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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_nf_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_nf_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_nf_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 void v4l2_async_nf_call_destroy(struct v4l2_async_notifier *n,
56 struct v4l2_async_subdev *asd)
57{
58 if (!n->ops || !n->ops->destroy)
59 return;
60
61 n->ops->destroy(asd);
62}
63
64static bool match_i2c(struct v4l2_async_notifier *notifier,
65 struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
66{
67#if IS_ENABLED(CONFIG_I2C)
68 struct i2c_client *client = i2c_verify_client(sd->dev);
69
70 return client &&
71 asd->match.i2c.adapter_id == client->adapter->nr &&
72 asd->match.i2c.address == client->addr;
73#else
74 return false;
75#endif
76}
77
78static bool
79match_fwnode_one(struct v4l2_async_notifier *notifier,
80 struct v4l2_subdev *sd, struct fwnode_handle *sd_fwnode,
81 struct v4l2_async_subdev *asd)
82{
83 struct fwnode_handle *other_fwnode;
84 struct fwnode_handle *dev_fwnode;
85 bool asd_fwnode_is_ep;
86 bool sd_fwnode_is_ep;
87 struct device *dev;
88
89 /*
90 * Both the subdev and the async subdev can provide either an endpoint
91 * fwnode or a device fwnode. Start with the simple case of direct
92 * fwnode matching.
93 */
94 if (sd_fwnode == asd->match.fwnode)
95 return true;
96
97 /*
98 * Otherwise, check if the sd fwnode and the asd fwnode refer to an
99 * endpoint or a device. If they're of the same type, there's no match.
100 * Technically speaking this checks if the nodes refer to a connected
101 * endpoint, which is the simplest check that works for both OF and
102 * ACPI. This won't make a difference, as drivers should not try to
103 * match unconnected endpoints.
104 */
105 sd_fwnode_is_ep = fwnode_graph_is_endpoint(sd_fwnode);
106 asd_fwnode_is_ep = fwnode_graph_is_endpoint(asd->match.fwnode);
107
108 if (sd_fwnode_is_ep == asd_fwnode_is_ep)
109 return false;
110
111 /*
112 * The sd and asd fwnodes are of different types. Get the device fwnode
113 * parent of the endpoint fwnode, and compare it with the other fwnode.
114 */
115 if (sd_fwnode_is_ep) {
116 dev_fwnode = fwnode_graph_get_port_parent(sd_fwnode);
117 other_fwnode = asd->match.fwnode;
118 } else {
119 dev_fwnode = fwnode_graph_get_port_parent(asd->match.fwnode);
120 other_fwnode = sd_fwnode;
121 }
122
123 fwnode_handle_put(dev_fwnode);
124
125 if (dev_fwnode != other_fwnode)
126 return false;
127
128 /*
129 * We have a heterogeneous match. Retrieve the struct device of the side
130 * that matched on a device fwnode to print its driver name.
