1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Industrial I/O event handling
3 *
4 * Copyright (c) 2008 Jonathan Cameron
5 *
6 * Based on elements of hwmon and input subsystems.
7 */
8
9 #include <linux/anon_inodes.h>
10 #include <linux/device.h>
11 #include <linux/fs.h>
12 #include <linux/kernel.h>
13 #include <linux/kfifo.h>
14 #include <linux/module.h>
15 #include <linux/poll.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/uaccess.h>
19 #include <linux/wait.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/iio-opaque.h>
22 #include "iio_core.h"
23 #include <linux/iio/sysfs.h>
24 #include <linux/iio/events.h>
25
26 /**
27 * struct iio_event_interface - chrdev interface for an event line
28 * @wait: wait queue to allow blocking reads of events
29 * @det_events: list of detected events
30 * @dev_attr_list: list of event interface sysfs attribute
31 * @flags: file operations related flags including busy flag.
32 * @group: event interface sysfs attribute group
33 * @read_lock: lock to protect kfifo read operations
34 * @ioctl_handler: handler for event ioctl() calls
35 */
36 struct iio_event_interface {
37 wait_queue_head_t wait;
38 DECLARE_KFIFO(det_events, struct iio_event_data, 16);
39
40 struct list_head dev_attr_list;
41 unsigned long flags;
42 struct attribute_group group;
43 struct mutex read_lock;
44 struct iio_ioctl_handler ioctl_handler;
45 };
46
iio_event_enabled(const struct iio_event_interface * ev_int)47 bool iio_event_enabled(const struct iio_event_interface *ev_int)
48 {
49 return !!test_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
50 }
51
52 /**
53 * iio_push_event() - try to add event to the list for userspace reading
54 * @indio_dev: IIO device structure
55 * @ev_code: What event
56 * @timestamp: When the event occurred
57 *
58 * Note: The caller must make sure that this function is not running
59 * concurrently for the same indio_dev more than once.
60 *
61 * This function may be safely used as soon as a valid reference to iio_dev has
62 * been obtained via iio_device_alloc(), but any events that are submitted
63 * before iio_device_register() has successfully completed will be silently
64 * discarded.
65 **/
iio_push_event(struct iio_dev * indio_dev,u64 ev_code,s64 timestamp)66 int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
67 {
68 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
69 struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
70 struct iio_event_data ev;
71 int copied;
72
73 if (!ev_int)
74 return 0;
75
76 /* Does anyone care? */
77 if (iio_event_enabled(ev_int)) {
78
79 ev.id = ev_code;
80 ev.timestamp = timestamp;
81
82 copied = kfifo_put(&ev_int->det_events, ev);
83 if (copied != 0)
84 wake_up_poll(&ev_int->wait, EPOLLIN);
85 }
86
87 return 0;
88 }
89 EXPORT_SYMBOL(iio_push_event);
90
91 /**
92 * iio_event_poll() - poll the event queue to find out if it has data
93 * @filep: File structure pointer to identify the device
94 * @wait: Poll table pointer to add the wait queue on
95 *
96 * Return: (EPOLLIN | EPOLLRDNORM) if data is available for reading
97 * or a negative error code on failure
98 */
iio_event_poll(struct file * filep,struct poll_table_struct * wait)99 static __poll_t iio_event_poll(struct file *filep,
100 struct poll_table_struct *wait)
101 {
102 struct iio_dev *indio_dev = filep->private_data;
103 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
104 struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
105 __poll_t events = 0;
106
107 if (!indio_dev->info)
108 return events;
109
110 poll_wait(filep, &ev_int->wait, wait);
111
112 if (!kfifo_is_empty(&ev_int->det_events))
113 events = EPOLLIN | EPOLLRDNORM;
114
115 return events;
116 }
117
iio_event_chrdev_read(struct file * filep,char __user * buf,size_t count,loff_t * f_ps)118 static ssize_t iio_event_chrdev_read(struct file *filep,
119 char __user *buf,
120 size_t count,
121 loff_t *f_ps)
122 {
123 struct iio_dev *indio_dev = filep->private_data;
124 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
125 struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
126 unsigned int copied;
127 int ret;
128
129 if (!indio_dev->info)
130 return -ENODEV;
131
132 if (count < sizeof(struct iio_event_data))
133 return -EINVAL;
134
135 do {
136 if (kfifo_is_empty(&ev_int->det_events)) {
137 if (filep->f_flags & O_NONBLOCK)
138 return -EAGAIN;
139
140 ret = wait_event_interruptible(ev_int->wait,
141 !kfifo_is_empty(&ev_int->det_events) ||
142 indio_dev->info == NULL);
143 if (ret)
144 return ret;
145 if (indio_dev->info == NULL)
146 return -ENODEV;
147 }
148
149 if (mutex_lock_interruptible(&ev_int->read_lock))
150 return -ERESTARTSYS;
151 ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
152 mutex_unlock(&ev_int->read_lock);
153
154 if (ret)
155 return ret;
156
157 /*
158 * If we couldn't read anything from the fifo (a different
159 * thread might have been faster) we either return -EAGAIN if
160 * the file descriptor is non-blocking, otherwise we go back to
161 * sleep and wait for more data to arrive.
