1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Media entity
4 *
5 * Copyright (C) 2010 Nokia Corporation
6 *
7 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
8 *	     Sakari Ailus <sakari.ailus@iki.fi>
9 */
10
11#include <linux/bitmap.h>
12#include <linux/property.h>
13#include <linux/slab.h>
14#include <media/media-entity.h>
15#include <media/media-device.h>
16
17static inline const char *gobj_type(enum media_gobj_type type)
18{
19	switch (type) {
20	case MEDIA_GRAPH_ENTITY:
21		return "entity";
22	case MEDIA_GRAPH_PAD:
23		return "pad";
24	case MEDIA_GRAPH_LINK:
25		return "link";
26	case MEDIA_GRAPH_INTF_DEVNODE:
27		return "intf-devnode";
28	default:
29		return "unknown";
30	}
31}
32
33static inline const char *intf_type(struct media_interface *intf)
34{
35	switch (intf->type) {
36	case MEDIA_INTF_T_DVB_FE:
37		return "dvb-frontend";
38	case MEDIA_INTF_T_DVB_DEMUX:
39		return "dvb-demux";
40	case MEDIA_INTF_T_DVB_DVR:
41		return "dvb-dvr";
42	case MEDIA_INTF_T_DVB_CA:
43		return  "dvb-ca";
44	case MEDIA_INTF_T_DVB_NET:
45		return "dvb-net";
46	case MEDIA_INTF_T_V4L_VIDEO:
47		return "v4l-video";
48	case MEDIA_INTF_T_V4L_VBI:
49		return "v4l-vbi";
50	case MEDIA_INTF_T_V4L_RADIO:
51		return "v4l-radio";
52	case MEDIA_INTF_T_V4L_SUBDEV:
53		return "v4l-subdev";
54	case MEDIA_INTF_T_V4L_SWRADIO:
55		return "v4l-swradio";
56	case MEDIA_INTF_T_V4L_TOUCH:
57		return "v4l-touch";
58	default:
59		return "unknown-intf";
60	}
61};
62
63__must_check int __media_entity_enum_init(struct media_entity_enum *ent_enum,
64					  int idx_max)
65{
66	idx_max = ALIGN(idx_max, BITS_PER_LONG);
67	ent_enum->bmap = kcalloc(idx_max / BITS_PER_LONG, sizeof(long),
68				 GFP_KERNEL);
69	if (!ent_enum->bmap)
70		return -ENOMEM;
71
72	bitmap_zero(ent_enum->bmap, idx_max);
73	ent_enum->idx_max = idx_max;
74
75	return 0;
76}
77EXPORT_SYMBOL_GPL(__media_entity_enum_init);
78
79void media_entity_enum_cleanup(struct media_entity_enum *ent_enum)
80{
81	kfree(ent_enum->bmap);
82}
83EXPORT_SYMBOL_GPL(media_entity_enum_cleanup);
84
85/**
86 *  dev_dbg_obj - Prints in debug mode a change on some object
87 *
88 * @event_name:	Name of the event to report. Could be __func__
89 * @gobj:	Pointer to the object
90 *
91 * Enabled only if DEBUG or CONFIG_DYNAMIC_DEBUG. Otherwise, it
92 * won't produce any code.
93 */
94static void dev_dbg_obj(const char *event_name,  struct media_gobj *gobj)
95{
96#if defined(DEBUG) || defined (CONFIG_DYNAMIC_DEBUG)
97	switch (media_type(gobj)) {
98	case MEDIA_GRAPH_ENTITY:
99		dev_dbg(gobj->mdev->dev,
100			"%s id %u: entity '%s'\n",
101			event_name, media_id(gobj),
102			gobj_to_entity(gobj)->name);
103		break;
104	case MEDIA_GRAPH_LINK:
105	{
106		struct media_link *link = gobj_to_link(gobj);
107
108		dev_dbg(gobj->mdev->dev,
109			"%s id %u: %s link id %u ==> id %u\n",
110			event_name, media_id(gobj),
111			media_type(link->gobj0) == MEDIA_GRAPH_PAD ?
