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 static struct iio_trigger
*__iio_trigger_find_by_name(const char *name
);
69 int __iio_trigger_register(struct iio_trigger
*trig_info
,
70 struct module
*this_mod
)
74 trig_info
->owner
= this_mod
;
76 trig_info
->id
= ida_simple_get(&iio_trigger_ida
, 0, 0, GFP_KERNEL
);
77 if (trig_info
->id
< 0)
80 /* Set the name used for the sysfs directory etc */
81 dev_set_name(&trig_info
->dev
, "trigger%ld",
82 (unsigned long) trig_info
->id
);
84 ret
= device_add(&trig_info
->dev
);
86 goto error_unregister_id
;
88 /* Add to list of available triggers held by the IIO core */
89 mutex_lock(&iio_trigger_list_lock
);
90 if (__iio_trigger_find_by_name(trig_info
->name
)) {
91 pr_err("Duplicate trigger name '%s'\n", trig_info
->name
);
93 goto error_device_del
;
95 list_add_tail(&trig_info
->list
, &iio_trigger_list
);
96 mutex_unlock(&iio_trigger_list_lock
);
101 mutex_unlock(&iio_trigger_list_lock
);
102 device_del(&trig_info
->dev
);
104 ida_simple_remove(&iio_trigger_ida
, trig_info
->id
);
107 EXPORT_SYMBOL(__iio_trigger_register
);
109 void iio_trigger_unregister(struct iio_trigger
*trig_info
)
111 mutex_lock(&iio_trigger_list_lock
);
112 list_del(&trig_info
->list
);
113 mutex_unlock(&iio_trigger_list_lock
);
115 ida_simple_remove(&iio_trigger_ida
, trig_info
->id
);
116 /* Possible issue in here */
117 device_del(&trig_info
->dev
);
119 EXPORT_SYMBOL(iio_trigger_unregister
);
121 int iio_trigger_set_immutable(struct iio_dev
*indio_dev
, struct iio_trigger
*trig
)
123 if (!indio_dev
|| !trig
)
126 mutex_lock(&indio_dev
->mlock
);
127 WARN_ON(indio_dev
->trig_readonly
);
129 indio_dev
->trig
= iio_trigger_get(trig
);
130 indio_dev
->trig_readonly
= true;
131 mutex_unlock(&indio_dev
->mlock
);
135 EXPORT_SYMBOL(iio_trigger_set_immutable
);
137 /* Search for trigger by name, assuming iio_trigger_list_lock held */
138 static struct iio_trigger
*__iio_trigger_find_by_name(const char *name
)
140 struct iio_trigger
*iter
;
142 list_for_each_entry(iter
, &iio_trigger_list
, list
)
143 if (!strcmp(iter
->name
, name
))
149 static struct iio_trigger
*iio_trigger_acquire_by_name(const char *name
)
151 struct iio_trigger
*trig
= NULL
, *iter
;
153 mutex_lock(&iio_trigger_list_lock
);
154 list_for_each_entry(iter
, &iio_trigger_list
, list
)
155 if (sysfs_streq(iter
->name
, name
)) {
157 iio_trigger_get(trig
);
160 mutex_unlock(&iio_trigger_list_lock
);
165 void iio_trigger_poll(struct iio_trigger
*trig
)
169 if (!atomic_read(&trig
->use_count
)) {
170 atomic_set(&trig
->use_count
, CONFIG_IIO_CONSUMERS_PER_TRIGGER
);
172 for (i
= 0; i
< CONFIG_IIO_CONSUMERS_PER_TRIGGER
; i
++) {
173 if (trig
->subirqs
[i
].enabled
)
174 generic_handle_irq(trig
->subirq_base
+ i
);
176 iio_trigger_notify_done(trig
);
180 EXPORT_SYMBOL(iio_trigger_poll
);
182 irqreturn_t
iio_trigger_generic_data_rdy_poll(int irq
, void *private)
184 iio_trigger_poll(private);
187 EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll
);
189 void iio_trigger_poll_chained(struct iio_trigger
*trig
)
193 if (!atomic_read(&trig
->use_count
)) {
194 atomic_set(&trig
->use_count
, CONFIG_IIO_CONSUMERS_PER_TRIGGER
);
196 for (i
= 0; i
< CONFIG_IIO_CONSUMERS_PER_TRIGGER
; i
++) {
197 if (trig
->subirqs
[i
].enabled
)
198 handle_nested_irq(trig
->subirq_base
+ i
);
200 iio_trigger_notify_done(trig
);
204 EXPORT_SYMBOL(iio_trigger_poll_chained
);
206 void iio_trigger_notify_done(struct iio_trigger
*trig
)
208 if (atomic_dec_and_test(&trig
->use_count
) && trig
->ops
&&
209 trig
->ops
->try_reenable
)
210 if (trig
->ops
->try_reenable(trig
))
211 /* Missed an interrupt so launch new poll now */
212 iio_trigger_poll(trig
);
