drivers/media/media-device.c

   1 /*
   2  * Media device
   3  *
   4  * Copyright (C) 2010 Nokia Corporation
   5  *
   6  * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   7  *           Sakari Ailus <sakari.ailus@iki.fi>
   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 version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/compat.h>
  24 #include <linux/export.h>
  25 #include <linux/ioctl.h>
  26 #include <linux/media.h>
  27 #include <linux/slab.h>
  28 #include <linux/types.h>
  29
  30 #include <media/media-device.h>
  31 #include <media/media-devnode.h>
  32 #include <media/media-entity.h>
  33
  34 #ifdef CONFIG_MEDIA_CONTROLLER
  35
  36 /* -----------------------------------------------------------------------------
  37  * Userspace API
  38  */
  39
  40 static int media_device_open(struct file *filp)
  41 {
  42         return 0;
  43 }
  44
  45 static int media_device_close(struct file *filp)
  46 {
  47         return 0;
  48 }
  49
  50 static int media_device_get_info(struct media_device *dev,
  51                                  struct media_device_info __user *__info)
  52 {
  53         struct media_device_info info;
  54
  55         memset(&info, 0, sizeof(info));
  56
  57         strlcpy(info.driver, dev->dev->driver->name, sizeof(info.driver));
  58         strlcpy(info.model, dev->model, sizeof(info.model));
  59         strlcpy(info.serial, dev->serial, sizeof(info.serial));
  60         strlcpy(info.bus_info, dev->bus_info, sizeof(info.bus_info));
  61
  62         info.media_version = MEDIA_API_VERSION;
  63         info.hw_revision = dev->hw_revision;
  64         info.driver_version = dev->driver_version;
  65
  66         if (copy_to_user(__info, &info, sizeof(*__info)))
  67                 return -EFAULT;
  68         return 0;
  69 }
  70
  71 static struct media_entity *find_entity(struct media_device *mdev, u32 id)
  72 {
  73         struct media_entity *entity;
  74         int next = id & MEDIA_ENT_ID_FLAG_NEXT;
  75
  76         id &= ~MEDIA_ENT_ID_FLAG_NEXT;
  77
  78         spin_lock(&mdev->lock);
  79
  80         media_device_for_each_entity(entity, mdev) {
  81                 if (((media_entity_id(entity) == id) && !next) ||
  82                     ((media_entity_id(entity) > id) && next)) {
  83                         spin_unlock(&mdev->lock);
  84                         return entity;
  85                 }
  86         }
  87
  88         spin_unlock(&mdev->lock);
  89
  90         return NULL;
  91 }
  92
  93 static long media_device_enum_entities(struct media_device *mdev,
  94                                        struct media_entity_desc __user *uent)
  95 {
  96         struct media_entity *ent;
  97         struct media_entity_desc u_ent;
  98
  99         memset(&u_ent, 0, sizeof(u_ent));
 100         if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
 101                 return -EFAULT;
 102
 103         ent = find_entity(mdev, u_ent.id);
 104
 105         if (ent == NULL)
 106                 return -EINVAL;
 107
 108         u_ent.id = media_entity_id(ent);
 109         if (ent->name)
 110                 strlcpy(u_ent.name, ent->name, sizeof(u_ent.name));
 111         u_ent.type = ent->function;
 112         u_ent.revision = 0;             /* Unused */
 113         u_ent.flags = ent->flags;
 114         u_ent.group_id = 0;             /* Unused */
 115         u_ent.pads = ent->num_pads;
 116         u_ent.links = ent->num_links - ent->num_backlinks;
 117         memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
 118         if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
 119                 return -EFAULT;
 120         return 0;
 121 }
 122
 123 static void media_device_kpad_to_upad(const struct media_pad *kpad,
 124                                       struct media_pad_desc *upad)
 125 {
 126         upad->entity = media_entity_id(kpad->entity);
 127         upad->index = kpad->index;
 128         upad->flags = kpad->flags;
 129 }
 130
 131 static long __media_device_enum_links(struct media_device *mdev,
 132                                       struct media_links_enum *links)
 133 {
 134         struct media_entity *entity;
 135
 136         entity = find_entity(mdev, links->entity);
