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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * V4L2 asynchronous subdevice registration API
4 *
5 * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
6 */
7
8#include <linux/debugfs.h>
9#include <linux/device.h>
10#include <linux/err.h>
11#include <linux/i2c.h>
12#include <linux/list.h>
13#include <linux/mm.h>
14#include <linux/module.h>
15#include <linux/mutex.h>
16#include <linux/of.h>
17#include <linux/platform_device.h>
18#include <linux/seq_file.h>
19#include <linux/slab.h>
20#include <linux/types.h>
21
22#include <media/v4l2-async.h>
23#include <media/v4l2-device.h>
24#include <media/v4l2-fwnode.h>
25#include <media/v4l2-subdev.h>
26
27static int v4l2_async_notifier_call_bound(struct v4l2_async_notifier *n,
28 struct v4l2_subdev *subdev,
29 struct v4l2_async_subdev *asd)
30{
31 if (!n->ops || !n->ops->bound)
32 return 0;
33
34 return n->ops->bound(n, subdev, asd);
35}
36
37static void v4l2_async_notifier_call_unbind(struct v4l2_async_notifier *n,
38 struct v4l2_subdev *subdev,
39 struct v4l2_async_subdev *asd)
40{
41 if (!n->ops || !n->ops->unbind)
42 return;
43
44 n->ops->unbind(n, subdev, asd);
45}
46
47static int v4l2_async_notifier_call_complete(struct v4l2_async_notifier *n)
48{
49 if (!n->ops || !n->ops->complete)
50 return 0;
51
52 return n->ops->complete(n);
53}
54
55static bool match_i2c(struct v4l2_async_notifier *notifier,
56 struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
57{
58#if IS_ENABLED(CONFIG_I2C)
59 struct i2c_client *client = i2c_verify_client(sd->dev);
60
61 return client &&
62 asd->match.i2c.adapter_id == client->adapter->nr &&
63 asd->match.i2c.address == client->addr;
64#else
65 return false;
66#endif
67}
68
69static bool match_fwnode(struct v4l2_async_notifier *notifier,
70 struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
71{
72 struct fwnode_handle *other_fwnode;
73 struct fwnode_handle *dev_fwnode;
74 bool asd_fwnode_is_ep;
75 bool sd_fwnode_is_ep;
76 struct device *dev;
77
78 /*
79 * Both the subdev and the async subdev can provide either an endpoint
80 * fwnode or a device fwnode. Start with the simple case of direct
81 * fwnode matching.
82 */
83 if (sd->fwnode == asd->match.fwnode)
84 return true;
85
86 /*
87 * Check the same situation for any possible secondary assigned to the
88 * subdev's fwnode
89 */
90 if (!IS_ERR_OR_NULL(sd->fwnode->secondary) &&
91 sd->fwnode->secondary == asd->match.fwnode)
92 return true;
93
94 /*
95 * Otherwise, check if the sd fwnode and the asd fwnode refer to an
96 * endpoint or a device. If they're of the same type, there's no match.
97 * Technically speaking this checks if the nodes refer to a connected
98 * endpoint, which is the simplest check that works for both OF and
99 * ACPI. This won't make a difference, as drivers should not try to
100 * match unconnected endpoints.
101 */
102 sd_fwnode_is_ep = fwnode_graph_is_endpoint(sd->fwnode);
103 asd_fwnode_is_ep = fwnode_graph_is_endpoint(asd->match.fwnode);
104
105 if (sd_fwnode_is_ep == asd_fwnode_is_ep)
106 return false;
107
108 /*
109 * The sd and asd fwnodes are of different types. Get the device fwnode
110 * parent of the endpoint fwnode, and compare it with the other fwnode.
