xref: /linux/drivers/media/mc/mc-entity.c (revision 8c3854d03bd7b86e8f36e6d9b07b4a6bc20deccd)
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 
19 #include <linux/bitmap.h>
20 #include <linux/property.h>
21 #include <linux/slab.h>
22 #include <media/media-entity.h>
23 #include <media/media-device.h>
24 
25 static inline const char *gobj_type(enum media_gobj_type type)
26 {
27 	switch (type) {
28 	case MEDIA_GRAPH_ENTITY:
29 		return "entity";
30 	case MEDIA_GRAPH_PAD:
31 		return "pad";
32 	case MEDIA_GRAPH_LINK:
33 		return "link";
34 	case MEDIA_GRAPH_INTF_DEVNODE:
35 		return "intf-devnode";
36 	default:
37 		return "unknown";
38 	}
39 }
40 
41 static inline const char *intf_type(struct media_interface *intf)
42 {
43 	switch (intf->type) {
44 	case MEDIA_INTF_T_DVB_FE:
45 		return "dvb-frontend";
46 	case MEDIA_INTF_T_DVB_DEMUX:
47 		return "dvb-demux";
48 	case MEDIA_INTF_T_DVB_DVR:
49 		return "dvb-dvr";
50 	case MEDIA_INTF_T_DVB_CA:
51 		return  "dvb-ca";
52 	case MEDIA_INTF_T_DVB_NET:
53 		return "dvb-net";
54 	case MEDIA_INTF_T_V4L_VIDEO:
55 		return "v4l-video";
56 	case MEDIA_INTF_T_V4L_VBI:
57 		return "v4l-vbi";
58 	case MEDIA_INTF_T_V4L_RADIO:
59 		return "v4l-radio";
60 	case MEDIA_INTF_T_V4L_SUBDEV:
61 		return "v4l-subdev";
62 	case MEDIA_INTF_T_V4L_SWRADIO:
63 		return "v4l-swradio";
64 	case MEDIA_INTF_T_V4L_TOUCH:
65 		return "v4l-touch";
66 	default:
67 		return "unknown-intf";
68 	}
69 };
70 
71 __must_check int __media_entity_enum_init(struct media_entity_enum *ent_enum,
72 					  int idx_max)
73 {
74 	idx_max = ALIGN(idx_max, BITS_PER_LONG);
75 	ent_enum->bmap = kcalloc(idx_max / BITS_PER_LONG, sizeof(long),
76 				 GFP_KERNEL);
77 	if (!ent_enum->bmap)
78 		return -ENOMEM;
79 
80 	bitmap_zero(ent_enum->bmap, idx_max);
81 	ent_enum->idx_max = idx_max;
82 
83 	return 0;
84 }
85 EXPORT_SYMBOL_GPL(__media_entity_enum_init);
86 
87 void media_entity_enum_cleanup(struct media_entity_enum *ent_enum)
88 {
89 	kfree(ent_enum->bmap);
90 }
91 EXPORT_SYMBOL_GPL(media_entity_enum_cleanup);
92 
93 /**
94  *  dev_dbg_obj - Prints in debug mode a change on some object
95  *
96  * @event_name:	Name of the event to report. Could be __func__
97  * @gobj:	Pointer to the object
98  *
99  * Enabled only if DEBUG or CONFIG_DYNAMIC_DEBUG. Otherwise, it
100  * won't produce any code.
101  */
102 static void dev_dbg_obj(const char *event_name,  struct media_gobj *gobj)
103 {
104 #if defined(DEBUG) || defined (CONFIG_DYNAMIC_DEBUG)
105 	switch (media_type(gobj)) {
106 	case MEDIA_GRAPH_ENTITY:
107 		dev_dbg(gobj->mdev->dev,
108 			"%s id %u: entity '%s'\n",
109 			event_name, media_id(gobj),
110 			gobj_to_entity(gobj)->name);
111 		break;
112 	case MEDIA_GRAPH_LINK:
113 	{
114 		struct media_link *link = gobj_to_link(gobj);
115 
116 		dev_dbg(gobj->mdev->dev,
117 			"%s id %u: %s link id %u ==> id %u\n",
118 			event_name, media_id(gobj),
119 			media_type(link->gobj0) == MEDIA_GRAPH_PAD ?
