Commit | Line | Data |
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53e269c1 LP |
1 | /* |
2 | * Media entity | |
3 | * | |
4 | * Copyright (C) 2010 Nokia Corporation | |
5 | * | |
6 | * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com> | |
7 | * Sakari Ailus <sakari.ailus@iki.fi> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
21 | */ | |
22 | ||
5c7b25b9 | 23 | #include <linux/bitmap.h> |
53e269c1 LP |
24 | #include <linux/module.h> |
25 | #include <linux/slab.h> | |
26 | #include <media/media-entity.h> | |
503c3d82 | 27 | #include <media/media-device.h> |
53e269c1 LP |
28 | |
29 | /** | |
30 | * media_entity_init - Initialize a media entity | |
31 | * | |
32 | * @num_pads: Total number of sink and source pads. | |
33 | * @extra_links: Initial estimate of the number of extra links. | |
34 | * @pads: Array of 'num_pads' pads. | |
35 | * | |
36 | * The total number of pads is an intrinsic property of entities known by the | |
37 | * entity driver, while the total number of links depends on hardware design | |
38 | * and is an extrinsic property unknown to the entity driver. However, in most | |
39 | * use cases the entity driver can guess the number of links which can safely | |
40 | * be assumed to be equal to or larger than the number of pads. | |
41 | * | |
42 | * For those reasons the links array can be preallocated based on the entity | |
43 | * driver guess and will be reallocated later if extra links need to be | |
44 | * created. | |
45 | * | |
46 | * This function allocates a links array with enough space to hold at least | |
47 | * 'num_pads' + 'extra_links' elements. The media_entity::max_links field will | |
48 | * be set to the number of allocated elements. | |
49 | * | |
50 | * The pads array is managed by the entity driver and passed to | |
51 | * media_entity_init() where its pointer will be stored in the entity structure. | |
52 | */ | |
53 | int | |
54 | media_entity_init(struct media_entity *entity, u16 num_pads, | |
55 | struct media_pad *pads, u16 extra_links) | |
56 | { | |
57 | struct media_link *links; | |
58 | unsigned int max_links = num_pads + extra_links; | |
59 | unsigned int i; | |
60 | ||
61 | links = kzalloc(max_links * sizeof(links[0]), GFP_KERNEL); | |
62 | if (links == NULL) | |
63 | return -ENOMEM; | |
64 | ||
65 | entity->group_id = 0; | |
66 | entity->max_links = max_links; | |
67 | entity->num_links = 0; | |
68 | entity->num_backlinks = 0; | |
69 | entity->num_pads = num_pads; | |
70 | entity->pads = pads; | |
71 | entity->links = links; | |
72 | ||
73 | for (i = 0; i < num_pads; i++) { | |
74 | pads[i].entity = entity; | |
75 | pads[i].index = i; | |
76 | } | |
77 | ||
78 | return 0; | |
79 | } | |
80 | EXPORT_SYMBOL_GPL(media_entity_init); | |
81 | ||
82 | void | |
83 | media_entity_cleanup(struct media_entity *entity) | |
84 | { | |
85 | kfree(entity->links); | |
86 | } | |
87 | EXPORT_SYMBOL_GPL(media_entity_cleanup); | |
88 | ||
a5ccc48a SA |
89 | /* ----------------------------------------------------------------------------- |
90 | * Graph traversal | |
91 | */ | |
92 | ||
93 | static struct media_entity * | |
94 | media_entity_other(struct media_entity *entity, struct media_link *link) | |
95 | { | |
96 | if (link->source->entity == entity) | |
97 | return link->sink->entity; | |
98 | else | |
99 | return link->source->entity; | |
100 | } | |
101 | ||