 137         if (entity == NULL)
 138                 return -EINVAL;
 139
 140         if (links->pads) {
 141                 unsigned int p;
 142
 143                 for (p = 0; p < entity->num_pads; p++) {
 144                         struct media_pad_desc pad;
 145
 146                         memset(&pad, 0, sizeof(pad));
 147                         media_device_kpad_to_upad(&entity->pads[p], &pad);
 148                         if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
 149                                 return -EFAULT;
 150                 }
 151         }
 152
 153         if (links->links) {
 154                 struct media_link *link;
 155                 struct media_link_desc __user *ulink_desc = links->links;
 156
 157                 list_for_each_entry(link, &entity->links, list) {
 158                         struct media_link_desc klink_desc;
 159
 160                         /* Ignore backlinks. */
 161                         if (link->source->entity != entity)
 162                                 continue;
 163                         memset(&klink_desc, 0, sizeof(klink_desc));
 164                         media_device_kpad_to_upad(link->source,
 165                                                   &klink_desc.source);
 166                         media_device_kpad_to_upad(link->sink,
 167                                                   &klink_desc.sink);
 168                         klink_desc.flags = link->flags;
 169                         if (copy_to_user(ulink_desc, &klink_desc,
 170                                          sizeof(*ulink_desc)))
 171                                 return -EFAULT;
 172                         ulink_desc++;
 173                 }
 174         }
 175
 176         return 0;
 177 }
 178
 179 static long media_device_enum_links(struct media_device *mdev,
 180                                     struct media_links_enum __user *ulinks)
 181 {
 182         struct media_links_enum links;
 183         int rval;
 184
 185         if (copy_from_user(&links, ulinks, sizeof(links)))
 186                 return -EFAULT;
 187
 188         rval = __media_device_enum_links(mdev, &links);
 189         if (rval < 0)
 190                 return rval;
 191
 192         if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
 193                 return -EFAULT;
 194
 195         return 0;
 196 }
 197
 198 static long media_device_setup_link(struct media_device *mdev,
 199                                     struct media_link_desc __user *_ulink)
 200 {
 201         struct media_link *link = NULL;
 202         struct media_link_desc ulink;
 203         struct media_entity *source;
 204         struct media_entity *sink;
 205         int ret;
 206
 207         if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
 208                 return -EFAULT;
 209
 210         /* Find the source and sink entities and link.
 211          */
 212         source = find_entity(mdev, ulink.source.entity);
 213         sink = find_entity(mdev, ulink.sink.entity);
 214
 215         if (source == NULL || sink == NULL)
 216                 return -EINVAL;
 217
 218         if (ulink.source.index >= source->num_pads ||
 219             ulink.sink.index >= sink->num_pads)
 220                 return -EINVAL;
 221
 222         link = media_entity_find_link(&source->pads[ulink.source.index],
 223                                       &sink->pads[ulink.sink.index]);
 224         if (link == NULL)
 225                 return -EINVAL;
 226
 227         /* Setup the link on both entities. */
 228         ret = __media_entity_setup_link(link, ulink.flags);
 229
 230         if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
 231                 return -EFAULT;
 232
 233         return ret;
 234 }
 235
 236 static long __media_device_get_topology(struct media_device *mdev,
 237                                       struct media_v2_topology *topo)
 238 {
 239         struct media_entity *entity;
 240         struct media_interface *intf;
 241         struct media_pad *pad;
 242         struct media_link *link;
 243         struct media_v2_entity uentity;
 244         struct media_v2_interface uintf;
 245         struct media_v2_pad upad;
 246         struct media_v2_link ulink;