112				"data" : "interface",
113			media_id(link->gobj0),
114			media_id(link->gobj1));
115		break;
116	}
117	case MEDIA_GRAPH_PAD:
118	{
119		struct media_pad *pad = gobj_to_pad(gobj);
120
121		dev_dbg(gobj->mdev->dev,
122			"%s id %u: %s%spad '%s':%d\n",
123			event_name, media_id(gobj),
124			pad->flags & MEDIA_PAD_FL_SINK   ? "sink " : "",
125			pad->flags & MEDIA_PAD_FL_SOURCE ? "source " : "",
126			pad->entity->name, pad->index);
127		break;
128	}
129	case MEDIA_GRAPH_INTF_DEVNODE:
130	{
131		struct media_interface *intf = gobj_to_intf(gobj);
132		struct media_intf_devnode *devnode = intf_to_devnode(intf);
133
134		dev_dbg(gobj->mdev->dev,
135			"%s id %u: intf_devnode %s - major: %d, minor: %d\n",
136			event_name, media_id(gobj),
137			intf_type(intf),
138			devnode->major, devnode->minor);
139		break;
140	}
141	}
142#endif
143}
144
145void media_gobj_create(struct media_device *mdev,
146			   enum media_gobj_type type,
147			   struct media_gobj *gobj)
148{
149	BUG_ON(!mdev);
150
151	gobj->mdev = mdev;
152
153	/* Create a per-type unique object ID */
154	gobj->id = media_gobj_gen_id(type, ++mdev->id);
155
156	switch (type) {
157	case MEDIA_GRAPH_ENTITY:
158		list_add_tail(&gobj->list, &mdev->entities);
159		break;
160	case MEDIA_GRAPH_PAD:
161		list_add_tail(&gobj->list, &mdev->pads);
162		break;
163	case MEDIA_GRAPH_LINK:
164		list_add_tail(&gobj->list, &mdev->links);
165		break;
166	case MEDIA_GRAPH_INTF_DEVNODE:
167		list_add_tail(&gobj->list, &mdev->interfaces);
168		break;
169	}
170
171	mdev->topology_version++;
172
173	dev_dbg_obj(__func__, gobj);
174}
175
176void media_gobj_destroy(struct media_gobj *gobj)
177{
178	/* Do nothing if the object is not linked. */
179	if (gobj->mdev == NULL)
180		return;
181
182	dev_dbg_obj(__func__, gobj);
183
184	gobj->mdev->topology_version++;
185
186	/* Remove the object from mdev list */
187	list_del(&gobj->list);
188
189	gobj->mdev = NULL;
190}
191
192/*
193 * TODO: Get rid of this.
194 */
195#define MEDIA_ENTITY_MAX_PADS		512
196
197int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
198			   struct media_pad *pads)
199{
200	struct media_device *mdev = entity->graph_obj.mdev;
201	unsigned int i;
202
203	if (num_pads >= MEDIA_ENTITY_MAX_PADS)
204		return -E2BIG;
205
206	entity->num_pads = num_pads;
207	entity->pads = pads;
208
209	if (mdev)
210		mutex_lock(&mdev->graph_mutex);
211
212	for (i = 0; i < num_pads; i++) {
213		pads[i].entity = entity;
214		pads[i].index = i;
215		if (mdev)
216			media_gobj_create(mdev, MEDIA_GRAPH_PAD,
217					&entity->pads[i].graph_obj);
218	}
219
220	if (mdev)
221		mutex_unlock(&mdev->graph_mutex);
222
223	return 0;
224}
225EXPORT_SYMBOL_GPL(media_entity_pads_init);
226
227/* -----------------------------------------------------------------------------
228 * Graph traversal
229 */
230
231static struct media_entity *
232media_entity_other(struct media_entity *entity, struct media_link *link)
233{
234	if (link->source->entity == entity)
235		return link->sink->entity;
236	else
237		return link->source->entity;
238}
239
240/* push an entity to traversal stack */
241static void stack_push(struct media_graph *graph,
242		       struct media_entity *entity)
243{
244	if (graph->top == MEDIA_ENTITY_ENUM_MAX_DEPTH - 1) {
245		WARN_ON(1);
246		return;
247	}
248	graph->top++;
249	graph->stack[graph->top].link = entity->links.next;
250	graph->stack[graph->top].entity = entity;
251}
252
253static struct media_entity *stack_pop(struct media_graph *graph)
254{
255	struct media_entity *entity;
256
257	entity = graph->stack[graph->top].entity;
258	graph->top--;
259
260	return entity;
261}
262
263#define link_top(en)	((en)->stack[(en)->top].link)
264#define stack_top(en)	((en)->stack[(en)->top].entity)
265
266/**
267 * media_graph_walk_init - Allocate resources for graph walk
268 * @graph: Media graph structure that will be used to walk the graph
269 * @mdev: Media device
270 *
271 * Reserve resources for graph walk in media device's current
272 * state. The memory must be released using
273 * media_graph_walk_free().
