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/idr.h>
  26 #include <linux/ioctl.h>
  27 #include <linux/media.h>
  28 #include <linux/slab.h>
  29 #include <linux/types.h>
  30
  31 #include <media/media-device.h>
  32 #include <media/media-devnode.h>
  33 #include <media/media-entity.h>
  34
  35 #ifdef CONFIG_MEDIA_CONTROLLER
  36
  37 /* -----------------------------------------------------------------------------
  38  * Userspace API
  39  */
  40
  41 static int media_device_open(struct file *filp)
  42 {
  43         return 0;
  44 }
  45
  46 static int media_device_close(struct file *filp)
  47 {
  48         return 0;
  49 }
  50
  51 static int media_device_get_info(struct media_device *dev,
  52                                  struct media_device_info __user *__info)
  53 {
  54         struct media_device_info info;
  55
  56         memset(&info, 0, sizeof(info));
  57
  58         strlcpy(info.driver, dev->dev->driver->name, sizeof(info.driver));
  59         strlcpy(info.model, dev->model, sizeof(info.model));
  60         strlcpy(info.serial, dev->serial, sizeof(info.serial));
  61         strlcpy(info.bus_info, dev->bus_info, sizeof(info.bus_info));
  62
  63         info.media_version = MEDIA_API_VERSION;
  64         info.hw_revision = dev->hw_revision;
  65         info.driver_version = dev->driver_version;
  66
  67         if (copy_to_user(__info, &info, sizeof(*__info)))
  68                 return -EFAULT;
  69         return 0;
  70 }
  71
  72 static struct media_entity *find_entity(struct media_device *mdev, u32 id)
  73 {
  74         struct media_entity *entity;
  75         int next = id & MEDIA_ENT_ID_FLAG_NEXT;
  76
  77         id &= ~MEDIA_ENT_ID_FLAG_NEXT;
  78
  79         spin_lock(&mdev->lock);
  80
  81         media_device_for_each_entity(entity, mdev) {
  82                 if (((media_entity_id(entity) == id) && !next) ||
  83                     ((media_entity_id(entity) > id) && next)) {
  84                         spin_unlock(&mdev->lock);
  85                         return entity;
  86                 }
  87         }
  88
  89         spin_unlock(&mdev->lock);
  90
  91         return NULL;
  92 }
  93
  94 static long media_device_enum_entities(struct media_device *mdev,
  95                                        struct media_entity_desc __user *uent)
  96 {
  97         struct media_entity *ent;
  98         struct media_entity_desc u_ent;
  99
 100         memset(&u_ent, 0, sizeof(u_ent));
 101         if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
 102                 return -EFAULT;
 103
 104         ent = find_entity(mdev, u_ent.id);
 105
 106         if (ent == NULL)
 107                 return -EINVAL;
 108
 109         u_ent.id = media_entity_id(ent);
 110         if (ent->name)
 111                 strlcpy(u_ent.name, ent->name, sizeof(u_ent.name));
 112         u_ent.type = ent->function;
 113         u_ent.revision = 0;             /* Unused */
 114         u_ent.flags = ent->flags;
 115         u_ent.group_id = 0;             /* Unused */
 116         u_ent.pads = ent->num_pads;
 117         u_ent.links = ent->num_links - ent->num_backlinks;
 118         memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
 119         if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
 120                 return -EFAULT;
 121         return 0;
 122 }
 123
 124 static void media_device_kpad_to_upad(const struct media_pad *kpad,
 125                                       struct media_pad_desc *upad)
 126 {
 127         upad->entity = media_entity_id(kpad->entity);
 128         upad->index = kpad->index;
 129         upad->flags = kpad->flags;
 130 }
 131
 132 static long __media_device_enum_links(struct media_device *mdev,
 133                                       struct media_links_enum *links)
 134 {
 135         struct media_entity *entity;
 136
 137         entity = find_entity(mdev, links->entity);
 138         if (entity == NULL)
 139                 return -EINVAL;
 140
 141         if (links->pads) {
 142                 unsigned int p;
 143
 144                 for (p = 0; p < entity->num_pads; p++) {
 145                         struct media_pad_desc pad;
 146
 147                         memset(&pad, 0, sizeof(pad));
