xref: /openbmc/linux/drivers/media/mc/mc-entity.c (revision 48cc39c3)
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 
17 static 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 
33 static 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 }
77 EXPORT_SYMBOL_GPL(__media_entity_enum_init);
78 
79 void media_entity_enum_cleanup(struct media_entity_enum *ent_enum)
80 {
81 	kfree(ent_enum->bmap);
82 }
83 EXPORT_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  */
94 static 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 
145 void 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 
176 void 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 
197 int 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 }
225 EXPORT_SYMBOL_GPL(media_entity_pads_init);
226 
227 /* -----------------------------------------------------------------------------
228  * Graph traversal
229  */
230 
231 static struct media_entity *
232 media_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 */
241 static 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 
253 static 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 }
282 EXPORT_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  */
288 void media_graph_walk_cleanup(struct media_graph *graph)
289 {
290 	media_entity_enum_cleanup(&graph->ent_enum);
291 }
292 EXPORT_SYMBOL_GPL(media_graph_walk_cleanup);
293 
294 void 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 }
306 EXPORT_SYMBOL_GPL(media_graph_walk_start);
307 
308 static 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 at 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 	lockdep_assert_held(&entity->graph_obj.mdev->graph_mutex);
344 }
345 
346 struct media_entity *media_graph_walk_next(struct media_graph *graph)
347 {
348 	struct media_entity *entity;
349 
350 	if (stack_top(graph) == NULL)
351 		return NULL;
352 
353 	/*
354 	 * Depth first search. Push entity to stack and continue from
355 	 * top of the stack until no more entities on the level can be
356 	 * found.
357 	 */
358 	while (link_top(graph) != &stack_top(graph)->links)
359 		media_graph_walk_iter(graph);
360 
361 	entity = stack_pop(graph);
362 	dev_dbg(entity->graph_obj.mdev->dev,
363 		"walk: returning entity '%s'\n", entity->name);
364 
365 	return entity;
366 }
367 EXPORT_SYMBOL_GPL(media_graph_walk_next);
368 
369 int media_entity_get_fwnode_pad(struct media_entity *entity,
370 				struct fwnode_handle *fwnode,
371 				unsigned long direction_flags)
372 {
373 	struct fwnode_endpoint endpoint;
374 	unsigned int i;
375 	int ret;
376 
377 	if (!entity->ops || !entity->ops->get_fwnode_pad) {
378 		for (i = 0; i < entity->num_pads; i++) {
379 			if (entity->pads[i].flags & direction_flags)
380 				return i;
381 		}
382 
383 		return -ENXIO;
384 	}
385 
386 	ret = fwnode_graph_parse_endpoint(fwnode, &endpoint);
387 	if (ret)
388 		return ret;
389 
390 	ret = entity->ops->get_fwnode_pad(entity, &endpoint);
391 	if (ret < 0)
392 		return ret;
393 
394 	if (ret >= entity->num_pads)
395 		return -ENXIO;
396 
397 	if (!(entity->pads[ret].flags & direction_flags))
398 		return -ENXIO;
399 
400 	return ret;
401 }
402 EXPORT_SYMBOL_GPL(media_entity_get_fwnode_pad);
403 
404 /* -----------------------------------------------------------------------------
405  * Pipeline management
406  */
407 
408 __must_check int __media_pipeline_start(struct media_entity *entity,
409 					struct media_pipeline *pipe)
410 {
411 	struct media_device *mdev = entity->graph_obj.mdev;
412 	struct media_graph *graph = &pipe->graph;
413 	struct media_entity *entity_err = entity;
414 	struct media_link *link;
415 	int ret;
416 
417 	if (!pipe->streaming_count++) {
418 		ret = media_graph_walk_init(&pipe->graph, mdev);
419 		if (ret)
420 			goto error_graph_walk_start;
421 	}
422 
423 	media_graph_walk_start(&pipe->graph, entity);
424 
425 	while ((entity = media_graph_walk_next(graph))) {
426 		DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
427 		DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
428 
429 		entity->stream_count++;
430 
431 		if (entity->pipe && entity->pipe != pipe) {
432 			pr_err("Pipe active for %s. Can't start for %s\n",
433 				entity->name,
434 				entity_err->name);
435 			ret = -EBUSY;
436 			goto error;
437 		}
438 
439 		entity->pipe = pipe;
440 
441 		/* Already streaming --- no need to check. */
442 		if (entity->stream_count > 1)
443 			continue;
444 
445 		if (!entity->ops || !entity->ops->link_validate)
446 			continue;
447 
448 		bitmap_zero(active, entity->num_pads);
449 		bitmap_fill(has_no_links, entity->num_pads);
450 
451 		list_for_each_entry(link, &entity->links, list) {
452 			struct media_pad *pad = link->sink->entity == entity
453 						? link->sink : link->source;
454 
455 			/* Mark that a pad is connected by a link. */
456 			bitmap_clear(has_no_links, pad->index, 1);
457 
458 			/*
459 			 * Pads that either do not need to connect or
460 			 * are connected through an enabled link are
461 			 * fine.