214 EXPORT_SYMBOL(iio_trigger_notify_done
);
216 /* Trigger Consumer related functions */
217 static int iio_trigger_get_irq(struct iio_trigger
*trig
)
220 mutex_lock(&trig
->pool_lock
);
221 ret
= bitmap_find_free_region(trig
->pool
,
222 CONFIG_IIO_CONSUMERS_PER_TRIGGER
,
224 mutex_unlock(&trig
->pool_lock
);
226 ret
+= trig
->subirq_base
;
231 static void iio_trigger_put_irq(struct iio_trigger
*trig
, int irq
)
233 mutex_lock(&trig
->pool_lock
);
234 clear_bit(irq
- trig
->subirq_base
, trig
->pool
);
235 mutex_unlock(&trig
->pool_lock
);
238 /* Complexity in here. With certain triggers (datardy) an acknowledgement
239 * may be needed if the pollfuncs do not include the data read for the
241 * This is not currently handled. Alternative of not enabling trigger unless
242 * the relevant function is in there may be the best option.
244 /* Worth protecting against double additions? */
245 static int iio_trigger_attach_poll_func(struct iio_trigger
*trig
,
246 struct iio_poll_func
*pf
)
250 = bitmap_empty(trig
->pool
, CONFIG_IIO_CONSUMERS_PER_TRIGGER
);
252 /* Prevent the module from being removed whilst attached to a trigger */
253 __module_get(pf
->indio_dev
->driver_module
);
256 pf
->irq
= iio_trigger_get_irq(trig
);
258 pr_err("Could not find an available irq for trigger %s, CONFIG_IIO_CONSUMERS_PER_TRIGGER=%d limit might be exceeded\n",
259 trig
->name
, CONFIG_IIO_CONSUMERS_PER_TRIGGER
);
264 ret
= request_threaded_irq(pf
->irq
, pf
->h
, pf
->thread
,
270 /* Enable trigger in driver */
271 if (trig
->ops
&& trig
->ops
->set_trigger_state
&& notinuse
) {
272 ret
= trig
->ops
->set_trigger_state(trig
, true);
278 * Check if we just registered to our own trigger: we determine that
279 * this is the case if the IIO device and the trigger device share the
280 * same parent device.
282 if (pf
->indio_dev
->dev
.parent
== trig
->dev
.parent
)
283 trig
->attached_own_device
= true;
288 free_irq(pf
->irq
, pf
);
290 iio_trigger_put_irq(trig
, pf
->irq
);
292 module_put(pf
->indio_dev
->driver_module
);
296 static int iio_trigger_detach_poll_func(struct iio_trigger
*trig
,
297 struct iio_poll_func
*pf
)
301 = (bitmap_weight(trig
->pool
,
302 CONFIG_IIO_CONSUMERS_PER_TRIGGER
)
304 if (trig
->ops
&& trig
->ops
->set_trigger_state
&& no_other_users
) {
305 ret
= trig
->ops
->set_trigger_state(trig
, false);
309 if (pf
->indio_dev
->dev
.parent
== trig
->dev
.parent
)
310 trig
->attached_own_device
= false;
311 iio_trigger_put_irq(trig
, pf
->irq
);
312 free_irq(pf
->irq
, pf
);
313 module_put(pf
->indio_dev
->driver_module
);
318 irqreturn_t
iio_pollfunc_store_time(int irq
, void *p
)
320 struct iio_poll_func
*pf
= p
;
321 pf
->timestamp
= iio_get_time_ns(pf
->indio_dev
);
322 return IRQ_WAKE_THREAD
;
324 EXPORT_SYMBOL(iio_pollfunc_store_time
);
327 *iio_alloc_pollfunc(irqreturn_t (*h
)(int irq
, void *p
),
328 irqreturn_t (*thread
)(int irq
, void *p
),
330 struct iio_dev
*indio_dev
,
335 struct iio_poll_func
*pf
;
337 pf
= kmalloc(sizeof *pf
, GFP_KERNEL
);
340 va_start(vargs
, fmt
);
341 pf
->name
= kvasprintf(GFP_KERNEL
, fmt
, vargs
);
343 if (pf
->name
== NULL
) {
350 pf
->indio_dev
= indio_dev
;
354 EXPORT_SYMBOL_GPL(iio_alloc_pollfunc
);
356 void iio_dealloc_pollfunc(struct iio_poll_func
*pf
)
361 EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc
);
364 * iio_trigger_read_current() - trigger consumer sysfs query current trigger
365 * @dev: device associated with an industrial I/O device
366 * @attr: pointer to the device_attribute structure that
368 * @buf: buffer where the current trigger name will be printed into
370 * For trigger consumers the current_trigger interface allows the trigger
371 * used by the device to be queried.
