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

   1 /*
   2  * Media Controller ancillary functions
   3  *
   4  * Copyright (c) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
   5  * Copyright (C) 2016 Shuah Khan <shuahkh@osg.samsung.com>
   6  * Copyright (C) 2006-2010 Nokia Corporation
   7  * Copyright (c) 2016 Intel Corporation.
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/pci.h>
  22 #include <linux/usb.h>
  23 #include <media/media-device.h>
  24 #include <media/media-entity.h>
  25 #include <media/v4l2-fh.h>
  26 #include <media/v4l2-mc.h>
  27 #include <media/v4l2-subdev.h>
  28 #include <media/videobuf2-core.h>
  29
  30 int v4l2_mc_create_media_graph(struct media_device *mdev)
  31
  32 {
  33         struct media_entity *entity;
  34         struct media_entity *if_vid = NULL, *if_aud = NULL;
  35         struct media_entity *tuner = NULL, *decoder = NULL;
  36         struct media_entity *io_v4l = NULL, *io_vbi = NULL, *io_swradio = NULL;
  37         bool is_webcam = false;
  38         u32 flags;
  39         int ret;
  40
  41         if (!mdev)
  42                 return 0;
  43
  44         media_device_for_each_entity(entity, mdev) {
  45                 switch (entity->function) {
  46                 case MEDIA_ENT_F_IF_VID_DECODER:
  47                         if_vid = entity;
  48                         break;
  49                 case MEDIA_ENT_F_IF_AUD_DECODER:
  50                         if_aud = entity;
  51                         break;
  52                 case MEDIA_ENT_F_TUNER:
  53                         tuner = entity;
  54                         break;
  55                 case MEDIA_ENT_F_ATV_DECODER:
  56                         decoder = entity;
  57                         break;
  58                 case MEDIA_ENT_F_IO_V4L:
  59                         io_v4l = entity;
  60                         break;
  61                 case MEDIA_ENT_F_IO_VBI:
  62                         io_vbi = entity;
  63                         break;
  64                 case MEDIA_ENT_F_IO_SWRADIO:
  65                         io_swradio = entity;
  66                         break;
  67                 case MEDIA_ENT_F_CAM_SENSOR:
  68                         is_webcam = true;
  69                         break;
  70                 }
  71         }
  72
  73         /* It should have at least one I/O entity */
  74         if (!io_v4l && !io_vbi && !io_swradio)
  75                 return -EINVAL;
  76
  77         /*
  78          * Here, webcams are modelled on a very simple way: the sensor is
  79          * connected directly to the I/O entity. All dirty details, like
  80          * scaler and crop HW are hidden. While such mapping is not enough
  81          * for mc-centric hardware, it is enough for v4l2 interface centric
  82          * PC-consumer's hardware.
  83          */
  84         if (is_webcam) {
  85                 if (!io_v4l)
  86                         return -EINVAL;
  87
  88                 media_device_for_each_entity(entity, mdev) {
  89                         if (entity->function != MEDIA_ENT_F_CAM_SENSOR)
  90                                 continue;
  91                         ret = media_create_pad_link(entity, 0,
  92                                                     io_v4l, 0,
  93                                                     MEDIA_LNK_FL_ENABLED);
  94                         if (ret)
  95                                 return ret;
  96                 }
  97                 if (!decoder)
  98                         return 0;
  99         }
 100
 101         /* The device isn't a webcam. So, it should have a decoder */
 102         if (!decoder)
 103                 return -EINVAL;
 104
 105         /* Link the tuner and IF video output pads */
 106         if (tuner) {
 107                 if (if_vid) {
 108                         ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
 109                                                     if_vid,
 110                                                     IF_VID_DEC_PAD_IF_INPUT,
 111                                                     MEDIA_LNK_FL_ENABLED);
 112                         if (ret)
 113                                 return ret;
 114                         ret = media_create_pad_link(if_vid, IF_VID_DEC_PAD_OUT,
 115                                                 decoder, DEMOD_PAD_IF_INPUT,
 116                                                 MEDIA_LNK_FL_ENABLED);
 117                         if (ret)
 118                                 return ret;
 119                 } else {
 120                         ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
 121                                                 decoder, DEMOD_PAD_IF_INPUT,
 122                                                 MEDIA_LNK_FL_ENABLED);
 123                         if (ret)
 124                                 return ret;
 125                 }
 126
 127                 if (if_aud) {
 128                         ret = media_create_pad_link(tuner, TUNER_PAD_AUD_OUT,
 129                                                     if_aud,
 130                                                     IF_AUD_DEC_PAD_IF_INPUT,