131 */
132 if (sd_fwnode_is_ep)
133 dev = notifier->v4l2_dev ? notifier->v4l2_dev->dev
134 : notifier->sd->dev;
135 else
136 dev = sd->dev;
137
138 if (dev && dev->driver) {
139 if (sd_fwnode_is_ep)
140 dev_warn(dev, "Driver %s uses device fwnode, incorrect match may occur\n",
141 dev->driver->name);
142 dev_notice(dev, "Consider updating driver %s to match on endpoints\n",
143 dev->driver->name);
144 }
145
146 return true;
147}
148
149static bool match_fwnode(struct v4l2_async_notifier *notifier,
150 struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
151{
152 if (match_fwnode_one(notifier, sd, sd->fwnode, asd))
153 return true;
154
155 /* Also check the secondary fwnode. */
156 if (IS_ERR_OR_NULL(sd->fwnode->secondary))
157 return false;
158
159 return match_fwnode_one(notifier, sd, sd->fwnode->secondary, asd);
160}
161
162static LIST_HEAD(subdev_list);
163static LIST_HEAD(notifier_list);
164static DEFINE_MUTEX(list_lock);
165
166static struct v4l2_async_subdev *
167v4l2_async_find_match(struct v4l2_async_notifier *notifier,
168 struct v4l2_subdev *sd)
169{
170 bool (*match)(struct v4l2_async_notifier *notifier,
171 struct v4l2_subdev *sd, struct v4l2_async_subdev *asd);
172 struct v4l2_async_subdev *asd;
173
174 list_for_each_entry(asd, ¬ifier->waiting, list) {
175 /* bus_type has been verified valid before */
176 switch (asd->match_type) {
177 case V4L2_ASYNC_MATCH_I2C:
178 match = match_i2c;
179 break;
180 case V4L2_ASYNC_MATCH_FWNODE:
181 match = match_fwnode;
182 break;
183 default:
184 /* Cannot happen, unless someone breaks us */
185 WARN_ON(true);
186 return NULL;
187 }
188
189 /* match cannot be NULL here */
190 if (match(notifier, sd, asd))
191 return asd;
192 }
193
194 return NULL;
195}
196
197/* Compare two async sub-device descriptors for equivalence */
198static bool asd_equal(struct v4l2_async_subdev *asd_x,
199 struct v4l2_async_subdev *asd_y)
200{
201 if (asd_x->match_type != asd_y->match_type)
202 return false;
203
204 switch (asd_x->match_type) {
205 case V4L2_ASYNC_MATCH_I2C:
206 return asd_x->match.i2c.adapter_id ==
207 asd_y->match.i2c.adapter_id &&
208 asd_x->match.i2c.address ==
209 asd_y->match.i2c.address;
210 case V4L2_ASYNC_MATCH_FWNODE:
211 return asd_x->match.fwnode == asd_y->match.fwnode;
212 default:
213 break;
214 }
215
216 return false;
217}
218
219/* Find the sub-device notifier registered by a sub-device driver. */
220static struct v4l2_async_notifier *
221v4l2_async_find_subdev_notifier(struct v4l2_subdev *sd)
222{
223 struct v4l2_async_notifier *n;
224
225 list_for_each_entry(n, ¬ifier_list, list)
226 if (n->sd == sd)
227 return n;
228
229 return NULL;
230}
231
232/* Get v4l2_device related to the notifier if one can be found. */
233static struct v4l2_device *
234v4l2_async_nf_find_v4l2_dev(struct v4l2_async_notifier *notifier)
235{
236 while (notifier->parent)
237 notifier = notifier->parent;
238
239 return notifier->v4l2_dev;
240}
241
242/*
243 * Return true if all child sub-device notifiers are complete, false otherwise.
244 */
245static bool
246v4l2_async_nf_can_complete(struct v4l2_async_notifier *notifier)
247{
248 struct v4l2_subdev *sd;
249
250 if (!list_empty(¬ifier->waiting))
251 return false;
252
253 list_for_each_entry(sd, ¬ifier->done, async_list) {
254 struct v4l2_async_notifier *subdev_notifier =
255 v4l2_async_find_subdev_notifier(sd);
256
257 if (subdev_notifier &&
258 !v4l2_async_nf_can_complete(subdev_notifier))
259 return false;
260 }
261
262 return true;
263}
264
265/*
266 * Complete the master notifier if possible. This is done when all async
267 * sub-devices have been bound; v4l2_device is also available then.
