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 = ent->revision;
 113         u_ent.flags = ent->flags;
 114         u_ent.group_id = ent->group_id;
 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 *ent_link;
 155                 struct media_link_desc __user *ulink = links->links;
 156
 157                 list_for_each_entry(ent_link, &entity->links, list) {
 158                         struct media_link_desc link;
 159
 160                         /* Ignore backlinks. */
 161                         if (ent_link->source->entity != entity)
 162                                 continue;
 163                         memset(&link, 0, sizeof(link));
 164                         media_device_kpad_to_upad(ent_link->source,
 165                                                   &link.source);
 166                         media_device_kpad_to_upad(ent_link->sink,
 167                                                   &link.sink);
 168                         link.flags = ent_link->flags;
 169                         if (copy_to_user(ulink, &link, sizeof(*ulink)))
 170                                 return -EFAULT;
 171                         ulink++;
 172                 }
 173         }
 174
 175         return 0;
 176 }
 177
 178 static long media_device_enum_links(struct media_device *mdev,
 179                                     struct media_links_enum __user *ulinks)
 180 {
 181         struct media_links_enum links;
 182         int rval;
 183
 184         if (copy_from_user(&links, ulinks, sizeof(links)))
 185                 return -EFAULT;
 186
 187         rval = __media_device_enum_links(mdev, &links);
 188         if (rval < 0)
 189                 return rval;
 190
 191         if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
 192                 return -EFAULT;
 193
 194         return 0;
 195 }
 196
 197 static long media_device_setup_link(struct media_device *mdev,
 198                                     struct media_link_desc __user *_ulink)
 199 {
 200         struct media_link *link = NULL;
 201         struct media_link_desc ulink;
 202         struct media_entity *source;
 203         struct media_entity *sink;
 204         int ret;
 205
 206         if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
 207                 return -EFAULT;
 208
 209         /* Find the source and sink entities and link.
 210          */
 211         source = find_entity(mdev, ulink.source.entity);
 212         sink = find_entity(mdev, ulink.sink.entity);
 213
 214         if (source == NULL || sink == NULL)
 215                 return -EINVAL;
 216
 217         if (ulink.source.index >= source->num_pads ||
 218             ulink.sink.index >= sink->num_pads)
 219                 return -EINVAL;
 220
 221         link = media_entity_find_link(&source->pads[ulink.source.index],
 222                                       &sink->pads[ulink.sink.index]);
 223         if (link == NULL)
 224                 return -EINVAL;
 225
 226         /* Setup the link on both entities. */
 227         ret = __media_entity_setup_link(link, ulink.flags);
 228
 229         if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
 230                 return -EFAULT;
 231
 232         return ret;
 233 }
 234
 235 static long __media_device_get_topology(struct media_device *mdev,
 236                                       struct media_v2_topology *topo)
 237 {
 238         struct media_entity *entity;
 239         struct media_interface *intf;
 240         struct media_pad *pad;
 241         struct media_link *link;
 242         struct media_v2_entity uentity;
 243         struct media_v2_interface uintf;
 244         struct media_v2_pad upad;
 245         struct media_v2_link ulink;
 246         unsigned int i;
 247         int ret = 0;
 248
 249         topo->topology_version = mdev->topology_version;
 250
 251         /* Get entities and number of entities */
 252         i = 0;
 253         media_device_for_each_entity(entity, mdev) {
 254                 i++;
 255
 256                 if (ret || !topo->entities)
 257                         continue;
 258