274 *
275 * Returns error on failure, zero on success.
276 */
277__must_check int media_graph_walk_init(
278	struct media_graph *graph, struct media_device *mdev)
279{
280	return media_entity_enum_init(&graph->ent_enum, mdev);
281}
282EXPORT_SYMBOL_GPL(media_graph_walk_init);
283
284/**
285 * media_graph_walk_cleanup - Release resources related to graph walking
286 * @graph: Media graph structure that was used to walk the graph
287 */
288void media_graph_walk_cleanup(struct media_graph *graph)
289{
290	media_entity_enum_cleanup(&graph->ent_enum);
291}
292EXPORT_SYMBOL_GPL(media_graph_walk_cleanup);
293
294void media_graph_walk_start(struct media_graph *graph,
295			    struct media_entity *entity)
296{
297	media_entity_enum_zero(&graph->ent_enum);
298	media_entity_enum_set(&graph->ent_enum, entity);
299
300	graph->top = 0;
301	graph->stack[graph->top].entity = NULL;
302	stack_push(graph, entity);
303	dev_dbg(entity->graph_obj.mdev->dev,
304		"begin graph walk at '%s'\n", entity->name);
305}
306EXPORT_SYMBOL_GPL(media_graph_walk_start);
307
308static void media_graph_walk_iter(struct media_graph *graph)
309{
310	struct media_entity *entity = stack_top(graph);
311	struct media_link *link;
312	struct media_entity *next;
313
314	link = list_entry(link_top(graph), typeof(*link), list);
315
316	/* The link is not enabled so we do not follow. */
317	if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
318		link_top(graph) = link_top(graph)->next;
319		dev_dbg(entity->graph_obj.mdev->dev,
320			"walk: skipping disabled link '%s':%u -> '%s':%u\n",
321			link->source->entity->name, link->source->index,
322			link->sink->entity->name, link->sink->index);
323		return;
324	}
325
326	/* Get the entity in the other end of the link . */
327	next = media_entity_other(entity, link);
328
329	/* Has the entity already been visited? */
330	if (media_entity_enum_test_and_set(&graph->ent_enum, next)) {
331		link_top(graph) = link_top(graph)->next;
332		dev_dbg(entity->graph_obj.mdev->dev,
333			"walk: skipping entity '%s' (already seen)\n",
334			next->name);
335		return;
336	}
337
338	/* Push the new entity to stack and start over. */
339	link_top(graph) = link_top(graph)->next;
340	stack_push(graph, next);
341	dev_dbg(entity->graph_obj.mdev->dev, "walk: pushing '%s' on stack\n",
342		next->name);
343}
344
345struct media_entity *media_graph_walk_next(struct media_graph *graph)
346{
347	struct media_entity *entity;
348
349	if (stack_top(graph) == NULL)
350		return NULL;
351
352	/*
353	 * Depth first search. Push entity to stack and continue from
354	 * top of the stack until no more entities on the level can be
355	 * found.