268 */
269static int
270v4l2_async_nf_try_complete(struct v4l2_async_notifier *notifier)
271{
272 /* Quick check whether there are still more sub-devices here. */
273 if (!list_empty(¬ifier->waiting))
274 return 0;
275
276 /* Check the entire notifier tree; find the root notifier first. */
277 while (notifier->parent)
278 notifier = notifier->parent;
279
280 /* This is root if it has v4l2_dev. */
281 if (!notifier->v4l2_dev)
282 return 0;
283
284 /* Is everything ready? */
285 if (!v4l2_async_nf_can_complete(notifier))
286 return 0;
287
288 return v4l2_async_nf_call_complete(notifier);
289}
290
291static int
292v4l2_async_nf_try_all_subdevs(struct v4l2_async_notifier *notifier);
293
294static int v4l2_async_create_ancillary_links(struct v4l2_async_notifier *n,
295 struct v4l2_subdev *sd)
296{
297 struct media_link *link = NULL;
298
299#if IS_ENABLED(CONFIG_MEDIA_CONTROLLER)
300
301 if (sd->entity.function != MEDIA_ENT_F_LENS &&
302 sd->entity.function != MEDIA_ENT_F_FLASH)
303 return 0;
304
305 link = media_create_ancillary_link(&n->sd->entity, &sd->entity);
306
307#endif
308
309 return IS_ERR(link) ? PTR_ERR(link) : 0;
310}
311
312static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
313 struct v4l2_device *v4l2_dev,
314 struct v4l2_subdev *sd,
315 struct v4l2_async_subdev *asd)
316{
317 struct v4l2_async_notifier *subdev_notifier;
318 int ret;
319
320 ret = v4l2_device_register_subdev(v4l2_dev, sd);
321 if (ret < 0)
322 return ret;
323
324 ret = v4l2_async_nf_call_bound(notifier, sd, asd);
325 if (ret < 0) {
326 v4l2_device_unregister_subdev(sd);
327 return ret;
328 }
329
330 /*
331 * Depending of the function of the entities involved, we may want to
332 * create links between them (for example between a sensor and its lens
333 * or between a sensor's source pad and the connected device's sink
334 * pad).
335 */
336 ret = v4l2_async_create_ancillary_links(notifier, sd);
337 if (ret) {
338 v4l2_async_nf_call_unbind(notifier, sd, asd);
339 v4l2_device_unregister_subdev(sd);
340 return ret;
341 }
342
343 /* Remove from the waiting list */
344 list_del(&asd->list);
345 sd->asd = asd;
346 sd->notifier = notifier;
347
348 /* Move from the global subdevice list to notifier's done */
349 list_move(&sd->async_list, ¬ifier->done);
350
351 /*
352 * See if the sub-device has a notifier. If not, return here.
353 */
354 subdev_notifier = v4l2_async_find_subdev_notifier(sd);
355 if (!subdev_notifier || subdev_notifier->parent)
356 return 0;
357
358 /*
359 * Proceed with checking for the sub-device notifier's async
360 * sub-devices, and return the result. The error will be handled by the
361 * caller.
362 */
363 subdev_notifier->parent = notifier;
364
365 return v4l2_async_nf_try_all_subdevs(subdev_notifier);
366}
367
368/* Test all async sub-devices in a notifier for a match. */
369static int
370v4l2_async_nf_try_all_subdevs(struct v4l2_async_notifier *notifier)
371{
372 struct v4l2_device *v4l2_dev =
373 v4l2_async_nf_find_v4l2_dev(notifier);
374 struct v4l2_subdev *sd;
375
376 if (!v4l2_dev)
377 return 0;
378
379again:
380 list_for_each_entry(sd, &subdev_list, async_list) {
381 struct v4l2_async_subdev *asd;
382 int ret;
383
384 asd = v4l2_async_find_match(notifier, sd);
385 if (!asd)
386 continue;
387
388 ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
389 if (ret < 0)
390 return ret;
391
392 /*
393 * v4l2_async_match_notify() may lead to registering a
394 * new notifier and thus changing the async subdevs
395 * list. In order to proceed safely from here, restart
396 * parsing the list from the beginning.