 247         unsigned int i;
 248         int ret = 0;
 249
 250         topo->topology_version = mdev->topology_version;
 251
 252         /* Get entities and number of entities */
 253         i = 0;
 254         media_device_for_each_entity(entity, mdev) {
 255                 i++;
 256
 257                 if (ret || !topo->entities)
 258                         continue;
 259
 260                 if (i > topo->num_entities) {
 261                         ret = -ENOSPC;
 262                         continue;
 263                 }
 264
 265                 /* Copy fields to userspace struct if not error */
 266                 memset(&uentity, 0, sizeof(uentity));
 267                 uentity.id = entity->graph_obj.id;
 268                 uentity.function = entity->function;
 269                 strncpy(uentity.name, entity->name,
 270                         sizeof(uentity.name));
 271
 272                 if (copy_to_user(&topo->entities[i - 1], &uentity, sizeof(uentity)))
 273                         ret = -EFAULT;
 274         }
 275         topo->num_entities = i;
 276
 277         /* Get interfaces and number of interfaces */
 278         i = 0;
 279         media_device_for_each_intf(intf, mdev) {
 280                 i++;
 281
 282                 if (ret || !topo->interfaces)
 283                         continue;
 284
 285                 if (i > topo->num_interfaces) {
 286                         ret = -ENOSPC;
 287                         continue;
 288                 }
 289
 290                 memset(&uintf, 0, sizeof(uintf));
 291
 292                 /* Copy intf fields to userspace struct */
 293                 uintf.id = intf->graph_obj.id;
 294                 uintf.intf_type = intf->type;
 295                 uintf.flags = intf->flags;
 296
 297                 if (media_type(&intf->graph_obj) == MEDIA_GRAPH_INTF_DEVNODE) {
 298                         struct media_intf_devnode *devnode;
 299
 300                         devnode = intf_to_devnode(intf);
 301
 302                         uintf.devnode.major = devnode->major;
 303                         uintf.devnode.minor = devnode->minor;
 304                 }
 305
 306                 if (copy_to_user(&topo->interfaces[i - 1], &uintf, sizeof(uintf)))
 307                         ret = -EFAULT;
 308         }
 309         topo->num_interfaces = i;
 310
 311         /* Get pads and number of pads */
 312         i = 0;
 313         media_device_for_each_pad(pad, mdev) {
 314                 i++;
 315
 316                 if (ret || !topo->pads)
 317                         continue;
 318
 319                 if (i > topo->num_pads) {
 320                         ret = -ENOSPC;
 321                         continue;
 322                 }
 323
 324                 memset(&upad, 0, sizeof(upad));
 325
 326                 /* Copy pad fields to userspace struct */
 327                 upad.id = pad->graph_obj.id;
 328                 upad.entity_id = pad->entity->graph_obj.id;
 329                 upad.flags = pad->flags;
 330
 331                 if (copy_to_user(&topo->pads[i - 1], &upad, sizeof(upad)))
 332                         ret = -EFAULT;
 333         }
 334         topo->num_pads = i;
 335
 336         /* Get links and number of links */
 337         i = 0;
 338         media_device_for_each_link(link, mdev) {
 339                 if (link->is_backlink)
 340                         continue;
 341
 342                 i++;
 343
 344                 if (ret || !topo->links)
 345                         continue;
 346
 347                 if (i > topo->num_links) {
 348                         ret = -ENOSPC;
 349                         continue;
 350                 }
 351
 352                 memset(&ulink, 0, sizeof(ulink));
 353
 354                 /* Copy link fields to userspace struct */
 355                 ulink.id = link->graph_obj.id;
 356                 ulink.source_id = link->gobj0->id;
 357                 ulink.sink_id = link->gobj1->id;
 358                 ulink.flags = link->flags;
 359
 360                 if (media_type(link->gobj0) != MEDIA_GRAPH_PAD)
 361                         ulink.flags |= MEDIA_LNK_FL_INTERFACE_LINK;
 362
 363                 if (copy_to_user(&topo->links[i - 1], &ulink, sizeof(ulink)))
