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 | 28 | |
ec6e4c95 MCC |
29 | /** |
30 | * media_gobj_init - Initialize a graph object | |
31 | * | |
32 | * @mdev: Pointer to the media_device that contains the object | |
33 | * @type: Type of the object | |
34 | * @gobj: Pointer to the object | |
35 | * | |
36 | * This routine initializes the embedded struct media_gobj inside a | |
37 | * media graph object. It is called automatically if media_*_create() | |
38 | * calls are used. However, if the object (entity, link, pad, interface) | |
39 | * is embedded on some other object, this function should be called before | |
40 | * registering the object at the media controller. | |
41 | */ | |
42 | void media_gobj_init(struct media_device *mdev, | |
43 | enum media_gobj_type type, | |
44 | struct media_gobj *gobj) | |
45 | { | |
bfab2aac MCC |
46 | /* Create a per-type unique object ID */ |
47 | switch (type) { | |
48 | case MEDIA_GRAPH_ENTITY: | |
49 | gobj->id = media_gobj_gen_id(type, ++mdev->entity_id); | |
50 | break; | |
18710dc6 MCC |
51 | case MEDIA_GRAPH_PAD: |
52 | gobj->id = media_gobj_gen_id(type, ++mdev->pad_id); | |
53 | break; | |
bfab2aac | 54 | } |
ec6e4c95 MCC |
55 | } |
56 | ||
57 | /** | |
58 | * media_gobj_remove - Stop using a graph object on a media device | |
59 | * | |
60 | * @graph_obj: Pointer to the object | |
61 | * | |
62 | * This should be called at media_device_unregister_*() routines | |
63 | */ | |
64 | void media_gobj_remove(struct media_gobj *gobj) | |
65 | { | |
66 | /* For now, nothing to do */ | |
67 | } | |
68 | ||
53e269c1 LP |
69 | /** |
70 | * media_entity_init - Initialize a media entity | |
71 | * | |
72 | * @num_pads: Total number of sink and source pads. | |
53e269c1 LP |
73 | * @pads: Array of 'num_pads' pads. |
74 | * | |
75 | * The total number of pads is an intrinsic property of entities known by the | |
76 | * entity driver, while the total number of links depends on hardware design | |
77 | * and is an extrinsic property unknown to the entity driver. However, in most | |
18095107 MCC |
78 | * use cases the number of links can safely be assumed to be equal to or |
79 | * larger than the number of pads. | |
53e269c1 | 80 | * |
18095107 MCC |
81 | * For those reasons the links array can be preallocated based on the number |
82 | * of pads and will be reallocated later if extra links need to be created. | |
53e269c1 LP |
83 | * |
84 | * This function allocates a links array with enough space to hold at least | |
18095107 MCC |
85 | * 'num_pads' elements. The media_entity::max_links field will be set to the |
86 | * number of allocated elements. | |
53e269c1 LP |
87 | * |
88 | * The pads array is managed by the entity driver and passed to | |
89 | * media_entity_init() where its pointer will be stored in the entity structure. | |
90 | */ | |
91 | int | |
92 | media_entity_init(struct media_entity *entity, u16 num_pads, | |
18095107 | 93 | struct media_pad *pads) |
53e269c1 LP |
94 | { |
95 | struct media_link *links; | |
18095107 | 96 | unsigned int max_links = num_pads; |
53e269c1 LP |
97 | unsigned int i; |
98 | ||
99 | links = kzalloc(max_links * sizeof(links[0]), GFP_KERNEL); | |
100 | if (links == NULL) | |
101 | return -ENOMEM; | |
102 | ||
103 | entity->group_id = 0; | |
104 | entity->max_links = max_links; | |
105 | entity->num_links = 0; | |
106 | entity->num_backlinks = 0; | |
107 | entity->num_pads = num_pads; | |
108 | entity->pads = pads; | |
109 | entity->links = links; | |
110 | ||
111 | for (i = 0; i < num_pads; i++) { | |
112 | pads[i].entity = entity; | |
113 | pads[i].index = i; | |