102 | /* push an entity to traversal stack */ | |
103 | static void stack_push(struct media_entity_graph *graph, | |
104 | struct media_entity *entity) | |
105 | { | |
106 | if (graph->top == MEDIA_ENTITY_ENUM_MAX_DEPTH - 1) { | |
107 | WARN_ON(1); | |
108 | return; | |
109 | } | |
110 | graph->top++; | |
111 | graph->stack[graph->top].link = 0; | |
112 | graph->stack[graph->top].entity = entity; | |
113 | } | |
114 | ||
115 | static struct media_entity *stack_pop(struct media_entity_graph *graph) | |
116 | { | |
117 | struct media_entity *entity; | |
118 | ||
119 | entity = graph->stack[graph->top].entity; | |
120 | graph->top--; | |
121 | ||
122 | return entity; | |
123 | } | |
124 | ||
a5ccc48a SA |
125 | #define link_top(en) ((en)->stack[(en)->top].link) |
126 | #define stack_top(en) ((en)->stack[(en)->top].entity) | |
127 | ||
128 | /** | |
129 | * media_entity_graph_walk_start - Start walking the media graph at a given entity | |
130 | * @graph: Media graph structure that will be used to walk the graph | |
131 | * @entity: Starting entity | |
132 | * | |
133 | * This function initializes the graph traversal structure to walk the entities | |
134 | * graph starting at the given entity. The traversal structure must not be | |
135 | * modified by the caller during graph traversal. When done the structure can | |
136 | * safely be freed. | |
137 | */ | |
138 | void media_entity_graph_walk_start(struct media_entity_graph *graph, | |
139 | struct media_entity *entity) | |
140 | { | |
141 | graph->top = 0; | |
142 | graph->stack[graph->top].entity = NULL; | |
5c7b25b9 LP |
143 | bitmap_zero(graph->entities, MEDIA_ENTITY_ENUM_MAX_ID); |
144 | ||
145 | if (WARN_ON(entity->id >= MEDIA_ENTITY_ENUM_MAX_ID)) | |
146 | return; | |
147 | ||
148 | __set_bit(entity->id, graph->entities); | |
a5ccc48a SA |
149 | stack_push(graph, entity); |
150 | } | |
151 | EXPORT_SYMBOL_GPL(media_entity_graph_walk_start); | |
152 | ||
153 | /** | |
154 | * media_entity_graph_walk_next - Get the next entity in the graph | |
155 | * @graph: Media graph structure | |
156 | * | |
157 | * Perform a depth-first traversal of the given media entities graph. | |
158 | * | |
159 | * The graph structure must have been previously initialized with a call to | |
160 | * media_entity_graph_walk_start(). | |
161 | * | |
162 | * Return the next entity in the graph or NULL if the whole graph have been | |
163 | * traversed. | |
164 | */ | |
165 | struct media_entity * | |
166 | media_entity_graph_walk_next(struct media_entity_graph *graph) | |
167 | { | |
168 | if (stack_top(graph) == NULL) | |
169 | return NULL; | |
170 | ||
171 | /* | |
172 | * Depth first search. Push entity to stack and continue from | |
173 | * top of the stack until no more entities on the level can be | |
174 | * found. | |
175 | */ | |
176 | while (link_top(graph) < stack_top(graph)->num_links) { | |
177 | struct media_entity *entity = stack_top(graph); | |
178 | struct media_link *link = &entity->links[link_top(graph)]; | |
179 | struct media_entity *next; | |
180 | ||
181 | /* The link is not enabled so we do not follow. */ | |
182 | if (!(link->flags & MEDIA_LNK_FL_ENABLED)) { | |
183 | link_top(graph)++; | |
184 | continue; | |
185 | } | |
186 | ||
187 | /* Get the entity in the other end of the link . */ | |
188 | next = media_entity_other(entity, link); | |
5c7b25b9 LP |