 259                 if (i > topo->num_entities) {
 260                         ret = -ENOSPC;
 261                         continue;
 262                 }
 263
 264                 /* Copy fields to userspace struct if not error */
 265                 memset(&uentity, 0, sizeof(uentity));
 266                 uentity.id = entity->graph_obj.id;
 267                 uentity.function = entity->function;
 268                 strncpy(uentity.name, entity->name,
 269                         sizeof(uentity.name));
 270
 271                 if (copy_to_user(&topo->entities[i - 1], &uentity, sizeof(uentity)))
 272                         ret = -EFAULT;
 273         }
 274         topo->num_entities = i;
 275
 276         /* Get interfaces and number of interfaces */
 277         i = 0;
 278         media_device_for_each_intf(intf, mdev) {
 279                 i++;
 280
 281                 if (ret || !topo->interfaces)
 282                         continue;
 283
 284                 if (i > topo->num_interfaces) {
 285                         ret = -ENOSPC;
 286                         continue;
 287                 }
 288
 289                 memset(&uintf, 0, sizeof(uintf));
 290
 291                 /* Copy intf fields to userspace struct */
 292                 uintf.id = intf->graph_obj.id;
 293                 uintf.intf_type = intf->type;
 294                 uintf.flags = intf->flags;
 295
 296                 if (media_type(&intf->graph_obj) == MEDIA_GRAPH_INTF_DEVNODE) {
 297                         struct media_intf_devnode *devnode;
 298
 299                         devnode = intf_to_devnode(intf);
 300
 301                         uintf.devnode.major = devnode->major;
 302                         uintf.devnode.minor = devnode->minor;
 303                 }
 304
 305                 if (copy_to_user(&topo->interfaces[i - 1], &uintf, sizeof(uintf)))
 306                         ret = -EFAULT;
 307         }
 308         topo->num_interfaces = i;
 309
 310         /* Get pads and number of pads */
 311         i = 0;
 312         media_device_for_each_pad(pad, mdev) {
 313                 i++;
 314
 315                 if (ret || !topo->pads)
 316                         continue;
 317
 318                 if (i > topo->num_pads) {
 319                         ret = -ENOSPC;
 320                         continue;
 321                 }
 322
 323                 memset(&upad, 0, sizeof(upad));
 324
 325                 /* Copy pad fields to userspace struct */
 326                 upad.id = pad->graph_obj.id;
 327                 upad.entity_id = pad->entity->graph_obj.id;
 328                 upad.flags = pad->flags;
 329
 330                 if (copy_to_user(&topo->pads[i - 1], &upad, sizeof(upad)))
 331                         ret = -EFAULT;
 332         }
 333         topo->num_pads = i;
 334
 335         /* Get links and number of links */
 336         i = 0;
 337         media_device_for_each_link(link, mdev) {
 338                 if (link->is_backlink)
 339                         continue;
 340
 341                 i++;
 342
 343                 if (ret || !topo->links)
 344                         continue;
 345
 346                 if (i > topo->num_links) {
 347                         ret = -ENOSPC;
 348                         continue;
 349                 }
 350
 351                 memset(&ulink, 0, sizeof(ulink));
 352
 353                 /* Copy link fields to userspace struct */
 354                 ulink.id = link->graph_obj.id;
 355                 ulink.source_id = link->gobj0->id;
 356                 ulink.sink_id = link->gobj1->id;
 357                 ulink.flags = link->flags;
 358
 359                 if (media_type(link->gobj0) != MEDIA_GRAPH_PAD)
 360                         ulink.flags |= MEDIA_LNK_FL_INTERFACE_LINK;
 361
 362                 if (copy_to_user(&topo->links[i - 1], &ulink, sizeof(ulink)))
 363                         ret = -EFAULT;
 364         }
 365         topo->num_links = i;
 366
 367         return ret;
 368 }
 369
 370 static long media_device_get_topology(struct media_device *mdev,
 371                                       struct media_v2_topology __user *utopo)