114 | } | |
115 | ||
116 | return 0; | |
117 | } | |
118 | EXPORT_SYMBOL_GPL(media_entity_init); | |
119 | ||
120 | void | |
121 | media_entity_cleanup(struct media_entity *entity) | |
122 | { | |
123 | kfree(entity->links); | |
124 | } | |
125 | EXPORT_SYMBOL_GPL(media_entity_cleanup); | |
126 | ||
a5ccc48a SA |
127 | /* ----------------------------------------------------------------------------- |
128 | * Graph traversal | |
129 | */ | |
130 | ||
131 | static struct media_entity * | |
132 | media_entity_other(struct media_entity *entity, struct media_link *link) | |
133 | { | |
134 | if (link->source->entity == entity) | |
135 | return link->sink->entity; | |
136 | else | |
137 | return link->source->entity; | |
138 | } | |
139 | ||
140 | /* push an entity to traversal stack */ | |
141 | static void stack_push(struct media_entity_graph *graph, | |
142 | struct media_entity *entity) | |
143 | { | |
144 | if (graph->top == MEDIA_ENTITY_ENUM_MAX_DEPTH - 1) { | |
145 | WARN_ON(1); | |
146 | return; | |
147 | } | |
148 | graph->top++; | |
149 | graph->stack[graph->top].link = 0; | |
150 | graph->stack[graph->top].entity = entity; | |
151 | } | |
152 | ||
153 | static struct media_entity *stack_pop(struct media_entity_graph *graph) | |
154 | { | |
155 | struct media_entity *entity; | |
156 | ||
157 | entity = graph->stack[graph->top].entity; | |
158 | graph->top--; | |
159 | ||
160 | return entity; | |
161 | } | |
162 | ||
a5ccc48a SA |
163 | #define link_top(en) ((en)->stack[(en)->top].link) |
164 | #define stack_top(en) ((en)->stack[(en)->top].entity) | |
165 | ||
166 | /** | |
167 | * media_entity_graph_walk_start - Start walking the media graph at a given entity | |
168 | * @graph: Media graph structure that will be used to walk the graph | |
169 | * @entity: Starting entity | |
170 | * | |
171 | * This function initializes the graph traversal structure to walk the entities | |
172 | * graph starting at the given entity. The traversal structure must not be | |
173 | * modified by the caller during graph traversal. When done the structure can | |
174 | * safely be freed. | |
175 | */ | |
176 | void media_entity_graph_walk_start(struct media_entity_graph *graph, | |
177 | struct media_entity *entity) | |
178 | { | |
179 | graph->top = 0; | |
180 | graph->stack[graph->top].entity = NULL; | |
5c7b25b9 LP |
181 | bitmap_zero(graph->entities, MEDIA_ENTITY_ENUM_MAX_ID); |
182 | ||
fa762394 | 183 | if (WARN_ON(media_entity_id(entity) >= MEDIA_ENTITY_ENUM_MAX_ID)) |
5c7b25b9 LP |
184 | return; |
185 | ||
fa762394 | 186 | __set_bit(media_entity_id(entity), graph->entities); |
a5ccc48a SA |
187 | stack_push(graph, entity); |
188 | } | |
189 | EXPORT_SYMBOL_GPL(media_entity_graph_walk_start); | |
190 | ||
191 | /** | |
192 | * media_entity_graph_walk_next - Get the next entity in the graph | |
193 | * @graph: Media graph structure | |
194 | * | |
195 | * Perform a depth-first traversal of the given media entities graph. | |
196 | * | |
197 | * The graph structure must have been previously initialized with a call to | |
198 | * media_entity_graph_walk_start(). | |
199 | * | |
200 | * Return the next entity in the graph or NULL if the whole graph have been | |
201 | * traversed. | |
202 | */ | |
203 | struct media_entity * | |
204 | media_entity_graph_walk_next(struct media_entity_graph *graph) | |
205 | { | |
206 | if (stack_top(graph) == NULL) | |
207 | return NULL; | |
208 | ||
209 | /* | |
210 | * Depth first search. Push entity to stack and continue from | |
211 | * top of the stack until no more entities on the level can be | |
212 | * found. | |