189 | if (WARN_ON(next->id >= MEDIA_ENTITY_ENUM_MAX_ID)) |
190 | return NULL; | |
a5ccc48a | 191 | |
5c7b25b9 LP |
192 | /* Has the entity already been visited? */ |
193 | if (__test_and_set_bit(next->id, graph->entities)) { | |
a5ccc48a SA |
194 | link_top(graph)++; |
195 | continue; | |
196 | } | |
197 | ||
198 | /* Push the new entity to stack and start over. */ | |
199 | link_top(graph)++; | |
200 | stack_push(graph, next); | |
201 | } | |
202 | ||
203 | return stack_pop(graph); | |
204 | } | |
205 | EXPORT_SYMBOL_GPL(media_entity_graph_walk_next); | |
206 | ||
e02188c9 LP |
207 | /* ----------------------------------------------------------------------------- |
208 | * Pipeline management | |
209 | */ | |
210 | ||
211 | /** | |
212 | * media_entity_pipeline_start - Mark a pipeline as streaming | |
213 | * @entity: Starting entity | |
214 | * @pipe: Media pipeline to be assigned to all entities in the pipeline. | |
215 | * | |
216 | * Mark all entities connected to a given entity through enabled links, either | |
217 | * directly or indirectly, as streaming. The given pipeline object is assigned to | |
218 | * every entity in the pipeline and stored in the media_entity pipe field. | |
219 | * | |
220 | * Calls to this function can be nested, in which case the same number of | |
221 | * media_entity_pipeline_stop() calls will be required to stop streaming. The | |
222 | * pipeline pointer must be identical for all nested calls to | |
223 | * media_entity_pipeline_start(). | |
224 | */ | |
af88be38 SA |
225 | __must_check int media_entity_pipeline_start(struct media_entity *entity, |
226 | struct media_pipeline *pipe) | |
e02188c9 LP |
227 | { |
228 | struct media_device *mdev = entity->parent; | |
229 | struct media_entity_graph graph; | |
af88be38 SA |
230 | struct media_entity *entity_err = entity; |
231 | int ret; | |
e02188c9 LP |
232 | |
233 | mutex_lock(&mdev->graph_mutex); | |
234 | ||
235 | media_entity_graph_walk_start(&graph, entity); | |
236 | ||
237 | while ((entity = media_entity_graph_walk_next(&graph))) { | |
de49c285 SA |
238 | DECLARE_BITMAP(active, entity->num_pads); |
239 | DECLARE_BITMAP(has_no_links, entity->num_pads); | |
af88be38 SA |
240 | unsigned int i; |
241 | ||
e02188c9 LP |
242 | entity->stream_count++; |
243 | WARN_ON(entity->pipe && entity->pipe != pipe); | |
244 | entity->pipe = pipe; | |
af88be38 SA |
245 | |
246 | /* Already streaming --- no need to check. */ | |
247 | if (entity->stream_count > 1) | |
248 | continue; | |
249 | ||
250 | if (!entity->ops || !entity->ops->link_validate) | |
251 | continue; | |
252 | ||
de49c285 SA |
253 | bitmap_zero(active, entity->num_pads); |
254 | bitmap_fill(has_no_links, entity->num_pads); | |
255 | ||
af88be38 SA |
256 | for (i = 0; i < entity->num_links; i++) { |
257 | struct media_link *link = &entity->links[i]; | |
de49c285 SA |
258 | struct media_pad *pad = link->sink->entity == entity |
259 | ? link->sink : link->source; | |
260 | ||
261 | /* Mark that a pad is connected by a link. */ | |
262 | bitmap_clear(has_no_links, pad->index, 1); | |
263 | ||
264 | /* | |
265 | * Pads that either do not need to connect or | |
266 | * are connected through an enabled link are | |
267 | * fine. | |
268 | */ | |
269 | if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) || | |
270 | link->flags & MEDIA_LNK_FL_ENABLED) | |
271 | bitmap_set(active, pad->index, 1); | |