111 */
112 if (sd_fwnode_is_ep) {
113 dev_fwnode = fwnode_graph_get_port_parent(sd->fwnode);
114 other_fwnode = asd->match.fwnode;
115 } else {
116 dev_fwnode = fwnode_graph_get_port_parent(asd->match.fwnode);
117 other_fwnode = sd->fwnode;
118 }
119
120 fwnode_handle_put(dev_fwnode);
121
122 if (dev_fwnode != other_fwnode)
123 return false;
124
125 /*
126 * We have a heterogeneous match. Retrieve the struct device of the side
127 * that matched on a device fwnode to print its driver name.
128 */
129 if (sd_fwnode_is_ep)
130 dev = notifier->v4l2_dev ? notifier->v4l2_dev->dev
131 : notifier->sd->dev;
132 else
133 dev = sd->dev;
134
135 if (dev && dev->driver) {
136 if (sd_fwnode_is_ep)
137 dev_warn(dev, "Driver %s uses device fwnode, incorrect match may occur\n",
138 dev->driver->name);
139 dev_notice(dev, "Consider updating driver %s to match on endpoints\n",
140 dev->driver->name);
141 }
142
143 return true;
144}
145
146static LIST_HEAD(subdev_list);
147static LIST_HEAD(notifier_list);
148static DEFINE_MUTEX(list_lock);
149
150static struct v4l2_async_subdev *
151v4l2_async_find_match(struct v4l2_async_notifier *notifier,
152 struct v4l2_subdev *sd)
153{
154 bool (*match)(struct v4l2_async_notifier *notifier,
155 struct v4l2_subdev *sd, struct v4l2_async_subdev *asd);
156 struct v4l2_async_subdev *asd;
157
158 list_for_each_entry(asd, ¬ifier->waiting, list) {
159 /* bus_type has been verified valid before */
160 switch (asd->match_type) {
161 case V4L2_ASYNC_MATCH_I2C:
162 match = match_i2c;
163 break;
164 case V4L2_ASYNC_MATCH_FWNODE:
165 match = match_fwnode;
166 break;
167 default:
168 /* Cannot happen, unless someone breaks us */
169 WARN_ON(true);
170 return NULL;
171 }
172
173 /* match cannot be NULL here */
174 if (match(notifier, sd, asd))
175 return asd;
176 }
177
178 return NULL;
179}
180
181/* Compare two async sub-device descriptors for equivalence */
182static bool asd_equal(struct v4l2_async_subdev *asd_x,
183 struct v4l2_async_subdev *asd_y)
184{
185 if (asd_x->match_type != asd_y->match_type)
186 return false;
187
188 switch (asd_x->match_type) {
189 case V4L2_ASYNC_MATCH_I2C:
190 return asd_x->match.i2c.adapter_id ==
191 asd_y->match.i2c.adapter_id &&
192 asd_x->match.i2c.address ==
193 asd_y->match.i2c.address;
194 case V4L2_ASYNC_MATCH_FWNODE:
195 return asd_x->match.fwnode == asd_y->match.fwnode;
196 default:
197 break;
198 }
199
200 return false;
201}
202
203/* Find the sub-device notifier registered by a sub-device driver. */
204static struct v4l2_async_notifier *
205v4l2_async_find_subdev_notifier(struct v4l2_subdev *sd)
206{
207 struct v4l2_async_notifier *n;
208
209 list_for_each_entry(n, ¬ifier_list, list)
210 if (n->sd == sd)
211 return n;
212
213 return NULL;
214}
215
216/* Get v4l2_device related to the notifier if one can be found. */
217static struct v4l2_device *
218v4l2_async_notifier_find_v4l2_dev(struct v4l2_async_notifier *notifier)
219{
220 while (notifier->parent)
221 notifier = notifier->parent;
222
223 return notifier->v4l2_dev;
224}
225
226/*
227 * Return true if all child sub-device notifiers are complete, false otherwise.
