LXR linux/drivers/media/v4l2-core/v4l2-mc.c

   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
  22int 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}
 267EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);
 268
 269int 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;
 283end:
 284        mutex_unlock(&mdev->graph_mutex);
 285        return ret;
 286}
 287EXPORT_SYMBOL_GPL(v4l_enable_media_source);
 288
 289void 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}
 300EXPORT_SYMBOL_GPL(v4l_disable_media_source);
 301
 302int 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}
 310EXPORT_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 */
 339static 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 */
 365static 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 */
 398static 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
 426int 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}
 447EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_use);
 448
 449int 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}
 484EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);
 485