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/media-device.h>
  29 #include <media/v4l2-mc.h>
  30 #include <media/videobuf2-core.h>
  31
  32 int v4l2_mc_create_media_graph(struct media_device *mdev)
  33
  34 {
  35         struct media_entity *entity;
  36         struct media_entity *if_vid = NULL, *if_aud = NULL;
  37         struct media_entity *tuner = NULL, *decoder = NULL;
  38         struct media_entity *io_v4l = NULL, *io_vbi = NULL, *io_swradio = NULL;
  39         bool is_webcam = false;
  40         u32 flags;
  41         int ret;
  42
  43         if (!mdev)
  44                 return 0;
  45
  46         media_device_for_each_entity(entity, mdev) {
  47                 switch (entity->function) {
  48                 case MEDIA_ENT_F_IF_VID_DECODER:
  49                         if_vid = entity;
  50                         break;
  51                 case MEDIA_ENT_F_IF_AUD_DECODER:
  52                         if_aud = entity;
  53                         break;
  54                 case MEDIA_ENT_F_TUNER:
  55                         tuner = entity;
  56                         break;
  57                 case MEDIA_ENT_F_ATV_DECODER:
  58                         decoder = entity;
  59                         break;
  60                 case MEDIA_ENT_F_IO_V4L:
  61                         io_v4l = entity;
  62                         break;
  63                 case MEDIA_ENT_F_IO_VBI:
  64                         io_vbi = entity;
  65                         break;
  66                 case MEDIA_ENT_F_IO_SWRADIO:
  67                         io_swradio = entity;
  68                         break;
  69                 case MEDIA_ENT_F_CAM_SENSOR:
  70                         is_webcam = true;
  71                         break;
  72                 }
  73         }
  74
  75         /* It should have at least one I/O entity */
  76         if (!io_v4l && !io_vbi && !io_swradio)
  77                 return -EINVAL;
  78
  79         /*
  80          * Here, webcams are modelled on a very simple way: the sensor is
  81          * connected directly to the I/O entity. All dirty details, like
  82          * scaler and crop HW are hidden. While such mapping is not enough
  83          * for mc-centric hardware, it is enough for v4l2 interface centric
  84          * PC-consumer's hardware.
  85          */
  86         if (is_webcam) {
  87                 if (!io_v4l)
  88                         return -EINVAL;
  89
  90                 media_device_for_each_entity(entity, mdev) {
  91                         if (entity->function != MEDIA_ENT_F_CAM_SENSOR)
  92                                 continue;
  93                         ret = media_create_pad_link(entity, 0,
  94                                                     io_v4l, 0,
  95                                                     MEDIA_LNK_FL_ENABLED);
  96                         if (ret)
  97                                 return ret;
  98                 }
  99                 if (!decoder)
 100                         return 0;
 101         }
 102
 103         /* The device isn't a webcam. So, it should have a decoder */
 104         if (!decoder)
 105                 return -EINVAL;
 106
 107         /* Link the tuner and IF video output pads */
 108         if (tuner) {
 109                 if (if_vid) {
 110                         ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
 111                                                     if_vid,
 112                                                     IF_VID_DEC_PAD_IF_INPUT,
 113                                                     MEDIA_LNK_FL_ENABLED);
 114                         if (ret)
 115                                 return ret;
 116                         ret = media_create_pad_link(if_vid, IF_VID_DEC_PAD_OUT,
 117                                                 decoder, DEMOD_PAD_IF_INPUT,
 118                                                 MEDIA_LNK_FL_ENABLED);
 119                         if (ret)
 120                                 return ret;
 121                 } else {
 122                         ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
 123                                                 decoder, DEMOD_PAD_IF_INPUT,
 124                                                 MEDIA_LNK_FL_ENABLED);
 125                         if (ret)
 126                                 return ret;
 127                 }
 128
 129                 if (if_aud) {
 130                         ret = media_create_pad_link(tuner, TUNER_PAD_AUD_OUT,
 131                                                     if_aud,
 132                                                     IF_AUD_DEC_PAD_IF_INPUT,
 133                                                     MEDIA_LNK_FL_ENABLED);
 134                         if (ret)
 135                                 return ret;
 136                 } else {
 137                         if_aud = tuner;