 364                         ret = -EFAULT;
 365         }
 366         topo->num_links = i;
 367
 368         return ret;
 369 }
 370
 371 static long media_device_get_topology(struct media_device *mdev,
 372                                       struct media_v2_topology __user *utopo)
 373 {
 374         struct media_v2_topology ktopo;
 375         int ret;
 376
 377         ret = copy_from_user(&ktopo, utopo, sizeof(ktopo));
 378
 379         if (ret < 0)
 380                 return ret;
 381
 382         ret = __media_device_get_topology(mdev, &ktopo);
 383         if (ret < 0)
 384                 return ret;
 385
 386         ret = copy_to_user(utopo, &ktopo, sizeof(*utopo));
 387
 388         return ret;
 389 }
 390
 391 static long media_device_ioctl(struct file *filp, unsigned int cmd,
 392                                unsigned long arg)
 393 {
 394         struct media_devnode *devnode = media_devnode_data(filp);
 395         struct media_device *dev = to_media_device(devnode);
 396         long ret;
 397
 398         switch (cmd) {
 399         case MEDIA_IOC_DEVICE_INFO:
 400                 ret = media_device_get_info(dev,
 401                                 (struct media_device_info __user *)arg);
 402                 break;
 403
 404         case MEDIA_IOC_ENUM_ENTITIES:
 405                 ret = media_device_enum_entities(dev,
 406                                 (struct media_entity_desc __user *)arg);
 407                 break;
 408
 409         case MEDIA_IOC_ENUM_LINKS:
 410                 mutex_lock(&dev->graph_mutex);
 411                 ret = media_device_enum_links(dev,
 412                                 (struct media_links_enum __user *)arg);
 413                 mutex_unlock(&dev->graph_mutex);
 414                 break;
 415
 416         case MEDIA_IOC_SETUP_LINK:
 417                 mutex_lock(&dev->graph_mutex);
 418                 ret = media_device_setup_link(dev,
 419                                 (struct media_link_desc __user *)arg);
 420                 mutex_unlock(&dev->graph_mutex);
 421                 break;
 422
 423         case MEDIA_IOC_G_TOPOLOGY:
 424                 mutex_lock(&dev->graph_mutex);
 425                 ret = media_device_get_topology(dev,
 426                                 (struct media_v2_topology __user *)arg);
 427                 mutex_unlock(&dev->graph_mutex);
 428                 break;
 429
 430         default:
 431                 ret = -ENOIOCTLCMD;
 432         }
 433
 434         return ret;
 435 }
 436
 437 #ifdef CONFIG_COMPAT
 438
 439 struct media_links_enum32 {
 440         __u32 entity;
 441         compat_uptr_t pads; /* struct media_pad_desc * */
 442         compat_uptr_t links; /* struct media_link_desc * */
 443         __u32 reserved[4];
 444 };
 445
 446 static long media_device_enum_links32(struct media_device *mdev,
 447                                       struct media_links_enum32 __user *ulinks)
 448 {
 449         struct media_links_enum links;
 450         compat_uptr_t pads_ptr, links_ptr;
 451
 452         memset(&links, 0, sizeof(links));
 453
 454         if (get_user(links.entity, &ulinks->entity)
 455             || get_user(pads_ptr, &ulinks->pads)
 456             || get_user(links_ptr, &ulinks->links))
 457                 return -EFAULT;
 458
 459         links.pads = compat_ptr(pads_ptr);
 460         links.links = compat_ptr(links_ptr);
 461
 462         return __media_device_enum_links(mdev, &links);
 463 }
 464
 465 #define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)
 466
 467 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
 468                                       unsigned long arg)
 469 {
 470         struct media_devnode *devnode = media_devnode_data(filp);
 471         struct media_device *dev = to_media_device(devnode);
 472         long ret;
 473
 474         switch (cmd) {
 475         case MEDIA_IOC_DEVICE_INFO:
 476         case MEDIA_IOC_ENUM_ENTITIES:
 477         case MEDIA_IOC_SETUP_LINK:
 478         case MEDIA_IOC_G_TOPOLOGY:
 479                 return media_device_ioctl(filp, cmd, arg);
 480
 481         case MEDIA_IOC_ENUM_LINKS32:
 482                 mutex_lock(&dev->graph_mutex);