120 				"data" : "interface",
121 			media_id(link->gobj0),
122 			media_id(link->gobj1));
123 		break;
124 	}
125 	case MEDIA_GRAPH_PAD:
126 	{
127 		struct media_pad *pad = gobj_to_pad(gobj);
128 
129 		dev_dbg(gobj->mdev->dev,
130 			"%s id %u: %s%spad '%s':%d\n",
131 			event_name, media_id(gobj),
132 			pad->flags & MEDIA_PAD_FL_SINK   ? "sink " : "",
133 			pad->flags & MEDIA_PAD_FL_SOURCE ? "source " : "",
134 			pad->entity->name, pad->index);
135 		break;
136 	}
137 	case MEDIA_GRAPH_INTF_DEVNODE:
138 	{
139 		struct media_interface *intf = gobj_to_intf(gobj);
140 		struct media_intf_devnode *devnode = intf_to_devnode(intf);
141 
142 		dev_dbg(gobj->mdev->dev,
143 			"%s id %u: intf_devnode %s - major: %d, minor: %d\n",
144 			event_name, media_id(gobj),
145 			intf_type(intf),
146 			devnode->major, devnode->minor);
147 		break;
148 	}
149 	}
150 #endif
151 }
152 
153 void media_gobj_create(struct media_device *mdev,
154 			   enum media_gobj_type type,
155 			   struct media_gobj *gobj)
156 {
157 	BUG_ON(!mdev);
158 
159 	gobj->mdev = mdev;
160 
161 	/* Create a per-type unique object ID */
162 	gobj->id = media_gobj_gen_id(type, ++mdev->id);
163 
164 	switch (type) {
165 	case MEDIA_GRAPH_ENTITY:
166 		list_add_tail(&gobj->list, &mdev->entities);
167 		break;
168 	case MEDIA_GRAPH_PAD:
169 		list_add_tail(&gobj->list, &mdev->pads);
170 		break;
171 	case MEDIA_GRAPH_LINK:
172 		list_add_tail(&gobj->list, &mdev->links);
173 		break;
174 	case MEDIA_GRAPH_INTF_DEVNODE:
175 		list_add_tail(&gobj->list, &mdev->interfaces);
176 		break;
177 	}
178 
179 	mdev->topology_version++;
180 
181 	dev_dbg_obj(__func__, gobj);
182 }
183 
184 void media_gobj_destroy(struct media_gobj *gobj)
185 {
186 	/* Do nothing if the object is not linked. */
187 	if (gobj->mdev == NULL)
188 		return;
189 
190 	dev_dbg_obj(__func__, gobj);
191 
192 	gobj->mdev->topology_version++;
193 
194 	/* Remove the object from mdev list */
195 	list_del(&gobj->list);
196 
197 	gobj->mdev = NULL;
198 }
199 
200 /*
201  * TODO: Get rid of this.
202  */
203 #define MEDIA_ENTITY_MAX_PADS		512
204 
205 int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
206 			   struct media_pad *pads)
207 {
208 	struct media_device *mdev = entity->graph_obj.mdev;
209 	unsigned int i;
210 
211 	if (num_pads >= MEDIA_ENTITY_MAX_PADS)
212 		return -E2BIG;
213 
214 	entity->num_pads = num_pads;
215 	entity->pads = pads;
216 
217 	if (mdev)
218 		mutex_lock(&mdev->graph_mutex);
219 
220 	for (i = 0; i < num_pads; i++) {
221 		pads[i].entity = entity;
222 		pads[i].index = i;
223 		if (mdev)
224 			media_gobj_create(mdev, MEDIA_GRAPH_PAD,
225 					&entity->pads[i].graph_obj);
226 	}
227 
228 	if (mdev)
229 		mutex_unlock(&mdev->graph_mutex);
230 
231 	return 0;
232 }
233 EXPORT_SYMBOL_GPL(media_entity_pads_init);
234 
235 /* -----------------------------------------------------------------------------
236  * Graph traversal
237  */
238 
239 static struct media_entity *
240 media_entity_other(struct media_entity *entity, struct media_link *link)
241 {
242 	if (link->source->entity == entity)
243 		return link->sink->entity;
244 	else
245 		return link->source->entity;
246 }
247 
248 /* push an entity to traversal stack */
249 static void stack_push(struct media_graph *graph,
250 		       struct media_entity *entity)
251 {
252 	if (graph->top == MEDIA_ENTITY_ENUM_MAX_DEPTH - 1) {
253 		WARN_ON(1);
254 		return;
255 	}
256 	graph->top++;
257 	graph->stack[graph->top].link = entity->links.next;
258 	graph->stack[graph->top].entity = entity;
259 }
260 
261 static struct media_entity *stack_pop(struct media_graph *graph)
262 {
263 	struct media_entity *entity;
264 
265 	entity = graph->stack[graph->top].entity;
266 	graph->top--;
267 
268 	return entity;
269 }
270 
271 #define link_top(en)	((en)->stack[(en)->top].link)
272 #define stack_top(en)	((en)->stack[(en)->top].entity)
273 
274 /**
275  * media_graph_walk_init - Allocate resources for graph walk
276  * @graph: Media graph structure that will be used to walk the graph
277  * @mdev: Media device
278  *
279  * Reserve resources for graph walk in media device's current
280  * state. The memory must be released using
281  * media_graph_walk_free().