462 			 */
463 			if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) ||
464 			    link->flags & MEDIA_LNK_FL_ENABLED)
465 				bitmap_set(active, pad->index, 1);
466 
467 			/*
468 			 * Link validation will only take place for
469 			 * sink ends of the link that are enabled.
470 			 */
471 			if (link->sink != pad ||
472 			    !(link->flags & MEDIA_LNK_FL_ENABLED))
473 				continue;
474 
475 			ret = entity->ops->link_validate(link);
476 			if (ret < 0 && ret != -ENOIOCTLCMD) {
477 				dev_dbg(entity->graph_obj.mdev->dev,
478 					"link validation failed for '%s':%u -> '%s':%u, error %d\n",
479 					link->source->entity->name,
480 					link->source->index,
481 					entity->name, link->sink->index, ret);
482 				goto error;
483 			}
484 		}
485 
486 		/* Either no links or validated links are fine. */
487 		bitmap_or(active, active, has_no_links, entity->num_pads);
488 
489 		if (!bitmap_full(active, entity->num_pads)) {
490 			ret = -ENOLINK;
491 			dev_dbg(entity->graph_obj.mdev->dev,
492 				"'%s':%u must be connected by an enabled link\n",
493 				entity->name,
494 				(unsigned)find_first_zero_bit(
495 					active, entity->num_pads));
496 			goto error;
497 		}
498 	}
499 
500 	return 0;
501 
502 error:
503 	/*
504 	 * Link validation on graph failed. We revert what we did and
505 	 * return the error.
506 	 */
507 	media_graph_walk_start(graph, entity_err);
508 
509 	while ((entity_err = media_graph_walk_next(graph))) {
510 		/* Sanity check for negative stream_count */
511 		if (!WARN_ON_ONCE(entity_err->stream_count <= 0)) {
512 			entity_err->stream_count--;
513 			if (entity_err->stream_count == 0)
514 				entity_err->pipe = NULL;
515 		}
516 
517 		/*
518 		 * We haven't increased stream_count further than this
519 		 * so we quit here.