162 */
163 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
164 return -EAGAIN;
165
166 } while (copied == 0);
167
168 return copied;
169 }
170
iio_event_chrdev_release(struct inode * inode,struct file * filep)171 static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
172 {
173 struct iio_dev *indio_dev = filep->private_data;
174 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
175 struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
176
177 clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
178
179 iio_device_put(indio_dev);
180
181 return 0;
182 }
183
184 static const struct file_operations iio_event_chrdev_fileops = {
185 .read = iio_event_chrdev_read,
186 .poll = iio_event_poll,
187 .release = iio_event_chrdev_release,
188 .owner = THIS_MODULE,
189 .llseek = noop_llseek,
190 };
191
iio_event_getfd(struct iio_dev * indio_dev)192 static int iio_event_getfd(struct iio_dev *indio_dev)
193 {
194 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
195 struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
196 int fd;
197
198 if (ev_int == NULL)
199 return -ENODEV;
200
201 fd = mutex_lock_interruptible(&iio_dev_opaque->mlock);
202 if (fd)
203 return fd;
204
205 if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
206 fd = -EBUSY;
207 goto unlock;
208 }
209
210 iio_device_get(indio_dev);
211
212 fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
213 indio_dev, O_RDONLY | O_CLOEXEC);
214 if (fd < 0) {
215 clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
216 iio_device_put(indio_dev);
217 } else {
218 kfifo_reset_out(&ev_int->det_events);
219 }
220
221 unlock:
222 mutex_unlock(&iio_dev_opaque->mlock);
223 return fd;
224 }
225
226 static const char * const iio_ev_type_text[] = {
227 [IIO_EV_TYPE_THRESH] = "thresh",
228 [IIO_EV_TYPE_MAG] = "mag",
229 [IIO_EV_TYPE_ROC] = "roc",
230 [IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
231 [IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
232 [IIO_EV_TYPE_CHANGE] = "change",
233 [IIO_EV_TYPE_MAG_REFERENCED] = "mag_referenced",
234 [IIO_EV_TYPE_GESTURE] = "gesture",
235 };
236
237 static const char * const iio_ev_dir_text[] = {
238 [IIO_EV_DIR_EITHER] = "either",
239 [IIO_EV_DIR_RISING] = "rising",
240 [IIO_EV_DIR_FALLING] = "falling",
241 [IIO_EV_DIR_SINGLETAP] = "singletap",
242 [IIO_EV_DIR_DOUBLETAP] = "doubletap",
243 };
244
245 static const char * const iio_ev_info_text[] = {
246 [IIO_EV_INFO_ENABLE] = "en",
247 [IIO_EV_INFO_VALUE] = "value",
248 [IIO_EV_INFO_HYSTERESIS] = "hysteresis",
249 [IIO_EV_INFO_PERIOD] = "period",
250 [IIO_EV_INFO_HIGH_PASS_FILTER_3DB] = "high_pass_filter_3db",
251 [IIO_EV_INFO_LOW_PASS_FILTER_3DB] = "low_pass_filter_3db",
252 [IIO_EV_INFO_TIMEOUT] = "timeout",
253 [IIO_EV_INFO_RESET_TIMEOUT] = "reset_timeout",
254 [IIO_EV_INFO_TAP2_MIN_DELAY] = "tap2_min_delay",
255 [IIO_EV_INFO_RUNNING_PERIOD] = "runningperiod",
256 [IIO_EV_INFO_RUNNING_COUNT] = "runningcount",
257 };
258
iio_ev_attr_dir(struct iio_dev_attr * attr)259 static enum iio_event_direction iio_ev_attr_dir(struct iio_dev_attr *attr)
260 {
261 return attr->c->event_spec[attr->address & 0xffff].dir;
262 }
263
iio_ev_attr_type(struct iio_dev_attr * attr)264 static enum iio_event_type iio_ev_attr_type(struct iio_dev_attr *attr)
265 {
266 return attr->c->event_spec[attr->address & 0xffff].type;
267 }
268
iio_ev_attr_info(struct iio_dev_attr * attr)269 static enum iio_event_info iio_ev_attr_info(struct iio_dev_attr *attr)
270 {
271 return (attr->address >> 16) & 0xffff;
272 }
273
iio_ev_state_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)274 static ssize_t iio_ev_state_store(struct device *dev,
275 struct device_attribute *attr,
276 const char *buf,
277 size_t len)
278 {
279 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
280 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
281 int ret;
282 bool val;
283
284 ret = kstrtobool(buf, &val);
285 if (ret < 0)
286 return ret;
287