356	 */
357	while (link_top(graph) != &stack_top(graph)->links)
358		media_graph_walk_iter(graph);
359
360	entity = stack_pop(graph);
361	dev_dbg(entity->graph_obj.mdev->dev,
362		"walk: returning entity '%s'\n", entity->name);
363
364	return entity;
365}
366EXPORT_SYMBOL_GPL(media_graph_walk_next);
367
368int media_entity_get_fwnode_pad(struct media_entity *entity,
369				struct fwnode_handle *fwnode,
370				unsigned long direction_flags)
371{
372	struct fwnode_endpoint endpoint;
373	unsigned int i;
374	int ret;
375
376	if (!entity->ops || !entity->ops->get_fwnode_pad) {
377		for (i = 0; i < entity->num_pads; i++) {
378			if (entity->pads[i].flags & direction_flags)
379				return i;
380		}
381
382		return -ENXIO;
383	}
384
385	ret = fwnode_graph_parse_endpoint(fwnode, &endpoint);
386	if (ret)
387		return ret;
388
389	ret = entity->ops->get_fwnode_pad(entity, &endpoint);
390	if (ret < 0)
391		return ret;
392
393	if (ret >= entity->num_pads)
394		return -ENXIO;
395
396	if (!(entity->pads[ret].flags & direction_flags))
397		return -ENXIO;
398
399	return ret;
400}
401EXPORT_SYMBOL_GPL(media_entity_get_fwnode_pad);
402
403/* -----------------------------------------------------------------------------
404 * Pipeline management
405 */
406
407__must_check int __media_pipeline_start(struct media_entity *entity,
408					struct media_pipeline *pipe)
409{
410	struct media_device *mdev = entity->graph_obj.mdev;
411	struct media_graph *graph = &pipe->graph;
412	struct media_entity *entity_err = entity;
413	struct media_link *link;
414	int ret;
415
416	if (!pipe->streaming_count++) {
417		ret = media_graph_walk_init(&pipe->graph, mdev);
418		if (ret)
419			goto error_graph_walk_start;
420	}
421
422	media_graph_walk_start(&pipe->graph, entity);
423
424	while ((entity = media_graph_walk_next(graph))) {
425		DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
426		DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
427
428		entity->stream_count++;
429
430		if (entity->pipe && entity->pipe != pipe) {
431			pr_err("Pipe active for %s. Can't start for %s\n",
432				entity->name,
433				entity_err->name);
434			ret = -EBUSY;
435			goto error;
436		}
437
438		entity->pipe = pipe;
439
440		/* Already streaming --- no need to check. */
441		if (entity->stream_count > 1)
442			continue;
443
444		if (!entity->ops || !entity->ops->link_validate)
445			continue;
446
447		bitmap_zero(active, entity->num_pads);
448		bitmap_fill(has_no_links, entity->num_pads);
449
450		list_for_each_entry(link, &entity->links, list) {
451			struct media_pad *pad = link->sink->entity == entity
452						? link->sink : link->source;
453
454			/* Mark that a pad is connected by a link. */
455			bitmap_clear(has_no_links, pad->index, 1);
456
457			/*
458			 * Pads that either do not need to connect or
459			 * are connected through an enabled link are
460			 * fine.
461			 */
462			if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) ||
463			    link->flags & MEDIA_LNK_FL_ENABLED)
464				bitmap_set(active, pad->index, 1);
465
466			/*
467			 * Link validation will only take place for
468			 * sink ends of the link that are enabled.
469			 */
470			if (link->sink != pad ||
471			    !(link->flags & MEDIA_LNK_FL_ENABLED))
472				continue;
473
474			ret = entity->ops->link_validate(link);
475			if (ret < 0 && ret != -ENOIOCTLCMD) {
476				dev_dbg(entity->graph_obj.mdev->dev,
477					"link validation failed for '%s':%u -> '%s':%u, error %d\n",
478					link->source->entity->name,
479					link->source->index,
480					entity->name, link->sink->index, ret);
481				goto error;
482			}
483		}
484
485		/* Either no links or validated links are fine. */
486		bitmap_or(active, active, has_no_links, entity->num_pads);
487
488		if (!bitmap_full(active, entity->num_pads)) {
489			ret = -ENOLINK;
490			dev_dbg(entity->graph_obj.mdev->dev,
491				"'%s':%u must be connected by an enabled link\n",
492				entity->name,
493				(unsigned)find_first_zero_bit(
494					active, entity->num_pads));
495			goto error;
496		}
497	}
498
499	return 0;
500
501error:
502	/*
503	 * Link validation on graph failed. We revert what we did and
504	 * return the error.