282  *
283  * Returns error on failure, zero on success.
284  */
285 __must_check int media_graph_walk_init(
286 	struct media_graph *graph, struct media_device *mdev)
287 {
288 	return media_entity_enum_init(&graph->ent_enum, mdev);
289 }
290 EXPORT_SYMBOL_GPL(media_graph_walk_init);
291 
292 /**
293  * media_graph_walk_cleanup - Release resources related to graph walking
294  * @graph: Media graph structure that was used to walk the graph
295  */
296 void media_graph_walk_cleanup(struct media_graph *graph)
297 {
298 	media_entity_enum_cleanup(&graph->ent_enum);
299 }
300 EXPORT_SYMBOL_GPL(media_graph_walk_cleanup);
301 
302 void media_graph_walk_start(struct media_graph *graph,
303 			    struct media_entity *entity)
304 {
305 	media_entity_enum_zero(&graph->ent_enum);
306 	media_entity_enum_set(&graph->ent_enum, entity);
307 
308 	graph->top = 0;
309 	graph->stack[graph->top].entity = NULL;
310 	stack_push(graph, entity);
311 	dev_dbg(entity->graph_obj.mdev->dev,
312 		"begin graph walk at '%s'\n", entity->name);
313 }
314 EXPORT_SYMBOL_GPL(media_graph_walk_start);
315 
316 static void media_graph_walk_iter(struct media_graph *graph)
317 {
318 	struct media_entity *entity = stack_top(graph);
319 	struct media_link *link;
320 	struct media_entity *next;
321 
322 	link = list_entry(link_top(graph), typeof(*link), list);
323 
324 	/* The link is not enabled so we do not follow. */
325 	if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
326 		link_top(graph) = link_top(graph)->next;
327 		dev_dbg(entity->graph_obj.mdev->dev,
328 			"walk: skipping disabled link '%s':%u -> '%s':%u\n",
329 			link->source->entity->name, link->source->index,
330 			link->sink->entity->name, link->sink->index);
331 		return;
332 	}
333 
334 	/* Get the entity in the other end of the link . */
335 	next = media_entity_other(entity, link);
336 
337 	/* Has the entity already been visited? */
338 	if (media_entity_enum_test_and_set(&graph->ent_enum, next)) {
339 		link_top(graph) = link_top(graph)->next;
340 		dev_dbg(entity->graph_obj.mdev->dev,
341 			"walk: skipping entity '%s' (already seen)\n",
342 			next->name);
343 		return;
344 	}
345 
346 	/* Push the new entity to stack and start over. */
347 	link_top(graph) = link_top(graph)->next;
348 	stack_push(graph, next);
349 	dev_dbg(entity->graph_obj.mdev->dev, "walk: pushing '%s' on stack\n",
350 		next->name);
351 }
352 
353 struct media_entity *media_graph_walk_next(struct media_graph *graph)
354 {
355 	struct media_entity *entity;
356 
357 	if (stack_top(graph) == NULL)
358 		return NULL;
359 
360 	/*
361 	 * Depth first search. Push entity to stack and continue from
362 	 * top of the stack until no more entities on the level can be
363 	 * found.
