xref: /linux/drivers/media/v4l2-core/v4l2-mc.c (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 /*
4  * Media Controller ancillary functions
5  *
6  * Copyright (c) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
7  * Copyright (C) 2016 Shuah Khan <shuahkh@osg.samsung.com>
8  * Copyright (C) 2006-2010 Nokia Corporation
9  * Copyright (c) 2016 Intel Corporation.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/pci.h>
14 #include <linux/usb.h>
15 #include <media/media-device.h>
16 #include <media/media-entity.h>
17 #include <media/v4l2-fh.h>
18 #include <media/v4l2-mc.h>
19 #include <media/v4l2-subdev.h>
20 #include <media/videobuf2-core.h>
21 
22 int v4l2_mc_create_media_graph(struct media_device *mdev)
23 
24 {
25 	struct media_entity *entity;
26 	struct media_entity *if_vid = NULL, *if_aud = NULL;
27 	struct media_entity *tuner = NULL, *decoder = NULL;
28 	struct media_entity *io_v4l = NULL, *io_vbi = NULL, *io_swradio = NULL;
29 	bool is_webcam = false;
30 	u32 flags;
31 	int ret, pad_sink, pad_source;
32 
33 	if (!mdev)
34 		return 0;
35 
36 	media_device_for_each_entity(entity, mdev) {
37 		switch (entity->function) {
38 		case MEDIA_ENT_F_IF_VID_DECODER:
39 			if_vid = entity;
40 			break;
41 		case MEDIA_ENT_F_IF_AUD_DECODER:
42 			if_aud = entity;
43 			break;
44 		case MEDIA_ENT_F_TUNER:
45 			tuner = entity;
46 			break;
47 		case MEDIA_ENT_F_ATV_DECODER:
48 			decoder = entity;
49 			break;
50 		case MEDIA_ENT_F_IO_V4L:
51 			io_v4l = entity;
52 			break;
53 		case MEDIA_ENT_F_IO_VBI:
54 			io_vbi = entity;
55 			break;
56 		case MEDIA_ENT_F_IO_SWRADIO:
57 			io_swradio = entity;
58 			break;
59 		case MEDIA_ENT_F_CAM_SENSOR:
60 			is_webcam = true;
61 			break;
62 		}
63 	}
64 
65 	/* It should have at least one I/O entity */
66 	if (!io_v4l && !io_vbi && !io_swradio) {
67 		dev_warn(mdev->dev, "Didn't find any I/O entity\n");
68 		return -EINVAL;
69 	}
70 
71 	/*
72 	 * Here, webcams are modelled on a very simple way: the sensor is
73 	 * connected directly to the I/O entity. All dirty details, like
74 	 * scaler and crop HW are hidden. While such mapping is not enough
75 	 * for mc-centric hardware, it is enough for v4l2 interface centric
76 	 * PC-consumer's hardware.
77 	 */
78 	if (is_webcam) {
79 		if (!io_v4l) {
80 			dev_warn(mdev->dev, "Didn't find a MEDIA_ENT_F_IO_V4L\n");
81 			return -EINVAL;
82 		}
83 
84 		media_device_for_each_entity(entity, mdev) {
85 			if (entity->function != MEDIA_ENT_F_CAM_SENSOR)
86 				continue;
87 			ret = media_create_pad_link(entity, 0,
88 						    io_v4l, 0,
89 						    MEDIA_LNK_FL_ENABLED);
90 			if (ret) {
91 				dev_warn(mdev->dev, "Failed to create a sensor link\n");
92 				return ret;
93 			}
94 		}
95 		if (!decoder)
96 			return 0;
97 	}
98 
99 	/* The device isn't a webcam. So, it should have a decoder */
100 	if (!decoder) {
101 		dev_warn(mdev->dev, "Decoder not found\n");
102 		return -EINVAL;
103 	}
104 
105 	/* Link the tuner and IF video output pads */
106 	if (tuner) {
107 		if (if_vid) {
108 			pad_source = media_get_pad_index(tuner, false,
109 							 PAD_SIGNAL_ANALOG);
110 			pad_sink = media_get_pad_index(if_vid, true,
111 						       PAD_SIGNAL_ANALOG);
112 			if (pad_source < 0 || pad_sink < 0) {
113 				dev_warn(mdev->dev, "Couldn't get tuner and/or PLL pad(s): (%d, %d)\n",
114 					 pad_source, pad_sink);
115 				return -EINVAL;
116 			}