397 */
398 goto again;
399 }
400
401 return 0;
402}
403
404static void v4l2_async_cleanup(struct v4l2_subdev *sd)
405{
406 v4l2_device_unregister_subdev(sd);
407 /*
408 * Subdevice driver will reprobe and put the subdev back
409 * onto the list
410 */
411 list_del_init(&sd->async_list);
412 sd->asd = NULL;
413}
414
415/* Unbind all sub-devices in the notifier tree. */
416static void
417v4l2_async_nf_unbind_all_subdevs(struct v4l2_async_notifier *notifier)
418{
419 struct v4l2_subdev *sd, *tmp;
420
421 list_for_each_entry_safe(sd, tmp, ¬ifier->done, async_list) {
422 struct v4l2_async_notifier *subdev_notifier =
423 v4l2_async_find_subdev_notifier(sd);
424
425 if (subdev_notifier)
426 v4l2_async_nf_unbind_all_subdevs(subdev_notifier);
427
428 v4l2_async_nf_call_unbind(notifier, sd, sd->asd);
429 v4l2_async_cleanup(sd);
430
431 list_move(&sd->async_list, &subdev_list);
432 }
433
434 notifier->parent = NULL;
435}
436
437/* See if an async sub-device can be found in a notifier's lists. */
438static bool
439__v4l2_async_nf_has_async_subdev(struct v4l2_async_notifier *notifier,
440 struct v4l2_async_subdev *asd)
441{
442 struct v4l2_async_subdev *asd_y;
443 struct v4l2_subdev *sd;
444
445 list_for_each_entry(asd_y, ¬ifier->waiting, list)
446 if (asd_equal(asd, asd_y))
447 return true;
448
449 list_for_each_entry(sd, ¬ifier->done, async_list) {
450 if (WARN_ON(!sd->asd))
451 continue;
452
453 if (asd_equal(asd, sd->asd))
454 return true;
455 }
456
457 return false;
458}
459
460/*
461 * Find out whether an async sub-device was set up already or
462 * whether it exists in a given notifier before @this_index.
463 * If @this_index < 0, search the notifier's entire @asd_list.
464 */
465static bool
466v4l2_async_nf_has_async_subdev(struct v4l2_async_notifier *notifier,
467 struct v4l2_async_subdev *asd, int this_index)
468{
469 struct v4l2_async_subdev *asd_y;
470 int j = 0;
471
472 lockdep_assert_held(&list_lock);
473
474 /* Check that an asd is not being added more than once. */
475 list_for_each_entry(asd_y, ¬ifier->asd_list, asd_list) {
476 if (this_index >= 0 && j++ >= this_index)
477 break;
478 if (asd_equal(asd, asd_y))
479 return true;
480 }
481
482 /* Check that an asd does not exist in other notifiers. */
483 list_for_each_entry(notifier, ¬ifier_list, list)
484 if (__v4l2_async_nf_has_async_subdev(notifier, asd))
485 return true;
486
487 return false;
488}
489
490static int v4l2_async_nf_asd_valid(struct v4l2_async_notifier *notifier,
491 struct v4l2_async_subdev *asd,
492 int this_index)
493{
494 struct device *dev =
495 notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
496
497 if (!asd)
498 return -EINVAL;
499
500 switch (asd->match_type) {
501 case V4L2_ASYNC_MATCH_I2C:
502 case V4L2_ASYNC_MATCH_FWNODE:
503 if (v4l2_async_nf_has_async_subdev(notifier, asd, this_index)) {
504 dev_dbg(dev, "subdev descriptor already listed in this or other notifiers\n");
505 return -EEXIST;
506 }
507 break;
508 default:
509 dev_err(dev, "Invalid match type %u on %p\n",
510 asd->match_type, asd);
511 return -EINVAL;
512 }
513
514 return 0;
515}
516
517void v4l2_async_nf_init(struct v4l2_async_notifier *notifier)
518{
519 INIT_LIST_HEAD(¬ifier->asd_list);
520}
521EXPORT_SYMBOL(v4l2_async_nf_init);
522
523static int __v4l2_async_nf_register(struct v4l2_async_notifier *notifier)
524{
525 struct v4l2_async_subdev *asd;
526 int ret, i = 0;
527
528 INIT_LIST_HEAD(¬ifier->waiting);
529 INIT_LIST_HEAD(¬ifier->done);
530
531 mutex_lock(&list_lock);
532
533 list_for_each_entry(asd, ¬ifier->asd_list, asd_list) {
534 ret = v4l2_async_nf_asd_valid(notifier, asd, i++);
535 if (ret)
536 goto err_unlock;
537
538 list_add_tail(&asd->list, ¬ifier->waiting);
539 }
540
541 ret = v4l2_async_nf_try_all_subdevs(notifier);
542 if (ret < 0)
543 goto err_unbind;
544
545 ret = v4l2_async_nf_try_complete(notifier);
546 if (ret < 0)
547 goto err_unbind;
548
549 /* Keep also completed notifiers on the list */
550 list_add(¬ifier->list, ¬ifier_list);
551
552 mutex_unlock(&list_lock);
553
554 return 0;
555
556err_unbind:
557 /*
558 * On failure, unbind all sub-devices registered through this notifier.