228 */
229static bool
230v4l2_async_notifier_can_complete(struct v4l2_async_notifier *notifier)
231{
232 struct v4l2_subdev *sd;
233
234 if (!list_empty(¬ifier->waiting))
235 return false;
236
237 list_for_each_entry(sd, ¬ifier->done, async_list) {
238 struct v4l2_async_notifier *subdev_notifier =
239 v4l2_async_find_subdev_notifier(sd);
240
241 if (subdev_notifier &&
242 !v4l2_async_notifier_can_complete(subdev_notifier))
243 return false;
244 }
245
246 return true;
247}
248
249/*
250 * Complete the master notifier if possible. This is done when all async
251 * sub-devices have been bound; v4l2_device is also available then.
252 */
253static int
254v4l2_async_notifier_try_complete(struct v4l2_async_notifier *notifier)
255{
256 /* Quick check whether there are still more sub-devices here. */
257 if (!list_empty(¬ifier->waiting))
258 return 0;
259
260 /* Check the entire notifier tree; find the root notifier first. */
261 while (notifier->parent)
262 notifier = notifier->parent;
263
264 /* This is root if it has v4l2_dev. */
265 if (!notifier->v4l2_dev)
266 return 0;
267
268 /* Is everything ready? */
269 if (!v4l2_async_notifier_can_complete(notifier))
270 return 0;
271
272 return v4l2_async_notifier_call_complete(notifier);
273}
274
275static int
276v4l2_async_notifier_try_all_subdevs(struct v4l2_async_notifier *notifier);
277
278static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
279 struct v4l2_device *v4l2_dev,
280 struct v4l2_subdev *sd,
281 struct v4l2_async_subdev *asd)
282{
283 struct v4l2_async_notifier *subdev_notifier;
284 int ret;
285
286 ret = v4l2_device_register_subdev(v4l2_dev, sd);
287 if (ret < 0)
288 return ret;
289
290 ret = v4l2_async_notifier_call_bound(notifier, sd, asd);
291 if (ret < 0) {
292 v4l2_device_unregister_subdev(sd);
293 return ret;
294 }
295
296 /* Remove from the waiting list */
297 list_del(&asd->list);
298 sd->asd = asd;
299 sd->notifier = notifier;
300
301 /* Move from the global subdevice list to notifier's done */
302 list_move(&sd->async_list, ¬ifier->done);
303
304 /*
305 * See if the sub-device has a notifier. If not, return here.
306 */
307 subdev_notifier = v4l2_async_find_subdev_notifier(sd);
308 if (!subdev_notifier || subdev_notifier->parent)
309 return 0;
310
311 /*
312 * Proceed with checking for the sub-device notifier's async
313 * sub-devices, and return the result. The error will be handled by the
314 * caller.
315 */
316 subdev_notifier->parent = notifier;
317
318 return v4l2_async_notifier_try_all_subdevs(subdev_notifier);
319}
320
321/* Test all async sub-devices in a notifier for a match. */
322static int
323v4l2_async_notifier_try_all_subdevs(struct v4l2_async_notifier *notifier)
324{
325 struct v4l2_device *v4l2_dev =
326 v4l2_async_notifier_find_v4l2_dev(notifier);
327 struct v4l2_subdev *sd;
328
329 if (!v4l2_dev)
330 return 0;
331
332again:
333 list_for_each_entry(sd, &subdev_list, async_list) {
334 struct v4l2_async_subdev *asd;
335 int ret;
336
337 asd = v4l2_async_find_match(notifier, sd);
338 if (!asd)
339 continue;
340
341 ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
342 if (ret < 0)
343 return ret;
344
345 /*
346 * v4l2_async_match_notify() may lead to registering a
347 * new notifier and thus changing the async subdevs
348 * list. In order to proceed safely from here, restart
349 * parsing the list from the beginning.
