister(struct iio_trigger *trig_info)
91 mutex_lock(&iio_trigger_list_lock);
92 list_del(&trig_info->list);
93 mutex_unlock(&iio_trigger_list_lock);
95 ida_simple_remove(&iio_trigger_ida, trig_info->id);
96 /* Possible issue in here */
97 device_del(&trig_info->dev);
99 EXPORT_SYMBOL(iio_trigger_unregister);
101 static struct iio_trigger *iio_trigger_find_by_name(const char *name,
104 struct iio_trigger *trig = NULL, *iter;
106 mutex_lock(&iio_trigger_list_lock);
107 list_for_each_entry(iter, &iio_trigger_list, list)
108 if (sysfs_streq(iter->name, name)) {
112 mutex_unlock(&iio_trigger_list_lock);
117 void iio_trigger_poll(struct iio_trigger *trig)
121 if (!atomic_read(&trig->use_count)) {
122 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
124 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
125 if (trig->subirqs[i].enabled)
126 generic_handle_irq(trig->subirq_base + i);
128 iio_trigger_notify_done(trig);
132 EXPORT_SYMBOL(iio_trigger_poll);
134 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
136 iio_trigger_poll(private);
139 EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
141 void iio_trigger_poll_chained(struct iio_trigger *trig)
145 if (!atomic_read(&trig->use_count)) {
146 atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
148 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
149 if (trig->subirqs[i].enabled)
150 handle_nested_irq(trig->subirq_base + i);
152 iio_trigger_notify_done(trig);
156 EXPORT_SYMBOL(iio_trigger_poll_chained);
158 void iio_trigger_notify_done(struct iio_trigger *trig)
160 if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
161 trig->ops->try_reenable)
162 if (trig->ops->try_reenable(trig))
163 /* Missed an interrupt so launch new poll now */
164 iio_trigger_poll(trig);
166 EXPORT_SYMBOL(iio_trigger_notify_done);
168 /* Trigger Consumer related functions */
169 static int iio_trigger_get_irq(struct iio_trigger *trig)
172 mutex_lock(&trig->pool_lock);
173 ret = bitmap_find_free_region(trig->pool,
174 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
176 mutex_unlock(&trig->pool_lock);
178 ret += trig->subirq_base;
183 static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
185 mutex_lock(&trig->pool_lock);
186 clear_bit(irq - trig->subirq_base, trig->pool);
187 mutex_unlock(&trig->pool_lock);
190 /* Complexity in here. With certain triggers (datardy) an acknowledgement
191 * may be needed if the pollfuncs do not include the data read for the
193 * This is not currently handled. Alternative of not enabling trigger unless
194 * the relevant function is in there may be the best option.
196 /* Worth protecting against double additions? */
197 static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
198 struct iio_poll_func *pf)
202 = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
204 /* Prevent the module from being removed whilst attached to a trigger */
205 __module_get(pf->indio_dev->info->driver_module);
206 pf->irq = iio_trigger_get_irq(trig);
207 ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
211 module_put(pf->indio_dev->info->driver_module);
215 if (trig->ops && trig->ops->set_trigger_state && notinuse) {
216 ret = trig->ops->set_trigger_state(trig, true);
218 module_put(pf->indio_dev->info->driver_module);
224 static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
225 struct iio_poll_func *pf)
229 = (bitmap_weight(trig->pool,
230 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
232 if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
233 ret = trig->ops->set_trigger_state(trig, false);
237 iio_trigger_put_irq(trig, pf->irq);
238 free_irq(pf->irq, pf);
239 module_put(pf->indio_dev->info->driver_module);
244 irqreturn_t iio_pollfunc_store_time(int irq, void *p)
246 struct iio_poll_func *pf = p;
247 pf->timestamp = iio_get_time_ns();
248 return IRQ_WAKE_THREAD;
250 EXPORT_SYMBOL(iio_pollfunc_store_time);
253 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
254 irqreturn_t (*thread)(int irq, void *p),
256 struct iio_dev *indio_dev,
261 struct iio_poll_func *pf;
263 pf = kmalloc(sizeof *pf, GFP_KERNEL);
266 va_start(vargs, fmt);
267 pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
269 if (pf->name == NULL) {
276 pf->indio_dev = indio_dev;
280 EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
282 void iio_dealloc_pollfunc(struct iio_poll_func *pf)
287 EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
290 * iio_trigger_read_current() - trigger consumer sysfs query current trigger
292 * For trigger consumers the current_trigger interface allows the trigger
293 * used by the device to be queried.