364 	 */
365 	while (link_top(graph) != &stack_top(graph)->links)
366 		media_graph_walk_iter(graph);
367 
368 	entity = stack_pop(graph);
369 	dev_dbg(entity->graph_obj.mdev->dev,
370 		"walk: returning entity '%s'\n", entity->name);
371 
372 	return entity;
373 }
374 EXPORT_SYMBOL_GPL(media_graph_walk_next);
375 
376 int media_entity_get_fwnode_pad(struct media_entity *entity,
377 				struct fwnode_handle *fwnode,
378 				unsigned long direction_flags)
379 {
380 	struct fwnode_endpoint endpoint;
381 	unsigned int i;
382 	int ret;
383 
384 	if (!entity->ops || !entity->ops->get_fwnode_pad) {
385 		for (i = 0; i < entity->num_pads; i++) {
386 			if (entity->pads[i].flags & direction_flags)
387 				return i;
388 		}
389 
390 		return -ENXIO;
391 	}
392 
393 	ret = fwnode_graph_parse_endpoint(fwnode, &endpoint);
394 	if (ret)
395 		return ret;
396 
397 	ret = entity->ops->get_fwnode_pad(&endpoint);
398 	if (ret < 0)
399 		return ret;
400 
401 	if (ret >= entity->num_pads)
402 		return -ENXIO;
403 
404 	if (!(entity->pads[ret].flags & direction_flags))
405 		return -ENXIO;
406 
407 	return ret;
408 }
409 EXPORT_SYMBOL_GPL(media_entity_get_fwnode_pad);
410 
411 /* -----------------------------------------------------------------------------
412  * Pipeline management
413  */
414 
415 __must_check int __media_pipeline_start(struct media_entity *entity,
416 					struct media_pipeline *pipe)
417 {
418 	struct media_device *mdev = entity->graph_obj.mdev;
419 	struct media_graph *graph = &pipe->graph;
420 	struct media_entity *entity_err = entity;
421 	struct media_link *link;
422 	int ret;
423 
424 	if (!pipe->streaming_count++) {
425 		ret = media_graph_walk_init(&pipe->graph, mdev);
426 		if (ret)
427 			goto error_graph_walk_start;
428 	}
429 
430 	media_graph_walk_start(&pipe->graph, entity);
431 
432 	while ((entity = media_graph_walk_next(graph))) {
433 		DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
434 		DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
435 
436 		entity->stream_count++;
437 
438 		if (entity->pipe && entity->pipe != pipe) {
439 			pr_err("Pipe active for %s. Can't start for %s\n",
440 				entity->name,
441 				entity_err->name);
442 			ret = -EBUSY;
443 			goto error;
444 		}
445 
446 		entity->pipe = pipe;
447 
448 		/* Already streaming --- no need to check. */
449 		if (entity->stream_count > 1)
450 			continue;
451 
452 		if (!entity->ops || !entity->ops->link_validate)
453 			continue;
454 
455 		bitmap_zero(active, entity->num_pads);
456 		bitmap_fill(has_no_links, entity->num_pads);
457 
458 		list_for_each_entry(link, &entity->links, list) {
459 			struct media_pad *pad = link->sink->entity == entity
460 						? link->sink : link->source;
461 
462 			/* Mark that a pad is connected by a link. */
463 			bitmap_clear(has_no_links, pad->index, 1);
464 
465 			/*
466 			 * Pads that either do not need to connect or
467 			 * are connected through an enabled link are
468 			 * fine.
469 			 */
470 			if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) ||
471 			    link->flags & MEDIA_LNK_FL_ENABLED)
472 				bitmap_set(active, pad->index, 1);
473 
474 			/*
475 			 * Link validation will only take place for
476 			 * sink ends of the link that are enabled.
477 			 */
478 			if (link->sink != pad ||
479 			    !(link->flags & MEDIA_LNK_FL_ENABLED))
480 				continue;
481 
482 			ret = entity->ops->link_validate(link);
483 			if (ret < 0 && ret != -ENOIOCTLCMD) {
484 				dev_dbg(entity->graph_obj.mdev->dev,
485 					"link validation failed for '%s':%u -> '%s':%u, error %d\n",
486 					link->source->entity->name,
487 					link->source->index,
488 					entity->name, link->sink->index, ret);
489 				goto error;
490 			}
491 		}
492 
493 		/* Either no links or validated links are fine. */
494 		bitmap_or(active, active, has_no_links, entity->num_pads);
495 
496 		if (!bitmap_full(active, entity->num_pads)) {
497 			ret = -ENOLINK;
498 			dev_dbg(entity->graph_obj.mdev->dev,
499 				"'%s':%u must be connected by an enabled link\n",
500 				entity->name,
501 				(unsigned)find_first_zero_bit(
502 					active, entity->num_pads));
503 			goto error;
504 		}
505 	}
506 
507 	return 0;
508 
509 error:
510 	/*
511 	 * Link validation on graph failed. We revert what we did and
512 	 * return the error.