559 */
560 v4l2_async_nf_unbind_all_subdevs(notifier);
561
562err_unlock:
563 mutex_unlock(&list_lock);
564
565 return ret;
566}
567
568int v4l2_async_nf_register(struct v4l2_device *v4l2_dev,
569 struct v4l2_async_notifier *notifier)
570{
571 int ret;
572
573 if (WARN_ON(!v4l2_dev || notifier->sd))
574 return -EINVAL;
575
576 notifier->v4l2_dev = v4l2_dev;
577
578 ret = __v4l2_async_nf_register(notifier);
579 if (ret)
580 notifier->v4l2_dev = NULL;
581
582 return ret;
583}
584EXPORT_SYMBOL(v4l2_async_nf_register);
585
586int v4l2_async_subdev_nf_register(struct v4l2_subdev *sd,
587 struct v4l2_async_notifier *notifier)
588{
589 int ret;
590
591 if (WARN_ON(!sd || notifier->v4l2_dev))
592 return -EINVAL;
593
594 notifier->sd = sd;
595
596 ret = __v4l2_async_nf_register(notifier);
597 if (ret)
598 notifier->sd = NULL;
599
600 return ret;
601}
602EXPORT_SYMBOL(v4l2_async_subdev_nf_register);
603
604static void
605__v4l2_async_nf_unregister(struct v4l2_async_notifier *notifier)
606{
607 if (!notifier || (!notifier->v4l2_dev && !notifier->sd))
608 return;
609
610 v4l2_async_nf_unbind_all_subdevs(notifier);
611
612 notifier->sd = NULL;
613 notifier->v4l2_dev = NULL;
614
615 list_del(¬ifier->list);
616}
617
618void v4l2_async_nf_unregister(struct v4l2_async_notifier *notifier)
619{
620 mutex_lock(&list_lock);
621
622 __v4l2_async_nf_unregister(notifier);
623
624 mutex_unlock(&list_lock);
625}
626EXPORT_SYMBOL(v4l2_async_nf_unregister);
627
628static void __v4l2_async_nf_cleanup(struct v4l2_async_notifier *notifier)
629{
630 struct v4l2_async_subdev *asd, *tmp;
631
632 if (!notifier || !notifier->asd_list.next)
633 return;
634
635 list_for_each_entry_safe(asd, tmp, ¬ifier->asd_list, asd_list) {
636 switch (asd->match_type) {
637 case V4L2_ASYNC_MATCH_FWNODE:
638 fwnode_handle_put(asd->match.fwnode);
639 break;
640 default:
641 break;
642 }
643
644 list_del(&asd->asd_list);
645 v4l2_async_nf_call_destroy(notifier, asd);
646 kfree(asd);
647 }
648}
649
650void v4l2_async_nf_cleanup(struct v4l2_async_notifier *notifier)
651{
652 mutex_lock(&list_lock);
653
654 __v4l2_async_nf_cleanup(notifier);
655
656 mutex_unlock(&list_lock);
657}
658EXPORT_SYMBOL_GPL(v4l2_async_nf_cleanup);
659
660int __v4l2_async_nf_add_subdev(struct v4l2_async_notifier *notifier,
661 struct v4l2_async_subdev *asd)
662{
663 int ret;
664
665 mutex_lock(&list_lock);
666
667 ret = v4l2_async_nf_asd_valid(notifier, asd, -1);
668 if (ret)
669 goto unlock;
670
671 list_add_tail(&asd->asd_list, ¬ifier->asd_list);
672
673unlock:
674 mutex_unlock(&list_lock);
675 return ret;
676}
677EXPORT_SYMBOL_GPL(__v4l2_async_nf_add_subdev);
678
679struct v4l2_async_subdev *
680__v4l2_async_nf_add_fwnode(struct v4l2_async_notifier *notifier,
681 struct fwnode_handle *fwnode,
682 unsigned int asd_struct_size)
683{
684 struct v4l2_async_subdev *asd;
685 int ret;
686
687 asd = kzalloc(asd_struct_size, GFP_KERNEL);
688 if (!asd)
689 return ERR_PTR(-ENOMEM);
690