350 */
351 goto again;
352 }
353
354 return 0;
355}
356
357static void v4l2_async_cleanup(struct v4l2_subdev *sd)
358{
359 v4l2_device_unregister_subdev(sd);
360 /*
361 * Subdevice driver will reprobe and put the subdev back
362 * onto the list
363 */
364 list_del_init(&sd->async_list);
365 sd->asd = NULL;
366}
367
368/* Unbind all sub-devices in the notifier tree. */
369static void
370v4l2_async_notifier_unbind_all_subdevs(struct v4l2_async_notifier *notifier)
371{
372 struct v4l2_subdev *sd, *tmp;
373
374 list_for_each_entry_safe(sd, tmp, ¬ifier->done, async_list) {
375 struct v4l2_async_notifier *subdev_notifier =
376 v4l2_async_find_subdev_notifier(sd);
377
378 if (subdev_notifier)
379 v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
380
381 v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
382 v4l2_async_cleanup(sd);
383
384 list_move(&sd->async_list, &subdev_list);
385 }
386
387 notifier->parent = NULL;
388}
389
390/* See if an async sub-device can be found in a notifier's lists. */
391static bool
392__v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
393 struct v4l2_async_subdev *asd)
394{
395 struct v4l2_async_subdev *asd_y;
396 struct v4l2_subdev *sd;
397
398 list_for_each_entry(asd_y, ¬ifier->waiting, list)
399 if (asd_equal(asd, asd_y))
400 return true;
401
402 list_for_each_entry(sd, ¬ifier->done, async_list) {
403 if (WARN_ON(!sd->asd))
404 continue;
405
406 if (asd_equal(asd, sd->asd))
407 return true;
408 }
409
410 return false;
411}
412
413/*
414 * Find out whether an async sub-device was set up already or
415 * whether it exists in a given notifier before @this_index.
416 * If @this_index < 0, search the notifier's entire @asd_list.
417 */
418static bool
419v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
420 struct v4l2_async_subdev *asd,
421 int this_index)
422{
423 struct v4l2_async_subdev *asd_y;
424 int j = 0;
425
426 lockdep_assert_held(&list_lock);
427
428 /* Check that an asd is not being added more than once. */
429 list_for_each_entry(asd_y, ¬ifier->asd_list, asd_list) {
430 if (this_index >= 0 && j++ >= this_index)
431 break;
432 if (asd_equal(asd, asd_y))
433 return true;
434 }
435
436 /* Check that an asd does not exist in other notifiers. */
437 list_for_each_entry(notifier, ¬ifier_list, list)
438 if (__v4l2_async_notifier_has_async_subdev(notifier, asd))
439 return true;
440
441 return false;
442}
443
444static int v4l2_async_notifier_asd_valid(struct v4l2_async_notifier *notifier,
445 struct v4l2_async_subdev *asd,
446 int this_index)
447{
448 struct device *dev =
449 notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
450
451 if (!asd)
452 return -EINVAL;
453
454 switch (asd->match_type) {
455 case V4L2_ASYNC_MATCH_I2C:
456 case V4L2_ASYNC_MATCH_FWNODE:
457 if (v4l2_async_notifier_has_async_subdev(notifier, asd,
458 this_index)) {
459 dev_dbg(dev, "subdev descriptor already listed in this or other notifiers\n");
460 return -EEXIST;
461 }
462 break;
463 default:
464 dev_err(dev, "Invalid match type %u on %p\n",
465 asd->match_type, asd);
466 return -EINVAL;
467 }
468
469 return 0;
470}
471
472void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier)
473{
474 INIT_LIST_HEAD(¬ifier->asd_list);
475}
476EXPORT_SYMBOL(v4l2_async_notifier_init);
477
478static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
479{
480 struct v4l2_async_subdev *asd;
481 int ret, i = 0;
482
483 INIT_LIST_HEAD(¬ifier->waiting);
484 INIT_LIST_HEAD(¬ifier->done);
485
486 mutex_lock(&list_lock);
487
488 list_for_each_entry(asd, ¬ifier->asd_list, asd_list) {
489 ret = v4l2_async_notifier_asd_valid(notifier, asd, i++);
490 if (ret)
491 goto err_unlock;
492
493 list_add_tail(&asd->list, ¬ifier->waiting);
494 }
495
496 ret = v4l2_async_notifier_try_all_subdevs(notifier);
497 if (ret < 0)
498 goto err_unbind;
499
500 ret = v4l2_async_notifier_try_complete(notifier);
501 if (ret < 0)
502 goto err_unbind;
503
504 /* Keep also completed notifiers on the list */
505 list_add(¬ifier->list, ¬ifier_list);
506
507 mutex_unlock(&list_lock);
508
509 return 0;
510
511err_unbind:
512 /*
513 * On failure, unbind all sub-devices registered through this notifier.