 138                 }
 139
 140         }
 141
 142         /* Create demod to V4L, VBI and SDR radio links */
 143         if (io_v4l) {
 144                 ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
 145                                         io_v4l, 0,
 146                                         MEDIA_LNK_FL_ENABLED);
 147                 if (ret)
 148                         return ret;
 149         }
 150
 151         if (io_swradio) {
 152                 ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
 153                                         io_swradio, 0,
 154                                         MEDIA_LNK_FL_ENABLED);
 155                 if (ret)
 156                         return ret;
 157         }
 158
 159         if (io_vbi) {
 160                 ret = media_create_pad_link(decoder, DEMOD_PAD_VBI_OUT,
 161                                             io_vbi, 0,
 162                                             MEDIA_LNK_FL_ENABLED);
 163                 if (ret)
 164                         return ret;
 165         }
 166
 167         /* Create links for the media connectors */
 168         flags = MEDIA_LNK_FL_ENABLED;
 169         media_device_for_each_entity(entity, mdev) {
 170                 switch (entity->function) {
 171                 case MEDIA_ENT_F_CONN_RF:
 172                         if (!tuner)
 173                                 continue;
 174
 175                         ret = media_create_pad_link(entity, 0, tuner,
 176                                                     TUNER_PAD_RF_INPUT,
 177                                                     flags);
 178                         break;
 179                 case MEDIA_ENT_F_CONN_SVIDEO:
 180                 case MEDIA_ENT_F_CONN_COMPOSITE:
 181                         ret = media_create_pad_link(entity, 0, decoder,
 182                                                     DEMOD_PAD_IF_INPUT,
 183                                                     flags);
 184                         break;
 185                 default:
 186                         continue;
 187                 }
 188                 if (ret)
 189                         return ret;
 190
 191                 flags = 0;
 192         }
 193
 194         return 0;
 195 }
 196 EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);
 197
 198 int v4l_enable_media_source(struct video_device *vdev)
 199 {
 200         struct media_device *mdev = vdev->entity.graph_obj.mdev;
 201         int ret = 0, err;
 202
 203         if (!mdev)
 204                 return 0;
 205
 206         mutex_lock(&mdev->graph_mutex);
 207         if (!mdev->enable_source)
 208                 goto end;
 209         err = mdev->enable_source(&vdev->entity, &vdev->pipe);
 210         if (err)
 211                 ret = -EBUSY;
 212 end:
 213         mutex_unlock(&mdev->graph_mutex);
 214         return ret;
 215 }
 216 EXPORT_SYMBOL_GPL(v4l_enable_media_source);
 217
 218 void v4l_disable_media_source(struct video_device *vdev)
 219 {
 220         struct media_device *mdev = vdev->entity.graph_obj.mdev;
 221
 222         if (mdev) {
 223                 mutex_lock(&mdev->graph_mutex);
 224                 if (mdev->disable_source)
 225                         mdev->disable_source(&vdev->entity);
 226                 mutex_unlock(&mdev->graph_mutex);
 227         }
 228 }
 229 EXPORT_SYMBOL_GPL(v4l_disable_media_source);
 230
 231 int v4l_vb2q_enable_media_source(struct vb2_queue *q)
 232 {
 233         struct v4l2_fh *fh = q->owner;
 234
 235         if (fh && fh->vdev)
 236                 return v4l_enable_media_source(fh->vdev);
 237         return 0;
 238 }
 239 EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
 240
 241 /* -----------------------------------------------------------------------------
 242  * Pipeline power management
 243  *
 244  * Entities must be powered up when part of a pipeline that contains at least
 245  * one open video device node.
 246  *
 247  * To achieve this use the entity use_count field to track the number of users.
 248  * For entities corresponding to video device nodes the use_count field stores
 249  * the users count of the node. For entities corresponding to subdevs the
 250  * use_count field stores the total number of users of all video device nodes
 251  * in the pipeline.
 252  *
 253  * The v4l2_pipeline_pm_use() function must be called in the open() and
 254  * close() handlers of video device nodes. It increments or decrements the use
 255  * count of all subdev entities in the pipeline.
 256  *
 257  * To react to link management on powered pipelines, the link setup notification
 258  * callback updates the use count of all entities in the source and sink sides
 259  * of the link.
 260  */
 261
 262 /*
 263  * pipeline_pm_use_count - Count the number of users of a pipeline
 264  * @entity: The entity
 265  *
 266  * Return the total number of users of all video device nodes in the pipeline.