213 | */ | |
214 | while (link_top(graph) < stack_top(graph)->num_links) { | |
215 | struct media_entity *entity = stack_top(graph); | |
216 | struct media_link *link = &entity->links[link_top(graph)]; | |
217 | struct media_entity *next; | |
218 | ||
219 | /* The link is not enabled so we do not follow. */ | |
220 | if (!(link->flags & MEDIA_LNK_FL_ENABLED)) { | |
221 | link_top(graph)++; | |
222 | continue; | |
223 | } | |
224 | ||
225 | /* Get the entity in the other end of the link . */ | |
226 | next = media_entity_other(entity, link); | |
fa762394 | 227 | if (WARN_ON(media_entity_id(next) >= MEDIA_ENTITY_ENUM_MAX_ID)) |
5c7b25b9 | 228 | return NULL; |
a5ccc48a | 229 | |
5c7b25b9 | 230 | /* Has the entity already been visited? */ |
fa762394 | 231 | if (__test_and_set_bit(media_entity_id(next), graph->entities)) { |
a5ccc48a SA |
232 | link_top(graph)++; |
233 | continue; | |
234 | } | |
235 | ||
236 | /* Push the new entity to stack and start over. */ | |
237 | link_top(graph)++; | |
238 | stack_push(graph, next); | |
239 | } | |
240 | ||
241 | return stack_pop(graph); | |
242 | } | |
243 | EXPORT_SYMBOL_GPL(media_entity_graph_walk_next); | |
244 | ||
e02188c9 LP |
245 | /* ----------------------------------------------------------------------------- |
246 | * Pipeline management | |
247 | */ | |
248 | ||
249 | /** | |
250 | * media_entity_pipeline_start - Mark a pipeline as streaming | |
251 | * @entity: Starting entity | |
252 | * @pipe: Media pipeline to be assigned to all entities in the pipeline. | |
253 | * | |
254 | * Mark all entities connected to a given entity through enabled links, either | |
255 | * directly or indirectly, as streaming. The given pipeline object is assigned to | |
256 | * every entity in the pipeline and stored in the media_entity pipe field. | |
257 | * | |
258 | * Calls to this function can be nested, in which case the same number of | |
259 | * media_entity_pipeline_stop() calls will be required to stop streaming. The | |
260 | * pipeline pointer must be identical for all nested calls to | |
261 | * media_entity_pipeline_start(). | |
262 | */ | |
af88be38 SA |
263 | __must_check int media_entity_pipeline_start(struct media_entity *entity, |
264 | struct media_pipeline *pipe) | |
e02188c9 LP |
265 | { |
266 | struct media_device *mdev = entity->parent; | |
267 | struct media_entity_graph graph; | |
af88be38 SA |
268 | struct media_entity *entity_err = entity; |
269 | int ret; | |
e02188c9 LP |
270 | |
271 | mutex_lock(&mdev->graph_mutex); | |
272 | ||
273 | media_entity_graph_walk_start(&graph, entity); | |
274 | ||
275 | while ((entity = media_entity_graph_walk_next(&graph))) { | |
ef69ee1b MCC |
276 | DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS); |
277 | DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS); | |
af88be38 SA |
278 | unsigned int i; |
279 | ||
e02188c9 LP |
280 | entity->stream_count++; |
281 | WARN_ON(entity->pipe && entity->pipe != pipe); | |
282 | entity->pipe = pipe; | |
af88be38 SA |
283 | |
284 | /* Already streaming --- no need to check. */ | |
285 | if (entity->stream_count > 1) | |
286 | continue; | |
287 | ||
288 | if (!entity->ops || !entity->ops->link_validate) | |
289 | continue; | |
290 | ||
de49c285 SA |
291 | bitmap_zero(active, entity->num_pads); |
292 | bitmap_fill(has_no_links, entity->num_pads); | |
293 | ||
af88be38 SA |
294 | for (i = 0; i < entity->num_links; i++) { |
295 | struct media_link *link = &entity->links[i]; | |
de49c285 SA |
296 | struct media_pad *pad = link->sink->entity == entity |
297 | ? link->sink : link->source; | |
298 | ||