514 */
515 v4l2_async_notifier_unbind_all_subdevs(notifier);
516
517err_unlock:
518 mutex_unlock(&list_lock);
519
520 return ret;
521}
522
523int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
524 struct v4l2_async_notifier *notifier)
525{
526 int ret;
527
528 if (WARN_ON(!v4l2_dev || notifier->sd))
529 return -EINVAL;
530
531 notifier->v4l2_dev = v4l2_dev;
532
533 ret = __v4l2_async_notifier_register(notifier);
534 if (ret)
535 notifier->v4l2_dev = NULL;
536
537 return ret;
538}
539EXPORT_SYMBOL(v4l2_async_notifier_register);
540
541int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
542 struct v4l2_async_notifier *notifier)
543{
544 int ret;
545
546 if (WARN_ON(!sd || notifier->v4l2_dev))
547 return -EINVAL;
548
549 notifier->sd = sd;
550
551 ret = __v4l2_async_notifier_register(notifier);
552 if (ret)
553 notifier->sd = NULL;
554
555 return ret;
556}
557EXPORT_SYMBOL(v4l2_async_subdev_notifier_register);
558
559static void
560__v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
561{
562 if (!notifier || (!notifier->v4l2_dev && !notifier->sd))
563 return;
564
565 v4l2_async_notifier_unbind_all_subdevs(notifier);
566
567 notifier->sd = NULL;
568 notifier->v4l2_dev = NULL;
569
570 list_del(¬ifier->list);
571}
572
573void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
574{
575 mutex_lock(&list_lock);
576
577 __v4l2_async_notifier_unregister(notifier);
578
579 mutex_unlock(&list_lock);
580}
581EXPORT_SYMBOL(v4l2_async_notifier_unregister);
582
583static void __v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
584{
585 struct v4l2_async_subdev *asd, *tmp;
586
587 if (!notifier || !notifier->asd_list.next)
588 return;
589
590 list_for_each_entry_safe(asd, tmp, ¬ifier->asd_list, asd_list) {
591 switch (asd->match_type) {
592 case V4L2_ASYNC_MATCH_FWNODE:
593 fwnode_handle_put(asd->match.fwnode);
594 break;
595 default:
596 break;
597 }
598
599 list_del(&asd->asd_list);
600 kfree(asd);
601 }
602}
603
604void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
605{
606 mutex_lock(&list_lock);
607
608 __v4l2_async_notifier_cleanup(notifier);
609
610 mutex_unlock(&list_lock);
611}
612EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
613
614int __v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
615 struct v4l2_async_subdev *asd)
616{
617 int ret;
618
619 mutex_lock(&list_lock);
620
621 ret = v4l2_async_notifier_asd_valid(notifier, asd, -1);
622 if (ret)
623 goto unlock;
624
625 list_add_tail(&asd->asd_list, ¬ifier->asd_list);
626
627unlock:
628 mutex_unlock(&list_lock);
629 return ret;
630}
631EXPORT_SYMBOL_GPL(__v4l2_async_notifier_add_subdev);
632
633struct v4l2_async_subdev *
634__v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
635 struct fwnode_handle *fwnode,
636 unsigned int asd_struct_size)
637{
638 struct v4l2_async_subdev *asd;
639 int ret;
640
641 asd = kzalloc(asd_struct_size, GFP_KERNEL);
642 if (!asd)
643 return ERR_PTR(-ENOMEM);
644
645 asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