117 			ret = media_create_pad_link(tuner, pad_source,
118 						    if_vid, pad_sink,
119 						    MEDIA_LNK_FL_ENABLED);
120 			if (ret) {
121 				dev_warn(mdev->dev, "Couldn't create tuner->PLL link)\n");
122 				return ret;
123 			}
124 
125 			pad_source = media_get_pad_index(if_vid, false,
126 							 PAD_SIGNAL_ANALOG);
127 			pad_sink = media_get_pad_index(decoder, true,
128 						       PAD_SIGNAL_ANALOG);
129 			if (pad_source < 0 || pad_sink < 0) {
130 				dev_warn(mdev->dev, "get decoder and/or PLL pad(s): (%d, %d)\n",
131 					 pad_source, pad_sink);
132 				return -EINVAL;
133 			}
134 			ret = media_create_pad_link(if_vid, pad_source,
135 						    decoder, pad_sink,
136 						    MEDIA_LNK_FL_ENABLED);
137 			if (ret) {
138 				dev_warn(mdev->dev, "couldn't link PLL to decoder\n");
139 				return ret;
140 			}
141 		} else {
142 			pad_source = media_get_pad_index(tuner, false,
143 							 PAD_SIGNAL_ANALOG);
144 			pad_sink = media_get_pad_index(decoder, true,
145 						       PAD_SIGNAL_ANALOG);
146 			if (pad_source < 0 || pad_sink < 0) {
147 				dev_warn(mdev->dev, "couldn't get tuner and/or decoder pad(s): (%d, %d)\n",
148 					 pad_source, pad_sink);
149 				return -EINVAL;
150 			}
151 			ret = media_create_pad_link(tuner, pad_source,
152 						    decoder, pad_sink,
153 						    MEDIA_LNK_FL_ENABLED);
154 			if (ret)
155 				return ret;
156 		}
157 
158 		if (if_aud) {
159 			pad_source = media_get_pad_index(tuner, false,
160 							 PAD_SIGNAL_AUDIO);
161 			pad_sink = media_get_pad_index(if_aud, true,
162 						       PAD_SIGNAL_AUDIO);
163 			if (pad_source < 0 || pad_sink < 0) {
164 				dev_warn(mdev->dev, "couldn't get tuner and/or decoder pad(s) for audio: (%d, %d)\n",
165 					 pad_source, pad_sink);
166 				return -EINVAL;
167 			}
168 			ret = media_create_pad_link(tuner, pad_source,
169 						    if_aud, pad_sink,
170 						    MEDIA_LNK_FL_ENABLED);
171 			if (ret) {
172 				dev_warn(mdev->dev, "couldn't link tuner->audio PLL\n");
173 				return ret;
174 			}
175 		} else {
176 			if_aud = tuner;
177 		}
178 
179 	}
180 
181 	/* Create demod to V4L, VBI and SDR radio links */
182 	if (io_v4l) {
183 		pad_source = media_get_pad_index(decoder, false, PAD_SIGNAL_DV);
184 		if (pad_source < 0) {
185 			dev_warn(mdev->dev, "couldn't get decoder output pad for V4L I/O\n");
186 			return -EINVAL;
187 		}
188 		ret = media_create_pad_link(decoder, pad_source,
189 					    io_v4l, 0,
190 					    MEDIA_LNK_FL_ENABLED);
191 		if (ret) {
192 			dev_warn(mdev->dev, "couldn't link decoder output to V4L I/O\n");
193 			return ret;
194 		}
195 	}
196 
197 	if (io_swradio) {
198 		pad_source = media_get_pad_index(decoder, false, PAD_SIGNAL_DV);
199 		if (pad_source < 0) {
200 			dev_warn(mdev->dev, "couldn't get decoder output pad for SDR\n");
201 			return -EINVAL;
202 		}
203 		ret = media_create_pad_link(decoder, pad_source,
204 					    io_swradio, 0,
205 					    MEDIA_LNK_FL_ENABLED);
206 		if (ret) {
207 			dev_warn(mdev->dev, "couldn't link decoder output to SDR\n");
208 			return ret;
209 		}
210 	}
211 
212 	if (io_vbi) {
213 		pad_source = media_get_pad_index(decoder, false, PAD_SIGNAL_DV);
214 		if (pad_source < 0) {
215 			dev_warn(mdev->dev, "couldn't get decoder output pad for VBI\n");
216 			return -EINVAL;
217 		}
218 		ret = media_create_pad_link(decoder, pad_source,
219 					    io_vbi, 0,
