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,
109 							 MEDIA_PAD_FL_SOURCE,
110 							 PAD_SIGNAL_ANALOG);
111 			pad_sink = media_get_pad_index(if_vid,
112 						       MEDIA_PAD_FL_SINK,
113 						       PAD_SIGNAL_ANALOG);
114 			if (pad_source < 0 || pad_sink < 0) {
115 				dev_warn(mdev->dev, "Couldn't get tuner and/or PLL pad(s): (%d, %d)\n",
116 					 pad_source, pad_sink);
117 				return -EINVAL;
118 			}
119 			ret = media_create_pad_link(tuner, pad_source,
120 						    if_vid, pad_sink,
121 						    MEDIA_LNK_FL_ENABLED);
122 			if (ret) {
123 				dev_warn(mdev->dev, "Couldn't create tuner->PLL link)\n");
124 				return ret;
125 			}
126 
127 			pad_source = media_get_pad_index(if_vid,
128 							 MEDIA_PAD_FL_SOURCE,
129 							 PAD_SIGNAL_ANALOG);
130 			pad_sink = media_get_pad_index(decoder,
131 						       MEDIA_PAD_FL_SINK,
132 						       PAD_SIGNAL_ANALOG);
133 			if (pad_source < 0 || pad_sink < 0) {
134 				dev_warn(mdev->dev, "get decoder and/or PLL pad(s): (%d, %d)\n",
135 					 pad_source, pad_sink);
136 				return -EINVAL;
137 			}
138 			ret = media_create_pad_link(if_vid, pad_source,
139 						    decoder, pad_sink,
140 						    MEDIA_LNK_FL_ENABLED);
141 			if (ret) {
142 				dev_warn(mdev->dev, "couldn't link PLL to decoder\n");
143 				return ret;
144 			}
145 		} else {
146 			pad_source = media_get_pad_index(tuner,
147 							 MEDIA_PAD_FL_SOURCE,
148 							 PAD_SIGNAL_ANALOG);
149 			pad_sink = media_get_pad_index(decoder,
150 						       MEDIA_PAD_FL_SINK,
151 						       PAD_SIGNAL_ANALOG);
152 			if (pad_source < 0 || pad_sink < 0) {
153 				dev_warn(mdev->dev, "couldn't get tuner and/or decoder pad(s): (%d, %d)\n",
154 					 pad_source, pad_sink);
155 				return -EINVAL;
156 			}
157 			ret = media_create_pad_link(tuner, pad_source,
158 						    decoder, pad_sink,
159 						    MEDIA_LNK_FL_ENABLED);
160 			if (ret)
161 				return ret;
162 		}
163 
164 		if (if_aud) {
165 			pad_source = media_get_pad_index(tuner,
166 							 MEDIA_PAD_FL_SOURCE,
167 							 PAD_SIGNAL_AUDIO);
168 			pad_sink = media_get_pad_index(if_aud,
169 						       MEDIA_PAD_FL_SINK,
170 						       PAD_SIGNAL_AUDIO);
171 			if (pad_source < 0 || pad_sink < 0) {
172 				dev_warn(mdev->dev, "couldn't get tuner and/or decoder pad(s) for audio: (%d, %d)\n",
173 					 pad_source, pad_sink);
174 				return -EINVAL;
175 			}
176 			ret = media_create_pad_link(tuner, pad_source,
177 						    if_aud, pad_sink,
178 						    MEDIA_LNK_FL_ENABLED);
179 			if (ret) {
180 				dev_warn(mdev->dev, "couldn't link tuner->audio PLL\n");
181 				return ret;
182 			}
183 		} else {
184 			if_aud = tuner;
185 		}
186 
187 	}
188 
189 	/* Create demod to V4L, VBI and SDR radio links */
190 	if (io_v4l) {
191 		pad_source = media_get_pad_index(decoder, MEDIA_PAD_FL_SOURCE,
192 						 PAD_SIGNAL_DV);
193 		if (pad_source < 0) {
194 			dev_warn(mdev->dev, "couldn't get decoder output pad for V4L I/O\n");
195 			return -EINVAL;
196 		}
197 		ret = media_create_pad_link(decoder, pad_source,
198 					    io_v4l, 0,
199 					    MEDIA_LNK_FL_ENABLED);
200 		if (ret) {
201 			dev_warn(mdev->dev, "couldn't link decoder output to V4L I/O\n");
202 			return ret;
203 		}
204 	}
205 
206 	if (io_swradio) {
207 		pad_source = media_get_pad_index(decoder, MEDIA_PAD_FL_SOURCE,
208 						 PAD_SIGNAL_DV);
209 		if (pad_source < 0) {
210 			dev_warn(mdev->dev, "couldn't get decoder output pad for SDR\n");
211 			return -EINVAL;
212 		}
213 		ret = media_create_pad_link(decoder, pad_source,
214 					    io_swradio, 0,
215 					    MEDIA_LNK_FL_ENABLED);
216 		if (ret) {
217 			dev_warn(mdev->dev, "couldn't link decoder output to SDR\n");