505	 */
506	media_graph_walk_start(graph, entity_err);
507
508	while ((entity_err = media_graph_walk_next(graph))) {
509		/* Sanity check for negative stream_count */
510		if (!WARN_ON_ONCE(entity_err->stream_count <= 0)) {
511			entity_err->stream_count--;
512			if (entity_err->stream_count == 0)
513				entity_err->pipe = NULL;
514		}
515
516		/*
517		 * We haven't increased stream_count further than this
518		 * so we quit here.
519		 */
520		if (entity_err == entity)
521			break;
522	}
523
524error_graph_walk_start:
525	if (!--pipe->streaming_count)
526		media_graph_walk_cleanup(graph);
527
528	return ret;
529}
530EXPORT_SYMBOL_GPL(__media_pipeline_start);
531
532__must_check int media_pipeline_start(struct media_entity *entity,
533				      struct media_pipeline *pipe)
534{
535	struct media_device *mdev = entity->graph_obj.mdev;
536	int ret;
537
538	mutex_lock(&mdev->graph_mutex);
539	ret = __media_pipeline_start(entity, pipe);
540	mutex_unlock(&mdev->graph_mutex);
541	return ret;
542}
543EXPORT_SYMBOL_GPL(media_pipeline_start);
544
545void __media_pipeline_stop(struct media_entity *entity)
546{
547	struct media_graph *graph = &entity->pipe->graph;
548	struct media_pipeline *pipe = entity->pipe;
549
550	/*
551	 * If the following check fails, the driver has performed an
552	 * unbalanced call to media_pipeline_stop()
553	 */
554	if (WARN_ON(!pipe))
555		return;
556
557	media_graph_walk_start(graph, entity);
558
559	while ((entity = media_graph_walk_next(graph))) {
560		/* Sanity check for negative stream_count */
561		if (!WARN_ON_ONCE(entity->stream_count <= 0)) {
562			entity->stream_count--;
563			if (entity->stream_count == 0)
564				entity->pipe = NULL;
565		}
566	}
567
568	if (!--pipe->streaming_count)
569		media_graph_walk_cleanup(graph);
570
571}
572EXPORT_SYMBOL_GPL(__media_pipeline_stop);
573
574void media_pipeline_stop(struct media_entity *entity)
575{
576	struct media_device *mdev = entity->graph_obj.mdev;
577
578	mutex_lock(&mdev->graph_mutex);
579	__media_pipeline_stop(entity);
580	mutex_unlock(&mdev->graph_mutex);
581}
582EXPORT_SYMBOL_GPL(media_pipeline_stop);
583
584/* -----------------------------------------------------------------------------
585 * Links management
586 */
587
588static struct media_link *media_add_link(struct list_head *head)
589{
590	struct media_link *link;
591
592	link = kzalloc(sizeof(*link), GFP_KERNEL);
593	if (link == NULL)
594		return NULL;
595
596	list_add_tail(&link->list, head);
597
598	return link;
599}
600
601static void __media_entity_remove_link(struct media_entity *entity,
602				       struct media_link *link)
603{
604	struct media_link *rlink, *tmp;
605	struct media_entity *remote;
606
607	if (link->source->entity == entity)
608		remote = link->sink->entity;
609	else
610		remote = link->source->entity;
611
612	list_for_each_entry_safe(rlink, tmp, &remote->links, list) {
613		if (rlink != link->reverse)
614			continue;
615
616		if (link->source->entity == entity)
617			remote->num_backlinks--;
618
619		/* Remove the remote link */
620		list_del(&rlink->list);
621		media_gobj_destroy(&rlink->graph_obj);
622		kfree(rlink);
623
624		if (--remote->num_links == 0)
625			break;
626	}
627	list_del(&link->list);
628	media_gobj_destroy(&link->graph_obj);
629	kfree(link);
630}
631
632int media_get_pad_index(struct media_entity *entity, bool is_sink,
633			enum media_pad_signal_type sig_type)
634{
635	int i;
636	bool pad_is_sink;
637
638	if (!entity)
639		return -EINVAL;
640
641	for (i = 0; i < entity->num_pads; i++) {
642		if (entity->pads[i].flags & MEDIA_PAD_FL_SINK)