513 	 */
514 	media_graph_walk_start(graph, entity_err);
515 
516 	while ((entity_err = media_graph_walk_next(graph))) {
517 		/* Sanity check for negative stream_count */
518 		if (!WARN_ON_ONCE(entity_err->stream_count <= 0)) {
519 			entity_err->stream_count--;
520 			if (entity_err->stream_count == 0)
521 				entity_err->pipe = NULL;
522 		}
523 
524 		/*
525 		 * We haven't increased stream_count further than this
526 		 * so we quit here.
527 		 */
528 		if (entity_err == entity)
529 			break;
530 	}
531 
532 error_graph_walk_start:
533 	if (!--pipe->streaming_count)
534 		media_graph_walk_cleanup(graph);
535 
536 	return ret;
537 }
538 EXPORT_SYMBOL_GPL(__media_pipeline_start);
539 
540 __must_check int media_pipeline_start(struct media_entity *entity,
541 				      struct media_pipeline *pipe)
542 {
543 	struct media_device *mdev = entity->graph_obj.mdev;
544 	int ret;
545 
546 	mutex_lock(&mdev->graph_mutex);
547 	ret = __media_pipeline_start(entity, pipe);
548 	mutex_unlock(&mdev->graph_mutex);
549 	return ret;
550 }
551 EXPORT_SYMBOL_GPL(media_pipeline_start);
552 
553 void __media_pipeline_stop(struct media_entity *entity)
554 {
555 	struct media_graph *graph = &entity->pipe->graph;
556 	struct media_pipeline *pipe = entity->pipe;
557 
558 	/*
559 	 * If the following check fails, the driver has performed an
560 	 * unbalanced call to media_pipeline_stop()
561 	 */
562 	if (WARN_ON(!pipe))
563 		return;
564 
565 	media_graph_walk_start(graph, entity);
566 
567 	while ((entity = media_graph_walk_next(graph))) {
568 		/* Sanity check for negative stream_count */
569 		if (!WARN_ON_ONCE(entity->stream_count <= 0)) {
570 			entity->stream_count--;
571 			if (entity->stream_count == 0)
572 				entity->pipe = NULL;
573 		}
574 	}
575 
576 	if (!--pipe->streaming_count)
577 		media_graph_walk_cleanup(graph);
578 
579 }
580 EXPORT_SYMBOL_GPL(__media_pipeline_stop);
581 
582 void media_pipeline_stop(struct media_entity *entity)
583 {
584 	struct media_device *mdev = entity->graph_obj.mdev;
585 
586 	mutex_lock(&mdev->graph_mutex);
587 	__media_pipeline_stop(entity);
588 	mutex_unlock(&mdev->graph_mutex);
589 }
590 EXPORT_SYMBOL_GPL(media_pipeline_stop);
591 
592 /* -----------------------------------------------------------------------------
593  * Links management
594  */
595 
596 static struct media_link *media_add_link(struct list_head *head)
597 {
598 	struct media_link *link;
599 
600 	link = kzalloc(sizeof(*link), GFP_KERNEL);
601 	if (link == NULL)
602 		return NULL;
603 
604 	list_add_tail(&link->list, head);
605 
606 	return link;
607 }
608 
609 static void __media_entity_remove_link(struct media_entity *entity,
610 				       struct media_link *link)
611 {
612 	struct media_link *rlink, *tmp;
613 	struct media_entity *remote;
614 
615 	if (link->source->entity == entity)
616 		remote = link->sink->entity;
617 	else
618 		remote = link->source->entity;
619 
620 	list_for_each_entry_safe(rlink, tmp, &remote->links, list) {
621 		if (rlink != link->reverse)
622 			continue;
623 
624 		if (link->source->entity == entity)
625 			remote->num_backlinks--;
626 
627 		/* Remove the remote link */
628 		list_del(&rlink->list);
629 		media_gobj_destroy(&rlink->graph_obj);
630 		kfree(rlink);
631 
632 		if (--remote->num_links == 0)
633 			break;
634 	}
635 	list_del(&link->list);
636 	media_gobj_destroy(&link->graph_obj);
637 	kfree(link);
638 }
639 
640 int media_get_pad_index(struct media_entity *entity, bool is_sink,
641 			enum media_pad_signal_type sig_type)
642 {
643 	int i;
644 	bool pad_is_sink;
645 
646 	if (!entity)
647 		return -EINVAL;
648 
649 	for (i = 0; i < entity->num_pads; i++) {