299 | /* Mark that a pad is connected by a link. */ | |
300 | bitmap_clear(has_no_links, pad->index, 1); | |
301 | ||
302 | /* | |
303 | * Pads that either do not need to connect or | |
304 | * are connected through an enabled link are | |
305 | * fine. | |
306 | */ | |
307 | if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) || | |
308 | link->flags & MEDIA_LNK_FL_ENABLED) | |
309 | bitmap_set(active, pad->index, 1); | |
310 | ||
311 | /* | |
312 | * Link validation will only take place for | |
313 | * sink ends of the link that are enabled. | |
314 | */ | |
315 | if (link->sink != pad || | |
316 | !(link->flags & MEDIA_LNK_FL_ENABLED)) | |
af88be38 SA |
317 | continue; |
318 | ||
319 | ret = entity->ops->link_validate(link); | |
fab9d30b SA |
320 | if (ret < 0 && ret != -ENOIOCTLCMD) { |
321 | dev_dbg(entity->parent->dev, | |
322 | "link validation failed for \"%s\":%u -> \"%s\":%u, error %d\n", | |
823ea2a6 SA |
323 | link->source->entity->name, |
324 | link->source->index, | |
325 | entity->name, link->sink->index, ret); | |
af88be38 | 326 | goto error; |
fab9d30b | 327 | } |
af88be38 | 328 | } |
de49c285 SA |
329 | |
330 | /* Either no links or validated links are fine. */ | |
331 | bitmap_or(active, active, has_no_links, entity->num_pads); | |
332 | ||
333 | if (!bitmap_full(active, entity->num_pads)) { | |
334 | ret = -EPIPE; | |
fab9d30b SA |
335 | dev_dbg(entity->parent->dev, |
336 | "\"%s\":%u must be connected by an enabled link\n", | |
337 | entity->name, | |
094f1ca5 SA |
338 | (unsigned)find_first_zero_bit( |
339 | active, entity->num_pads)); | |
de49c285 SA |
340 | goto error; |
341 | } | |
e02188c9 LP |
342 | } |
343 | ||
344 | mutex_unlock(&mdev->graph_mutex); | |
af88be38 SA |
345 | |
346 | return 0; | |
347 | ||
348 | error: | |
349 | /* | |
350 | * Link validation on graph failed. We revert what we did and | |
351 | * return the error. | |
352 | */ | |
353 | media_entity_graph_walk_start(&graph, entity_err); | |
354 | ||
355 | while ((entity_err = media_entity_graph_walk_next(&graph))) { | |
356 | entity_err->stream_count--; | |
357 | if (entity_err->stream_count == 0) | |
358 | entity_err->pipe = NULL; | |
359 | ||
360 | /* | |
361 | * We haven't increased stream_count further than this | |
362 | * so we quit here. | |
363 | */ | |
364 | if (entity_err == entity) | |
365 | break; | |
366 | } | |
367 | ||
368 | mutex_unlock(&mdev->graph_mutex); | |
369 | ||
370 | return ret; | |
e02188c9 LP |
371 | } |
372 | EXPORT_SYMBOL_GPL(media_entity_pipeline_start); | |
373 | ||
374 | /** | |
375 | * media_entity_pipeline_stop - Mark a pipeline as not streaming | |
376 | * @entity: Starting entity | |
377 | * | |
378 | * Mark all entities connected to a given entity through enabled links, either | |
379 | * directly or indirectly, as not streaming. The media_entity pipe field is | |
380 | * reset to NULL. | |
381 | * | |
382 | * If multiple calls to media_entity_pipeline_start() have been made, the same | |
383 | * number of calls to this function are required to mark the pipeline as not | |
384 | * streaming. | |
385 | */ | |
386 | void media_entity_pipeline_stop(struct media_entity *entity) | |
387 | { | |
388 | struct media_device *mdev = entity->parent; | |
389 | struct media_entity_graph graph; | |
390 | ||
391 | mutex_lock(&mdev->graph_mutex); | |
392 | ||
393 | media_entity_graph_walk_start(&graph, entity); | |
394 | ||
395 | while ((entity = media_entity_graph_walk_next(&graph))) { | |
396 | entity->stream_count--; | |
397 | if (entity->stream_count == 0) | |
398 | entity->pipe = NULL; | |
399 | } | |
400 | ||
401 | mutex_unlock(&mdev->graph_mutex); | |