218 			return ret;
219 		}
220 	}
221 
222 	if (io_vbi) {
223 		pad_source = media_get_pad_index(decoder, MEDIA_PAD_FL_SOURCE,
224 						 PAD_SIGNAL_DV);
225 		if (pad_source < 0) {
226 			dev_warn(mdev->dev, "couldn't get decoder output pad for VBI\n");
227 			return -EINVAL;
228 		}
229 		ret = media_create_pad_link(decoder, pad_source,
230 					    io_vbi, 0,
231 					    MEDIA_LNK_FL_ENABLED);
232 		if (ret) {
233 			dev_warn(mdev->dev, "couldn't link decoder output to VBI\n");
234 			return ret;
235 		}
236 	}
237 
238 	/* Create links for the media connectors */
239 	flags = MEDIA_LNK_FL_ENABLED;
240 	media_device_for_each_entity(entity, mdev) {
241 		switch (entity->function) {
242 		case MEDIA_ENT_F_CONN_RF:
243 			if (!tuner)
244 				continue;
245 			pad_sink = media_get_pad_index(tuner, MEDIA_PAD_FL_SINK,
246 						       PAD_SIGNAL_ANALOG);
247 			if (pad_sink < 0) {
248 				dev_warn(mdev->dev, "couldn't get tuner analog pad sink\n");
249 				return -EINVAL;
250 			}
251 			ret = media_create_pad_link(entity, 0, tuner,
252 						    pad_sink,
253 						    flags);
254 			break;
255 		case MEDIA_ENT_F_CONN_SVIDEO:
256 		case MEDIA_ENT_F_CONN_COMPOSITE:
257 			pad_sink = media_get_pad_index(decoder,
258 						       MEDIA_PAD_FL_SINK,
259 						       PAD_SIGNAL_ANALOG);
260 			if (pad_sink < 0) {
261 				dev_warn(mdev->dev, "couldn't get decoder analog pad sink\n");
262 				return -EINVAL;
263 			}
264 			ret = media_create_pad_link(entity, 0, decoder,
265 						    pad_sink,
266 						    flags);
267 			break;
268 		default:
269 			continue;
270 		}
271 		if (ret)
272 			return ret;
273 
274 		flags = 0;
275 	}
276 
277 	return 0;
278 }
279 EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);
280 
281 int v4l_enable_media_source(struct video_device *vdev)
282 {
283 	struct media_device *mdev = vdev->entity.graph_obj.mdev;
284 	int ret = 0, err;
285 
286 	if (!mdev)
287 		return 0;
288 
289 	mutex_lock(&mdev->graph_mutex);
290 	if (!mdev->enable_source)
291 		goto end;
292 	err = mdev->enable_source(&vdev->entity, &vdev->pipe);
293 	if (err)
294 		ret = -EBUSY;
295 end:
296 	mutex_unlock(&mdev->graph_mutex);
297 	return ret;
298 }
299 EXPORT_SYMBOL_GPL(v4l_enable_media_source);
300 
301 void v4l_disable_media_source(struct video_device *vdev)
302 {
303 	struct media_device *mdev = vdev->entity.graph_obj.mdev;
304 
305 	if (mdev) {
306 		mutex_lock(&mdev->graph_mutex);
307 		if (mdev->disable_source)
308 			mdev->disable_source(&vdev->entity);
309 		mutex_unlock(&mdev->graph_mutex);
310 	}
311 }
312 EXPORT_SYMBOL_GPL(v4l_disable_media_source);
313 
314 int v4l_vb2q_enable_media_source(struct vb2_queue *q)
315 {
316 	struct v4l2_fh *fh = q->owner;
317 
318 	if (fh && fh->vdev)
319 		return v4l_enable_media_source(fh->vdev);
320 	return 0;
321 }
322 EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
323 
324 int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
325 				    struct media_pad *sink, u32 flags)
326 {
327 	struct fwnode_handle *endpoint;
328 
329 	if (!(sink->flags & MEDIA_PAD_FL_SINK))
330 		return -EINVAL;
331 
332 	fwnode_graph_for_each_endpoint(dev_fwnode(src_sd->dev), endpoint) {
333 		struct fwnode_handle *remote_ep;
334 		int src_idx, sink_idx, ret;
335 		struct media_pad *src;
336 
337 		src_idx = media_entity_get_fwnode_pad(&src_sd->entity,
338 						      endpoint,
339 						      MEDIA_PAD_FL_SOURCE);
340 		if (src_idx < 0)
341 			continue;
342 
343 		remote_ep = fwnode_graph_get_remote_endpoint(endpoint);
344 		if (!remote_ep)
345 			continue;
346 
347 		/*
348 		 * ask the sink to verify it owns the remote endpoint,
349 		 * and translate to a sink pad.
