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 [IIO_EV_TYPE_FAULT] = "fault",
236 };
237
238 static const char * const iio_ev_dir_text[] = {
239 [IIO_EV_DIR_EITHER] = "either",
240 [IIO_EV_DIR_RISING] = "rising",
241 [IIO_EV_DIR_FALLING] = "falling",
242 [IIO_EV_DIR_SINGLETAP] = "singletap",
243 [IIO_EV_DIR_DOUBLETAP] = "doubletap",
244 [IIO_EV_DIR_FAULT_OPENWIRE] = "openwire",
245 };
246
247 static const char * const iio_ev_info_text[] = {
248 [IIO_EV_INFO_ENABLE] = "en",
249 [IIO_EV_INFO_VALUE] = "value",
250 [IIO_EV_INFO_HYSTERESIS] = "hysteresis",
251 [IIO_EV_INFO_PERIOD] = "period",
252 [IIO_EV_INFO_HIGH_PASS_FILTER_3DB] = "high_pass_filter_3db",
253 [IIO_EV_INFO_LOW_PASS_FILTER_3DB] = "low_pass_filter_3db",
254 [IIO_EV_INFO_TIMEOUT] = "timeout",
255 [IIO_EV_INFO_RESET_TIMEOUT] = "reset_timeout",
256 [IIO_EV_INFO_TAP2_MIN_DELAY] = "tap2_min_delay",
257 [IIO_EV_INFO_RUNNING_PERIOD] = "runningperiod",
258 [IIO_EV_INFO_RUNNING_COUNT] = "runningcount",
259 [IIO_EV_INFO_SCALE] = "scale",
260 };
261
iio_ev_attr_dir(struct iio_dev_attr * attr)262 static enum iio_event_direction iio_ev_attr_dir(struct iio_dev_attr *attr)
263 {
264 return attr->c->event_spec[attr->address & 0xffff].dir;
265 }
266
iio_ev_attr_type(struct iio_dev_attr * attr)267 static enum iio_event_type iio_ev_attr_type(struct iio_dev_attr *attr)
268 {
269 return attr->c->event_spec[attr->address & 0xffff].type;
270 }
271
iio_ev_attr_info(struct iio_dev_attr * attr)272 static enum iio_event_info iio_ev_attr_info(struct iio_dev_attr *attr)
273 {
274 return (attr->address >> 16) & 0xffff;
275 }
276
iio_ev_state_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)277 static ssize_t iio_ev_state_store(struct device *dev,
278 struct device_attribute *attr,
279 const char *buf,
280 size_t len)
281 {
282 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
283 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
284 int ret;
285 bool val;
286
287 ret = kstrtobool(buf, &val);
288 if (ret < 0)
289 return ret;
290
291 if (!indio_dev->info->write_event_config)
292 return -EINVAL;
293
294 ret = indio_dev->info->write_event_config(indio_dev,
295 this_attr->c, iio_ev_attr_type(this_attr),
296 iio_ev_attr_dir(this_attr), val);
297
298 return (ret < 0) ? ret : len;
299 }
300
iio_ev_state_show(struct device * dev,struct device_attribute * attr,char * buf)301 static ssize_t iio_ev_state_show(struct device *dev,
302 struct device_attribute *attr,
303 char *buf)
304 {
305 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
306 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
307 int val;
308
309 if (!indio_dev->info->read_event_config)
310 return -EINVAL;
311
312 val = indio_dev->info->read_event_config(indio_dev,
313 this_attr->c, iio_ev_attr_type(this_attr),
314 iio_ev_attr_dir(this_attr));
315 if (val < 0)
316 return val;
317 else
318 return sysfs_emit(buf, "%d\n", val);
319 }
320
iio_ev_value_show(struct device * dev,struct device_attribute * attr,char * buf)321 static ssize_t iio_ev_value_show(struct device *dev,
322 struct device_attribute *attr,
323 char *buf)
324 {
325 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
326 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
327 int val, val2, val_arr[2];
328 int ret;
329
330 if (!indio_dev->info->read_event_value)
331 return -EINVAL;
332
333 ret = indio_dev->info->read_event_value(indio_dev,
334 this_attr->c, iio_ev_attr_type(this_attr),