220 					    MEDIA_LNK_FL_ENABLED);
221 		if (ret) {
222 			dev_warn(mdev->dev, "couldn't link decoder output to VBI\n");
223 			return ret;
224 		}
225 	}
226 
227 	/* Create links for the media connectors */
228 	flags = MEDIA_LNK_FL_ENABLED;
229 	media_device_for_each_entity(entity, mdev) {
230 		switch (entity->function) {
231 		case MEDIA_ENT_F_CONN_RF:
232 			if (!tuner)
233 				continue;
234 			pad_sink = media_get_pad_index(tuner, true,
235 						       PAD_SIGNAL_ANALOG);
236 			if (pad_sink < 0) {
237 				dev_warn(mdev->dev, "couldn't get tuner analog pad sink\n");
238 				return -EINVAL;
239 			}
240 			ret = media_create_pad_link(entity, 0, tuner,
241 						    pad_sink,
242 						    flags);
243 			break;
244 		case MEDIA_ENT_F_CONN_SVIDEO:
245 		case MEDIA_ENT_F_CONN_COMPOSITE:
246 			pad_sink = media_get_pad_index(decoder, true,
247 						       PAD_SIGNAL_ANALOG);
248 			if (pad_sink < 0) {
249 				dev_warn(mdev->dev, "couldn't get tuner analog pad sink\n");
250 				return -EINVAL;
251 			}
252 			ret = media_create_pad_link(entity, 0, decoder,
253 						    pad_sink,
254 						    flags);
255 			break;
256 		default:
257 			continue;
258 		}
259 		if (ret)
260 			return ret;
261 
262 		flags = 0;
263 	}
264 
265 	return 0;
266 }
267 EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);
268 
269 int v4l_enable_media_source(struct video_device *vdev)
270 {
271 	struct media_device *mdev = vdev->entity.graph_obj.mdev;
272 	int ret = 0, err;
273 
274 	if (!mdev)
275 		return 0;
276 
277 	mutex_lock(&mdev->graph_mutex);
278 	if (!mdev->enable_source)
279 		goto end;
280 	err = mdev->enable_source(&vdev->entity, &vdev->pipe);
281 	if (err)
282 		ret = -EBUSY;
283 end:
284 	mutex_unlock(&mdev->graph_mutex);
285 	return ret;
286 }
287 EXPORT_SYMBOL_GPL(v4l_enable_media_source);
288 
289 void v4l_disable_media_source(struct video_device *vdev)
290 {
291 	struct media_device *mdev = vdev->entity.graph_obj.mdev;
292 
293 	if (mdev) {
294 		mutex_lock(&mdev->graph_mutex);
295 		if (mdev->disable_source)
296 			mdev->disable_source(&vdev->entity);
297 		mutex_unlock(&mdev->graph_mutex);
298 	}
299 }
300 EXPORT_SYMBOL_GPL(v4l_disable_media_source);
301 
302 int v4l_vb2q_enable_media_source(struct vb2_queue *q)
303 {
304 	struct v4l2_fh *fh = q->owner;
305 
306 	if (fh && fh->vdev)
307 		return v4l_enable_media_source(fh->vdev);
308 	return 0;
309 }
310 EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
311 
312 int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
313 				    struct media_pad *sink)
314 {
315 	struct fwnode_handle *endpoint;
316 	struct v4l2_subdev *sink_sd;
317 
318 	if (!(sink->flags & MEDIA_PAD_FL_SINK) ||
319 	    !is_media_entity_v4l2_subdev(sink->entity))
320 		return -EINVAL;
321 
322 	sink_sd = media_entity_to_v4l2_subdev(sink->entity);
323 
324 	fwnode_graph_for_each_endpoint(dev_fwnode(src_sd->dev), endpoint) {
325 		struct fwnode_handle *remote_ep;
326 		int src_idx, sink_idx, ret;
327 		struct media_pad *src;
328 
329 		src_idx = media_entity_get_fwnode_pad(&src_sd->entity,
330 						      endpoint,
331 						      MEDIA_PAD_FL_SOURCE);
332 		if (src_idx < 0)
333 			continue;
334 
335 		remote_ep = fwnode_graph_get_remote_endpoint(endpoint);
336 		if (!remote_ep)
337 			continue;
338 
339 		/*
340 		 * ask the sink to verify it owns the remote endpoint,
341 		 * and translate to a sink pad.