650 		if (entity->pads[i].flags == MEDIA_PAD_FL_SINK)
651 			pad_is_sink = true;
652 		else if (entity->pads[i].flags == MEDIA_PAD_FL_SOURCE)
653 			pad_is_sink = false;
654 		else
655 			continue;	/* This is an error! */
656 
657 		if (pad_is_sink != is_sink)
658 			continue;
659 		if (entity->pads[i].sig_type == sig_type)
660 			return i;
661 	}
662 	return -EINVAL;
663 }
664 EXPORT_SYMBOL_GPL(media_get_pad_index);
665 
666 int
667 media_create_pad_link(struct media_entity *source, u16 source_pad,
668 			 struct media_entity *sink, u16 sink_pad, u32 flags)
669 {
670 	struct media_link *link;
671 	struct media_link *backlink;
672 
673 	BUG_ON(source == NULL || sink == NULL);
674 	BUG_ON(source_pad >= source->num_pads);
675 	BUG_ON(sink_pad >= sink->num_pads);
676 
677 	link = media_add_link(&source->links);
678 	if (link == NULL)
679 		return -ENOMEM;
680 
681 	link->source = &source->pads[source_pad];
682 	link->sink = &sink->pads[sink_pad];
683 	link->flags = flags & ~MEDIA_LNK_FL_INTERFACE_LINK;
684 
685 	/* Initialize graph object embedded at the new link */
686 	media_gobj_create(source->graph_obj.mdev, MEDIA_GRAPH_LINK,
687 			&link->graph_obj);
688 
689 	/* Create the backlink. Backlinks are used to help graph traversal and
690 	 * are not reported to userspace.
691 	 */
692 	backlink = media_add_link(&sink->links);
693 	if (backlink == NULL) {
694 		__media_entity_remove_link(source, link);
695 		return -ENOMEM;
696 	}
697 
698 	backlink->source = &source->pads[source_pad];
699 	backlink->sink = &sink->pads[sink_pad];
700 	backlink->flags = flags;
701 	backlink->is_backlink = true;
702 
703 	/* Initialize graph object embedded at the new link */
704 	media_gobj_create(sink->graph_obj.mdev, MEDIA_GRAPH_LINK,
705 			&backlink->graph_obj);
706 
707 	link->reverse = backlink;
708 	backlink->reverse = link;
709 
710 	sink->num_backlinks++;
711 	sink->num_links++;
712 	source->num_links++;
713 
714 	return 0;
715 }
716 EXPORT_SYMBOL_GPL(media_create_pad_link);
717 
718 int media_create_pad_links(const struct media_device *mdev,
719 			   const u32 source_function,
720 			   struct media_entity *source,
721 			   const u16 source_pad,
722 			   const u32 sink_function,
723 			   struct media_entity *sink,
724 			   const u16 sink_pad,
725 			   u32 flags,
726 			   const bool allow_both_undefined)
727 {
728 	struct media_entity *entity;
729 	unsigned function;
730 	int ret;
731 
732 	/* Trivial case: 1:1 relation */
733 	if (source && sink)
734 		return media_create_pad_link(source, source_pad,
735 					     sink, sink_pad, flags);
736 
737 	/* Worse case scenario: n:n relation */
738 	if (!source && !sink) {
739 		if (!allow_both_undefined)
740 			return 0;
741 		media_device_for_each_entity(source, mdev) {
742 			if (source->function != source_function)
743 				continue;
744 			media_device_for_each_entity(sink, mdev) {
745 				if (sink->function != sink_function)
746 					continue;
747 				ret = media_create_pad_link(source, source_pad,
748 							    sink, sink_pad,
749 							    flags);
750 				if (ret)
751 					return ret;
752 				flags &= ~(MEDIA_LNK_FL_ENABLED |
753 					   MEDIA_LNK_FL_IMMUTABLE);
754 			}
755 		}
756 		return 0;
757 	}
758 
759 	/* Handle 1:n and n:1 cases */
760 	if (source)
761 		function = sink_function;
762 	else
763 		function = source_function;
764 
765 	media_device_for_each_entity(entity, mdev) {
766 		if (entity->function != function)
767 			continue;
768 
769 		if (source)
770 			ret = media_create_pad_link(source, source_pad,
771 						    entity, sink_pad, flags);
772 		else
773 			ret = media_create_pad_link(entity, source_pad,
774 						    sink, sink_pad, flags);