 372 {
 373         struct media_v2_topology ktopo;
 374         int ret;
 375
 376         ret = copy_from_user(&ktopo, utopo, sizeof(ktopo));
 377
 378         if (ret < 0)
 379                 return ret;
 380
 381         ret = __media_device_get_topology(mdev, &ktopo);
 382         if (ret < 0)
 383                 return ret;
 384
 385         ret = copy_to_user(utopo, &ktopo, sizeof(*utopo));
 386
 387         return ret;
 388 }
 389
 390 static long media_device_ioctl(struct file *filp, unsigned int cmd,
 391                                unsigned long arg)
 392 {
 393         struct media_devnode *devnode = media_devnode_data(filp);
 394         struct media_device *dev = to_media_device(devnode);
 395         long ret;
 396
 397         switch (cmd) {
 398         case MEDIA_IOC_DEVICE_INFO:
 399                 ret = media_device_get_info(dev,
 400                                 (struct media_device_info __user *)arg);
 401                 break;
 402
 403         case MEDIA_IOC_ENUM_ENTITIES:
 404                 ret = media_device_enum_entities(dev,
 405                                 (struct media_entity_desc __user *)arg);
 406                 break;
 407
 408         case MEDIA_IOC_ENUM_LINKS:
 409                 mutex_lock(&dev->graph_mutex);
 410                 ret = media_device_enum_links(dev,
 411                                 (struct media_links_enum __user *)arg);
 412                 mutex_unlock(&dev->graph_mutex);
 413                 break;
 414
 415         case MEDIA_IOC_SETUP_LINK:
 416                 mutex_lock(&dev->graph_mutex);
 417                 ret = media_device_setup_link(dev,
 418                                 (struct media_link_desc __user *)arg);
 419                 mutex_unlock(&dev->graph_mutex);
 420                 break;
 421
 422         case MEDIA_IOC_G_TOPOLOGY:
 423                 mutex_lock(&dev->graph_mutex);
 424                 ret = media_device_get_topology(dev,
 425                                 (struct media_v2_topology __user *)arg);
 426                 mutex_unlock(&dev->graph_mutex);
 427                 break;
 428
 429         default:
 430                 ret = -ENOIOCTLCMD;
 431         }
 432
 433         return ret;
 434 }
 435
 436 #ifdef CONFIG_COMPAT
 437
 438 struct media_links_enum32 {
 439         __u32 entity;
 440         compat_uptr_t pads; /* struct media_pad_desc * */
 441         compat_uptr_t links; /* struct media_link_desc * */
 442         __u32 reserved[4];
 443 };
 444
 445 static long media_device_enum_links32(struct media_device *mdev,
 446                                       struct media_links_enum32 __user *ulinks)
 447 {
 448         struct media_links_enum links;
 449         compat_uptr_t pads_ptr, links_ptr;
 450
 451         memset(&links, 0, sizeof(links));
 452
 453         if (get_user(links.entity, &ulinks->entity)
 454             || get_user(pads_ptr, &ulinks->pads)
 455             || get_user(links_ptr, &ulinks->links))
 456                 return -EFAULT;
 457
 458         links.pads = compat_ptr(pads_ptr);
 459         links.links = compat_ptr(links_ptr);
 460
 461         return __media_device_enum_links(mdev, &links);
 462 }
 463
 464 #define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)
 465
 466 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
 467                                       unsigned long arg)
 468 {
 469         struct media_devnode *devnode = media_devnode_data(filp);
 470         struct media_device *dev = to_media_device(devnode);
 471         long ret;
 472
 473         switch (cmd) {
 474         case MEDIA_IOC_DEVICE_INFO:
 475         case MEDIA_IOC_ENUM_ENTITIES:
 476         case MEDIA_IOC_SETUP_LINK:
 477         case MEDIA_IOC_G_TOPOLOGY:
 478                 return media_device_ioctl(filp, cmd, arg);
 479
 480         case MEDIA_IOC_ENUM_LINKS32:
 481                 mutex_lock(&dev->graph_mutex);
 482                 ret = media_device_enum_links32(dev,
 483                                 (struct media_links_enum32 __user *)arg);
 484                 mutex_unlock(&dev->graph_mutex);