342 		 */
343 		sink_idx = media_entity_get_fwnode_pad(&sink_sd->entity,
344 						       remote_ep,
345 						       MEDIA_PAD_FL_SINK);
346 		fwnode_handle_put(remote_ep);
347 
348 		if (sink_idx < 0 || sink_idx != sink->index)
349 			continue;
350 
351 		/*
352 		 * the source endpoint corresponds to one of its source pads,
353 		 * the source endpoint connects to an endpoint at the sink
354 		 * entity, and the sink endpoint corresponds to the sink
355 		 * pad requested, so we have found an endpoint connection
356 		 * that works, create the media link for it.
357 		 */
358 
359 		src = &src_sd->entity.pads[src_idx];
360 
361 		/* skip if link already exists */
362 		if (media_entity_find_link(src, sink))
363 			continue;
364 
365 		dev_dbg(sink_sd->dev, "creating link %s:%d -> %s:%d\n",
366 			src_sd->entity.name, src_idx,
367 			sink_sd->entity.name, sink_idx);
368 
369 		ret = media_create_pad_link(&src_sd->entity, src_idx,
370 					    &sink_sd->entity, sink_idx, 0);
371 		if (ret) {
372 			dev_err(sink_sd->dev,
373 				"link %s:%d -> %s:%d failed with %d\n",
374 				src_sd->entity.name, src_idx,
375 				sink_sd->entity.name, sink_idx, ret);
376 
377 			fwnode_handle_put(endpoint);
378 			return ret;
379 		}
380 	}
381 
382 	return 0;
383 }
384 EXPORT_SYMBOL_GPL(v4l2_create_fwnode_links_to_pad);
385 
386 int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
387 			     struct v4l2_subdev *sink_sd)
388 {
389 	unsigned int i;
390 
391 	for (i = 0; i < sink_sd->entity.num_pads; i++) {
392 		struct media_pad *pad = &sink_sd->entity.pads[i];
393 		int ret;
394 
395 		if (!(pad->flags & MEDIA_PAD_FL_SINK))
396 			continue;
397 
398 		ret = v4l2_create_fwnode_links_to_pad(src_sd, pad);
399 		if (ret)
400 			return ret;
401 	}
402 
403 	return 0;
404 }
405 EXPORT_SYMBOL_GPL(v4l2_create_fwnode_links);
406 
407 /* -----------------------------------------------------------------------------
408  * Pipeline power management
409  *
410  * Entities must be powered up when part of a pipeline that contains at least
411  * one open video device node.
412  *
413  * To achieve this use the entity use_count field to track the number of users.
414  * For entities corresponding to video device nodes the use_count field stores
415  * the users count of the node. For entities corresponding to subdevs the
416  * use_count field stores the total number of users of all video device nodes
417  * in the pipeline.
418  *
419  * The v4l2_pipeline_pm_{get, put}() functions must be called in the open() and
420  * close() handlers of video device nodes. It increments or decrements the use
421  * count of all subdev entities in the pipeline.
422  *
423  * To react to link management on powered pipelines, the link setup notification
424  * callback updates the use count of all entities in the source and sink sides
425  * of the link.
426  */
427 
428 /*
429  * pipeline_pm_use_count - Count the number of users of a pipeline
430  * @entity: The entity
431  *
432  * Return the total number of users of all video device nodes in the pipeline.
433  */
434 static int pipeline_pm_use_count(struct media_entity *entity,
435 	struct media_graph *graph)
436 {
437 	int use = 0;
438 
439 	media_graph_walk_start(graph, entity);
440 
441 	while ((entity = media_graph_walk_next(graph))) {
442 		if (is_media_entity_v4l2_video_device(entity))
443 			use += entity->use_count;
444 	}
445 
446 	return use;
447 }
448 
449 /*
450  * pipeline_pm_power_one - Apply power change to an entity
451  * @entity: The entity
452  * @change: Use count change
453  *
454  * Change the entity use count by @change. If the entity is a subdev update its
455  * power state by calling the core::s_power operation when the use count goes
456  * from 0 to != 0 or from != 0 to 0.
457  *
458  * Return 0 on success or a negative error code on failure.