272 | ||
273 | /* | |
274 | * Link validation will only take place for | |
275 | * sink ends of the link that are enabled. | |
276 | */ | |
277 | if (link->sink != pad || | |
278 | !(link->flags & MEDIA_LNK_FL_ENABLED)) | |
af88be38 SA |
279 | continue; |
280 | ||
281 | ret = entity->ops->link_validate(link); | |
282 | if (ret < 0 && ret != -ENOIOCTLCMD) | |
283 | goto error; | |
284 | } | |
de49c285 SA |
285 | |
286 | /* Either no links or validated links are fine. */ | |
287 | bitmap_or(active, active, has_no_links, entity->num_pads); | |
288 | ||
289 | if (!bitmap_full(active, entity->num_pads)) { | |
290 | ret = -EPIPE; | |
291 | goto error; | |
292 | } | |
e02188c9 LP |
293 | } |
294 | ||
295 | mutex_unlock(&mdev->graph_mutex); | |
af88be38 SA |
296 | |
297 | return 0; | |
298 | ||
299 | error: | |
300 | /* | |
301 | * Link validation on graph failed. We revert what we did and | |
302 | * return the error. | |
303 | */ | |
304 | media_entity_graph_walk_start(&graph, entity_err); | |
305 | ||
306 | while ((entity_err = media_entity_graph_walk_next(&graph))) { | |
307 | entity_err->stream_count--; | |
308 | if (entity_err->stream_count == 0) | |
309 | entity_err->pipe = NULL; | |
310 | ||
311 | /* | |
312 | * We haven't increased stream_count further than this | |
313 | * so we quit here. | |
314 | */ | |
315 | if (entity_err == entity) | |
316 | break; | |
317 | } | |
318 | ||
319 | mutex_unlock(&mdev->graph_mutex); | |
320 | ||
321 | return ret; | |
e02188c9 LP |
322 | } |
323 | EXPORT_SYMBOL_GPL(media_entity_pipeline_start); | |
324 | ||
325 | /** | |
326 | * media_entity_pipeline_stop - Mark a pipeline as not streaming | |
327 | * @entity: Starting entity | |
328 | * | |
329 | * Mark all entities connected to a given entity through enabled links, either | |
330 | * directly or indirectly, as not streaming. The media_entity pipe field is | |
331 | * reset to NULL. | |
332 | * | |
333 | * If multiple calls to media_entity_pipeline_start() have been made, the same | |
334 | * number of calls to this function are required to mark the pipeline as not | |
335 | * streaming. | |
336 | */ | |
337 | void media_entity_pipeline_stop(struct media_entity *entity) | |
338 | { | |
339 | struct media_device *mdev = entity->parent; | |
340 | struct media_entity_graph graph; | |
341 | ||
342 | mutex_lock(&mdev->graph_mutex); | |
343 | ||
344 | media_entity_graph_walk_start(&graph, entity); | |
345 | ||
346 | while ((entity = media_entity_graph_walk_next(&graph))) { | |
347 | entity->stream_count--; | |
348 | if (entity->stream_count == 0) | |
349 | entity->pipe = NULL; | |
350 | } | |
351 | ||
352 | mutex_unlock(&mdev->graph_mutex); | |
353 | } | |
354 | EXPORT_SYMBOL_GPL(media_entity_pipeline_stop); | |
355 | ||
503c3d82 LP |
356 | /* ----------------------------------------------------------------------------- |
357 | * Module use count | |
358 | */ | |
359 | ||
360 | /* | |
361 | * media_entity_get - Get a reference to the parent module | |
362 | * @entity: The entity | |
363 | * | |
364 | * Get a reference to the parent media device module. | |
365 | * | |
366 | * The function will return immediately if @entity is NULL. | |
367 | * | |
368 | * Return a pointer to the entity on success or NULL on failure. | |
369 | */ | |
370 | struct media_entity *media_entity_get(struct media_entity *entity) | |
371 | { | |