 148                         media_device_kpad_to_upad(&entity->pads[p], &pad);
 149                         if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
 150                                 return -EFAULT;
 151                 }
 152         }
 153
 154         if (links->links) {
 155                 struct media_link *link;
 156                 struct media_link_desc __user *ulink_desc = links->links;
 157
 158                 list_for_each_entry(link, &entity->links, list) {
 159                         struct media_link_desc klink_desc;
 160
 161                         /* Ignore backlinks. */
 162                         if (link->source->entity != entity)
 163                                 continue;
 164                         memset(&klink_desc, 0, sizeof(klink_desc));
 165                         media_device_kpad_to_upad(link->source,
 166                                                   &klink_desc.source);
 167                         media_device_kpad_to_upad(link->sink,
 168                                                   &klink_desc.sink);
 169                         klink_desc.flags = link->flags;
 170                         if (copy_to_user(ulink_desc, &klink_desc,
 171                                          sizeof(*ulink_desc)))
 172                                 return -EFAULT;
 173                         ulink_desc++;
 174                 }
 175         }
 176
 177         return 0;
 178 }
 179
 180 static long media_device_enum_links(struct media_device *mdev,
 181                                     struct media_links_enum __user *ulinks)
 182 {
 183         struct media_links_enum links;
 184         int rval;
 185
 186         if (copy_from_user(&links, ulinks, sizeof(links)))
 187                 return -EFAULT;
 188
 189         rval = __media_device_enum_links(mdev, &links);
 190         if (rval < 0)
 191                 return rval;
 192
 193         if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
 194                 return -EFAULT;
 195
 196         return 0;
 197 }
 198
 199 static long media_device_setup_link(struct media_device *mdev,
 200                                     struct media_link_desc __user *_ulink)
 201 {
 202         struct media_link *link = NULL;
 203         struct media_link_desc ulink;
 204         struct media_entity *source;
 205         struct media_entity *sink;
 206         int ret;
 207
 208         if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
 209                 return -EFAULT;
 210
 211         /* Find the source and sink entities and link.
 212          */
 213         source = find_entity(mdev, ulink.source.entity);
 214         sink = find_entity(mdev, ulink.sink.entity);
 215
 216         if (source == NULL || sink == NULL)
 217                 return -EINVAL;
 218
 219         if (ulink.source.index >= source->num_pads ||
 220             ulink.sink.index >= sink->num_pads)
 221                 return -EINVAL;
 222
 223         link = media_entity_find_link(&source->pads[ulink.source.index],
 224                                       &sink->pads[ulink.sink.index]);
 225         if (link == NULL)
 226                 return -EINVAL;
 227
 228         /* Setup the link on both entities. */
 229         ret = __media_entity_setup_link(link, ulink.flags);
 230
 231         if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
 232                 return -EFAULT;
 233
 234         return ret;
 235 }
 236
 237 #if 0 /* Let's postpone it to Kernel 4.6 */
 238 static long __media_device_get_topology(struct media_device *mdev,
 239                                       struct media_v2_topology *topo)
 240 {
 241         struct media_entity *entity;
 242         struct media_interface *intf;
 243         struct media_pad *pad;
 244         struct media_link *link;
 245         struct media_v2_entity kentity, *uentity;
 246         struct media_v2_interface kintf, *uintf;
 247         struct media_v2_pad kpad, *upad;
 248         struct media_v2_link klink, *ulink;
 249         unsigned int i;
 250         int ret = 0;
 251
 252         topo->topology_version = mdev->topology_version;
 253
 254         /* Get entities and number of entities */
 255         i = 0;