373 * Return: a negative number on failure, the number of characters written
374 * on success or 0 if no trigger is available
376 static ssize_t
iio_trigger_read_current(struct device
*dev
,
377 struct device_attribute
*attr
,
380 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
383 return sprintf(buf
, "%s\n", indio_dev
->trig
->name
);
388 * iio_trigger_write_current() - trigger consumer sysfs set current trigger
389 * @dev: device associated with an industrial I/O device
390 * @attr: device attribute that is being processed
391 * @buf: string buffer that holds the name of the trigger
392 * @len: length of the trigger name held by buf
394 * For trigger consumers the current_trigger interface allows the trigger
395 * used for this device to be specified at run time based on the trigger's
398 * Return: negative error code on failure or length of the buffer
401 static ssize_t
iio_trigger_write_current(struct device
*dev
,
402 struct device_attribute
*attr
,
406 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
407 struct iio_trigger
*oldtrig
= indio_dev
->trig
;
408 struct iio_trigger
*trig
;
411 mutex_lock(&indio_dev
->mlock
);
412 if (indio_dev
->currentmode
== INDIO_BUFFER_TRIGGERED
) {
413 mutex_unlock(&indio_dev
->mlock
);
416 if (indio_dev
->trig_readonly
) {
417 mutex_unlock(&indio_dev
->mlock
);
420 mutex_unlock(&indio_dev
->mlock
);
422 trig
= iio_trigger_acquire_by_name(buf
);
423 if (oldtrig
== trig
) {
425 goto out_trigger_put
;
428 if (trig
&& indio_dev
->info
->validate_trigger
) {
429 ret
= indio_dev
->info
->validate_trigger(indio_dev
, trig
);
431 goto out_trigger_put
;
434 if (trig
&& trig
->ops
&& trig
->ops
->validate_device
) {
435 ret
= trig
->ops
->validate_device(trig
, indio_dev
);
437 goto out_trigger_put
;
440 indio_dev
->trig
= trig
;
443 if (indio_dev
->modes
& INDIO_EVENT_TRIGGERED
)
444 iio_trigger_detach_poll_func(oldtrig
,
445 indio_dev
->pollfunc_event
);
446 iio_trigger_put(oldtrig
);
448 if (indio_dev
->trig
) {
449 if (indio_dev
->modes
& INDIO_EVENT_TRIGGERED
)
450 iio_trigger_attach_poll_func(indio_dev
->trig
,
451 indio_dev
->pollfunc_event
);
458 iio_trigger_put(trig
);
462 static DEVICE_ATTR(current_trigger
, S_IRUGO
| S_IWUSR
,
463 iio_trigger_read_current
,
464 iio_trigger_write_current
);
466 static struct attribute
*iio_trigger_consumer_attrs
[] = {
467 &dev_attr_current_trigger
.attr
,
471 static const struct attribute_group iio_trigger_consumer_attr_group
= {
473 .attrs
= iio_trigger_consumer_attrs
,
476 static void iio_trig_release(struct device
*device
)
478 struct iio_trigger
*trig
= to_iio_trigger(device
);
481 if (trig
->subirq_base
) {
482 for (i
= 0; i
< CONFIG_IIO_CONSUMERS_PER_TRIGGER
; i
++) {
483 irq_modify_status(trig
->subirq_base
+ i
,
485 IRQ_NOREQUEST
| IRQ_NOPROBE
);
486 irq_set_chip(trig
->subirq_base
+ i
,
488 irq_set_handler(trig
->subirq_base
+ i
,
492 irq_free_descs(trig
->subirq_base
,
493 CONFIG_IIO_CONSUMERS_PER_TRIGGER
);
499 static const struct device_type iio_trig_type