335 iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
336 &val, &val2);
337 if (ret < 0)
338 return ret;
339 val_arr[0] = val;
340 val_arr[1] = val2;
341 return iio_format_value(buf, ret, 2, val_arr);
342 }
343
iio_ev_value_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)344 static ssize_t iio_ev_value_store(struct device *dev,
345 struct device_attribute *attr,
346 const char *buf,
347 size_t len)
348 {
349 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
350 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
351 int val, val2;
352 int ret;
353
354 if (!indio_dev->info->write_event_value)
355 return -EINVAL;
356
357 ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
358 if (ret)
359 return ret;
360 ret = indio_dev->info->write_event_value(indio_dev,
361 this_attr->c, iio_ev_attr_type(this_attr),
362 iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
363 val, val2);
364 if (ret < 0)
365 return ret;
366
367 return len;
368 }
369
iio_ev_label_show(struct device * dev,struct device_attribute * attr,char * buf)370 static ssize_t iio_ev_label_show(struct device *dev,
371 struct device_attribute *attr,
372 char *buf)
373 {
374 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
375 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
376
377 if (indio_dev->info->read_event_label)
378 return indio_dev->info->read_event_label(indio_dev,
379 this_attr->c, iio_ev_attr_type(this_attr),
380 iio_ev_attr_dir(this_attr), buf);
381
382 return -EINVAL;
383 }
384
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)385 static int iio_device_add_event(struct iio_dev *indio_dev,
386 const struct iio_chan_spec *chan, unsigned int spec_index,
387 enum iio_event_type type, enum iio_event_direction dir,
388 enum iio_shared_by shared_by, const unsigned long *mask)
389 {
390 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
391 ssize_t (*show)(struct device *dev, struct device_attribute *attr,
392 char *buf);
393 ssize_t (*store)(struct device *dev, struct device_attribute *attr,
394 const char *buf, size_t len);
395 unsigned int attrcount = 0;
396 unsigned int i;
397 char *postfix;
398 int ret;
399
400 for_each_set_bit(i, mask, sizeof(*mask)*8) {
401 if (i >= ARRAY_SIZE(iio_ev_info_text))
402 return -EINVAL;
403 if (dir != IIO_EV_DIR_NONE)
404 postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
405 iio_ev_type_text[type],
406 iio_ev_dir_text[dir],
407 iio_ev_info_text[i]);
408 else
409 postfix = kasprintf(GFP_KERNEL, "%s_%s",
410 iio_ev_type_text[type],
411 iio_ev_info_text[i]);
412 if (postfix == NULL)
413 return -ENOMEM;
414
415 if (i == IIO_EV_INFO_ENABLE) {
416 show = iio_ev_state_show;
417 store = iio_ev_state_store;
418 } else {
419 show = iio_ev_value_show;
420 store = iio_ev_value_store;
421 }
422
423 ret = __iio_add_chan_devattr(postfix, chan, show, store,
424 (i << 16) | spec_index, shared_by, &indio_dev->dev,
425 NULL,
426 &iio_dev_opaque->event_interface->dev_attr_list);
427 kfree(postfix);
428
429 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
430 continue;
431
432 if (ret)
433 return ret;
434
435 attrcount++;
436 }
437
438 return attrcount;
439 }
440
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)441 static int iio_device_add_event_label(struct iio_dev *indio_dev,
442 const struct iio_chan_spec *chan,
443 unsigned int spec_index,
444 enum iio_event_type type,
445 enum iio_event_direction dir)