402 | } | |
403 | EXPORT_SYMBOL_GPL(media_entity_pipeline_stop); | |
404 | ||
503c3d82 LP |
405 | /* ----------------------------------------------------------------------------- |
406 | * Module use count | |
407 | */ | |
408 | ||
409 | /* | |
410 | * media_entity_get - Get a reference to the parent module | |
411 | * @entity: The entity | |
412 | * | |
413 | * Get a reference to the parent media device module. | |
414 | * | |
415 | * The function will return immediately if @entity is NULL. | |
416 | * | |
417 | * Return a pointer to the entity on success or NULL on failure. | |
418 | */ | |
419 | struct media_entity *media_entity_get(struct media_entity *entity) | |
420 | { | |
421 | if (entity == NULL) | |
422 | return NULL; | |
423 | ||
424 | if (entity->parent->dev && | |
425 | !try_module_get(entity->parent->dev->driver->owner)) | |
426 | return NULL; | |
427 | ||
428 | return entity; | |
429 | } | |
430 | EXPORT_SYMBOL_GPL(media_entity_get); | |
431 | ||
432 | /* | |
433 | * media_entity_put - Release the reference to the parent module | |
434 | * @entity: The entity | |
435 | * | |
436 | * Release the reference count acquired by media_entity_get(). | |
437 | * | |
438 | * The function will return immediately if @entity is NULL. | |
439 | */ | |
440 | void media_entity_put(struct media_entity *entity) | |
441 | { | |
442 | if (entity == NULL) | |
443 | return; | |
444 | ||
445 | if (entity->parent->dev) | |
446 | module_put(entity->parent->dev->driver->owner); | |
447 | } | |
448 | EXPORT_SYMBOL_GPL(media_entity_put); | |
449 | ||
a5ccc48a SA |
450 | /* ----------------------------------------------------------------------------- |
451 | * Links management | |
452 | */ | |
453 | ||
53e269c1 LP |
454 | static struct media_link *media_entity_add_link(struct media_entity *entity) |
455 | { | |
456 | if (entity->num_links >= entity->max_links) { | |
457 | struct media_link *links = entity->links; | |
458 | unsigned int max_links = entity->max_links + 2; | |
459 | unsigned int i; | |
460 | ||
461 | links = krealloc(links, max_links * sizeof(*links), GFP_KERNEL); | |
462 | if (links == NULL) | |
463 | return NULL; | |
464 | ||
465 | for (i = 0; i < entity->num_links; i++) | |
466 | links[i].reverse->reverse = &links[i]; | |
467 | ||
468 | entity->max_links = max_links; | |
469 | entity->links = links; | |
470 | } | |
471 | ||
472 | return &entity->links[entity->num_links++]; | |
473 | } | |
474 | ||
475 | int | |
476 | media_entity_create_link(struct media_entity *source, u16 source_pad, | |
477 | struct media_entity *sink, u16 sink_pad, u32 flags) | |
478 | { | |
479 | struct media_link *link; | |
480 | struct media_link *backlink; | |
481 | ||
482 | BUG_ON(source == NULL || sink == NULL); | |
483 | BUG_ON(source_pad >= source->num_pads); | |
484 | BUG_ON(sink_pad >= sink->num_pads); | |
485 | ||
486 | link = media_entity_add_link(source); | |
487 | if (link == NULL) | |
488 | return -ENOMEM; | |
489 | ||
490 | link->source = &source->pads[source_pad]; | |
491 | link->sink = &sink->pads[sink_pad]; | |
492 | link->flags = flags; | |
493 | ||
494 | /* Create the backlink. Backlinks are used to help graph traversal and | |
495 | * are not reported to userspace. | |
496 | */ | |
497 | backlink = media_entity_add_link(sink); | |
498 | if (backlink == NULL) { | |
499 | source->num_links--; | |
500 | return -ENOMEM; | |
501 | } | |
502 | ||
503 | backlink->source = &source->pads[source_pad]; | |
504 | backlink->sink = &sink->pads[sink_pad]; | |
505 | backlink->flags = flags; | |
506 | ||
507 | link->reverse = backlink; | |
508 | backlink->reverse = link; | |