775 		if (ret)
776 			return ret;
777 		flags &= ~(MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
778 	}
779 	return 0;
780 }
781 EXPORT_SYMBOL_GPL(media_create_pad_links);
782 
783 void __media_entity_remove_links(struct media_entity *entity)
784 {
785 	struct media_link *link, *tmp;
786 
787 	list_for_each_entry_safe(link, tmp, &entity->links, list)
788 		__media_entity_remove_link(entity, link);
789 
790 	entity->num_links = 0;
791 	entity->num_backlinks = 0;
792 }
793 EXPORT_SYMBOL_GPL(__media_entity_remove_links);
794 
795 void media_entity_remove_links(struct media_entity *entity)
796 {
797 	struct media_device *mdev = entity->graph_obj.mdev;
798 
799 	/* Do nothing if the entity is not registered. */
800 	if (mdev == NULL)
801 		return;
802 
803 	mutex_lock(&mdev->graph_mutex);
804 	__media_entity_remove_links(entity);
805 	mutex_unlock(&mdev->graph_mutex);
806 }
807 EXPORT_SYMBOL_GPL(media_entity_remove_links);
808 
809 static int __media_entity_setup_link_notify(struct media_link *link, u32 flags)
810 {
811 	int ret;
812 
813 	/* Notify both entities. */
814 	ret = media_entity_call(link->source->entity, link_setup,
815 				link->source, link->sink, flags);
816 	if (ret < 0 && ret != -ENOIOCTLCMD)
817 		return ret;
818 
819 	ret = media_entity_call(link->sink->entity, link_setup,
820 				link->sink, link->source, flags);
821 	if (ret < 0 && ret != -ENOIOCTLCMD) {
822 		media_entity_call(link->source->entity, link_setup,
823 				  link->source, link->sink, link->flags);
824 		return ret;
825 	}
826 
827 	link->flags = flags;
828 	link->reverse->flags = link->flags;
829 
830 	return 0;
831 }
832 
833 int __media_entity_setup_link(struct media_link *link, u32 flags)
834 {
835 	const u32 mask = MEDIA_LNK_FL_ENABLED;
836 	struct media_device *mdev;
837 	struct media_entity *source, *sink;
838 	int ret = -EBUSY;
839 
840 	if (link == NULL)
841 		return -EINVAL;
842 
843 	/* The non-modifiable link flags must not be modified. */
844 	if ((link->flags & ~mask) != (flags & ~mask))
845 		return -EINVAL;
846 
847 	if (link->flags & MEDIA_LNK_FL_IMMUTABLE)
848 		return link->flags == flags ? 0 : -EINVAL;
849 
850 	if (link->flags == flags)
851 		return 0;
852 
853 	source = link->source->entity;
854 	sink = link->sink->entity;
855 
856 	if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) &&
857 	    (source->stream_count || sink->stream_count))
858 		return -EBUSY;
859 
860 	mdev = source->graph_obj.mdev;
861 
862 	if (mdev->ops && mdev->ops->link_notify) {
863 		ret = mdev->ops->link_notify(link, flags,
864 					     MEDIA_DEV_NOTIFY_PRE_LINK_CH);
865 		if (ret < 0)
866 			return ret;
867 	}
868 
869 	ret = __media_entity_setup_link_notify(link, flags);
870 
871 	if (mdev->ops && mdev->ops->link_notify)
872 		mdev->ops->link_notify(link, flags,
873 				       MEDIA_DEV_NOTIFY_POST_LINK_CH);
874 
875 	return ret;
876 }
877 EXPORT_SYMBOL_GPL(__media_entity_setup_link);
878 
879 int media_entity_setup_link(struct media_link *link, u32 flags)
880 {
881 	int ret;
882 
883 	mutex_lock(&link->graph_obj.mdev->graph_mutex);
884 	ret = __media_entity_setup_link(link, flags);
885 	mutex_unlock(&link->graph_obj.mdev->graph_mutex);
886 
887 	return ret;
888 }
889 EXPORT_SYMBOL_GPL(media_entity_setup_link);
890 
891 struct media_link *
892 media_entity_find_link(struct media_pad *source, struct media_pad *sink)
893 {
894 	struct media_link *link;
895 
896 	list_for_each_entry(link, &source->entity->links, list) {
897 		if (link->source->entity == source->entity &&
898 		    link->source->index == source->index &&
899 		    link->sink->entity == sink->entity &&
900 		    link->sink->index == sink->index)
901 			return link;