288 if (!indio_dev->info->write_event_config)
289 return -EINVAL;
290
291 ret = indio_dev->info->write_event_config(indio_dev,
292 this_attr->c, iio_ev_attr_type(this_attr),
293 iio_ev_attr_dir(this_attr), val);
294
295 return (ret < 0) ? ret : len;
296 }
297
iio_ev_state_show(struct device * dev,struct device_attribute * attr,char * buf)298 static ssize_t iio_ev_state_show(struct device *dev,
299 struct device_attribute *attr,
300 char *buf)
301 {
302 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
303 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
304 int val;
305
306 if (!indio_dev->info->read_event_config)
307 return -EINVAL;
308
309 val = indio_dev->info->read_event_config(indio_dev,
310 this_attr->c, iio_ev_attr_type(this_attr),
311 iio_ev_attr_dir(this_attr));
312 if (val < 0)
313 return val;
314 else
315 return sysfs_emit(buf, "%d\n", val);
316 }
317
iio_ev_value_show(struct device * dev,struct device_attribute * attr,char * buf)318 static ssize_t iio_ev_value_show(struct device *dev,
319 struct device_attribute *attr,
320 char *buf)
321 {
322 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
323 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
324 int val, val2, val_arr[2];
325 int ret;
326
327 if (!indio_dev->info->read_event_value)
328 return -EINVAL;
329
330 ret = indio_dev->info->read_event_value(indio_dev,
331 this_attr->c, iio_ev_attr_type(this_attr),
332 iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
333 &val, &val2);
334 if (ret < 0)
335 return ret;
336 val_arr[0] = val;
337 val_arr[1] = val2;
338 return iio_format_value(buf, ret, 2, val_arr);
339 }
340
iio_ev_value_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)341 static ssize_t iio_ev_value_store(struct device *dev,
342 struct device_attribute *attr,
343 const char *buf,
344 size_t len)
345 {
346 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
347 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
348 int val, val2;
349 int ret;
350
351 if (!indio_dev->info->write_event_value)
352 return -EINVAL;
353
354 ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
355 if (ret)
356 return ret;
357 ret = indio_dev->info->write_event_value(indio_dev,
358 this_attr->c, iio_ev_attr_type(this_attr),
359 iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
360 val, val2);
361 if (ret < 0)
362 return ret;
363
364 return len;
365 }
366
iio_ev_label_show(struct device * dev,struct device_attribute * attr,char * buf)367 static ssize_t iio_ev_label_show(struct device *dev,
368 struct device_attribute *attr,
369 char *buf)
370 {
371 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
372 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
373
374 if (indio_dev->info->read_event_label)
375 return indio_dev->info->read_event_label(indio_dev,
376 this_attr->c, iio_ev_attr_type(this_attr),
377 iio_ev_attr_dir(this_attr), buf);
378
379 return -EINVAL;
380 }
381
iio_device_add_event(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int spec_index,enum iio_event_type type,enum iio_event_direction dir,enum iio_shared_by shared_by,const unsigned long * mask)382 static int iio_device_add_event(struct iio_dev *indio_dev,
383 const struct iio_chan_spec *chan, unsigned int spec_index,
384 enum iio_event_type type, enum iio_event_direction dir,
385 enum iio_shared_by shared_by, const unsigned long *mask)
386 {
387 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
388 ssize_t (*show)(struct device *dev, struct device_attribute *attr,
389 char *buf);
390 ssize_t (*store)(struct device *dev, struct device_attribute *attr,
391 const char *buf, size_t len);
392 unsigned int attrcount = 0;
393 unsigned int i;
394 char *postfix;
395 int ret;
396
397 for_each_set_bit(i, mask, sizeof(*mask)*8) {
398 if (i >= ARRAY_SIZE(iio_ev_info_text))
399 return -EINVAL;
400 if (dir != IIO_EV_DIR_NONE)
401 postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
402 iio_ev_type_text[type],
403 iio_ev_dir_text[dir],