= {
500 .release
= iio_trig_release
,
501 .groups
= iio_trig_dev_groups
,
504 static void iio_trig_subirqmask(struct irq_data
*d
)
506 struct irq_chip
*chip
= irq_data_get_irq_chip(d
);
507 struct iio_trigger
*trig
509 struct iio_trigger
, subirq_chip
);
510 trig
->subirqs
[d
->irq
- trig
->subirq_base
].enabled
= false;
513 static void iio_trig_subirqunmask(struct irq_data
*d
)
515 struct irq_chip
*chip
= irq_data_get_irq_chip(d
);
516 struct iio_trigger
*trig
518 struct iio_trigger
, subirq_chip
);
519 trig
->subirqs
[d
->irq
- trig
->subirq_base
].enabled
= true;
522 static struct iio_trigger
*viio_trigger_alloc(const char *fmt
, va_list vargs
)
524 struct iio_trigger
*trig
;
527 trig
= kzalloc(sizeof *trig
, GFP_KERNEL
);
531 trig
->dev
.type
= &iio_trig_type
;
532 trig
->dev
.bus
= &iio_bus_type
;
533 device_initialize(&trig
->dev
);
535 mutex_init(&trig
->pool_lock
);
536 trig
->subirq_base
= irq_alloc_descs(-1, 0,
537 CONFIG_IIO_CONSUMERS_PER_TRIGGER
,
539 if (trig
->subirq_base
< 0)
542 trig
->name
= kvasprintf(GFP_KERNEL
, fmt
, vargs
);
543 if (trig
->name
== NULL
)
546 trig
->subirq_chip
.name
= trig
->name
;
547 trig
->subirq_chip
.irq_mask
= &iio_trig_subirqmask
;
548 trig
->subirq_chip
.irq_unmask
= &iio_trig_subirqunmask
;
549 for (i
= 0; i
< CONFIG_IIO_CONSUMERS_PER_TRIGGER
; i
++) {
550 irq_set_chip(trig
->subirq_base
+ i
, &trig
->subirq_chip
);
551 irq_set_handler(trig
->subirq_base
+ i
, &handle_simple_irq
);
552 irq_modify_status(trig
->subirq_base
+ i
,
553 IRQ_NOREQUEST
| IRQ_NOAUTOEN
, IRQ_NOPROBE
);
555 get_device(&trig
->dev
);
560 irq_free_descs(trig
->subirq_base
, CONFIG_IIO_CONSUMERS_PER_TRIGGER
);
566 struct iio_trigger
*iio_trigger_alloc(const char *fmt
, ...)
568 struct iio_trigger
*trig
;
571 va_start(vargs
, fmt
);
572 trig
= viio_trigger_alloc(fmt
, vargs
);
577 EXPORT_SYMBOL(iio_trigger_alloc
);
579 void iio_trigger_free(struct iio_trigger
*trig
)
582 put_device(&trig
->dev
);
584 EXPORT_SYMBOL(iio_trigger_free
);
586 static void devm_iio_trigger_release(struct device
*dev
, void *res
)
588 iio_trigger_free(*(struct iio_trigger
**)res
);
591 static int devm_iio_trigger_match(struct device
*dev
, void *res
, void *data
)
593 struct iio_trigger
**r
= res
;
604 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
605 * @dev: Device to allocate iio_trigger for
606 * @fmt: trigger name format. If it includes format
607 * specifiers, the additional arguments following
608 * format are formatted and inserted in the resulting
609 * string replacing their respective specifiers.
611 * Managed iio_trigger_alloc. iio_trigger allocated with this function is
612 * automatically freed on driver detach.
614 * If an iio_trigger allocated with this function needs to be freed separately,
615 * devm_iio_trigger_free() must be used.
618 * Pointer to allocated iio_trigger on success, NULL on failure.
620 struct iio_trigger
*devm_iio_trigger_alloc(struct device
*dev
,
621 const char *fmt
, ...)