520 		 */
521 		if (entity_err == entity)
522 			break;
523 	}
524 
525 error_graph_walk_start:
526 	if (!--pipe->streaming_count)
527 		media_graph_walk_cleanup(graph);
528 
529 	return ret;
530 }
531 EXPORT_SYMBOL_GPL(__media_pipeline_start);
532 
533 __must_check int media_pipeline_start(struct media_entity *entity,
534 				      struct media_pipeline *pipe)
535 {
536 	struct media_device *mdev = entity->graph_obj.mdev;
537 	int ret;
538 
539 	mutex_lock(&mdev->graph_mutex);
540 	ret = __media_pipeline_start(entity, pipe);
541 	mutex_unlock(&mdev->graph_mutex);
542 	return ret;
543 }
544 EXPORT_SYMBOL_GPL(media_pipeline_start);
545 
546 void __media_pipeline_stop(struct media_entity *entity)
547 {
548 	struct media_graph *graph = &entity->pipe->graph;
549 	struct media_pipeline *pipe = entity->pipe;
550 
551 	/*
552 	 * If the following check fails, the driver has performed an
553 	 * unbalanced call to media_pipeline_stop()
554 	 */
555 	if (WARN_ON(!pipe))
556 		return;
557 
558 	media_graph_walk_start(graph, entity);
559 
560 	while ((entity = media_graph_walk_next(graph))) {
561 		/* Sanity check for negative stream_count */
562 		if (!WARN_ON_ONCE(entity->stream_count <= 0)) {
563 			entity->stream_count--;
564 			if (entity->stream_count == 0)
565 				entity->pipe = NULL;
566 		}
567 	}
568 
569 	if (!--pipe->streaming_count)
570 		media_graph_walk_cleanup(graph);
571 
572 }
573 EXPORT_SYMBOL_GPL(__media_pipeline_stop);
574 
575 void media_pipeline_stop(struct media_entity *entity)
576 {
577 	struct media_device *mdev = entity->graph_obj.mdev;
578 
579 	mutex_lock(&mdev->graph_mutex);
580 	__media_pipeline_stop(entity);
581 	mutex_unlock(&mdev->graph_mutex);
582 }
583 EXPORT_SYMBOL_GPL(media_pipeline_stop);
584 
585 /* -----------------------------------------------------------------------------
586  * Links management
587  */
588 
589 static struct media_link *media_add_link(struct list_head *head)
590 {
591 	struct media_link *link;
592 
593 	link = kzalloc(sizeof(*link), GFP_KERNEL);
594 	if (link == NULL)
595 		return NULL;
596 
597 	list_add_tail(&link->list, head);
598 
599 	return link;
600 }
601 
602 static void __media_entity_remove_link(struct media_entity *entity,
603 				       struct media_link *link)
604 {
605 	struct media_link *rlink, *tmp;
606 	struct media_entity *remote;
607 
608 	if (link->source->entity == entity)
609 		remote = link->sink->entity;
610 	else
611 		remote = link->source->entity;
612 
613 	list_for_each_entry_safe(rlink, tmp, &remote->links, list) {
614 		if (rlink != link->reverse)
615 			continue;
616 
617 		if (link->source->entity == entity)
618 			remote->num_backlinks--;
619 
620 		/* Remove the remote link */
621 		list_del(&rlink->list);
622 		media_gobj_destroy(&rlink->graph_obj);
623 		kfree(rlink);
624 
625 		if (--remote->num_links == 0)
626 			break;
627 	}
628 	list_del(&link->list);
629 	media_gobj_destroy(&link->graph_obj);
630 	kfree(link);
631 }
632 
633 int media_get_pad_index(struct media_entity *entity, bool is_sink,
634 			enum media_pad_signal_type sig_type)
635 {
636 	int i;
637 	bool pad_is_sink;
638 
639 	if (!entity)
640 		return -EINVAL;
641 
642 	for (i = 0; i < entity->num_pads; i++) {
643 		if (entity->pads[i].flags & MEDIA_PAD_FL_SINK)
644 			pad_is_sink = true;
645 		else if (entity->pads[i].flags & MEDIA_PAD_FL_SOURCE)
646 			pad_is_sink = false;
647 		else
648 			continue;	/* This is an error! */
649 
650 		if (pad_is_sink != is_sink)
651 			continue;
652 		if (entity->pads[i].sig_type == sig_type)
653 			return i;
654 	}
655 	return -EINVAL;
656 }
657 EXPORT_SYMBOL_GPL(media_get_pad_index);
658 
659 int
660 media_create_pad_link(struct media_entity *source, u16 source_pad,
661 			 struct media_entity *sink, u16 sink_pad, u32 flags)
662 {
663 	struct media_link *link;
664 	struct media_link *backlink;
665 
666 	if (WARN_ON(!source || !sink) ||
667 	    WARN_ON(source_pad >= source->num_pads) ||
668 	    WARN_ON(sink_pad >= sink->num_pads))
669 		return -EINVAL;
670 	if (WARN_ON(!(source->pads[source_pad].flags & MEDIA_PAD_FL_SOURCE)))
671 		return -EINVAL;
672 	if (WARN_ON(!(sink->pads[sink_pad].flags & MEDIA_PAD_FL_SINK)))
673 		return -EINVAL;
674 
675 	link = media_add_link(&source->links);
676 	if (link == NULL)
677 		return -ENOMEM;
678 
679 	link->source = &source->pads[source_pad];
680 	link->sink = &sink->pads[sink_pad];
681 	link->flags = flags & ~MEDIA_LNK_FL_INTERFACE_LINK;
682 
683 	/* Initialize graph object embedded at the new link */
684 	media_gobj_create(source->graph_obj.mdev, MEDIA_GRAPH_LINK,
685 			&link->graph_obj);
686 
687 	/* Create the backlink. Backlinks are used to help graph traversal and
688 	 * are not reported to userspace.