 483                 ret = media_device_enum_links32(dev,
 484                                 (struct media_links_enum32 __user *)arg);
 485                 mutex_unlock(&dev->graph_mutex);
 486                 break;
 487
 488         default:
 489                 ret = -ENOIOCTLCMD;
 490         }
 491
 492         return ret;
 493 }
 494 #endif /* CONFIG_COMPAT */
 495
 496 static const struct media_file_operations media_device_fops = {
 497         .owner = THIS_MODULE,
 498         .open = media_device_open,
 499         .ioctl = media_device_ioctl,
 500 #ifdef CONFIG_COMPAT
 501         .compat_ioctl = media_device_compat_ioctl,
 502 #endif /* CONFIG_COMPAT */
 503         .release = media_device_close,
 504 };
 505
 506 /* -----------------------------------------------------------------------------
 507  * sysfs
 508  */
 509
 510 static ssize_t show_model(struct device *cd,
 511                           struct device_attribute *attr, char *buf)
 512 {
 513         struct media_device *mdev = to_media_device(to_media_devnode(cd));
 514
 515         return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 516 }
 517
 518 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 519
 520 /* -----------------------------------------------------------------------------
 521  * Registration/unregistration
 522  */
 523
 524 static void media_device_release(struct media_devnode *mdev)
 525 {
 526         dev_dbg(mdev->parent, "Media device released\n");
 527 }
 528
 529 /**
 530  * media_device_register - register a media device
 531  * @mdev:       The media device
 532  *
 533  * The caller is responsible for initializing the media device before
 534  * registration. The following fields must be set:
 535  *
 536  * - dev must point to the parent device
 537  * - model must be filled with the device model name
 538  */
 539 int __must_check __media_device_register(struct media_device *mdev,
 540                                          struct module *owner)
 541 {
 542         int ret;
 543
 544         if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
 545                 return -EINVAL;
 546
 547         INIT_LIST_HEAD(&mdev->entities);
 548         INIT_LIST_HEAD(&mdev->interfaces);
 549         INIT_LIST_HEAD(&mdev->pads);
 550         INIT_LIST_HEAD(&mdev->links);
 551         spin_lock_init(&mdev->lock);
 552         mutex_init(&mdev->graph_mutex);
 553
 554         /* Register the device node. */
 555         mdev->devnode.fops = &media_device_fops;
 556         mdev->devnode.parent = mdev->dev;
 557         mdev->devnode.release = media_device_release;
 558         ret = media_devnode_register(&mdev->devnode, owner);
 559         if (ret < 0)
 560                 return ret;
 561
 562         ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
 563         if (ret < 0) {
 564                 media_devnode_unregister(&mdev->devnode);
 565                 return ret;
 566         }
 567
 568         dev_dbg(mdev->dev, "Media device registered\n");
 569
 570         return 0;
 571 }
 572 EXPORT_SYMBOL_GPL(__media_device_register);
 573
 574 /**
 575  * media_device_unregister - unregister a media device
 576  * @mdev:       The media device
 577  *
 578  */
 579 void media_device_unregister(struct media_device *mdev)
 580 {
 581         struct media_entity *entity;
 582         struct media_entity *next;
 583         struct media_interface *intf, *tmp_intf;
 584
 585         /* Remove all entities from the media device */
 586         list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
 587                 media_device_unregister_entity(entity);
 588
 589         /* Remove all interfaces from the media device */
 590         spin_lock(&mdev->lock);
 591         list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
 592                                  graph_obj.list) {
 593                 __media_remove_intf_links(intf);
 594                 media_gobj_remove(&intf->graph_obj);
 595                 kfree(intf);
 596         }
 597         spin_unlock(&mdev->lock);
 598
 599         device_remove_file(&mdev->devnode.dev, &dev_attr_model);
 600         media_devnode_unregister(&mdev->devnode);
 601
 602         dev_dbg(mdev->dev, "Media device unregistered\n");
 603 }