643			pad_is_sink = true;
644		else if (entity->pads[i].flags & MEDIA_PAD_FL_SOURCE)
645			pad_is_sink = false;
646		else
647			continue;	/* This is an error! */
648
649		if (pad_is_sink != is_sink)
650			continue;
651		if (entity->pads[i].sig_type == sig_type)
652			return i;
653	}
654	return -EINVAL;
655}
656EXPORT_SYMBOL_GPL(media_get_pad_index);
657
658int
659media_create_pad_link(struct media_entity *source, u16 source_pad,
660			 struct media_entity *sink, u16 sink_pad, u32 flags)
661{
662	struct media_link *link;
663	struct media_link *backlink;
664
665	if (WARN_ON(!source || !sink) ||
666	    WARN_ON(source_pad >= source->num_pads) ||
667	    WARN_ON(sink_pad >= sink->num_pads))
668		return -EINVAL;
669	if (WARN_ON(!(source->pads[source_pad].flags & MEDIA_PAD_FL_SOURCE)))
670		return -EINVAL;
671	if (WARN_ON(!(sink->pads[sink_pad].flags & MEDIA_PAD_FL_SINK)))
672		return -EINVAL;
673
674	link = media_add_link(&source->links);
675	if (link == NULL)
676		return -ENOMEM;
677
678	link->source = &source->pads[source_pad];
679	link->sink = &sink->pads[sink_pad];
680	link->flags = flags & ~MEDIA_LNK_FL_INTERFACE_LINK;
681
682	/* Initialize graph object embedded at the new link */
683	media_gobj_create(source->graph_obj.mdev, MEDIA_GRAPH_LINK,
684			&link->graph_obj);
685
686	/* Create the backlink. Backlinks are used to help graph traversal and
687	 * are not reported to userspace.
688	 */
689	backlink = media_add_link(&sink->links);
690	if (backlink == NULL) {
691		__media_entity_remove_link(source, link);
692		return -ENOMEM;
693	}
694
695	backlink->source = &source->pads[source_pad];
696	backlink->sink = &sink->pads[sink_pad];
697	backlink->flags = flags;
698	backlink->is_backlink = true;
699
700	/* Initialize graph object embedded at the new link */
701	media_gobj_create(sink->graph_obj.mdev, MEDIA_GRAPH_LINK,
702			&backlink->graph_obj);
703
704	link->reverse = backlink;
705	backlink->reverse = link;
706
707	sink->num_backlinks++;
708	sink->num_links++;
709	source->num_links++;
710
711	return 0;
712}
713EXPORT_SYMBOL_GPL(media_create_pad_link);
714
715int media_create_pad_links(const struct media_device *mdev,
716			   const u32 source_function,
717			   struct media_entity *source,
718			   const u16 source_pad,
719			   const u32 sink_function,
720			   struct media_entity *sink,
721			   const u16 sink_pad,
722			   u32 flags,
723			   const bool allow_both_undefined)
724{
725	struct media_entity *entity;
726	unsigned function;
727	int ret;
728
729	/* Trivial case: 1:1 relation */
730	if (source && sink)
731		return media_create_pad_link(source, source_pad,
732					     sink, sink_pad, flags);
733
734	/* Worse case scenario: n:n relation */
735	if (!source && !sink) {
736		if (!allow_both_undefined)
737			return 0;
738		media_device_for_each_entity(source, mdev) {
739			if (source->function != source_function)
740				continue;
741			media_device_for_each_entity(sink, mdev) {
742				if (sink->function != sink_function)
743					continue;
744				ret = media_create_pad_link(source, source_pad,
745							    sink, sink_pad,
746							    flags);
747				if (ret)
748					return ret;
749				flags &= ~(MEDIA_LNK_FL_ENABLED |
750					   MEDIA_LNK_FL_IMMUTABLE);
751			}
752		}
753		return 0;
754	}
755
756	/* Handle 1:n and n:1 cases */
757	if (source)
758		function = sink_function;
759	else
760		function = source_function;
761
762	media_device_for_each_entity(entity, mdev) {
763		if (entity->function != function)
764			continue;
765
766		if (source)
767			ret = media_create_pad_link(source, source_pad,
768						    entity, sink_pad, flags);