372 | if (entity == NULL) | |
373 | return NULL; | |
374 | ||
375 | if (entity->parent->dev && | |
376 | !try_module_get(entity->parent->dev->driver->owner)) | |
377 | return NULL; | |
378 | ||
379 | return entity; | |
380 | } | |
381 | EXPORT_SYMBOL_GPL(media_entity_get); | |
382 | ||
383 | /* | |
384 | * media_entity_put - Release the reference to the parent module | |
385 | * @entity: The entity | |
386 | * | |
387 | * Release the reference count acquired by media_entity_get(). | |
388 | * | |
389 | * The function will return immediately if @entity is NULL. | |
390 | */ | |
391 | void media_entity_put(struct media_entity *entity) | |
392 | { | |
393 | if (entity == NULL) | |
394 | return; | |
395 | ||
396 | if (entity->parent->dev) | |
397 | module_put(entity->parent->dev->driver->owner); | |
398 | } | |
399 | EXPORT_SYMBOL_GPL(media_entity_put); | |
400 | ||
a5ccc48a SA |
401 | /* ----------------------------------------------------------------------------- |
402 | * Links management | |
403 | */ | |
404 | ||
53e269c1 LP |
405 | static struct media_link *media_entity_add_link(struct media_entity *entity) |
406 | { | |
407 | if (entity->num_links >= entity->max_links) { | |
408 | struct media_link *links = entity->links; | |
409 | unsigned int max_links = entity->max_links + 2; | |
410 | unsigned int i; | |
411 | ||
412 | links = krealloc(links, max_links * sizeof(*links), GFP_KERNEL); | |
413 | if (links == NULL) | |
414 | return NULL; | |
415 | ||
416 | for (i = 0; i < entity->num_links; i++) | |
417 | links[i].reverse->reverse = &links[i]; | |
418 | ||
419 | entity->max_links = max_links; | |
420 | entity->links = links; | |
421 | } | |
422 | ||
423 | return &entity->links[entity->num_links++]; | |
424 | } | |
425 | ||
426 | int | |
427 | media_entity_create_link(struct media_entity *source, u16 source_pad, | |
428 | struct media_entity *sink, u16 sink_pad, u32 flags) | |
429 | { | |
430 | struct media_link *link; | |
431 | struct media_link *backlink; | |
432 | ||
433 | BUG_ON(source == NULL || sink == NULL); | |
434 | BUG_ON(source_pad >= source->num_pads); | |
435 | BUG_ON(sink_pad >= sink->num_pads); | |
436 | ||
437 | link = media_entity_add_link(source); | |
438 | if (link == NULL) | |
439 | return -ENOMEM; | |
440 | ||
441 | link->source = &source->pads[source_pad]; | |
442 | link->sink = &sink->pads[sink_pad]; | |
443 | link->flags = flags; | |
444 | ||
445 | /* Create the backlink. Backlinks are used to help graph traversal and | |
446 | * are not reported to userspace. | |
447 | */ | |
448 | backlink = media_entity_add_link(sink); | |
449 | if (backlink == NULL) { | |
450 | source->num_links--; | |
451 | return -ENOMEM; | |
452 | } | |
453 | ||
454 | backlink->source = &source->pads[source_pad]; | |
455 | backlink->sink = &sink->pads[sink_pad]; | |
456 | backlink->flags = flags; | |
457 | ||
458 | link->reverse = backlink; | |
459 | backlink->reverse = link; | |
460 | ||
461 | sink->num_backlinks++; | |
462 | ||
463 | return 0; | |
464 | } | |
465 | EXPORT_SYMBOL_GPL(media_entity_create_link); | |
97548ed4 | 466 | |
7349cec1 SN |
467 | void __media_entity_remove_links(struct media_entity *entity) |
468 | { | |
469 | unsigned int i; | |
470 | ||
471 | for (i = 0; i < entity->num_links; i++) { | |
472 | struct media_link *link = &entity->links[i]; | |
473 | struct media_entity *remote; | |
474 | unsigned int r = 0; | |