404 iio_ev_info_text[i]);
405 else
406 postfix = kasprintf(GFP_KERNEL, "%s_%s",
407 iio_ev_type_text[type],
408 iio_ev_info_text[i]);
409 if (postfix == NULL)
410 return -ENOMEM;
411
412 if (i == IIO_EV_INFO_ENABLE) {
413 show = iio_ev_state_show;
414 store = iio_ev_state_store;
415 } else {
416 show = iio_ev_value_show;
417 store = iio_ev_value_store;
418 }
419
420 ret = __iio_add_chan_devattr(postfix, chan, show, store,
421 (i << 16) | spec_index, shared_by, &indio_dev->dev,
422 NULL,
423 &iio_dev_opaque->event_interface->dev_attr_list);
424 kfree(postfix);
425
426 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
427 continue;
428
429 if (ret)
430 return ret;
431
432 attrcount++;
433 }
434
435 return attrcount;
436 }
437
iio_device_add_event_label(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int spec_index,enum iio_event_type type,enum iio_event_direction dir)438 static int iio_device_add_event_label(struct iio_dev *indio_dev,
439 const struct iio_chan_spec *chan,
440 unsigned int spec_index,
441 enum iio_event_type type,
442 enum iio_event_direction dir)
443 {
444 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
445 char *postfix;
446 int ret;
447
448 if (!indio_dev->info->read_event_label)
449 return 0;
450
451 if (dir != IIO_EV_DIR_NONE)
452 postfix = kasprintf(GFP_KERNEL, "%s_%s_label",
453 iio_ev_type_text[type],
454 iio_ev_dir_text[dir]);
455 else
456 postfix = kasprintf(GFP_KERNEL, "%s_label",
457 iio_ev_type_text[type]);
458 if (postfix == NULL)
459 return -ENOMEM;
460
461 ret = __iio_add_chan_devattr(postfix, chan, &iio_ev_label_show, NULL,
462 spec_index, IIO_SEPARATE, &indio_dev->dev, NULL,
463 &iio_dev_opaque->event_interface->dev_attr_list);
464
465 kfree(postfix);
466
467 if (ret < 0)
468 return ret;
469
470 return 1;
471 }
472
iio_device_add_event_sysfs(struct iio_dev * indio_dev,struct iio_chan_spec const * chan)473 static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
474 struct iio_chan_spec const *chan)
475 {
476 int ret = 0, i, attrcount = 0;
477 enum iio_event_direction dir;
478 enum iio_event_type type;
479
480 for (i = 0; i < chan->num_event_specs; i++) {
481 type = chan->event_spec[i].type;
482 dir = chan->event_spec[i].dir;
483
484 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
485 IIO_SEPARATE, &chan->event_spec[i].mask_separate);
486 if (ret < 0)
487 return ret;
488 attrcount += ret;
489
490 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
491 IIO_SHARED_BY_TYPE,
492 &chan->event_spec[i].mask_shared_by_type);
493 if (ret < 0)
494 return ret;
495 attrcount += ret;
496
497 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
498 IIO_SHARED_BY_DIR,
499 &chan->event_spec[i].mask_shared_by_dir);
500 if (ret < 0)
501 return ret;
502 attrcount += ret;
503
504 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
505 IIO_SHARED_BY_ALL,
506 &chan->event_spec[i].mask_shared_by_all);
507 if (ret < 0)
508 return ret;
509 attrcount += ret;
510
511 ret = iio_device_add_event_label(indio_dev, chan, i, type, dir);
512 if (ret < 0)
513 return ret;
514 attrcount += ret;
515 }
516 ret = attrcount;
517 return ret;
518 }
519
__iio_add_event_config_attrs(struct iio_dev * indio_dev)520 static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
521 {
522 int j, ret, attrcount = 0;
523
524 /* Dynamically created from the channels array */
525 for (j = 0; j < indio_dev->num_channels; j++) {
526 ret = iio_device_add_event_sysfs(indio_dev,
527 &indio_dev->channels[j]);
528 if (ret < 0)
529 return ret;
530 attrcount += ret;
531 }
532 return attrcount;
533 }
534
iio_check_for_dynamic_events(struct iio_dev * indio_dev)535 static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
536 {
537 int j;
538
539 for (j = 0; j < indio_dev->num_channels; j++) {
540 if (indio_dev->channels[j].num_event_specs != 0)
541 return true;
542 }
543 return false;
544 }
545
iio_setup_ev_int(struct iio_event_interface * ev_int)546 static void iio_setup_ev_int(struct iio_event_interface *ev_int)