689 	 */
690 	backlink = media_add_link(&sink->links);
691 	if (backlink == NULL) {
692 		__media_entity_remove_link(source, link);
693 		return -ENOMEM;
694 	}
695 
696 	backlink->source = &source->pads[source_pad];
697 	backlink->sink = &sink->pads[sink_pad];
698 	backlink->flags = flags;
699 	backlink->is_backlink = true;
700 
701 	/* Initialize graph object embedded at the new link */
702 	media_gobj_create(sink->graph_obj.mdev, MEDIA_GRAPH_LINK,
703 			&backlink->graph_obj);
704 
705 	link->reverse = backlink;
706 	backlink->reverse = link;
707 
708 	sink->num_backlinks++;
709 	sink->num_links++;
710 	source->num_links++;
711 
712 	return 0;
713 }
714 EXPORT_SYMBOL_GPL(media_create_pad_link);
715 
716 int media_create_pad_links(const struct media_device *mdev,
717 			   const u32 source_function,
718 			   struct media_entity *source,
719 			   const u16 source_pad,
720 			   const u32 sink_function,
721 			   struct media_entity *sink,
722 			   const u16 sink_pad,
723 			   u32 flags,
724 			   const bool allow_both_undefined)
725 {
726 	struct media_entity *entity;
727 	unsigned function;
728 	int ret;
729 
730 	/* Trivial case: 1:1 relation */
731 	if (source && sink)
732 		return media_create_pad_link(source, source_pad,
733 					     sink, sink_pad, flags);
734 
735 	/* Worse case scenario: n:n relation */
736 	if (!source && !sink) {
737 		if (!allow_both_undefined)
738 			return 0;
739 		media_device_for_each_entity(source, mdev) {
740 			if (source->function != source_function)
741 				continue;
742 			media_device_for_each_entity(sink, mdev) {
743 				if (sink->function != sink_function)
744 					continue;
745 				ret = media_create_pad_link(source, source_pad,
746 							    sink, sink_pad,
747 							    flags);
748 				if (ret)
749 					return ret;
750 				flags &= ~(MEDIA_LNK_FL_ENABLED |
751 					   MEDIA_LNK_FL_IMMUTABLE);
752 			}
753 		}
754 		return 0;
755 	}
756 
757 	/* Handle 1:n and n:1 cases */
758 	if (source)
759 		function = sink_function;
760 	else
761 		function = source_function;
762 
763 	media_device_for_each_entity(entity, mdev) {
764 		if (entity->function != function)
765 			continue;
766 
767 		if (source)
768 			ret = media_create_pad_link(source, source_pad,
769 						    entity, sink_pad, flags);
770 		else
771 			ret = media_create_pad_link(entity, source_pad,
772 						    sink, sink_pad, flags);
773 		if (ret)
774 			return ret;
775 		flags &= ~(MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
776 	}
777 	return 0;
778 }
779 EXPORT_SYMBOL_GPL(media_create_pad_links);
780 
781 void __media_entity_remove_links(struct media_entity *entity)
782 {
783 	struct media_link *link, *tmp;
784 
785 	list_for_each_entry_safe(link, tmp, &entity->links, list)
786 		__media_entity_remove_link(entity, link);
787 
788 	entity->num_links = 0;
789 	entity->num_backlinks = 0;
790 }
791 EXPORT_SYMBOL_GPL(__media_entity_remove_links);
792 
793 void media_entity_remove_links(struct media_entity *entity)
794 {
795 	struct media_device *mdev = entity->graph_obj.mdev;
796 
797 	/* Do nothing if the entity is not registered. */
798 	if (mdev == NULL)
799 		return;
800 
801 	mutex_lock(&mdev->graph_mutex);
802 	__media_entity_remove_links(entity);