509 | ||
510 | sink->num_backlinks++; | |
511 | ||
512 | return 0; | |
513 | } | |
514 | EXPORT_SYMBOL_GPL(media_entity_create_link); | |
97548ed4 | 515 | |
7349cec1 SN |
516 | void __media_entity_remove_links(struct media_entity *entity) |
517 | { | |
518 | unsigned int i; | |
519 | ||
520 | for (i = 0; i < entity->num_links; i++) { | |
521 | struct media_link *link = &entity->links[i]; | |
522 | struct media_entity *remote; | |
523 | unsigned int r = 0; | |
524 | ||
525 | if (link->source->entity == entity) | |
526 | remote = link->sink->entity; | |
527 | else | |
528 | remote = link->source->entity; | |
529 | ||
530 | while (r < remote->num_links) { | |
531 | struct media_link *rlink = &remote->links[r]; | |
532 | ||
533 | if (rlink != link->reverse) { | |
534 | r++; | |
535 | continue; | |
536 | } | |
537 | ||
538 | if (link->source->entity == entity) | |
539 | remote->num_backlinks--; | |
540 | ||
541 | if (--remote->num_links == 0) | |
542 | break; | |
543 | ||
544 | /* Insert last entry in place of the dropped link. */ | |
545 | *rlink = remote->links[remote->num_links]; | |
546 | } | |
547 | } | |
548 | ||
549 | entity->num_links = 0; | |
550 | entity->num_backlinks = 0; | |
551 | } | |
552 | EXPORT_SYMBOL_GPL(__media_entity_remove_links); | |
553 | ||
554 | void media_entity_remove_links(struct media_entity *entity) | |
555 | { | |
556 | /* Do nothing if the entity is not registered. */ | |
557 | if (entity->parent == NULL) | |
558 | return; | |
559 | ||
560 | mutex_lock(&entity->parent->graph_mutex); | |
561 | __media_entity_remove_links(entity); | |
562 | mutex_unlock(&entity->parent->graph_mutex); | |
563 | } | |
564 | EXPORT_SYMBOL_GPL(media_entity_remove_links); | |
565 | ||
97548ed4 LP |
566 | static int __media_entity_setup_link_notify(struct media_link *link, u32 flags) |
567 | { | |
97548ed4 LP |
568 | int ret; |
569 | ||
570 | /* Notify both entities. */ | |
571 | ret = media_entity_call(link->source->entity, link_setup, | |
572 | link->source, link->sink, flags); | |
573 | if (ret < 0 && ret != -ENOIOCTLCMD) | |
574 | return ret; | |
575 | ||
576 | ret = media_entity_call(link->sink->entity, link_setup, | |
577 | link->sink, link->source, flags); | |
578 | if (ret < 0 && ret != -ENOIOCTLCMD) { | |
579 | media_entity_call(link->source->entity, link_setup, | |
580 | link->source, link->sink, link->flags); | |
581 | return ret; | |
582 | } | |
583 | ||
7a6f0b22 | 584 | link->flags = flags; |
97548ed4 LP |
585 | link->reverse->flags = link->flags; |
586 | ||
587 | return 0; | |
588 | } | |
589 | ||
590 | /** | |
591 | * __media_entity_setup_link - Configure a media link | |
592 | * @link: The link being configured | |
593 | * @flags: Link configuration flags | |
594 | * | |
595 | * The bulk of link setup is handled by the two entities connected through the | |
596 | * link. This function notifies both entities of the link configuration change. | |
597 | * | |
598 | * If the link is immutable or if the current and new configuration are | |
599 | * identical, return immediately. | |
600 | * | |
601 | * The user is expected to hold link->source->parent->mutex. If not, | |
602 | * media_entity_setup_link() should be used instead. | |
603 | */ | |
604 | int __media_entity_setup_link(struct media_link *link, u32 flags) | |
605 | { | |
7a6f0b22 | 606 | const u32 mask = MEDIA_LNK_FL_ENABLED; |
97548ed4 LP |
607 | struct media_device *mdev; |
608 | struct media_entity *source, *sink; | |
609 | int ret = -EBUSY; | |
610 | ||
611 | if (link == NULL) | |
612 | return -EINVAL; | |
613 | ||
7a6f0b22 LP |