902 	}
903 
904 	return NULL;
905 }
906 EXPORT_SYMBOL_GPL(media_entity_find_link);
907 
908 struct media_pad *media_entity_remote_pad(const struct media_pad *pad)
909 {
910 	struct media_link *link;
911 
912 	list_for_each_entry(link, &pad->entity->links, list) {
913 		if (!(link->flags & MEDIA_LNK_FL_ENABLED))
914 			continue;
915 
916 		if (link->source == pad)
917 			return link->sink;
918 
919 		if (link->sink == pad)
920 			return link->source;
921 	}
922 
923 	return NULL;
924 
925 }
926 EXPORT_SYMBOL_GPL(media_entity_remote_pad);
927 
928 static void media_interface_init(struct media_device *mdev,
929 				 struct media_interface *intf,
930 				 u32 gobj_type,
931 				 u32 intf_type, u32 flags)
932 {
933 	intf->type = intf_type;
934 	intf->flags = flags;
935 	INIT_LIST_HEAD(&intf->links);
936 
937 	media_gobj_create(mdev, gobj_type, &intf->graph_obj);
938 }
939 
940 /* Functions related to the media interface via device nodes */
941 
942 struct media_intf_devnode *media_devnode_create(struct media_device *mdev,
943 						u32 type, u32 flags,
944 						u32 major, u32 minor)
945 {
946 	struct media_intf_devnode *devnode;
947 
948 	devnode = kzalloc(sizeof(*devnode), GFP_KERNEL);
949 	if (!devnode)
950 		return NULL;
951 
952 	devnode->major = major;
953 	devnode->minor = minor;
954 
955 	media_interface_init(mdev, &devnode->intf, MEDIA_GRAPH_INTF_DEVNODE,
956 			     type, flags);
957 
958 	return devnode;
959 }
960 EXPORT_SYMBOL_GPL(media_devnode_create);
961 
962 void media_devnode_remove(struct media_intf_devnode *devnode)
963 {
964 	media_remove_intf_links(&devnode->intf);
965 	media_gobj_destroy(&devnode->intf.graph_obj);
966 	kfree(devnode);
967 }
968 EXPORT_SYMBOL_GPL(media_devnode_remove);
969 
970 struct media_link *media_create_intf_link(struct media_entity *entity,
971 					    struct media_interface *intf,
972 					    u32 flags)
973 {
974 	struct media_link *link;
975 
976 	link = media_add_link(&intf->links);
977 	if (link == NULL)
978 		return NULL;
979 
980 	link->intf = intf;
981 	link->entity = entity;
982 	link->flags = flags | MEDIA_LNK_FL_INTERFACE_LINK;
983 
984 	/* Initialize graph object embedded at the new link */
985 	media_gobj_create(intf->graph_obj.mdev, MEDIA_GRAPH_LINK,
986 			&link->graph_obj);
987 
988 	return link;
989 }
990 EXPORT_SYMBOL_GPL(media_create_intf_link);
991 
992 void __media_remove_intf_link(struct media_link *link)
993 {
994 	list_del(&link->list);
995 	media_gobj_destroy(&link->graph_obj);
996 	kfree(link);
997 }
998 EXPORT_SYMBOL_GPL(__media_remove_intf_link);
999 
1000 void media_remove_intf_link(struct media_link *link)
1001 {
1002 	struct media_device *mdev = link->graph_obj.mdev;
1003 
1004 	/* Do nothing if the intf is not registered. */
1005 	if (mdev == NULL)
1006 		return;
1007 
1008 	mutex_lock(&mdev->graph_mutex);
1009 	__media_remove_intf_link(link);
1010 	mutex_unlock(&mdev->graph_mutex);
1011 }
1012 EXPORT_SYMBOL_GPL(media_remove_intf_link);
1013 
1014 void __media_remove_intf_links(struct media_interface *intf)
1015 {
1016 	struct media_link *link, *tmp;
1017 
1018 	list_for_each_entry_safe(link, tmp, &intf->links, list)
1019 		__media_remove_intf_link(link);
1020 
1021 }
1022 EXPORT_SYMBOL_GPL(__media_remove_intf_links);
1023 
1024 void media_remove_intf_links(struct media_interface *intf)
1025 {
1026 	struct media_device *mdev = intf->graph_obj.mdev;
1027 
1028 	/* Do nothing if the intf is not registered. */
1029 	if (mdev == NULL)
1030 		return;
1031 
1032 	mutex_lock(&mdev->graph_mutex);
1033 	__media_remove_intf_links(intf);
1034 	mutex_unlock(&mdev->graph_mutex);
1035 }
1036 EXPORT_SYMBOL_GPL(media_remove_intf_links);
1037