350 		 */
351 		sink_idx = media_entity_get_fwnode_pad(sink->entity,
352 						       remote_ep,
353 						       MEDIA_PAD_FL_SINK);
354 		fwnode_handle_put(remote_ep);
355 
356 		if (sink_idx < 0 || sink_idx != sink->index)
357 			continue;
358 
359 		/*
360 		 * the source endpoint corresponds to one of its source pads,
361 		 * the source endpoint connects to an endpoint at the sink
362 		 * entity, and the sink endpoint corresponds to the sink
363 		 * pad requested, so we have found an endpoint connection
364 		 * that works, create the media link for it.
365 		 */
366 
367 		src = &src_sd->entity.pads[src_idx];
368 
369 		/* skip if link already exists */
370 		if (media_entity_find_link(src, sink))
371 			continue;
372 
373 		dev_dbg(src_sd->dev, "creating link %s:%d -> %s:%d\n",
374 			src_sd->entity.name, src_idx,
375 			sink->entity->name, sink_idx);
376 
377 		ret = media_create_pad_link(&src_sd->entity, src_idx,
378 					    sink->entity, sink_idx, flags);
379 		if (ret) {
380 			dev_err(src_sd->dev,
381 				"link %s:%d -> %s:%d failed with %d\n",
382 				src_sd->entity.name, src_idx,
383 				sink->entity->name, sink_idx, ret);
384 
385 			fwnode_handle_put(endpoint);
386 			return ret;
387 		}
388 	}
389 
390 	return 0;
391 }
392 EXPORT_SYMBOL_GPL(v4l2_create_fwnode_links_to_pad);
393 
394 int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
395 			     struct v4l2_subdev *sink_sd)
396 {
397 	unsigned int i;
398 
399 	for (i = 0; i < sink_sd->entity.num_pads; i++) {
400 		struct media_pad *pad = &sink_sd->entity.pads[i];
401 		int ret;
402 
403 		if (!(pad->flags & MEDIA_PAD_FL_SINK))
404 			continue;
405 
406 		ret = v4l2_create_fwnode_links_to_pad(src_sd, pad, 0);
407 		if (ret)
408 			return ret;
409 	}
410 
411 	return 0;
412 }
413 EXPORT_SYMBOL_GPL(v4l2_create_fwnode_links);
414 
415 /* -----------------------------------------------------------------------------
416  * Pipeline power management
417  *
418  * Entities must be powered up when part of a pipeline that contains at least
419  * one open video device node.
420  *
421  * To achieve this use the entity use_count field to track the number of users.
422  * For entities corresponding to video device nodes the use_count field stores
423  * the users count of the node. For entities corresponding to subdevs the
424  * use_count field stores the total number of users of all video device nodes
425  * in the pipeline.
426  *
427  * The v4l2_pipeline_pm_{get, put}() functions must be called in the open() and
428  * close() handlers of video device nodes. It increments or decrements the use
429  * count of all subdev entities in the pipeline.
430  *
431  * To react to link management on powered pipelines, the link setup notification
432  * callback updates the use count of all entities in the source and sink sides
433  * of the link.
434  */
435 
436 /*
437  * pipeline_pm_use_count - Count the number of users of a pipeline
438  * @entity: The entity
439  *
440  * Return the total number of users of all video device nodes in the pipeline.
441  */
442 static int pipeline_pm_use_count(struct media_entity *entity,
443 	struct media_graph *graph)
444 {
445 	int use = 0;
446 
447 	media_graph_walk_start(graph, entity);
448 
449 	while ((entity = media_graph_walk_next(graph))) {
450 		if (is_media_entity_v4l2_video_device(entity))
451 			use += entity->use_count;
452 	}
453 
454 	return use;
455 }
456 
457 /*
458  * pipeline_pm_power_one - Apply power change to an entity
459  * @entity: The entity
460  * @change: Use count change
461  *
462  * Change the entity use count by @change. If the entity is a subdev update its
463  * power state by calling the core::s_power operation when the use count goes
464  * from 0 to != 0 or from != 0 to 0.