769		else
770			ret = media_create_pad_link(entity, source_pad,
771						    sink, sink_pad, flags);
772		if (ret)
773			return ret;
774		flags &= ~(MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
775	}
776	return 0;
777}
778EXPORT_SYMBOL_GPL(media_create_pad_links);
779
780void __media_entity_remove_links(struct media_entity *entity)
781{
782	struct media_link *link, *tmp;
783
784	list_for_each_entry_safe(link, tmp, &entity->links, list)
785		__media_entity_remove_link(entity, link);
786
787	entity->num_links = 0;
788	entity->num_backlinks = 0;
789}
790EXPORT_SYMBOL_GPL(__media_entity_remove_links);
791
792void media_entity_remove_links(struct media_entity *entity)
793{
794	struct media_device *mdev = entity->graph_obj.mdev;
795
796	/* Do nothing if the entity is not registered. */
797	if (mdev == NULL)
798		return;
799
800	mutex_lock(&mdev->graph_mutex);
801	__media_entity_remove_links(entity);
802	mutex_unlock(&mdev->graph_mutex);
803}
804EXPORT_SYMBOL_GPL(media_entity_remove_links);
805
806static int __media_entity_setup_link_notify(struct media_link *link, u32 flags)
807{
808	int ret;
809
810	/* Notify both entities. */
811	ret = media_entity_call(link->source->entity, link_setup,
812				link->source, link->sink, flags);
813	if (ret < 0 && ret != -ENOIOCTLCMD)
814		return ret;
815
816	ret = media_entity_call(link->sink->entity, link_setup,
817				link->sink, link->source, flags);
818	if (ret < 0 && ret != -ENOIOCTLCMD) {
819		media_entity_call(link->source->entity, link_setup,
820				  link->source, link->sink, link->flags);
821		return ret;
822	}
823
824	link->flags = flags;
825	link->reverse->flags = link->flags;
826
827	return 0;
828}
829
830int __media_entity_setup_link(struct media_link *link, u32 flags)
831{
832	const u32 mask = MEDIA_LNK_FL_ENABLED;
833	struct media_device *mdev;
834	struct media_entity *source, *sink;
835	int ret = -EBUSY;
836
837	if (link == NULL)
838		return -EINVAL;
839
840	/* The non-modifiable link flags must not be modified. */
841	if ((link->flags & ~mask) != (flags & ~mask))
842		return -EINVAL;
843
844	if (link->flags & MEDIA_LNK_FL_IMMUTABLE)
845		return link->flags == flags ? 0 : -EINVAL;
846
847	if (link->flags == flags)
848		return 0;
849
850	source = link->source->entity;
851	sink = link->sink->entity;
852
853	if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) &&
854	    (source->stream_count || sink->stream_count))
855		return -EBUSY;
856
857	mdev = source->graph_obj.mdev;
858
859	if (mdev->ops && mdev->ops->link_notify) {
860		ret = mdev->ops->link_notify(link, flags,
861					     MEDIA_DEV_NOTIFY_PRE_LINK_CH);
862		if (ret < 0)
863			return ret;
864	}
865
866	ret = __media_entity_setup_link_notify(link, flags);
867
868	if (mdev->ops && mdev->ops->link_notify)
869		mdev->ops->link_notify(link, flags,
870				       MEDIA_DEV_NOTIFY_POST_LINK_CH);
871
872	return ret;
873}
874EXPORT_SYMBOL_GPL(__media_entity_setup_link);
875
876int media_entity_setup_link(struct media_link *link, u32 flags)
877{
878	int ret;
879
880	mutex_lock(&link->graph_obj.mdev->graph_mutex);
881	ret = __media_entity_setup_link(link, flags);
882	mutex_unlock(&link->graph_obj.mdev->graph_mutex);
883
884	return ret;
885}
886EXPORT_SYMBOL_GPL(media_entity_setup_link);
887
888struct media_link *
889media_entity_find_link(struct media_pad *source, struct media_pad *sink)
890{
891	struct media_link *link;
892
893	list_for_each_entry(link, &source->entity->links, list) {
894		if (link->source->entity == source->entity &&
895		    link->source->index == source->index &&
896		    link->sink->entity == sink->entity &&