 256         uentity = media_get_uptr(topo->ptr_entities);
 257         media_device_for_each_entity(entity, mdev) {
 258                 i++;
 259                 if (ret || !uentity)
 260                         continue;
 261
 262                 if (i > topo->num_entities) {
 263                         ret = -ENOSPC;
 264                         continue;
 265                 }
 266
 267                 /* Copy fields to userspace struct if not error */
 268                 memset(&kentity, 0, sizeof(kentity));
 269                 kentity.id = entity->graph_obj.id;
 270                 kentity.function = entity->function;
 271                 strncpy(kentity.name, entity->name,
 272                         sizeof(kentity.name));
 273
 274                 if (copy_to_user(uentity, &kentity, sizeof(kentity)))
 275                         ret = -EFAULT;
 276                 uentity++;
 277         }
 278         topo->num_entities = i;
 279
 280         /* Get interfaces and number of interfaces */
 281         i = 0;
 282         uintf = media_get_uptr(topo->ptr_interfaces);
 283         media_device_for_each_intf(intf, mdev) {
 284                 i++;
 285                 if (ret || !uintf)
 286                         continue;
 287
 288                 if (i > topo->num_interfaces) {
 289                         ret = -ENOSPC;
 290                         continue;
 291                 }
 292
 293                 memset(&kintf, 0, sizeof(kintf));
 294
 295                 /* Copy intf fields to userspace struct */
 296                 kintf.id = intf->graph_obj.id;
 297                 kintf.intf_type = intf->type;
 298                 kintf.flags = intf->flags;
 299
 300                 if (media_type(&intf->graph_obj) == MEDIA_GRAPH_INTF_DEVNODE) {
 301                         struct media_intf_devnode *devnode;
 302
 303                         devnode = intf_to_devnode(intf);
 304
 305                         kintf.devnode.major = devnode->major;
 306                         kintf.devnode.minor = devnode->minor;
 307                 }
 308
 309                 if (copy_to_user(uintf, &kintf, sizeof(kintf)))
 310                         ret = -EFAULT;
 311                 uintf++;
 312         }
 313         topo->num_interfaces = i;
 314
 315         /* Get pads and number of pads */
 316         i = 0;
 317         upad = media_get_uptr(topo->ptr_pads);
 318         media_device_for_each_pad(pad, mdev) {
 319                 i++;
 320                 if (ret || !upad)
 321                         continue;
 322
 323                 if (i > topo->num_pads) {
 324                         ret = -ENOSPC;
 325                         continue;
 326                 }
 327
 328                 memset(&kpad, 0, sizeof(kpad));
 329
 330                 /* Copy pad fields to userspace struct */
 331                 kpad.id = pad->graph_obj.id;
 332                 kpad.entity_id = pad->entity->graph_obj.id;
 333                 kpad.flags = pad->flags;
 334
 335                 if (copy_to_user(upad, &kpad, sizeof(kpad)))
 336                         ret = -EFAULT;
 337                 upad++;
 338         }
 339         topo->num_pads = i;
 340
 341         /* Get links and number of links */
 342         i = 0;
 343         ulink = media_get_uptr(topo->ptr_links);
 344         media_device_for_each_link(link, mdev) {
 345                 if (link->is_backlink)
 346                         continue;
 347
 348                 i++;
 349
 350                 if (ret || !ulink)
 351                         continue;
 352
 353                 if (i > topo->num_links) {
 354                         ret = -ENOSPC;
 355                         continue;
 356                 }
 357
 358                 memset(&klink, 0, sizeof(klink));
 359
 360                 /* Copy link fields to userspace struct */
 361                 klink.id = link->graph_obj.id;
 362                 klink.source_id = link->gobj0->id;
 363                 klink.sink_id = link->gobj1->id;
 364                 klink.flags = link->flags;
 365
 366                 if (copy_to_user(ulink, &klink, sizeof(klink)))
 367                         ret = -EFAULT;
 368                 ulink++;
 369         }
 370         topo->num_links = i;