 485                 break;
 486
 487         default:
 488                 ret = -ENOIOCTLCMD;
 489         }
 490
 491         return ret;
 492 }
 493 #endif /* CONFIG_COMPAT */
 494
 495 static const struct media_file_operations media_device_fops = {
 496         .owner = THIS_MODULE,
 497         .open = media_device_open,
 498         .ioctl = media_device_ioctl,
 499 #ifdef CONFIG_COMPAT
 500         .compat_ioctl = media_device_compat_ioctl,
 501 #endif /* CONFIG_COMPAT */
 502         .release = media_device_close,
 503 };
 504
 505 /* -----------------------------------------------------------------------------
 506  * sysfs
 507  */
 508
 509 static ssize_t show_model(struct device *cd,
 510                           struct device_attribute *attr, char *buf)
 511 {
 512         struct media_device *mdev = to_media_device(to_media_devnode(cd));
 513
 514         return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 515 }
 516
 517 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 518
 519 /* -----------------------------------------------------------------------------
 520  * Registration/unregistration
 521  */
 522
 523 static void media_device_release(struct media_devnode *mdev)
 524 {
 525         dev_dbg(mdev->parent, "Media device released\n");
 526 }
 527
 528 /**
 529  * media_device_register - register a media device
 530  * @mdev:       The media device
 531  *
 532  * The caller is responsible for initializing the media device before
 533  * registration. The following fields must be set:
 534  *
 535  * - dev must point to the parent device
 536  * - model must be filled with the device model name
 537  */
 538 int __must_check __media_device_register(struct media_device *mdev,
 539                                          struct module *owner)
 540 {
 541         int ret;
 542
 543         if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
 544                 return -EINVAL;
 545
 546         INIT_LIST_HEAD(&mdev->entities);
 547         INIT_LIST_HEAD(&mdev->interfaces);
 548         INIT_LIST_HEAD(&mdev->pads);
 549         INIT_LIST_HEAD(&mdev->links);
 550         spin_lock_init(&mdev->lock);
 551         mutex_init(&mdev->graph_mutex);
 552
 553         /* Register the device node. */
 554         mdev->devnode.fops = &media_device_fops;
 555         mdev->devnode.parent = mdev->dev;
 556         mdev->devnode.release = media_device_release;
 557         ret = media_devnode_register(&mdev->devnode, owner);
 558         if (ret < 0)
 559                 return ret;
 560
 561         ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
 562         if (ret < 0) {
 563                 media_devnode_unregister(&mdev->devnode);
 564                 return ret;
 565         }
 566
 567         dev_dbg(mdev->dev, "Media device registered\n");
 568
 569         return 0;
 570 }
 571 EXPORT_SYMBOL_GPL(__media_device_register);
 572
 573 /**
 574  * media_device_unregister - unregister a media device
 575  * @mdev:       The media device
 576  *
 577  */
 578 void media_device_unregister(struct media_device *mdev)
 579 {
 580         struct media_entity *entity;
 581         struct media_entity *next;
 582         struct media_interface *intf, *tmp_intf;
 583
 584         /* Remove all entities from the media device */
 585         list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
 586                 media_device_unregister_entity(entity);
 587
 588         /* Remove all interfaces from the media device */
 589         spin_lock(&mdev->lock);
 590         list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
 591                                  graph_obj.list) {
 592                 __media_remove_intf_links(intf);
 593                 media_gobj_remove(&intf->graph_obj);
 594                 kfree(intf);
 595         }
 596         spin_unlock(&mdev->lock);
 597
 598         device_remove_file(&mdev->devnode.dev, &dev_attr_model);
 599         media_devnode_unregister(&mdev->devnode);
 600
 601         dev_dbg(mdev->dev, "Media device unregistered\n");
 602 }
 603 EXPORT_SYMBOL_GPL(media_device_unregister);
 604
 605 /**