 604 EXPORT_SYMBOL_GPL(media_device_unregister);
 605
 606 /**
 607  * media_device_register_entity - Register an entity with a media device
 608  * @mdev:       The media device
 609  * @entity:     The entity
 610  */
 611 int __must_check media_device_register_entity(struct media_device *mdev,
 612                                               struct media_entity *entity)
 613 {
 614         unsigned int i;
 615
 616         if (entity->function == MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN ||
 617             entity->function == MEDIA_ENT_F_UNKNOWN)
 618                 dev_warn(mdev->dev,
 619                          "Entity type for entity %s was not initialized!\n",
 620                          entity->name);
 621
 622         /* Warn if we apparently re-register an entity */
 623         WARN_ON(entity->graph_obj.mdev != NULL);
 624         entity->graph_obj.mdev = mdev;
 625         INIT_LIST_HEAD(&entity->links);
 626         entity->num_links = 0;
 627         entity->num_backlinks = 0;
 628
 629         spin_lock(&mdev->lock);
 630         /* Initialize media_gobj embedded at the entity */
 631         media_gobj_init(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
 632
 633         /* Initialize objects at the pads */
 634         for (i = 0; i < entity->num_pads; i++)
 635                 media_gobj_init(mdev, MEDIA_GRAPH_PAD,
 636                                &entity->pads[i].graph_obj);
 637
 638         spin_unlock(&mdev->lock);
 639
 640         return 0;
 641 }
 642 EXPORT_SYMBOL_GPL(media_device_register_entity);
 643
 644 /**
 645  * media_device_unregister_entity - Unregister an entity
 646  * @entity:     The entity
 647  *
 648  * If the entity has never been registered this function will return
 649  * immediately.
 650  */
 651 void media_device_unregister_entity(struct media_entity *entity)
 652 {
 653         struct media_device *mdev = entity->graph_obj.mdev;
 654         struct media_link *link, *tmp;
 655         struct media_interface *intf;
 656         unsigned int i;
 657
 658         if (mdev == NULL)
 659                 return;
 660
 661         spin_lock(&mdev->lock);
 662
 663         /* Remove all interface links pointing to this entity */
 664         list_for_each_entry(intf, &mdev->interfaces, graph_obj.list) {
 665                 list_for_each_entry_safe(link, tmp, &intf->links, list) {
 666                         if (link->entity == entity)
 667                                 __media_remove_intf_link(link);
 668                 }
 669         }
 670
 671         /* Remove all data links that belong to this entity */
 672         __media_entity_remove_links(entity);
 673
 674         /* Remove all pads that belong to this entity */
 675         for (i = 0; i < entity->num_pads; i++)
 676                 media_gobj_remove(&entity->pads[i].graph_obj);
 677
 678         /* Remove the entity */
 679         media_gobj_remove(&entity->graph_obj);
 680
 681         spin_unlock(&mdev->lock);
 682         entity->graph_obj.mdev = NULL;
 683 }
 684 EXPORT_SYMBOL_GPL(media_device_unregister_entity);
 685
 686 static void media_device_release_devres(struct device *dev, void *res)
 687 {
 688 }
 689
 690 /*
 691  * media_device_get_devres() -  get media device as device resource
 692  *                              creates if one doesn't exist
 693 */
 694 struct media_device *media_device_get_devres(struct device *dev)
 695 {
 696         struct media_device *mdev;
 697
 698         mdev = devres_find(dev, media_device_release_devres, NULL, NULL);
 699         if (mdev)
 700                 return mdev;
 701
 702         mdev = devres_alloc(media_device_release_devres,
 703                                 sizeof(struct media_device), GFP_KERNEL);
 704         if (!mdev)
 705                 return NULL;
 706         return devres_get(dev, mdev, NULL, NULL);
 707 }
 708 EXPORT_SYMBOL_GPL(media_device_get_devres);
 709
 710 /*
 711  * media_device_find_devres() - find media device as device resource
 712 */
 713 struct media_device *media_device_find_devres(struct device *dev)
 714 {
 715         return devres_find(dev, media_device_release_devres, NULL, NULL);
 716 }
 717 EXPORT_SYMBOL_GPL(media_device_find_devres);
 718
 719 #endif /* CONFIG_MEDIA_CONTROLLER */