295 static ssize_t iio_trigger_read_current(struct device *dev,
296 struct device_attribute *attr,
299 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
302 return sprintf(buf, "%s\n", indio_dev->trig->name);
307 * iio_trigger_write_current() - trigger consumer sysfs set current trigger
309 * For trigger consumers the current_trigger interface allows the trigger
310 * used for this device to be specified at run time based on the trigger's
313 static ssize_t iio_trigger_write_current(struct device *dev,
314 struct device_attribute *attr,
318 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
319 struct iio_trigger *oldtrig = indio_dev->trig;
320 struct iio_trigger *trig;
323 mutex_lock(&indio_dev->mlock);
324 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
325 mutex_unlock(&indio_dev->mlock);
328 mutex_unlock(&indio_dev->mlock);
330 trig = iio_trigger_find_by_name(buf, len);
334 if (trig && indio_dev->info->validate_trigger) {
335 ret = indio_dev->info->validate_trigger(indio_dev, trig);
340 if (trig && trig->ops && trig->ops->validate_device) {
341 ret = trig->ops->validate_device(trig, indio_dev);
346 indio_dev->trig = trig;
349 iio_trigger_put(oldtrig);
351 iio_trigger_get(indio_dev->trig);
356 static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
357 iio_trigger_read_current,
358 iio_trigger_write_current);
360 static struct attribute *iio_trigger_consumer_attrs[] = {
361 &dev_attr_current_trigger.attr,
365 static const struct attribute_group iio_trigger_consumer_attr_group = {
367 .attrs = iio_trigger_consumer_attrs,
370 static void iio_trig_release(struct device *device)
372 struct iio_trigger *trig = to_iio_trigger(device);
375 if (trig->subirq_base) {
376 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
377 irq_modify_status(trig->subirq_base + i,
379 IRQ_NOREQUEST | IRQ_NOPROBE);
380 irq_set_chip(trig->subirq_base + i,
382 irq_set_handler(trig->subirq_base + i,
386 irq_free_descs(trig->subirq_base,
387 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
393 static struct device_type iio_trig_type = {
394 .release = iio_trig_release,
395 .groups = iio_trig_dev_groups,
398 static void iio_trig_subirqmask(struct irq_data *d)
400 struct irq_chip *chip = irq_data_get_irq_chip(d);
401 struct iio_trigger *trig
403 struct iio_trigger, subirq_chip);
404 trig->subirqs[d->irq - trig->subirq_base].enabled = false;
407 static void iio_trig_subirqunmask(struct irq_data *d)
409 struct irq_chip *chip = irq_data_get_irq_chip(d);
410 struct iio_trigger *trig
412 struct iio_trigger, subirq_chip);
413 trig->subirqs[d->irq - trig->subirq_base].enabled = true;
416 static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
418 struct iio_trigger *trig;
419 trig = kzalloc(sizeof *trig, GFP_KERNEL);
422 trig->dev.type = &iio_trig_type;
423 trig->dev.bus = &iio_bus_type;
424 device_initialize(&trig->dev);
426 mutex_init(&trig->pool_lock);
428 = irq_alloc_descs(-1, 0,
429 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
431 if (trig->subirq_base < 0) {
436 trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
437 if (trig->name == NULL) {
438 irq_free_descs(trig->subirq_base,
439 CONFIG_IIO_CONSUMERS_PER_TRIGGER);
443 trig->subirq_chip.name = trig->name;
444 trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
445 trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
446 for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
447 irq_set_chip(trig->subirq_base + i,
449 irq_set_handler(trig->subirq_base + i,
451 irq_modify_status(trig->subirq_base + i,
452 IRQ_NOREQUEST | IRQ_NOAUTOEN,
455 get_device(&trig->dev);
461 struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
463 struct iio_trigger *trig;
466 va_start(vargs, fmt);
467 trig = viio_trigger_alloc(fmt, vargs);
472 EXPORT_SYMBOL(iio_trigger_alloc);
474 void iio_trigger_free(struct iio_trigger *trig)
477 put_device(&trig->dev);
479 EXPORT_SYMBOL(iio_trigger_free);
481 static void devm_iio_trigger_release(struct device *dev, void *res)
483 iio_trigger_free(*(struct iio_trigger **)res);
486 static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
488 struct iio_trigger **r = res;
499 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
500 * @dev: Device to allocate iio_trigger for
501 * @fmt: trigger name format. If it includes format
502 * specifiers, the additional arguments following
503 * format are formatted and inserted in the resulting
504 * string replacing their respective specifiers.
506 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
507 * automatically freed on driver detach.
509 * If an iio_trigger allocated with this function needs to be freed separately,
510 * devm_iio_trigger_free() must be used.
513 * Pointer to allocated iio_trigger on success, NULL on failure.
515 struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
516 const char *fmt, ...)
518 struct iio_trigger **ptr, *trig;
521 ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
526 /* use raw alloc_dr for kmalloc caller tracing */
527 va_start(vargs, fmt);
528 trig = viio_trigger_alloc(fmt, vargs);
532 devres_add(dev, ptr);
539 EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
542 * devm_iio_trigger_free - Resource-managed iio_trigger_free()
543 * @dev: Device this iio_dev belongs to
544 * @iio_trig: the iio_trigger associated with the device
546 * Free iio_trigger allocated with devm_iio_trigger_alloc().
548 void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
552 rc = devres_release(dev, devm_iio_trigger_release,
553 devm_iio_trigger_match, iio_trig);
556 EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
558 void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
560 indio_dev->groups[indio_dev->groupcounter++] =
561 &iio_trigger_consumer_attr_group;
564 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
566 /* Clean up an associated but not attached trigger reference */
568 iio_trigger_put(indio_dev->trig);
571 int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
573 return iio_trigger_attach_poll_func(indio_dev->trig,
574 indio_dev->pollfunc);
576 EXPORT_SYMBOL(iio_triggered_buffer_postenable);
578 int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
580 return iio_trigger_detach_poll_func(indio_dev->trig,
581 indio_dev->pollfunc);
583 EXPORT_SYMBOL(iio_triggered_buffer_predisable);