root/drivers/media/v4l2-core/v4l2-mc.c

DEFINITIONS

1. v4l2_mc_create_media_graph
2. v4l_enable_media_source
3. v4l_disable_media_source
4. v4l_vb2q_enable_media_source
5. pipeline_pm_use_count
6. pipeline_pm_power_one
7. pipeline_pm_power
8. v4l2_pipeline_pm_use
9. v4l2_pipeline_link_notify

   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 /* -----------------------------------------------------------------------------
 313  * Pipeline power management
 314  *
 315  * Entities must be powered up when part of a pipeline that contains at least
 316  * one open video device node.
 317  *
 318  * To achieve this use the entity use_count field to track the number of users.
 319  * For entities corresponding to video device nodes the use_count field stores
 320  * the users count of the node. For entities corresponding to subdevs the
 321  * use_count field stores the total number of users of all video device nodes
 322  * in the pipeline.
 323  *
 324  * The v4l2_pipeline_pm_use() function must be called in the open() and
 325  * close() handlers of video device nodes. It increments or decrements the use
 326  * count of all subdev entities in the pipeline.
 327  *
 328  * To react to link management on powered pipelines, the link setup notification
 329  * callback updates the use count of all entities in the source and sink sides
 330  * of the link.
 331  */
 332 
 333 /*
 334  * pipeline_pm_use_count - Count the number of users of a pipeline
 335  * @entity: The entity
 336  *
 337  * Return the total number of users of all video device nodes in the pipeline.
 338  */
 339 static int pipeline_pm_use_count(struct media_entity *entity,
 340         struct media_graph *graph)
 341 {
 342         int use = 0;
 343 
 344         media_graph_walk_start(graph, entity);
 345 
 346         while ((entity = media_graph_walk_next(graph))) {
 347                 if (is_media_entity_v4l2_video_device(entity))
 348                         use += entity->use_count;
 349         }
 350 
 351         return use;
 352 }
 353 
 354 /*
 355  * pipeline_pm_power_one - Apply power change to an entity
 356  * @entity: The entity
 357  * @change: Use count change
 358  *
 359  * Change the entity use count by @change. If the entity is a subdev update its
 360  * power state by calling the core::s_power operation when the use count goes
 361  * from 0 to != 0 or from != 0 to 0.
 362  *
 363  * Return 0 on success or a negative error code on failure.
 364  */
 365 static int pipeline_pm_power_one(struct media_entity *entity, int change)
 366 {
 367         struct v4l2_subdev *subdev;
 368         int ret;
 369 
 370         subdev = is_media_entity_v4l2_subdev(entity)
 371                ? media_entity_to_v4l2_subdev(entity) : NULL;
 372 
 373         if (entity->use_count == 0 && change > 0 && subdev != NULL) {
 374                 ret = v4l2_subdev_call(subdev, core, s_power, 1);
 375                 if (ret < 0 && ret != -ENOIOCTLCMD)
 376                         return ret;
 377         }
 378 
 379         entity->use_count += change;
 380         WARN_ON(entity->use_count < 0);
 381 
 382         if (entity->use_count == 0 && change < 0 && subdev != NULL)
 383                 v4l2_subdev_call(subdev, core, s_power, 0);
 384 
 385         return 0;
 386 }
 387 
 388 /*
 389  * pipeline_pm_power - Apply power change to all entities in a pipeline
 390  * @entity: The entity
 391  * @change: Use count change
 392  *
 393  * Walk the pipeline to update the use count and the power state of all non-node
 394  * entities.
 395  *
 396  * Return 0 on success or a negative error code on failure.
 397  */
 398 static int pipeline_pm_power(struct media_entity *entity, int change,
 399         struct media_graph *graph)
 400 {
 401         struct media_entity *first = entity;
 402         int ret = 0;
 403 
 404         if (!change)
 405                 return 0;
 406 
 407         media_graph_walk_start(graph, entity);
 408 
 409         while (!ret && (entity = media_graph_walk_next(graph)))
 410                 if (is_media_entity_v4l2_subdev(entity))
 411                         ret = pipeline_pm_power_one(entity, change);
 412 
 413         if (!ret)
 414                 return ret;
 415 
 416         media_graph_walk_start(graph, first);
 417 
 418         while ((first = media_graph_walk_next(graph))
 419                && first != entity)
 420                 if (is_media_entity_v4l2_subdev(first))
 421                         pipeline_pm_power_one(first, -change);
 422 
 423         return ret;
 424 }
 425 
 426 int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
 427 {
 428         struct media_device *mdev = entity->graph_obj.mdev;
 429         int change = use ? 1 : -1;
 430         int ret;
 431 
 432         mutex_lock(&mdev->graph_mutex);
 433 
 434         /* Apply use count to node. */
 435         entity->use_count += change;
 436         WARN_ON(entity->use_count < 0);
 437 
 438         /* Apply power change to connected non-nodes. */
 439         ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
 440         if (ret < 0)
 441                 entity->use_count -= change;
 442 
 443         mutex_unlock(&mdev->graph_mutex);
 444 
 445         return ret;
 446 }
 447 EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_use);
 448 
 449 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
 450                               unsigned int notification)
 451 {
 452         struct media_graph *graph = &link->graph_obj.mdev->pm_count_walk;
 453         struct media_entity *source = link->source->entity;
 454         struct media_entity *sink = link->sink->entity;
 455         int source_use;
 456         int sink_use;
 457         int ret = 0;
 458 
 459         source_use = pipeline_pm_use_count(source, graph);
 460         sink_use = pipeline_pm_use_count(sink, graph);
 461 
 462         if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
 463             !(flags & MEDIA_LNK_FL_ENABLED)) {
 464                 /* Powering off entities is assumed to never fail. */
 465                 pipeline_pm_power(source, -sink_use, graph);
 466                 pipeline_pm_power(sink, -source_use, graph);
 467                 return 0;
 468         }
 469 
 470         if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
 471                 (flags & MEDIA_LNK_FL_ENABLED)) {
 472 
 473                 ret = pipeline_pm_power(source, sink_use, graph);
 474                 if (ret < 0)
 475                         return ret;
 476 
 477                 ret = pipeline_pm_power(sink, source_use, graph);
 478                 if (ret < 0)
 479                         pipeline_pm_power(source, -sink_use, graph);
 480         }
 481 
 482         return ret;
 483 }
 484 EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);