 267  */
 268 static int pipeline_pm_use_count(struct media_entity *entity,
 269         struct media_graph *graph)
 270 {
 271         int use = 0;
 272
 273         media_graph_walk_start(graph, entity);
 274
 275         while ((entity = media_graph_walk_next(graph))) {
 276                 if (is_media_entity_v4l2_video_device(entity))
 277                         use += entity->use_count;
 278         }
 279
 280         return use;
 281 }
 282
 283 /*
 284  * pipeline_pm_power_one - Apply power change to an entity
 285  * @entity: The entity
 286  * @change: Use count change
 287  *
 288  * Change the entity use count by @change. If the entity is a subdev update its
 289  * power state by calling the core::s_power operation when the use count goes
 290  * from 0 to != 0 or from != 0 to 0.
 291  *
 292  * Return 0 on success or a negative error code on failure.
 293  */
 294 static int pipeline_pm_power_one(struct media_entity *entity, int change)
 295 {
 296         struct v4l2_subdev *subdev;
 297         int ret;
 298
 299         subdev = is_media_entity_v4l2_subdev(entity)
 300                ? media_entity_to_v4l2_subdev(entity) : NULL;
 301
 302         if (entity->use_count == 0 && change > 0 && subdev != NULL) {
 303                 ret = v4l2_subdev_call(subdev, core, s_power, 1);
 304                 if (ret < 0 && ret != -ENOIOCTLCMD)
 305                         return ret;
 306         }
 307
 308         entity->use_count += change;
 309         WARN_ON(entity->use_count < 0);
 310
 311         if (entity->use_count == 0 && change < 0 && subdev != NULL)
 312                 v4l2_subdev_call(subdev, core, s_power, 0);
 313
 314         return 0;
 315 }
 316
 317 /*
 318  * pipeline_pm_power - Apply power change to all entities in a pipeline
 319  * @entity: The entity
 320  * @change: Use count change
 321  *
 322  * Walk the pipeline to update the use count and the power state of all non-node
 323  * entities.
 324  *
 325  * Return 0 on success or a negative error code on failure.
 326  */
 327 static int pipeline_pm_power(struct media_entity *entity, int change,
 328         struct media_graph *graph)
 329 {
 330         struct media_entity *first = entity;
 331         int ret = 0;
 332
 333         if (!change)
 334                 return 0;
 335
 336         media_graph_walk_start(graph, entity);
 337
 338         while (!ret && (entity = media_graph_walk_next(graph)))
 339                 if (is_media_entity_v4l2_subdev(entity))
 340                         ret = pipeline_pm_power_one(entity, change);
 341
 342         if (!ret)
 343                 return ret;
 344
 345         media_graph_walk_start(graph, first);
 346
 347         while ((first = media_graph_walk_next(graph))
 348                && first != entity)
 349                 if (is_media_entity_v4l2_subdev(first))
 350                         pipeline_pm_power_one(first, -change);
 351
 352         return ret;
 353 }
 354
 355 int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
 356 {
 357         struct media_device *mdev = entity->graph_obj.mdev;
 358         int change = use ? 1 : -1;
 359         int ret;
 360
 361         mutex_lock(&mdev->graph_mutex);
 362
 363         /* Apply use count to node. */
 364         entity->use_count += change;
 365         WARN_ON(entity->use_count < 0);
 366
 367         /* Apply power change to connected non-nodes. */
 368         ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
 369         if (ret < 0)
 370                 entity->use_count -= change;
 371
 372         mutex_unlock(&mdev->graph_mutex);
 373
 374         return ret;
 375 }
 376 EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_use);
 377
 378 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
 379                               unsigned int notification)
 380 {
 381         struct media_graph *graph = &link->graph_obj.mdev->pm_count_walk;
 382         struct media_entity *source = link->source->entity;
 383         struct media_entity *sink = link->sink->entity;
 384         int source_use;
 385         int sink_use;
 386         int ret = 0;
 387
 388         source_use = pipeline_pm_use_count(source, graph);
 389         sink_use = pipeline_pm_use_count(sink, graph);
 390
 391         if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
 392             !(flags & MEDIA_LNK_FL_ENABLED)) {
 393                 /* Powering off entities is assumed to never fail. */
 394                 pipeline_pm_power(source, -sink_use, graph);
 395                 pipeline_pm_power(sink, -source_use, graph);
 396                 return 0;
 397         }
 398
 399         if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
 400                 (flags & MEDIA_LNK_FL_ENABLED)) {
 401
 402                 ret = pipeline_pm_power(source, sink_use, graph);
 403                 if (ret < 0)
 404                         return ret;
 405
 406                 ret = pipeline_pm_power(sink, source_use, graph);
 407                 if (ret < 0)
 408                         pipeline_pm_power(source, -sink_use, graph);
 409         }
 410
 411         return ret;
 412 }
 413 EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);