446 {
447 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
448 char *postfix;
449 int ret;
450
451 if (!indio_dev->info->read_event_label)
452 return 0;
453
454 if (dir != IIO_EV_DIR_NONE)
455 postfix = kasprintf(GFP_KERNEL, "%s_%s_label",
456 iio_ev_type_text[type],
457 iio_ev_dir_text[dir]);
458 else
459 postfix = kasprintf(GFP_KERNEL, "%s_label",
460 iio_ev_type_text[type]);
461 if (postfix == NULL)
462 return -ENOMEM;
463
464 ret = __iio_add_chan_devattr(postfix, chan, &iio_ev_label_show, NULL,
465 spec_index, IIO_SEPARATE, &indio_dev->dev, NULL,
466 &iio_dev_opaque->event_interface->dev_attr_list);
467
468 kfree(postfix);
469
470 if (ret < 0)
471 return ret;
472
473 return 1;
474 }
475
iio_device_add_event_sysfs(struct iio_dev * indio_dev,struct iio_chan_spec const * chan)476 static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
477 struct iio_chan_spec const *chan)
478 {
479 int ret = 0, i, attrcount = 0;
480 enum iio_event_direction dir;
481 enum iio_event_type type;
482
483 for (i = 0; i < chan->num_event_specs; i++) {
484 type = chan->event_spec[i].type;
485 dir = chan->event_spec[i].dir;
486
487 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
488 IIO_SEPARATE, &chan->event_spec[i].mask_separate);
489 if (ret < 0)
490 return ret;
491 attrcount += ret;
492
493 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
494 IIO_SHARED_BY_TYPE,
495 &chan->event_spec[i].mask_shared_by_type);
496 if (ret < 0)
497 return ret;
498 attrcount += ret;
499
500 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
501 IIO_SHARED_BY_DIR,
502 &chan->event_spec[i].mask_shared_by_dir);
503 if (ret < 0)
504 return ret;
505 attrcount += ret;
506
507 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
508 IIO_SHARED_BY_ALL,
509 &chan->event_spec[i].mask_shared_by_all);
510 if (ret < 0)
511 return ret;
512 attrcount += ret;
513
514 ret = iio_device_add_event_label(indio_dev, chan, i, type, dir);
515 if (ret < 0)
516 return ret;
517 attrcount += ret;
518 }
519 ret = attrcount;
520 return ret;
521 }
522
__iio_add_event_config_attrs(struct iio_dev * indio_dev)523 static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
524 {
525 int j, ret, attrcount = 0;
526
527 /* Dynamically created from the channels array */
528 for (j = 0; j < indio_dev->num_channels; j++) {
529 ret = iio_device_add_event_sysfs(indio_dev,
530 &indio_dev->channels[j]);
531 if (ret < 0)
532 return ret;
533 attrcount += ret;
534 }
535 return attrcount;
536 }
537
iio_check_for_dynamic_events(struct iio_dev * indio_dev)538 static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
539 {
540 int j;
541
542 for (j = 0; j < indio_dev->num_channels; j++) {
543 if (indio_dev->channels[j].num_event_specs != 0)
544 return true;
545 }
546 return false;
547 }
548
iio_setup_ev_int(struct iio_event_interface * ev_int)549 static void iio_setup_ev_int(struct iio_event_interface *ev_int)
550 {
551 INIT_KFIFO(ev_int->det_events);
552 init_waitqueue_head(&ev_int->wait);
553 mutex_init(&ev_int->read_lock);
554 }
555
iio_event_ioctl(struct iio_dev * indio_dev,struct file * filp,unsigned int cmd,unsigned long arg)556 static long iio_event_ioctl(struct iio_dev *indio_dev, struct file *filp,
557 unsigned int cmd, unsigned long arg)
558 {
559 int __user *ip = (int __user *)arg;
560 int fd;
561
562 if (cmd == IIO_GET_EVENT_FD_IOCTL) {
563 fd = iio_event_getfd(indio_dev);