623 struct iio_trigger
**ptr
, *trig
;
626 ptr
= devres_alloc(devm_iio_trigger_release
, sizeof(*ptr
),
631 /* use raw alloc_dr for kmalloc caller tracing */
632 va_start(vargs
, fmt
);
633 trig
= viio_trigger_alloc(fmt
, vargs
);
637 devres_add(dev
, ptr
);
644 EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc
);
647 * devm_iio_trigger_free - Resource-managed iio_trigger_free()
648 * @dev: Device this iio_dev belongs to
649 * @iio_trig: the iio_trigger associated with the device
651 * Free iio_trigger allocated with devm_iio_trigger_alloc().
653 void devm_iio_trigger_free(struct device
*dev
, struct iio_trigger
*iio_trig
)
657 rc
= devres_release(dev
, devm_iio_trigger_release
,
658 devm_iio_trigger_match
, iio_trig
);
661 EXPORT_SYMBOL_GPL(devm_iio_trigger_free
);
663 static void devm_iio_trigger_unreg(struct device
*dev
, void *res
)
665 iio_trigger_unregister(*(struct iio_trigger
**)res
);
669 * __devm_iio_trigger_register - Resource-managed iio_trigger_register()
670 * @dev: device this trigger was allocated for
671 * @trig_info: trigger to register
672 * @this_mod: module registering the trigger
674 * Managed iio_trigger_register(). The IIO trigger registered with this
675 * function is automatically unregistered on driver detach. This function
676 * calls iio_trigger_register() internally. Refer to that function for more
679 * If an iio_trigger registered with this function needs to be unregistered
680 * separately, devm_iio_trigger_unregister() must be used.
683 * 0 on success, negative error number on failure.
685 int __devm_iio_trigger_register(struct device
*dev
,
686 struct iio_trigger
*trig_info
,
687 struct module
*this_mod
)
689 struct iio_trigger
**ptr
;
692 ptr
= devres_alloc(devm_iio_trigger_unreg
, sizeof(*ptr
), GFP_KERNEL
);
697 ret
= __iio_trigger_register(trig_info
, this_mod
);
699 devres_add(dev
, ptr
);
705 EXPORT_SYMBOL_GPL(__devm_iio_trigger_register
);
708 * devm_iio_trigger_unregister - Resource-managed iio_trigger_unregister()
709 * @dev: device this iio_trigger belongs to
710 * @trig_info: the trigger associated with the device
712 * Unregister trigger registered with devm_iio_trigger_register().
714 void devm_iio_trigger_unregister(struct device
*dev
,
715 struct iio_trigger
*trig_info
)
719 rc
= devres_release(dev
, devm_iio_trigger_unreg
, devm_iio_trigger_match
,
723 EXPORT_SYMBOL_GPL(devm_iio_trigger_unregister
);
725 bool iio_trigger_using_own(struct iio_dev
*indio_dev
)
727 return indio_dev
->trig
->attached_own_device
;
729 EXPORT_SYMBOL(iio_trigger_using_own
);
732 * iio_trigger_validate_own_device - Check if a trigger and IIO device belong to
734 * @trig: The IIO trigger to check
735 * @indio_dev: the IIO device to check
737 * This function can be used as the validate_device callback for triggers that
738 * can only be attached to their own device.
740 * Return: 0 if both the trigger and the IIO device belong to the same
741 * device, -EINVAL otherwise.
743 int iio_trigger_validate_own_device(struct iio_trigger
*trig
,
744 struct iio_dev
*indio_dev
)
746 if (indio_dev
->dev
.parent
!= trig
->dev
.parent
)
750 EXPORT_SYMBOL(iio_trigger_validate_own_device
);
752 void iio_device_register_trigger_consumer(struct iio_dev
*indio_dev
)
754 indio_dev
->groups
[indio_dev
->groupcounter
++] =
755 &iio_trigger_consumer_attr_group
;
758 void iio_device_unregister_trigger_consumer(struct iio_dev
*indio_dev
)
760 /* Clean up an associated but not attached trigger reference */
762 iio_trigger_put(indio_dev
->trig
);
765 int iio_triggered_buffer_postenable(struct iio_dev
*indio_dev
)
767 return iio_trigger_attach_poll_func(indio_dev
->trig
,
768 indio_dev
->pollfunc
);
770 EXPORT_SYMBOL(iio_triggered_buffer_postenable
);
772 int iio_triggered_buffer_predisable(struct iio_dev
*indio_dev
)
774 return iio_trigger_detach_poll_func(indio_dev
->trig
,
775 indio_dev
->pollfunc
);
777 EXPORT_SYMBOL(iio_triggered_buffer_predisable
);