691 asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
692 asd->match.fwnode = fwnode_handle_get(fwnode);
693
694 ret = __v4l2_async_nf_add_subdev(notifier, asd);
695 if (ret) {
696 fwnode_handle_put(fwnode);
697 kfree(asd);
698 return ERR_PTR(ret);
699 }
700
701 return asd;
702}
703EXPORT_SYMBOL_GPL(__v4l2_async_nf_add_fwnode);
704
705struct v4l2_async_subdev *
706__v4l2_async_nf_add_fwnode_remote(struct v4l2_async_notifier *notif,
707 struct fwnode_handle *endpoint,
708 unsigned int asd_struct_size)
709{
710 struct v4l2_async_subdev *asd;
711 struct fwnode_handle *remote;
712
713 remote = fwnode_graph_get_remote_endpoint(endpoint);
714 if (!remote)
715 return ERR_PTR(-ENOTCONN);
716
717 asd = __v4l2_async_nf_add_fwnode(notif, remote, asd_struct_size);
718 /*
719 * Calling __v4l2_async_nf_add_fwnode grabs a refcount,
720 * so drop the one we got in fwnode_graph_get_remote_port_parent.
721 */
722 fwnode_handle_put(remote);
723 return asd;
724}
725EXPORT_SYMBOL_GPL(__v4l2_async_nf_add_fwnode_remote);
726
727struct v4l2_async_subdev *
728__v4l2_async_nf_add_i2c(struct v4l2_async_notifier *notifier, int adapter_id,
729 unsigned short address, unsigned int asd_struct_size)
730{
731 struct v4l2_async_subdev *asd;
732 int ret;
733
734 asd = kzalloc(asd_struct_size, GFP_KERNEL);
735 if (!asd)
736 return ERR_PTR(-ENOMEM);
737
738 asd->match_type = V4L2_ASYNC_MATCH_I2C;
739 asd->match.i2c.adapter_id = adapter_id;
740 asd->match.i2c.address = address;
741
742 ret = __v4l2_async_nf_add_subdev(notifier, asd);
743 if (ret) {
744 kfree(asd);
745 return ERR_PTR(ret);
746 }
747
748 return asd;
749}
750EXPORT_SYMBOL_GPL(__v4l2_async_nf_add_i2c);
751
752int v4l2_async_register_subdev(struct v4l2_subdev *sd)
753{
754 struct v4l2_async_notifier *subdev_notifier;
755 struct v4l2_async_notifier *notifier;
756 int ret;
757
758 /*
759 * No reference taken. The reference is held by the device
760 * (struct v4l2_subdev.dev), and async sub-device does not
761 * exist independently of the device at any point of time.
762 */
763 if (!sd->fwnode && sd->dev)
764 sd->fwnode = dev_fwnode(sd->dev);
765
766 mutex_lock(&list_lock);
767
768 INIT_LIST_HEAD(&sd->async_list);
769
770 list_for_each_entry(notifier, ¬ifier_list, list) {
771 struct v4l2_device *v4l2_dev =
772 v4l2_async_nf_find_v4l2_dev(notifier);
773 struct v4l2_async_subdev *asd;
774
775 if (!v4l2_dev)
776 continue;
777
778 asd = v4l2_async_find_match(notifier, sd);
779 if (!asd)
780 continue;
781
782 ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
783 if (ret)
784 goto err_unbind;
785
786 ret = v4l2_async_nf_try_complete(notifier);
787 if (ret)
788 goto err_unbind;
789
790 goto out_unlock;
791 }
792
793 /* None matched, wait for hot-plugging */
794 list_add(&sd->async_list, &subdev_list);
795
796out_unlock:
797 mutex_unlock(&list_lock);
798
799 return 0;
800
801err_unbind:
802 /*
803 * Complete failed. Unbind the sub-devices bound through registering
804 * this async sub-device.