 131                                                     MEDIA_LNK_FL_ENABLED);
 132                         if (ret)
 133                                 return ret;
 134                 } else {
 135                         if_aud = tuner;
 136                 }
 137
 138         }
 139
 140         /* Create demod to V4L, VBI and SDR radio links */
 141         if (io_v4l) {
 142                 ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
 143                                         io_v4l, 0,
 144                                         MEDIA_LNK_FL_ENABLED);
 145                 if (ret)
 146                         return ret;
 147         }
 148
 149         if (io_swradio) {
 150                 ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
 151                                         io_swradio, 0,
 152                                         MEDIA_LNK_FL_ENABLED);
 153                 if (ret)
 154                         return ret;
 155         }
 156
 157         if (io_vbi) {
 158                 ret = media_create_pad_link(decoder, DEMOD_PAD_VBI_OUT,
 159                                             io_vbi, 0,
 160                                             MEDIA_LNK_FL_ENABLED);
 161                 if (ret)
 162                         return ret;
 163         }
 164
 165         /* Create links for the media connectors */
 166         flags = MEDIA_LNK_FL_ENABLED;
 167         media_device_for_each_entity(entity, mdev) {
 168                 switch (entity->function) {
 169                 case MEDIA_ENT_F_CONN_RF:
 170                         if (!tuner)
 171                                 continue;
 172
 173                         ret = media_create_pad_link(entity, 0, tuner,
 174                                                     TUNER_PAD_RF_INPUT,
 175                                                     flags);
 176                         break;
 177                 case MEDIA_ENT_F_CONN_SVIDEO:
 178                 case MEDIA_ENT_F_CONN_COMPOSITE:
 179                         ret = media_create_pad_link(entity, 0, decoder,
 180                                                     DEMOD_PAD_IF_INPUT,
 181                                                     flags);
 182                         break;
 183                 default:
 184                         continue;
 185                 }
 186                 if (ret)
 187                         return ret;
 188
 189                 flags = 0;
 190         }
 191
 192         return 0;
 193 }
 194 EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);
 195
 196 int v4l_enable_media_source(struct video_device *vdev)
 197 {
 198         struct media_device *mdev = vdev->entity.graph_obj.mdev;
 199         int ret = 0, err;
 200
 201         if (!mdev)
 202                 return 0;
 203
 204         mutex_lock(&mdev->graph_mutex);
 205         if (!mdev->enable_source)
 206                 goto end;
 207         err = mdev->enable_source(&vdev->entity, &vdev->pipe);
 208         if (err)
 209                 ret = -EBUSY;
 210 end:
 211         mutex_unlock(&mdev->graph_mutex);
 212         return ret;
 213 }
 214 EXPORT_SYMBOL_GPL(v4l_enable_media_source);
 215
 216 void v4l_disable_media_source(struct video_device *vdev)
 217 {
 218         struct media_device *mdev = vdev->entity.graph_obj.mdev;
 219
 220         if (mdev) {
 221                 mutex_lock(&mdev->graph_mutex);
 222                 if (mdev->disable_source)
 223                         mdev->disable_source(&vdev->entity);
 224                 mutex_unlock(&mdev->graph_mutex);
 225         }
 226 }
 227 EXPORT_SYMBOL_GPL(v4l_disable_media_source);
 228
 229 int v4l_vb2q_enable_media_source(struct vb2_queue *q)
 230 {
 231         struct v4l2_fh *fh = q->owner;
 232
 233         if (fh && fh->vdev)
 234                 return v4l_enable_media_source(fh->vdev);
 235         return 0;
 236 }
 237 EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
 238
 239 /* -----------------------------------------------------------------------------
 240  * Pipeline power management
 241  *
 242  * Entities must be powered up when part of a pipeline that contains at least
 243  * one open video device node.
 244  *
 245  * To achieve this use the entity use_count field to track the number of users.
 246  * For entities corresponding to video device nodes the use_count field stores
 247  * the users count of the node. For entities corresponding to subdevs the
 248  * use_count field stores the total number of users of all video device nodes
 249  * in the pipeline.
 250  *
 251  * The v4l2_pipeline_pm_use() function must be called in the open() and
 252  * close() handlers of video device nodes. It increments or decrements the use
 253  * count of all subdev entities in the pipeline.
 254  *
 255  * To react to link management on powered pipelines, the link setup notification
 256  * callback updates the use count of all entities in the source and sink sides
 257  * of the link.
 258  */
 259
 260 /*
 261  * pipeline_pm_use_count - Count the number of users of a pipeline
 262  * @entity: The entity
 263  *
 264  * Return the total number of users of all video device nodes in the pipeline.