646 asd->match.fwnode = fwnode_handle_get(fwnode);
647
648 ret = __v4l2_async_notifier_add_subdev(notifier, asd);
649 if (ret) {
650 fwnode_handle_put(fwnode);
651 kfree(asd);
652 return ERR_PTR(ret);
653 }
654
655 return asd;
656}
657EXPORT_SYMBOL_GPL(__v4l2_async_notifier_add_fwnode_subdev);
658
659struct v4l2_async_subdev *
660__v4l2_async_notifier_add_fwnode_remote_subdev(struct v4l2_async_notifier *notif,
661 struct fwnode_handle *endpoint,
662 unsigned int asd_struct_size)
663{
664 struct v4l2_async_subdev *asd;
665 struct fwnode_handle *remote;
666
667 remote = fwnode_graph_get_remote_port_parent(endpoint);
668 if (!remote)
669 return ERR_PTR(-ENOTCONN);
670
671 asd = __v4l2_async_notifier_add_fwnode_subdev(notif, remote,
672 asd_struct_size);
673 /*
674 * Calling __v4l2_async_notifier_add_fwnode_subdev grabs a refcount,
675 * so drop the one we got in fwnode_graph_get_remote_port_parent.
676 */
677 fwnode_handle_put(remote);
678 return asd;
679}
680EXPORT_SYMBOL_GPL(__v4l2_async_notifier_add_fwnode_remote_subdev);
681
682struct v4l2_async_subdev *
683__v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
684 int adapter_id, unsigned short address,
685 unsigned int asd_struct_size)
686{
687 struct v4l2_async_subdev *asd;
688 int ret;
689
690 asd = kzalloc(asd_struct_size, GFP_KERNEL);
691 if (!asd)
692 return ERR_PTR(-ENOMEM);
693
694 asd->match_type = V4L2_ASYNC_MATCH_I2C;
695 asd->match.i2c.adapter_id = adapter_id;
696 asd->match.i2c.address = address;
697
698 ret = __v4l2_async_notifier_add_subdev(notifier, asd);
699 if (ret) {
700 kfree(asd);
701 return ERR_PTR(ret);
702 }
703
704 return asd;
705}
706EXPORT_SYMBOL_GPL(__v4l2_async_notifier_add_i2c_subdev);
707
708int v4l2_async_register_subdev(struct v4l2_subdev *sd)
709{
710 struct v4l2_async_notifier *subdev_notifier;
711 struct v4l2_async_notifier *notifier;
712 int ret;
713
714 /*
715 * No reference taken. The reference is held by the device
716 * (struct v4l2_subdev.dev), and async sub-device does not
717 * exist independently of the device at any point of time.
718 */
719 if (!sd->fwnode && sd->dev)
720 sd->fwnode = dev_fwnode(sd->dev);
721
722 mutex_lock(&list_lock);
723
724 INIT_LIST_HEAD(&sd->async_list);
725
726 list_for_each_entry(notifier, ¬ifier_list, list) {
727 struct v4l2_device *v4l2_dev =
728 v4l2_async_notifier_find_v4l2_dev(notifier);
729 struct v4l2_async_subdev *asd;
730
731 if (!v4l2_dev)
732 continue;
733
734 asd = v4l2_async_find_match(notifier, sd);
735 if (!asd)
736 continue;
737
738 ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
739 if (ret)
740 goto err_unbind;
741
742 ret = v4l2_async_notifier_try_complete(notifier);
743 if (ret)
744 goto err_unbind;
745
746 goto out_unlock;
747 }
748
749 /* None matched, wait for hot-plugging */
750 list_add(&sd->async_list, &subdev_list);
751
752out_unlock:
753 mutex_unlock(&list_lock);
754
755 return 0;
756
757err_unbind:
758 /*
759 * Complete failed. Unbind the sub-devices bound through registering
760 * this async sub-device.