475 | ||
476 | if (link->source->entity == entity) | |
477 | remote = link->sink->entity; | |
478 | else | |
479 | remote = link->source->entity; | |
480 | ||
481 | while (r < remote->num_links) { | |
482 | struct media_link *rlink = &remote->links[r]; | |
483 | ||
484 | if (rlink != link->reverse) { | |
485 | r++; | |
486 | continue; | |
487 | } | |
488 | ||
489 | if (link->source->entity == entity) | |
490 | remote->num_backlinks--; | |
491 | ||
492 | if (--remote->num_links == 0) | |
493 | break; | |
494 | ||
495 | /* Insert last entry in place of the dropped link. */ | |
496 | *rlink = remote->links[remote->num_links]; | |
497 | } | |
498 | } | |
499 | ||
500 | entity->num_links = 0; | |
501 | entity->num_backlinks = 0; | |
502 | } | |
503 | EXPORT_SYMBOL_GPL(__media_entity_remove_links); | |
504 | ||
505 | void media_entity_remove_links(struct media_entity *entity) | |
506 | { | |
507 | /* Do nothing if the entity is not registered. */ | |
508 | if (entity->parent == NULL) | |
509 | return; | |
510 | ||
511 | mutex_lock(&entity->parent->graph_mutex); | |
512 | __media_entity_remove_links(entity); | |
513 | mutex_unlock(&entity->parent->graph_mutex); | |
514 | } | |
515 | EXPORT_SYMBOL_GPL(media_entity_remove_links); | |
516 | ||
97548ed4 LP |
517 | static int __media_entity_setup_link_notify(struct media_link *link, u32 flags) |
518 | { | |
97548ed4 LP |
519 | int ret; |
520 | ||
521 | /* Notify both entities. */ | |
522 | ret = media_entity_call(link->source->entity, link_setup, | |
523 | link->source, link->sink, flags); | |
524 | if (ret < 0 && ret != -ENOIOCTLCMD) | |
525 | return ret; | |
526 | ||
527 | ret = media_entity_call(link->sink->entity, link_setup, | |
528 | link->sink, link->source, flags); | |
529 | if (ret < 0 && ret != -ENOIOCTLCMD) { | |
530 | media_entity_call(link->source->entity, link_setup, | |
531 | link->source, link->sink, link->flags); | |
532 | return ret; | |
533 | } | |
534 | ||
7a6f0b22 | 535 | link->flags = flags; |
97548ed4 LP |
536 | link->reverse->flags = link->flags; |
537 | ||
538 | return 0; | |
539 | } | |
540 | ||
541 | /** | |
542 | * __media_entity_setup_link - Configure a media link | |
543 | * @link: The link being configured | |
544 | * @flags: Link configuration flags | |
545 | * | |
546 | * The bulk of link setup is handled by the two entities connected through the | |
547 | * link. This function notifies both entities of the link configuration change. | |
548 | * | |
549 | * If the link is immutable or if the current and new configuration are | |
550 | * identical, return immediately. | |
551 | * | |
552 | * The user is expected to hold link->source->parent->mutex. If not, | |
553 | * media_entity_setup_link() should be used instead. | |
554 | */ | |
555 | int __media_entity_setup_link(struct media_link *link, u32 flags) | |
556 | { | |
7a6f0b22 | 557 | const u32 mask = MEDIA_LNK_FL_ENABLED; |
97548ed4 LP |
558 | struct media_device *mdev; |
559 | struct media_entity *source, *sink; | |
560 | int ret = -EBUSY; | |
561 | ||
562 | if (link == NULL) | |
563 | return -EINVAL; | |
564 | ||
7a6f0b22 LP |
565 | /* The non-modifiable link flags must not be modified. */ |
566 | if ((link->flags & ~mask) != (flags & ~mask)) | |
567 | return -EINVAL; | |
568 | ||
97548ed4 LP |
569 | if (link->flags & MEDIA_LNK_FL_IMMUTABLE) |
570 | return link->flags == flags ? 0 : -EINVAL; | |