803 	mutex_unlock(&mdev->graph_mutex);
804 }
805 EXPORT_SYMBOL_GPL(media_entity_remove_links);
806 
807 static int __media_entity_setup_link_notify(struct media_link *link, u32 flags)
808 {
809 	int ret;
810 
811 	/* Notify both entities. */
812 	ret = media_entity_call(link->source->entity, link_setup,
813 				link->source, link->sink, flags);
814 	if (ret < 0 && ret != -ENOIOCTLCMD)
815 		return ret;
816 
817 	ret = media_entity_call(link->sink->entity, link_setup,
818 				link->sink, link->source, flags);
819 	if (ret < 0 && ret != -ENOIOCTLCMD) {
820 		media_entity_call(link->source->entity, link_setup,
821 				  link->source, link->sink, link->flags);
822 		return ret;
823 	}
824 
825 	link->flags = flags;
826 	link->reverse->flags = link->flags;
827 
828 	return 0;
829 }
830 
831 int __media_entity_setup_link(struct media_link *link, u32 flags)
832 {
833 	const u32 mask = MEDIA_LNK_FL_ENABLED;
834 	struct media_device *mdev;
835 	struct media_entity *source, *sink;
836 	int ret = -EBUSY;
837 
838 	if (link == NULL)
839 		return -EINVAL;
840 
841 	/* The non-modifiable link flags must not be modified. */
842 	if ((link->flags & ~mask) != (flags & ~mask))
843 		return -EINVAL;
844 
845 	if (link->flags & MEDIA_LNK_FL_IMMUTABLE)
846 		return link->flags == flags ? 0 : -EINVAL;
847 
848 	if (link->flags == flags)
849 		return 0;
850 
851 	source = link->source->entity;
852 	sink = link->sink->entity;
853 
854 	if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) &&
855 	    (source->stream_count || sink->stream_count))
856 		return -EBUSY;
857 
858 	mdev = source->graph_obj.mdev;
859 
860 	if (mdev->ops && mdev->ops->link_notify) {
861 		ret = mdev->ops->link_notify(link, flags,
862 					     MEDIA_DEV_NOTIFY_PRE_LINK_CH);
863 		if (ret < 0)
864 			return ret;
865 	}
866 
867 	ret = __media_entity_setup_link_notify(link, flags);
868 
869 	if (mdev->ops && mdev->ops->link_notify)
870 		mdev->ops->link_notify(link, flags,
871 				       MEDIA_DEV_NOTIFY_POST_LINK_CH);
872 
873 	return ret;
874 }
875 EXPORT_SYMBOL_GPL(__media_entity_setup_link);
876 
877 int media_entity_setup_link(struct media_link *link, u32 flags)
878 {
879 	int ret;
880 
881 	mutex_lock(&link->graph_obj.mdev->graph_mutex);
882 	ret = __media_entity_setup_link(link, flags);
883 	mutex_unlock(&link->graph_obj.mdev->graph_mutex);
884 
885 	return ret;
886 }
887 EXPORT_SYMBOL_GPL(media_entity_setup_link);
888 
889 struct media_link *
890 media_entity_find_link(struct media_pad *source, struct media_pad *sink)
891 {
892 	struct media_link *link;
893 
894 	list_for_each_entry(link, &source->entity->links, list) {
895 		if (link->source->entity == source->entity &&
896 		    link->source->index == source->index &&
897 		    link->sink->entity == sink->entity &&
898 		    link->sink->index == sink->index)
899 			return link;
900 	}
901 
902 	return NULL;
903 }
904 EXPORT_SYMBOL_GPL(media_entity_find_link);
905 
906 struct media_pad *media_entity_remote_pad(const struct media_pad *pad)
907 {
908 	struct media_link *link;
909 
910 	list_for_each_entry(link, &pad->entity->links, list) {
911 		if (!(link->flags & MEDIA_LNK_FL_ENABLED))
912 			continue;
913 
914 		if (link->source == pad)
915 			return link->sink;
916 
917 		if (link->sink == pad)