547 {
548 INIT_KFIFO(ev_int->det_events);
549 init_waitqueue_head(&ev_int->wait);
550 mutex_init(&ev_int->read_lock);
551 }
552
iio_event_ioctl(struct iio_dev * indio_dev,struct file * filp,unsigned int cmd,unsigned long arg)553 static long iio_event_ioctl(struct iio_dev *indio_dev, struct file *filp,
554 unsigned int cmd, unsigned long arg)
555 {
556 int __user *ip = (int __user *)arg;
557 int fd;
558
559 if (cmd == IIO_GET_EVENT_FD_IOCTL) {
560 fd = iio_event_getfd(indio_dev);
561 if (fd < 0)
562 return fd;
563 if (copy_to_user(ip, &fd, sizeof(fd)))
564 return -EFAULT;
565 return 0;
566 }
567
568 return IIO_IOCTL_UNHANDLED;
569 }
570
571 static const char *iio_event_group_name = "events";
iio_device_register_eventset(struct iio_dev * indio_dev)572 int iio_device_register_eventset(struct iio_dev *indio_dev)
573 {
574 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
575 struct iio_event_interface *ev_int;
576 struct iio_dev_attr *p;
577 int ret = 0, attrcount_orig = 0, attrcount, attrn;
578 struct attribute **attr;
579
580 if (!(indio_dev->info->event_attrs ||
581 iio_check_for_dynamic_events(indio_dev)))
582 return 0;
583
584 ev_int = kzalloc(sizeof(*ev_int), GFP_KERNEL);
585 if (!ev_int)
586 return -ENOMEM;
587
588 iio_dev_opaque->event_interface = ev_int;
589
590 INIT_LIST_HEAD(&ev_int->dev_attr_list);
591
592 iio_setup_ev_int(ev_int);
593 if (indio_dev->info->event_attrs != NULL) {
594 attr = indio_dev->info->event_attrs->attrs;
595 while (*attr++ != NULL)
596 attrcount_orig++;
597 }
598 attrcount = attrcount_orig;
599 if (indio_dev->channels) {
600 ret = __iio_add_event_config_attrs(indio_dev);
601 if (ret < 0)
602 goto error_free_setup_event_lines;
603 attrcount += ret;
604 }
605
606 ev_int->group.name = iio_event_group_name;
607 ev_int->group.attrs = kcalloc(attrcount + 1,
608 sizeof(ev_int->group.attrs[0]),
609 GFP_KERNEL);
610 if (ev_int->group.attrs == NULL) {
611 ret = -ENOMEM;
612 goto error_free_setup_event_lines;
613 }
614 if (indio_dev->info->event_attrs)
615 memcpy(ev_int->group.attrs,
616 indio_dev->info->event_attrs->attrs,
617 sizeof(ev_int->group.attrs[0]) * attrcount_orig);
618 attrn = attrcount_orig;
619 /* Add all elements from the list. */
620 list_for_each_entry(p, &ev_int->dev_attr_list, l)
621 ev_int->group.attrs[attrn++] = &p->dev_attr.attr;
622
623 ret = iio_device_register_sysfs_group(indio_dev, &ev_int->group);
624 if (ret)
625 goto error_free_group_attrs;
626
627 ev_int->ioctl_handler.ioctl = iio_event_ioctl;
628 iio_device_ioctl_handler_register(&iio_dev_opaque->indio_dev,
629 &ev_int->ioctl_handler);
630
631 return 0;
632
633 error_free_group_attrs:
634 kfree(ev_int->group.attrs);
635 error_free_setup_event_lines:
636 iio_free_chan_devattr_list(&ev_int->dev_attr_list);
637 kfree(ev_int);
638 iio_dev_opaque->event_interface = NULL;
639 return ret;
640 }
641
642 /**
643 * iio_device_wakeup_eventset - Wakes up the event waitqueue
644 * @indio_dev: The IIO device
645 *
646 * Wakes up the event waitqueue used for poll() and blocking read().
647 * Should usually be called when the device is unregistered.
648 */
iio_device_wakeup_eventset(struct iio_dev * indio_dev)649 void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
650 {
651 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
652
653 if (iio_dev_opaque->event_interface == NULL)
654 return;
655 wake_up(&iio_dev_opaque->event_interface->wait);
656 }
657
iio_device_unregister_eventset(struct iio_dev * indio_dev)658 void iio_device_unregister_eventset(struct iio_dev *indio_dev)
659 {
660 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
661 struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
662
663 if (ev_int == NULL)
664 return;
665
666 iio_device_ioctl_handler_unregister(&ev_int->ioctl_handler);
667 iio_free_chan_devattr_list(&ev_int->dev_attr_list);
668 kfree(ev_int->group.attrs);
669 kfree(ev_int);
670 iio_dev_opaque->event_interface = NULL;
671 }
672