571 | ||
572 | if (link->flags == flags) | |
573 | return 0; | |
574 | ||
575 | source = link->source->entity; | |
576 | sink = link->sink->entity; | |
577 | ||
e02188c9 LP |
578 | if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) && |
579 | (source->stream_count || sink->stream_count)) | |
580 | return -EBUSY; | |
581 | ||
97548ed4 LP |
582 | mdev = source->parent; |
583 | ||
813f5c0a SN |
584 | if (mdev->link_notify) { |
585 | ret = mdev->link_notify(link, flags, | |
586 | MEDIA_DEV_NOTIFY_PRE_LINK_CH); | |
97548ed4 LP |
587 | if (ret < 0) |
588 | return ret; | |
589 | } | |
590 | ||
591 | ret = __media_entity_setup_link_notify(link, flags); | |
97548ed4 | 592 | |
813f5c0a SN |
593 | if (mdev->link_notify) |
594 | mdev->link_notify(link, flags, MEDIA_DEV_NOTIFY_POST_LINK_CH); | |
97548ed4 LP |
595 | |
596 | return ret; | |
597 | } | |
598 | ||
599 | int media_entity_setup_link(struct media_link *link, u32 flags) | |
600 | { | |
601 | int ret; | |
602 | ||
603 | mutex_lock(&link->source->entity->parent->graph_mutex); | |
604 | ret = __media_entity_setup_link(link, flags); | |
605 | mutex_unlock(&link->source->entity->parent->graph_mutex); | |
606 | ||
607 | return ret; | |
608 | } | |
609 | EXPORT_SYMBOL_GPL(media_entity_setup_link); | |
610 | ||
611 | /** | |
612 | * media_entity_find_link - Find a link between two pads | |
613 | * @source: Source pad | |
614 | * @sink: Sink pad | |
615 | * | |
616 | * Return a pointer to the link between the two entities. If no such link | |
617 | * exists, return NULL. | |
618 | */ | |
619 | struct media_link * | |
620 | media_entity_find_link(struct media_pad *source, struct media_pad *sink) | |
621 | { | |
622 | struct media_link *link; | |
623 | unsigned int i; | |
624 | ||
625 | for (i = 0; i < source->entity->num_links; ++i) { | |
626 | link = &source->entity->links[i]; | |
627 | ||
628 | if (link->source->entity == source->entity && | |
629 | link->source->index == source->index && | |
630 | link->sink->entity == sink->entity && | |
631 | link->sink->index == sink->index) | |
632 | return link; | |
633 | } | |
634 | ||
635 | return NULL; | |
636 | } | |
637 | EXPORT_SYMBOL_GPL(media_entity_find_link); | |
638 | ||
639 | /** | |
1bddf1b3 AH |
640 | * media_entity_remote_pad - Find the pad at the remote end of a link |
641 | * @pad: Pad at the local end of the link | |
97548ed4 | 642 | * |
1bddf1b3 AH |
643 | * Search for a remote pad connected to the given pad by iterating over all |
644 | * links originating or terminating at that pad until an enabled link is found. | |
97548ed4 LP |
645 | * |
646 | * Return a pointer to the pad at the remote end of the first found enabled | |
647 | * link, or NULL if no enabled link has been found. | |
648 | */ | |
1bddf1b3 | 649 | struct media_pad *media_entity_remote_pad(struct media_pad *pad) |
97548ed4 LP |
650 | { |
651 | unsigned int i; | |
652 | ||
653 | for (i = 0; i < pad->entity->num_links; i++) { | |
654 | struct media_link *link = &pad->entity->links[i]; | |
655 | ||
656 | if (!(link->flags & MEDIA_LNK_FL_ENABLED)) | |
657 | continue; | |
658 | ||
659 | if (link->source == pad) | |
660 | return link->sink; | |
661 | ||
662 | if (link->sink == pad) | |
663 | return link->source; | |
664 | } | |
665 | ||
666 | return NULL; | |
667 | ||
668 | } | |
1bddf1b3 | 669 | EXPORT_SYMBOL_GPL(media_entity_remote_pad); |