 606  * media_device_register_entity - Register an entity with a media device
 607  * @mdev:       The media device
 608  * @entity:     The entity
 609  */
 610 int __must_check media_device_register_entity(struct media_device *mdev,
 611                                               struct media_entity *entity)
 612 {
 613         unsigned int i;
 614
 615         if (entity->function == MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN ||
 616             entity->function == MEDIA_ENT_F_UNKNOWN)
 617                 dev_warn(mdev->dev,
 618                          "Entity type for entity %s was not initialized!\n",
 619                          entity->name);
 620
 621         /* Warn if we apparently re-register an entity */
 622         WARN_ON(entity->graph_obj.mdev != NULL);
 623         entity->graph_obj.mdev = mdev;
 624         INIT_LIST_HEAD(&entity->links);
 625
 626         spin_lock(&mdev->lock);
 627         /* Initialize media_gobj embedded at the entity */
 628         media_gobj_init(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
 629
 630         /* Initialize objects at the pads */
 631         for (i = 0; i < entity->num_pads; i++)
 632                 media_gobj_init(mdev, MEDIA_GRAPH_PAD,
 633                                &entity->pads[i].graph_obj);
 634
 635         spin_unlock(&mdev->lock);
 636
 637         return 0;
 638 }
 639 EXPORT_SYMBOL_GPL(media_device_register_entity);
 640
 641 /**
 642  * media_device_unregister_entity - Unregister an entity
 643  * @entity:     The entity
 644  *
 645  * If the entity has never been registered this function will return
 646  * immediately.
 647  */
 648 void media_device_unregister_entity(struct media_entity *entity)
 649 {
 650         struct media_device *mdev = entity->graph_obj.mdev;
 651         struct media_link *link, *tmp;
 652         struct media_interface *intf;
 653         unsigned int i;
 654
 655         if (mdev == NULL)
 656                 return;
 657
 658         spin_lock(&mdev->lock);
 659
 660         /* Remove all interface links pointing to this entity */
 661         list_for_each_entry(intf, &mdev->interfaces, graph_obj.list) {
 662                 list_for_each_entry_safe(link, tmp, &intf->links, list) {
 663                         if (link->entity == entity)
 664                                 __media_remove_intf_link(link);
 665                 }
 666         }
 667
 668         /* Remove all data links that belong to this entity */
 669         __media_entity_remove_links(entity);
 670
 671         /* Remove all pads that belong to this entity */
 672         for (i = 0; i < entity->num_pads; i++)
 673                 media_gobj_remove(&entity->pads[i].graph_obj);
 674
 675         /* Remove the entity */
 676         media_gobj_remove(&entity->graph_obj);
 677
 678         spin_unlock(&mdev->lock);
 679         entity->graph_obj.mdev = NULL;
 680 }
 681 EXPORT_SYMBOL_GPL(media_device_unregister_entity);
 682
 683 static void media_device_release_devres(struct device *dev, void *res)
 684 {
 685 }
 686
 687 /*
 688  * media_device_get_devres() -  get media device as device resource
 689  *                              creates if one doesn't exist
 690 */
 691 struct media_device *media_device_get_devres(struct device *dev)
 692 {
 693         struct media_device *mdev;
 694
 695         mdev = devres_find(dev, media_device_release_devres, NULL, NULL);
 696         if (mdev)
 697                 return mdev;
 698
 699         mdev = devres_alloc(media_device_release_devres,
 700                                 sizeof(struct media_device), GFP_KERNEL);
 701         if (!mdev)
 702                 return NULL;
 703         return devres_get(dev, mdev, NULL, NULL);
 704 }
 705 EXPORT_SYMBOL_GPL(media_device_get_devres);
 706
 707 /*
 708  * media_device_find_devres() - find media device as device resource
 709 */
 710 struct media_device *media_device_find_devres(struct device *dev)
 711 {
 712         return devres_find(dev, media_device_release_devres, NULL, NULL);
 713 }
 714 EXPORT_SYMBOL_GPL(media_device_find_devres);
 715
 716 #endif /* CONFIG_MEDIA_CONTROLLER */