 265  */
 266 static int pipeline_pm_use_count(struct media_entity *entity,
 267         struct media_graph *graph)
 268 {
 269         int use = 0;
 270
 271         media_graph_walk_start(graph, entity);
 272
 273         while ((entity = media_graph_walk_next(graph))) {
 274                 if (is_media_entity_v4l2_video_device(entity))
 275                         use += entity->use_count;
 276         }
 277
 278         return use;
 279 }
 280
 281 /*
 282  * pipeline_pm_power_one - Apply power change to an entity
 283  * @entity: The entity
 284  * @change: Use count change
 285  *
 286  * Change the entity use count by @change. If the entity is a subdev update its
 287  * power state by calling the core::s_power operation when the use count goes
 288  * from 0 to != 0 or from != 0 to 0.
 289  *
 290  * Return 0 on success or a negative error code on failure.
 291  */
 292 static int pipeline_pm_power_one(struct media_entity *entity, int change)
 293 {
 294         struct v4l2_subdev *subdev;
 295         int ret;
 296
 297         subdev = is_media_entity_v4l2_subdev(entity)
 298                ? media_entity_to_v4l2_subdev(entity) : NULL;
 299
 300         if (entity->use_count == 0 && change > 0 && subdev != NULL) {
 301                 ret = v4l2_subdev_call(subdev, core, s_power, 1);
 302                 if (ret < 0 && ret != -ENOIOCTLCMD)
 303                         return ret;
 304         }
 305
 306         entity->use_count += change;
 307         WARN_ON(entity->use_count < 0);
 308
 309         if (entity->use_count == 0 && change < 0 && subdev != NULL)
 310                 v4l2_subdev_call(subdev, core, s_power, 0);
 311
 312         return 0;
 313 }
 314
 315 /*
 316  * pipeline_pm_power - Apply power change to all entities in a pipeline
 317  * @entity: The entity
 318  * @change: Use count change
 319  *
 320  * Walk the pipeline to update the use count and the power state of all non-node
 321  * entities.
 322  *
 323  * Return 0 on success or a negative error code on failure.
 324  */
 325 static int pipeline_pm_power(struct media_entity *entity, int change,
 326         struct media_graph *graph)
 327 {
 328         struct media_entity *first = entity;
 329         int ret = 0;
 330
 331         if (!change)
 332                 return 0;
 333
 334         media_graph_walk_start(graph, entity);
 335
 336         while (!ret && (entity = media_graph_walk_next(graph)))
 337                 if (is_media_entity_v4l2_subdev(entity))
 338                         ret = pipeline_pm_power_one(entity, change);
 339
 340         if (!ret)
 341                 return ret;
 342
 343         media_graph_walk_start(graph, first);
 344
 345         while ((first = media_graph_walk_next(graph))
 346                && first != entity)
 347                 if (is_media_entity_v4l2_subdev(first))
 348                         pipeline_pm_power_one(first, -change);
 349
 350         return ret;
 351 }
 352
 353 int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
 354 {
 355         struct media_device *mdev = entity->graph_obj.mdev;
 356         int change = use ? 1 : -1;
 357         int ret;
 358
 359         mutex_lock(&mdev->graph_mutex);
 360
 361         /* Apply use count to node. */
 362         entity->use_count += change;
 363         WARN_ON(entity->use_count < 0);
 364
 365         /* Apply power change to connected non-nodes. */
 366         ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
 367         if (ret < 0)
 368                 entity->use_count -= change;
 369
 370         mutex_unlock(&mdev->graph_mutex);
 371
 372         return ret;
 373 }
 374 EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_use);
 375
 376 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
 377                               unsigned int notification)
 378 {
 379         struct media_graph *graph = &link->graph_obj.mdev->pm_count_walk;
 380         struct media_entity *source = link->source->entity;
 381         struct media_entity *sink = link->sink->entity;
 382         int source_use;
 383         int sink_use;
 384         int ret = 0;
 385
 386         source_use = pipeline_pm_use_count(source, graph);
 387         sink_use = pipeline_pm_use_count(sink, graph);
 388
 389         if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
 390             !(flags & MEDIA_LNK_FL_ENABLED)) {
 391                 /* Powering off entities is assumed to never fail. */
 392                 pipeline_pm_power(source, -sink_use, graph);
 393                 pipeline_pm_power(sink, -source_use, graph);
 394                 return 0;
 395         }
 396
 397         if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
 398                 (flags & MEDIA_LNK_FL_ENABLED)) {
 399
 400                 ret = pipeline_pm_power(source, sink_use, graph);
 401                 if (ret < 0)
 402                         return ret;
 403
 404                 ret = pipeline_pm_power(sink, source_use, graph);
 405                 if (ret < 0)
 406                         pipeline_pm_power(source, -sink_use, graph);
 407         }
 408
 409         return ret;
 410 }
 411 EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);