xref: /openbmc/linux/drivers/media/mc/mc-entity.c (revision 842ed298)
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 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 
345 struct 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 }
366 EXPORT_SYMBOL_GPL(media_graph_walk_next);
367 
368 int 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 }
401 EXPORT_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 
501 error:
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 
524 error_graph_walk_start:
525 	if (!--pipe->streaming_count)
526 		media_graph_walk_cleanup(graph);
527 
528 	return ret;
529 }
530 EXPORT_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 }
543 EXPORT_SYMBOL_GPL(media_pipeline_start);
544 
545 void __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 }
572 EXPORT_SYMBOL_GPL(__media_pipeline_stop);
573 
574 void 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 }
582 EXPORT_SYMBOL_GPL(media_pipeline_stop);
583 
584 /* -----------------------------------------------------------------------------
585  * Links management
586  */
587 
588 static 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 
601 static 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 
632 int 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 }
656 EXPORT_SYMBOL_GPL(media_get_pad_index);
657 
658 int
659 media_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 }
713 EXPORT_SYMBOL_GPL(media_create_pad_link);
714 
715 int 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 }
778 EXPORT_SYMBOL_GPL(media_create_pad_links);
779 
780 void __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 }
790 EXPORT_SYMBOL_GPL(__media_entity_remove_links);
791 
792 void 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 }
804 EXPORT_SYMBOL_GPL(media_entity_remove_links);
805 
806 static 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 
830 int __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 }
874 EXPORT_SYMBOL_GPL(__media_entity_setup_link);
875 
876 int 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 }
886 EXPORT_SYMBOL_GPL(media_entity_setup_link);
887 
888 struct media_link *
889 media_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 }
903 EXPORT_SYMBOL_GPL(media_entity_find_link);
904 
905 struct 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 }
923 EXPORT_SYMBOL_GPL(media_entity_remote_pad);
924 
925 static 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 
939 struct 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 }
957 EXPORT_SYMBOL_GPL(media_devnode_create);
958 
959 void 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 }
965 EXPORT_SYMBOL_GPL(media_devnode_remove);
966 
967 struct 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 }
987 EXPORT_SYMBOL_GPL(media_create_intf_link);
988 
989 void __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 }
995 EXPORT_SYMBOL_GPL(__media_remove_intf_link);
996 
997 void 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 }
1009 EXPORT_SYMBOL_GPL(media_remove_intf_link);
1010 
1011 void __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 }
1019 EXPORT_SYMBOL_GPL(__media_remove_intf_links);
1020 
1021 void 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 }
1033 EXPORT_SYMBOL_GPL(media_remove_intf_links);
1034