614 | /* The non-modifiable link flags must not be modified. */ |
615 | if ((link->flags & ~mask) != (flags & ~mask)) | |
616 | return -EINVAL; | |
617 | ||
97548ed4 LP |
618 | if (link->flags & MEDIA_LNK_FL_IMMUTABLE) |
619 | return link->flags == flags ? 0 : -EINVAL; | |
620 | ||
621 | if (link->flags == flags) | |
622 | return 0; | |
623 | ||
624 | source = link->source->entity; | |
625 | sink = link->sink->entity; | |
626 | ||
e02188c9 LP |
627 | if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) && |
628 | (source->stream_count || sink->stream_count)) | |
629 | return -EBUSY; | |
630 | ||
97548ed4 LP |
631 | mdev = source->parent; |
632 | ||
813f5c0a SN |
633 | if (mdev->link_notify) { |
634 | ret = mdev->link_notify(link, flags, | |
635 | MEDIA_DEV_NOTIFY_PRE_LINK_CH); | |
97548ed4 LP |
636 | if (ret < 0) |
637 | return ret; | |
638 | } | |
639 | ||
640 | ret = __media_entity_setup_link_notify(link, flags); | |
97548ed4 | 641 | |
813f5c0a SN |
642 | if (mdev->link_notify) |
643 | mdev->link_notify(link, flags, MEDIA_DEV_NOTIFY_POST_LINK_CH); | |
97548ed4 LP |
644 | |
645 | return ret; | |
646 | } | |
647 | ||
648 | int media_entity_setup_link(struct media_link *link, u32 flags) | |
649 | { | |
650 | int ret; | |
651 | ||
652 | mutex_lock(&link->source->entity->parent->graph_mutex); | |
653 | ret = __media_entity_setup_link(link, flags); | |
654 | mutex_unlock(&link->source->entity->parent->graph_mutex); | |
655 | ||
656 | return ret; | |
657 | } | |
658 | EXPORT_SYMBOL_GPL(media_entity_setup_link); | |
659 | ||
660 | /** | |
661 | * media_entity_find_link - Find a link between two pads | |
662 | * @source: Source pad | |
663 | * @sink: Sink pad | |
664 | * | |
665 | * Return a pointer to the link between the two entities. If no such link | |
666 | * exists, return NULL. | |
667 | */ | |
668 | struct media_link * | |
669 | media_entity_find_link(struct media_pad *source, struct media_pad *sink) | |
670 | { | |
671 | struct media_link *link; | |
672 | unsigned int i; | |
673 | ||
674 | for (i = 0; i < source->entity->num_links; ++i) { | |
675 | link = &source->entity->links[i]; | |
676 | ||
677 | if (link->source->entity == source->entity && | |
678 | link->source->index == source->index && | |
679 | link->sink->entity == sink->entity && | |
680 | link->sink->index == sink->index) | |
681 | return link; | |
682 | } | |
683 | ||
684 | return NULL; | |
685 | } | |
686 | EXPORT_SYMBOL_GPL(media_entity_find_link); | |
687 | ||
688 | /** | |
1bddf1b3 AH |
689 | * media_entity_remote_pad - Find the pad at the remote end of a link |
690 | * @pad: Pad at the local end of the link | |
97548ed4 | 691 | * |
1bddf1b3 AH |
692 | * Search for a remote pad connected to the given pad by iterating over all |
693 | * links originating or terminating at that pad until an enabled link is found. | |
97548ed4 LP |
694 | * |
695 | * Return a pointer to the pad at the remote end of the first found enabled | |
696 | * link, or NULL if no enabled link has been found. | |
697 | */ | |
1bddf1b3 | 698 | struct media_pad *media_entity_remote_pad(struct media_pad *pad) |
97548ed4 LP |
699 | { |
700 | unsigned int i; | |
701 | ||
702 | for (i = 0; i < pad->entity->num_links; i++) { | |
703 | struct media_link *link = &pad->entity->links[i]; | |
704 | ||
705 | if (!(link->flags & MEDIA_LNK_FL_ENABLED)) | |
706 | continue; | |
707 | ||
708 | if (link->source == pad) | |
709 | return link->sink; | |
710 | ||
711 | if (link->sink == pad) | |
712 | return link->source; | |
713 | } | |
714 | ||
715 | return NULL; | |
716 | ||
717 | } | |
1bddf1b3 | 718 | EXPORT_SYMBOL_GPL(media_entity_remote_pad); |