918 			return link->source;
919 	}
920 
921 	return NULL;
922 
923 }
924 EXPORT_SYMBOL_GPL(media_entity_remote_pad);
925 
926 static void media_interface_init(struct media_device *mdev,
927 				 struct media_interface *intf,
928 				 u32 gobj_type,
929 				 u32 intf_type, u32 flags)
930 {
931 	intf->type = intf_type;
932 	intf->flags = flags;
933 	INIT_LIST_HEAD(&intf->links);
934 
935 	media_gobj_create(mdev, gobj_type, &intf->graph_obj);
936 }
937 
938 /* Functions related to the media interface via device nodes */
939 
940 struct media_intf_devnode *media_devnode_create(struct media_device *mdev,
941 						u32 type, u32 flags,
942 						u32 major, u32 minor)
943 {
944 	struct media_intf_devnode *devnode;
945 
946 	devnode = kzalloc(sizeof(*devnode), GFP_KERNEL);
947 	if (!devnode)
948 		return NULL;
949 
950 	devnode->major = major;
951 	devnode->minor = minor;
952 
953 	media_interface_init(mdev, &devnode->intf, MEDIA_GRAPH_INTF_DEVNODE,
954 			     type, flags);
955 
956 	return devnode;
957 }
958 EXPORT_SYMBOL_GPL(media_devnode_create);
959 
960 void media_devnode_remove(struct media_intf_devnode *devnode)
961 {
962 	media_remove_intf_links(&devnode->intf);
963 	media_gobj_destroy(&devnode->intf.graph_obj);
964 	kfree(devnode);
965 }
966 EXPORT_SYMBOL_GPL(media_devnode_remove);
967 
968 struct media_link *media_create_intf_link(struct media_entity *entity,
969 					    struct media_interface *intf,
970 					    u32 flags)
971 {
972 	struct media_link *link;
973 
974 	link = media_add_link(&intf->links);
975 	if (link == NULL)
976 		return NULL;
977 
978 	link->intf = intf;
979 	link->entity = entity;
980 	link->flags = flags | MEDIA_LNK_FL_INTERFACE_LINK;
981 
982 	/* Initialize graph object embedded at the new link */
983 	media_gobj_create(intf->graph_obj.mdev, MEDIA_GRAPH_LINK,
984 			&link->graph_obj);
985 
986 	return link;
987 }
988 EXPORT_SYMBOL_GPL(media_create_intf_link);
989 
990 void __media_remove_intf_link(struct media_link *link)
991 {
992 	list_del(&link->list);
993 	media_gobj_destroy(&link->graph_obj);
994 	kfree(link);
995 }
996 EXPORT_SYMBOL_GPL(__media_remove_intf_link);
997 
998 void media_remove_intf_link(struct media_link *link)
999 {
1000 	struct media_device *mdev = link->graph_obj.mdev;
1001 
1002 	/* Do nothing if the intf is not registered. */
1003 	if (mdev == NULL)
1004 		return;
1005 
1006 	mutex_lock(&mdev->graph_mutex);
1007 	__media_remove_intf_link(link);
1008 	mutex_unlock(&mdev->graph_mutex);
1009 }
1010 EXPORT_SYMBOL_GPL(media_remove_intf_link);
1011 
1012 void __media_remove_intf_links(struct media_interface *intf)
1013 {
1014 	struct media_link *link, *tmp;
1015 
1016 	list_for_each_entry_safe(link, tmp, &intf->links, list)
1017 		__media_remove_intf_link(link);
1018 
1019 }
1020 EXPORT_SYMBOL_GPL(__media_remove_intf_links);
1021 
1022 void media_remove_intf_links(struct media_interface *intf)
1023 {
1024 	struct media_device *mdev = intf->graph_obj.mdev;
1025 
1026 	/* Do nothing if the intf is not registered. */
1027 	if (mdev == NULL)
1028 		return;
1029 
1030 	mutex_lock(&mdev->graph_mutex);
1031 	__media_remove_intf_links(intf);
1032 	mutex_unlock(&mdev->graph_mutex);
1033 }
1034 EXPORT_SYMBOL_GPL(media_remove_intf_links);
1035