564 if (fd < 0)
565 return fd;
566 if (copy_to_user(ip, &fd, sizeof(fd)))
567 return -EFAULT;
568 return 0;
569 }
570
571 return IIO_IOCTL_UNHANDLED;
572 }
573
574 static const char *iio_event_group_name = "events";
iio_device_register_eventset(struct iio_dev * indio_dev)575 int iio_device_register_eventset(struct iio_dev *indio_dev)
576 {
577 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
578 struct iio_event_interface *ev_int;
579 struct iio_dev_attr *p;
580 int ret = 0, attrcount_orig = 0, attrcount, attrn;
581 struct attribute **attr;
582
583 if (!(indio_dev->info->event_attrs ||
584 iio_check_for_dynamic_events(indio_dev)))
585 return 0;
586
587 ev_int = kzalloc_obj(*ev_int);
588 if (!ev_int)
589 return -ENOMEM;
590
591 iio_dev_opaque->event_interface = ev_int;
592
593 INIT_LIST_HEAD(&ev_int->dev_attr_list);
594
595 iio_setup_ev_int(ev_int);
596 if (indio_dev->info->event_attrs != NULL) {
597 attr = indio_dev->info->event_attrs->attrs;
598 while (*attr++ != NULL)
599 attrcount_orig++;
600 }
601 attrcount = attrcount_orig;
602 if (indio_dev->channels) {
603 ret = __iio_add_event_config_attrs(indio_dev);
604 if (ret < 0)
605 goto error_free_setup_event_lines;
606 attrcount += ret;
607 }
608
609 ev_int->group.name = iio_event_group_name;
610 ev_int->group.attrs = kzalloc_objs(ev_int->group.attrs[0],
611 attrcount + 1);
612 if (ev_int->group.attrs == NULL) {
613 ret = -ENOMEM;
614 goto error_free_setup_event_lines;
615 }
616 if (indio_dev->info->event_attrs)
617 memcpy(ev_int->group.attrs,
618 indio_dev->info->event_attrs->attrs,
619 sizeof(ev_int->group.attrs[0]) * attrcount_orig);
620 attrn = attrcount_orig;
621 /* Add all elements from the list. */
622 list_for_each_entry(p, &ev_int->dev_attr_list, l)
623 ev_int->group.attrs[attrn++] = &p->dev_attr.attr;
624
625 ret = iio_device_register_sysfs_group(indio_dev, &ev_int->group);
626 if (ret)
627 goto error_free_group_attrs;
628
629 ev_int->ioctl_handler.ioctl = iio_event_ioctl;
630 iio_device_ioctl_handler_register(&iio_dev_opaque->indio_dev,
631 &ev_int->ioctl_handler);
632
633 return 0;
634
635 error_free_group_attrs:
636 kfree(ev_int->group.attrs);
637 error_free_setup_event_lines:
638 iio_free_chan_devattr_list(&ev_int->dev_attr_list);
639 kfree(ev_int);
640 iio_dev_opaque->event_interface = NULL;
641 return ret;
642 }
643
644 /**
645 * iio_device_wakeup_eventset - Wakes up the event waitqueue
646 * @indio_dev: The IIO device
647 *
648 * Wakes up the event waitqueue used for poll() and blocking read().
649 * Should usually be called when the device is unregistered.
650 */
iio_device_wakeup_eventset(struct iio_dev * indio_dev)651 void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
652 {
653 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
654
655 if (iio_dev_opaque->event_interface == NULL)
656 return;
657 wake_up(&iio_dev_opaque->event_interface->wait);
658 }
659
iio_device_unregister_eventset(struct iio_dev * indio_dev)660 void iio_device_unregister_eventset(struct iio_dev *indio_dev)
661 {
662 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
663 struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
664
665 if (ev_int == NULL)
666 return;
667
668 iio_device_ioctl_handler_unregister(&ev_int->ioctl_handler);
669 iio_free_chan_devattr_list(&ev_int->dev_attr_list);
670 kfree(ev_int->group.attrs);
671 kfree(ev_int);
672 iio_dev_opaque->event_interface = NULL;
673 }
674