805 */
806 subdev_notifier = v4l2_async_find_subdev_notifier(sd);
807 if (subdev_notifier)
808 v4l2_async_nf_unbind_all_subdevs(subdev_notifier);
809
810 if (sd->asd)
811 v4l2_async_nf_call_unbind(notifier, sd, sd->asd);
812 v4l2_async_cleanup(sd);
813
814 mutex_unlock(&list_lock);
815
816 return ret;
817}
818EXPORT_SYMBOL(v4l2_async_register_subdev);
819
820void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
821{
822 if (!sd->async_list.next)
823 return;
824
825 mutex_lock(&list_lock);
826
827 __v4l2_async_nf_unregister(sd->subdev_notifier);
828 __v4l2_async_nf_cleanup(sd->subdev_notifier);
829 kfree(sd->subdev_notifier);
830 sd->subdev_notifier = NULL;
831
832 if (sd->asd) {
833 struct v4l2_async_notifier *notifier = sd->notifier;
834
835 list_add(&sd->asd->list, ¬ifier->waiting);
836
837 v4l2_async_nf_call_unbind(notifier, sd, sd->asd);
838 }
839
840 v4l2_async_cleanup(sd);
841
842 mutex_unlock(&list_lock);
843}
844EXPORT_SYMBOL(v4l2_async_unregister_subdev);
845
846static void print_waiting_subdev(struct seq_file *s,
847 struct v4l2_async_subdev *asd)
848{
849 switch (asd->match_type) {
850 case V4L2_ASYNC_MATCH_I2C:
851 seq_printf(s, " [i2c] dev=%d-%04x\n", asd->match.i2c.adapter_id,
852 asd->match.i2c.address);
853 break;
854 case V4L2_ASYNC_MATCH_FWNODE: {
855 struct fwnode_handle *devnode, *fwnode = asd->match.fwnode;
856
857 devnode = fwnode_graph_is_endpoint(fwnode) ?
858 fwnode_graph_get_port_parent(fwnode) :
859 fwnode_handle_get(fwnode);
860
861 seq_printf(s, " [fwnode] dev=%s, node=%pfw\n",
862 devnode->dev ? dev_name(devnode->dev) : "nil",
863 fwnode);
864
865 fwnode_handle_put(devnode);
866 break;
867 }
868 }
869}
870
871static const char *
872v4l2_async_nf_name(struct v4l2_async_notifier *notifier)
873{
874 if (notifier->v4l2_dev)
875 return notifier->v4l2_dev->name;
876 else if (notifier->sd)
877 return notifier->sd->name;
878 else
879 return "nil";
880}
881
882static int pending_subdevs_show(struct seq_file *s, void *data)
883{
884 struct v4l2_async_notifier *notif;
885 struct v4l2_async_subdev *asd;
886
887 mutex_lock(&list_lock);
888
889 list_for_each_entry(notif, ¬ifier_list, list) {
890 seq_printf(s, "%s:\n", v4l2_async_nf_name(notif));
891 list_for_each_entry(asd, ¬if->waiting, list)
892 print_waiting_subdev(s, asd);
893 }
894
895 mutex_unlock(&list_lock);
896
897 return 0;
898}
899DEFINE_SHOW_ATTRIBUTE(pending_subdevs);
900
901static struct dentry *v4l2_async_debugfs_dir;
902
903static int __init v4l2_async_init(void)
904{
905 v4l2_async_debugfs_dir = debugfs_create_dir("v4l2-async", NULL);
906 debugfs_create_file("pending_async_subdevices", 0444,
907 v4l2_async_debugfs_dir, NULL,
908 &pending_subdevs_fops);
909
910 return 0;
911}
912
913static void __exit v4l2_async_exit(void)
914{
915 debugfs_remove_recursive(v4l2_async_debugfs_dir);
916}
917
918subsys_initcall(v4l2_async_init);
919module_exit(v4l2_async_exit);
920
921MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
922MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
923MODULE_AUTHOR("Ezequiel Garcia <ezequiel@collabora.com>");
924MODULE_LICENSE("GPL");