summaryrefslogtreecommitdiffstats
path: root/drivers/media/v4l2-core/v4l2-mc.c
blob: 8bef4331bd511261acacf1b58acbeb56749a90ff (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
/*
 * Media Controller ancillary functions
 *
 * Copyright (c) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
 * Copyright (C) 2016 Shuah Khan <shuahkh@osg.samsung.com>
 * Copyright (C) 2006-2010 Nokia Corporation
 * Copyright (c) 2016 Intel Corporation.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/usb.h>
#include <media/media-device.h>
#include <media/media-entity.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-mc.h>
#include <media/v4l2-subdev.h>
#include <media/media-device.h>
#include <media/v4l2-mc.h>
#include <media/videobuf2-core.h>

int v4l2_mc_create_media_graph(struct media_device *mdev)

{
	struct media_entity *entity;
	struct media_entity *if_vid = NULL, *if_aud = NULL;
	struct media_entity *tuner = NULL, *decoder = NULL;
	struct media_entity *io_v4l = NULL, *io_vbi = NULL, *io_swradio = NULL;
	bool is_webcam = false;
	u32 flags;
	int ret;

	if (!mdev)
		return 0;

	media_device_for_each_entity(entity, mdev) {
		switch (entity->function) {
		case MEDIA_ENT_F_IF_VID_DECODER:
			if_vid = entity;
			break;
		case MEDIA_ENT_F_IF_AUD_DECODER:
			if_aud = entity;
			break;
		case MEDIA_ENT_F_TUNER:
			tuner = entity;
			break;
		case MEDIA_ENT_F_ATV_DECODER:
			decoder = entity;
			break;
		case MEDIA_ENT_F_IO_V4L:
			io_v4l = entity;
			break;
		case MEDIA_ENT_F_IO_VBI:
			io_vbi = entity;
			break;
		case MEDIA_ENT_F_IO_SWRADIO:
			io_swradio = entity;
			break;
		case MEDIA_ENT_F_CAM_SENSOR:
			is_webcam = true;
			break;
		}
	}

	/* It should have at least one I/O entity */
	if (!io_v4l && !io_vbi && !io_swradio)
		return -EINVAL;

	/*
	 * Here, webcams are modelled on a very simple way: the sensor is
	 * connected directly to the I/O entity. All dirty details, like
	 * scaler and crop HW are hidden. While such mapping is not enough
	 * for mc-centric hardware, it is enough for v4l2 interface centric
	 * PC-consumer's hardware.
	 */
	if (is_webcam) {
		if (!io_v4l)
			return -EINVAL;

		media_device_for_each_entity(entity, mdev) {
			if (entity->function != MEDIA_ENT_F_CAM_SENSOR)
				continue;
			ret = media_create_pad_link(entity, 0,
						    io_v4l, 0,
						    MEDIA_LNK_FL_ENABLED);
			if (ret)
				return ret;
		}
		if (!decoder)
			return 0;
	}

	/* The device isn't a webcam. So, it should have a decoder */
	if (!decoder)
		return -EINVAL;

	/* Link the tuner and IF video output pads */
	if (tuner) {
		if (if_vid) {
			ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
						    if_vid,
						    IF_VID_DEC_PAD_IF_INPUT,
						    MEDIA_LNK_FL_ENABLED);
			if (ret)
				return ret;
			ret = media_create_pad_link(if_vid, IF_VID_DEC_PAD_OUT,
						decoder, DEMOD_PAD_IF_INPUT,
						MEDIA_LNK_FL_ENABLED);
			if (ret)
				return ret;
		} else {
			ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
						decoder, DEMOD_PAD_IF_INPUT,
						MEDIA_LNK_FL_ENABLED);
			if (ret)
				return ret;
		}

		if (if_aud) {
			ret = media_create_pad_link(tuner, TUNER_PAD_AUD_OUT,
						    if_aud,
						    IF_AUD_DEC_PAD_IF_INPUT,
						    MEDIA_LNK_FL_ENABLED);
			if (ret)
				return ret;
		} else {
			if_aud = tuner;
		}

	}

	/* Create demod to V4L, VBI and SDR radio links */
	if (io_v4l) {
		ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
					io_v4l, 0,
					MEDIA_LNK_FL_ENABLED);
		if (ret)
			return ret;
	}

	if (io_swradio) {
		ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
					io_swradio, 0,
					MEDIA_LNK_FL_ENABLED);
		if (ret)
			return ret;
	}

	if (io_vbi) {
		ret = media_create_pad_link(decoder, DEMOD_PAD_VBI_OUT,
					    io_vbi, 0,
					    MEDIA_LNK_FL_ENABLED);
		if (ret)
			return ret;
	}

	/* Create links for the media connectors */
	flags = MEDIA_LNK_FL_ENABLED;
	media_device_for_each_entity(entity, mdev) {
		switch (entity->function) {
		case MEDIA_ENT_F_CONN_RF:
			if (!tuner)
				continue;

			ret = media_create_pad_link(entity, 0, tuner,
						    TUNER_PAD_RF_INPUT,
						    flags);
			break;
		case MEDIA_ENT_F_CONN_SVIDEO:
		case MEDIA_ENT_F_CONN_COMPOSITE:
			ret = media_create_pad_link(entity, 0, decoder,
						    DEMOD_PAD_IF_INPUT,
						    flags);
			break;
		default:
			continue;
		}
		if (ret)
			return ret;

		flags = 0;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);

int v4l_enable_media_source(struct video_device *vdev)
{
	struct media_device *mdev = vdev->entity.graph_obj.mdev;
	int ret;

	if (!mdev || !mdev->enable_source)
		return 0;
	ret = mdev->enable_source(&vdev->entity, &vdev->pipe);
	if (ret)
		return -EBUSY;
	return 0;
}
EXPORT_SYMBOL_GPL(v4l_enable_media_source);

void v4l_disable_media_source(struct video_device *vdev)
{
	struct media_device *mdev = vdev->entity.graph_obj.mdev;

	if (mdev && mdev->disable_source)
		mdev->disable_source(&vdev->entity);
}
EXPORT_SYMBOL_GPL(v4l_disable_media_source);

int v4l_vb2q_enable_media_source(struct vb2_queue *q)
{
	struct v4l2_fh *fh = q->owner;

	if (fh && fh->vdev)
		return v4l_enable_media_source(fh->vdev);
	return 0;
}
EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);