465  *
466  * Return 0 on success or a negative error code on failure.
467  */
468 static int pipeline_pm_power_one(struct media_entity *entity, int change)
469 {
470 	struct v4l2_subdev *subdev;
471 	int ret;
472 
473 	subdev = is_media_entity_v4l2_subdev(entity)
474 	       ? media_entity_to_v4l2_subdev(entity) : NULL;
475 
476 	if (entity->use_count == 0 && change > 0 && subdev != NULL) {
477 		ret = v4l2_subdev_call(subdev, core, s_power, 1);
478 		if (ret < 0 && ret != -ENOIOCTLCMD)
479 			return ret;
480 	}
481 
482 	entity->use_count += change;
483 	WARN_ON(entity->use_count < 0);
484 
485 	if (entity->use_count == 0 && change < 0 && subdev != NULL)
486 		v4l2_subdev_call(subdev, core, s_power, 0);
487 
488 	return 0;
489 }
490 
491 /*
492  * pipeline_pm_power - Apply power change to all entities in a pipeline
493  * @entity: The entity
494  * @change: Use count change
495  *
496  * Walk the pipeline to update the use count and the power state of all non-node
497  * entities.
498  *
499  * Return 0 on success or a negative error code on failure.
500  */
501 static int pipeline_pm_power(struct media_entity *entity, int change,
502 	struct media_graph *graph)
503 {
504 	struct media_entity *first = entity;
505 	int ret = 0;
506 
507 	if (!change)
508 		return 0;
509 
510 	media_graph_walk_start(graph, entity);
511 
512 	while (!ret && (entity = media_graph_walk_next(graph)))
513 		if (is_media_entity_v4l2_subdev(entity))
514 			ret = pipeline_pm_power_one(entity, change);
515 
516 	if (!ret)
517 		return ret;
518 
519 	media_graph_walk_start(graph, first);
520 
521 	while ((first = media_graph_walk_next(graph))
522 	       && first != entity)
523 		if (is_media_entity_v4l2_subdev(first))
524 			pipeline_pm_power_one(first, -change);
525 
526 	return ret;
527 }
528 
529 static int v4l2_pipeline_pm_use(struct media_entity *entity, unsigned int use)
530 {
531 	struct media_device *mdev = entity->graph_obj.mdev;
532 	int change = use ? 1 : -1;
533 	int ret;
534 
535 	mutex_lock(&mdev->graph_mutex);
536 
537 	/* Apply use count to node. */
538 	entity->use_count += change;
539 	WARN_ON(entity->use_count < 0);
540 
541 	/* Apply power change to connected non-nodes. */
542 	ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
543 	if (ret < 0)
544 		entity->use_count -= change;
545 
546 	mutex_unlock(&mdev->graph_mutex);
547 
548 	return ret;
549 }
550 
551 int v4l2_pipeline_pm_get(struct media_entity *entity)
552 {
553 	return v4l2_pipeline_pm_use(entity, 1);
554 }
555 EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_get);
556 
557 void v4l2_pipeline_pm_put(struct media_entity *entity)
558 {
559 	/* Powering off entities shouldn't fail. */
560 	WARN_ON(v4l2_pipeline_pm_use(entity, 0));
561 }
562 EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_put);
563 
564 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
565 			      unsigned int notification)
566 {
567 	struct media_graph *graph = &link->graph_obj.mdev->pm_count_walk;
568 	struct media_entity *source = link->source->entity;
569 	struct media_entity *sink = link->sink->entity;
570 	int source_use;
571 	int sink_use;
572 	int ret = 0;
573 
574 	source_use = pipeline_pm_use_count(source, graph);
575 	sink_use = pipeline_pm_use_count(sink, graph);
576 
577 	if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
578 	    !(flags & MEDIA_LNK_FL_ENABLED)) {
579 		/* Powering off entities is assumed to never fail. */
580 		pipeline_pm_power(source, -sink_use, graph);
581 		pipeline_pm_power(sink, -source_use, graph);
582 		return 0;
583 	}
584 
585 	if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
586 		(flags & MEDIA_LNK_FL_ENABLED)) {
587 
588 		ret = pipeline_pm_power(source, sink_use, graph);
589 		if (ret < 0)
590 			return ret;
591 
592 		ret = pipeline_pm_power(sink, source_use, graph);
593 		if (ret < 0)
594 			pipeline_pm_power(source, -sink_use, graph);
595 	}
596 
597 	return ret;
598 }
599 EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);
600