761 */
762 subdev_notifier = v4l2_async_find_subdev_notifier(sd);
763 if (subdev_notifier)
764 v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
765
766 if (sd->asd)
767 v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
768 v4l2_async_cleanup(sd);
769
770 mutex_unlock(&list_lock);
771
772 return ret;
773}
774EXPORT_SYMBOL(v4l2_async_register_subdev);
775
776void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
777{
778 if (!sd->async_list.next)
779 return;
780
781 mutex_lock(&list_lock);
782
783 __v4l2_async_notifier_unregister(sd->subdev_notifier);
784 __v4l2_async_notifier_cleanup(sd->subdev_notifier);
785 kfree(sd->subdev_notifier);
786 sd->subdev_notifier = NULL;
787
788 if (sd->asd) {
789 struct v4l2_async_notifier *notifier = sd->notifier;
790
791 list_add(&sd->asd->list, ¬ifier->waiting);
792
793 v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
794 }
795
796 v4l2_async_cleanup(sd);
797
798 mutex_unlock(&list_lock);
799}
800EXPORT_SYMBOL(v4l2_async_unregister_subdev);
801
802static void print_waiting_subdev(struct seq_file *s,
803 struct v4l2_async_subdev *asd)
804{
805 switch (asd->match_type) {
806 case V4L2_ASYNC_MATCH_I2C:
807 seq_printf(s, " [i2c] dev=%d-%04x\n", asd->match.i2c.adapter_id,
808 asd->match.i2c.address);
809 break;
810 case V4L2_ASYNC_MATCH_FWNODE: {
811 struct fwnode_handle *devnode, *fwnode = asd->match.fwnode;
812
813 devnode = fwnode_graph_is_endpoint(fwnode) ?
814 fwnode_graph_get_port_parent(fwnode) :
815 fwnode_handle_get(fwnode);
816
817 seq_printf(s, " [fwnode] dev=%s, node=%pfw\n",
818 devnode->dev ? dev_name(devnode->dev) : "nil",
819 fwnode);
820
821 fwnode_handle_put(devnode);
822 break;
823 }
824 }
825}
826
827static const char *
828v4l2_async_notifier_name(struct v4l2_async_notifier *notifier)
829{
830 if (notifier->v4l2_dev)
831 return notifier->v4l2_dev->name;
832 else if (notifier->sd)
833 return notifier->sd->name;
834 else
835 return "nil";
836}
837
838static int pending_subdevs_show(struct seq_file *s, void *data)
839{
840 struct v4l2_async_notifier *notif;
841 struct v4l2_async_subdev *asd;
842
843 mutex_lock(&list_lock);
844
845 list_for_each_entry(notif, ¬ifier_list, list) {
846 seq_printf(s, "%s:\n", v4l2_async_notifier_name(notif));
847 list_for_each_entry(asd, ¬if->waiting, list)
848 print_waiting_subdev(s, asd);
849 }
850
851 mutex_unlock(&list_lock);
852
853 return 0;
854}
855DEFINE_SHOW_ATTRIBUTE(pending_subdevs);
856
857static struct dentry *v4l2_async_debugfs_dir;
858
859static int __init v4l2_async_init(void)
860{
861 v4l2_async_debugfs_dir = debugfs_create_dir("v4l2-async", NULL);
862 debugfs_create_file("pending_async_subdevices", 0444,
863 v4l2_async_debugfs_dir, NULL,
864 &pending_subdevs_fops);
865
866 return 0;
867}
868
869static void __exit v4l2_async_exit(void)
870{
871 debugfs_remove_recursive(v4l2_async_debugfs_dir);
872}
873
874subsys_initcall(v4l2_async_init);
875module_exit(v4l2_async_exit);
876
877MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
878MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
879MODULE_AUTHOR("Ezequiel Garcia <ezequiel@collabora.com>");
880MODULE_LICENSE("GPL");