/* -----------------------------------------------------------------------------
 * Pipeline power management
 *
 * Entities must be powered up when part of a pipeline that contains at least
 * one open video device node.
 *
 * To achieve this use the entity use_count field to track the number of users.
 * For entities corresponding to video device nodes the use_count field stores
 * the users count of the node. For entities corresponding to subdevs the
 * use_count field stores the total number of users of all video device nodes
 * in the pipeline.
 *
 * The v4l2_pipeline_pm_use() function must be called in the open() and
 * close() handlers of video device nodes. It increments or decrements the use
 * count of all subdev entities in the pipeline.
 *
 * To react to link management on powered pipelines, the link setup notification
 * callback updates the use count of all entities in the source and sink sides
 * of the link.
 */

/*
 * pipeline_pm_use_count - Count the number of users of a pipeline
 * @entity: The entity
 *
 * Return the total number of users of all video device nodes in the pipeline.
 */
static int pipeline_pm_use_count(struct media_entity *entity,
	struct media_entity_graph *graph)
{
	int use = 0;

	media_entity_graph_walk_start(graph, entity);

	while ((entity = media_entity_graph_walk_next(graph))) {
		if (is_media_entity_v4l2_video_device(entity))
			use += entity->use_count;
	}

	return use;
}

/*
 * pipeline_pm_power_one - Apply power change to an entity
 * @entity: The entity
 * @change: Use count change
 *
 * Change the entity use count by @change. If the entity is a subdev update its
 * power state by calling the core::s_power operation when the use count goes
 * from 0 to != 0 or from != 0 to 0.
 *
 * Return 0 on success or a negative error code on failure.
 */
static int pipeline_pm_power_one(struct media_entity *entity, int change)
{
	struct v4l2_subdev *subdev;
	int ret;

	subdev = is_media_entity_v4l2_subdev(entity)
	       ? media_entity_to_v4l2_subdev(entity) : NULL;

	if (entity->use_count == 0 && change > 0 && subdev != NULL) {
		ret = v4l2_subdev_call(subdev, core, s_power, 1);
		if (ret < 0 && ret != -ENOIOCTLCMD)
			return ret;
	}

	entity->use_count += change;
	WARN_ON(entity->use_count < 0);

	if (entity->use_count == 0 && change < 0 && subdev != NULL)
		v4l2_subdev_call(subdev, core, s_power, 0);

	return 0;
}

/*
 * pipeline_pm_power - Apply power change to all entities in a pipeline
 * @entity: The entity
 * @change: Use count change
 *
 * Walk the pipeline to update the use count and the power state of all non-node
 * entities.
 *
 * Return 0 on success or a negative error code on failure.
 */
static int pipeline_pm_power(struct media_entity *entity, int change,
	struct media_entity_graph *graph)
{
	struct media_entity *first = entity;
	int ret = 0;

	if (!change)
		return 0;

	media_entity_graph_walk_start(graph, entity);

	while (!ret && (entity = media_entity_graph_walk_next(graph)))
		if (is_media_entity_v4l2_subdev(entity))
			ret = pipeline_pm_power_one(entity, change);

	if (!ret)
		return ret;

	media_entity_graph_walk_start(graph, first);

	while ((first = media_entity_graph_walk_next(graph))
	       && first != entity)
		if (is_media_entity_v4l2_subdev(first))
			pipeline_pm_power_one(first, -change);

	return ret;
}

int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
{
	struct media_device *mdev = entity->graph_obj.mdev;
	int change = use ? 1 : -1;
	int ret;

	mutex_lock(&mdev->graph_mutex);

	/* Apply use count to node. */
	entity->use_count += change;
	WARN_ON(entity->use_count < 0);

	/* Apply power change to connected non-nodes. */
	ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
	if (ret < 0)
		entity->use_count -= change;

	mutex_unlock(&mdev->graph_mutex);

	return ret;
}
EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_use);

int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
			      unsigned int notification)
{
	struct media_entity_graph *graph = &link->graph_obj.mdev->pm_count_walk;
	struct media_entity *source = link->source->entity;
	struct media_entity *sink = link->sink->entity;
	int source_use;
	int sink_use;
	int ret = 0;

	source_use = pipeline_pm_use_count(source, graph);
	sink_use = pipeline_pm_use_count(sink, graph);

	if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
	    !(flags & MEDIA_LNK_FL_ENABLED)) {
		/* Powering off entities is assumed to never fail. */
		pipeline_pm_power(source, -sink_use, graph);
		pipeline_pm_power(sink, -source_use, graph);
		return 0;
	}

	if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
		(flags & MEDIA_LNK_FL_ENABLED)) {

		ret = pipeline_pm_power(source, sink_use, graph);
		if (ret < 0)
			return ret;

		ret = pipeline_pm_power(sink, source_use, graph);
		if (ret < 0)
			pipeline_pm_power(source, -sink_use, graph);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);
OpenPOWER on IntegriCloud