897		    link->sink->index == sink->index)
898			return link;
899	}
900
901	return NULL;
902}
903EXPORT_SYMBOL_GPL(media_entity_find_link);
904
905struct media_pad *media_entity_remote_pad(const struct media_pad *pad)
906{
907	struct media_link *link;
908
909	list_for_each_entry(link, &pad->entity->links, list) {
910		if (!(link->flags & MEDIA_LNK_FL_ENABLED))
911			continue;
912
913		if (link->source == pad)
914			return link->sink;
915
916		if (link->sink == pad)
917			return link->source;
918	}
919
920	return NULL;
921
922}
923EXPORT_SYMBOL_GPL(media_entity_remote_pad);
924
925static void media_interface_init(struct media_device *mdev,
926				 struct media_interface *intf,
927				 u32 gobj_type,
928				 u32 intf_type, u32 flags)
929{
930	intf->type = intf_type;
931	intf->flags = flags;
932	INIT_LIST_HEAD(&intf->links);
933
934	media_gobj_create(mdev, gobj_type, &intf->graph_obj);
935}
936
937/* Functions related to the media interface via device nodes */
938
939struct media_intf_devnode *media_devnode_create(struct media_device *mdev,
940						u32 type, u32 flags,
941						u32 major, u32 minor)
942{
943	struct media_intf_devnode *devnode;
944
945	devnode = kzalloc(sizeof(*devnode), GFP_KERNEL);
946	if (!devnode)
947		return NULL;
948
949	devnode->major = major;
950	devnode->minor = minor;
951
952	media_interface_init(mdev, &devnode->intf, MEDIA_GRAPH_INTF_DEVNODE,
953			     type, flags);
954
955	return devnode;
956}
957EXPORT_SYMBOL_GPL(media_devnode_create);
958
959void media_devnode_remove(struct media_intf_devnode *devnode)
960{
961	media_remove_intf_links(&devnode->intf);
962	media_gobj_destroy(&devnode->intf.graph_obj);
963	kfree(devnode);
964}
965EXPORT_SYMBOL_GPL(media_devnode_remove);
966
967struct media_link *media_create_intf_link(struct media_entity *entity,
968					    struct media_interface *intf,
969					    u32 flags)
970{
971	struct media_link *link;
972
973	link = media_add_link(&intf->links);
974	if (link == NULL)
975		return NULL;
976
977	link->intf = intf;
978	link->entity = entity;
979	link->flags = flags | MEDIA_LNK_FL_INTERFACE_LINK;
980
981	/* Initialize graph object embedded at the new link */
982	media_gobj_create(intf->graph_obj.mdev, MEDIA_GRAPH_LINK,
983			&link->graph_obj);
984
985	return link;
986}
987EXPORT_SYMBOL_GPL(media_create_intf_link);
988
989void __media_remove_intf_link(struct media_link *link)
990{
991	list_del(&link->list);
992	media_gobj_destroy(&link->graph_obj);
993	kfree(link);
994}
995EXPORT_SYMBOL_GPL(__media_remove_intf_link);
996
997void media_remove_intf_link(struct media_link *link)
998{
999	struct media_device *mdev = link->graph_obj.mdev;
1000
1001	/* Do nothing if the intf is not registered. */
1002	if (mdev == NULL)
1003		return;
1004
1005	mutex_lock(&mdev->graph_mutex);
1006	__media_remove_intf_link(link);
1007	mutex_unlock(&mdev->graph_mutex);
1008}
1009EXPORT_SYMBOL_GPL(media_remove_intf_link);
1010
1011void __media_remove_intf_links(struct media_interface *intf)
1012{
1013	struct media_link *link, *tmp;
1014
1015	list_for_each_entry_safe(link, tmp, &intf->links, list)
1016		__media_remove_intf_link(link);
1017
1018}
1019EXPORT_SYMBOL_GPL(__media_remove_intf_links);
1020
1021void media_remove_intf_links(struct media_interface *intf)
1022{
1023	struct media_device *mdev = intf->graph_obj.mdev;
1024
1025	/* Do nothing if the intf is not registered. */
1026	if (mdev == NULL)
1027		return;
1028
1029	mutex_lock(&mdev->graph_mutex);
1030	__media_remove_intf_links(intf);
1031	mutex_unlock(&mdev->graph_mutex);
1032}
1033EXPORT_SYMBOL_GPL(media_remove_intf_links);
1034