459  */
460 static int pipeline_pm_power_one(struct media_entity *entity, int change)
461 {
462 	struct v4l2_subdev *subdev;
463 	int ret;
464 
465 	subdev = is_media_entity_v4l2_subdev(entity)
466 	       ? media_entity_to_v4l2_subdev(entity) : NULL;
467 
468 	if (entity->use_count == 0 && change > 0 && subdev != NULL) {
469 		ret = v4l2_subdev_call(subdev, core, s_power, 1);
470 		if (ret < 0 && ret != -ENOIOCTLCMD)
471 			return ret;
472 	}
473 
474 	entity->use_count += change;
475 	WARN_ON(entity->use_count < 0);
476 
477 	if (entity->use_count == 0 && change < 0 && subdev != NULL)
478 		v4l2_subdev_call(subdev, core, s_power, 0);
479 
480 	return 0;
481 }
482 
483 /*
484  * pipeline_pm_power - Apply power change to all entities in a pipeline
485  * @entity: The entity
486  * @change: Use count change
487  *
488  * Walk the pipeline to update the use count and the power state of all non-node
489  * entities.
490  *
491  * Return 0 on success or a negative error code on failure.
492  */
493 static int pipeline_pm_power(struct media_entity *entity, int change,
494 	struct media_graph *graph)
495 {
496 	struct media_entity *first = entity;
497 	int ret = 0;
498 
499 	if (!change)
500 		return 0;
501 
502 	media_graph_walk_start(graph, entity);
503 
504 	while (!ret && (entity = media_graph_walk_next(graph)))
505 		if (is_media_entity_v4l2_subdev(entity))
506 			ret = pipeline_pm_power_one(entity, change);
507 
508 	if (!ret)
509 		return ret;
510 
511 	media_graph_walk_start(graph, first);
512 
513 	while ((first = media_graph_walk_next(graph))
514 	       && first != entity)
515 		if (is_media_entity_v4l2_subdev(first))
516 			pipeline_pm_power_one(first, -change);
517 
518 	return ret;
519 }
520 
521 static int v4l2_pipeline_pm_use(struct media_entity *entity, unsigned int use)
522 {
523 	struct media_device *mdev = entity->graph_obj.mdev;
524 	int change = use ? 1 : -1;
525 	int ret;
526 
527 	mutex_lock(&mdev->graph_mutex);
528 
529 	/* Apply use count to node. */
530 	entity->use_count += change;
531 	WARN_ON(entity->use_count < 0);
532 
533 	/* Apply power change to connected non-nodes. */
534 	ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
535 	if (ret < 0)
536 		entity->use_count -= change;
537 
538 	mutex_unlock(&mdev->graph_mutex);
539 
540 	return ret;
541 }
542 
543 int v4l2_pipeline_pm_get(struct media_entity *entity)
544 {
545 	return v4l2_pipeline_pm_use(entity, 1);
546 }
547 EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_get);
548 
549 void v4l2_pipeline_pm_put(struct media_entity *entity)
550 {
551 	/* Powering off entities shouldn't fail. */
552 	WARN_ON(v4l2_pipeline_pm_use(entity, 0));
553 }
554 EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_put);
555 
556 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
557 			      unsigned int notification)
558 {
559 	struct media_graph *graph = &link->graph_obj.mdev->pm_count_walk;
560 	struct media_entity *source = link->source->entity;
561 	struct media_entity *sink = link->sink->entity;
562 	int source_use;
563 	int sink_use;
564 	int ret = 0;
565 
566 	source_use = pipeline_pm_use_count(source, graph);
567 	sink_use = pipeline_pm_use_count(sink, graph);
568 
569 	if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
570 	    !(flags & MEDIA_LNK_FL_ENABLED)) {
571 		/* Powering off entities is assumed to never fail. */
572 		pipeline_pm_power(source, -sink_use, graph);
573 		pipeline_pm_power(sink, -source_use, graph);
574 		return 0;
575 	}
576 
577 	if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
578 		(flags & MEDIA_LNK_FL_ENABLED)) {
579 
580 		ret = pipeline_pm_power(source, sink_use, graph);
581 		if (ret < 0)
582 			return ret;
583 
584 		ret = pipeline_pm_power(sink, source_use, graph);
585 		if (ret < 0)
586 			pipeline_pm_power(source, -sink_use, graph);
587 	}
588 
589 	return ret;
590 }
591 EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);
592