 371
 372         return ret;
 373 }
 374
 375 static long media_device_get_topology(struct media_device *mdev,
 376                                       struct media_v2_topology __user *utopo)
 377 {
 378         struct media_v2_topology ktopo;
 379         int ret;
 380
 381         if (copy_from_user(&ktopo, utopo, sizeof(ktopo)))
 382                 return -EFAULT;
 383
 384         ret = __media_device_get_topology(mdev, &ktopo);
 385         if (ret < 0)
 386                 return ret;
 387
 388         if (copy_to_user(utopo, &ktopo, sizeof(*utopo)))
 389                 return -EFAULT;
 390
 391         return 0;
 392 }
 393 #endif
 394
 395 static long media_device_ioctl(struct file *filp, unsigned int cmd,
 396                                unsigned long arg)
 397 {
 398         struct media_devnode *devnode = media_devnode_data(filp);
 399         struct media_device *dev = to_media_device(devnode);
 400         long ret;
 401
 402         switch (cmd) {
 403         case MEDIA_IOC_DEVICE_INFO:
 404                 ret = media_device_get_info(dev,
 405                                 (struct media_device_info __user *)arg);
 406                 break;
 407
 408         case MEDIA_IOC_ENUM_ENTITIES:
 409                 ret = media_device_enum_entities(dev,
 410                                 (struct media_entity_desc __user *)arg);
 411                 break;
 412
 413         case MEDIA_IOC_ENUM_LINKS:
 414                 mutex_lock(&dev->graph_mutex);
 415                 ret = media_device_enum_links(dev,
 416                                 (struct media_links_enum __user *)arg);
 417                 mutex_unlock(&dev->graph_mutex);
 418                 break;
 419
 420         case MEDIA_IOC_SETUP_LINK:
 421                 mutex_lock(&dev->graph_mutex);
 422                 ret = media_device_setup_link(dev,
 423                                 (struct media_link_desc __user *)arg);
 424                 mutex_unlock(&dev->graph_mutex);
 425                 break;
 426
 427 #if 0 /* Let's postpone it to Kernel 4.6 */
 428         case MEDIA_IOC_G_TOPOLOGY:
 429                 mutex_lock(&dev->graph_mutex);
 430                 ret = media_device_get_topology(dev,
 431                                 (struct media_v2_topology __user *)arg);
 432                 mutex_unlock(&dev->graph_mutex);
 433                 break;
 434 #endif
 435         default:
 436                 ret = -ENOIOCTLCMD;
 437         }
 438
 439         return ret;
 440 }
 441
 442 #ifdef CONFIG_COMPAT
 443
 444 struct media_links_enum32 {
 445         __u32 entity;
 446         compat_uptr_t pads; /* struct media_pad_desc * */
 447         compat_uptr_t links; /* struct media_link_desc * */
 448         __u32 reserved[4];
 449 };
 450
 451 static long media_device_enum_links32(struct media_device *mdev,
 452                                       struct media_links_enum32 __user *ulinks)
 453 {
 454         struct media_links_enum links;
 455         compat_uptr_t pads_ptr, links_ptr;
 456
 457         memset(&links, 0, sizeof(links));
 458
 459         if (get_user(links.entity, &ulinks->entity)
 460             || get_user(pads_ptr, &ulinks->pads)
 461             || get_user(links_ptr, &ulinks->links))
 462                 return -EFAULT;
 463
 464         links.pads = compat_ptr(pads_ptr);
 465         links.links = compat_ptr(links_ptr);
 466
 467         return __media_device_enum_links(mdev, &links);
 468 }
 469
 470 #define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)
 471
 472 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
 473                                       unsigned long arg)
 474 {
 475         struct media_devnode *devnode = media_devnode_data(filp);
 476         struct media_device *dev = to_media_device(devnode);
 477         long ret;
 478
 479         switch (cmd) {
 480         case MEDIA_IOC_DEVICE_INFO:
 481         case MEDIA_IOC_ENUM_ENTITIES:
 482         case MEDIA_IOC_SETUP_LINK:
 483 #if 0 /* Let's postpone it to Kernel 4.6 */
 484         case MEDIA_IOC_G_TOPOLOGY:
 485 #endif
 486                 return media_device_ioctl(filp, cmd, arg);
 487
 488         case MEDIA_IOC_ENUM_LINKS32:
 489                 mutex_lock(&dev->graph_mutex);
 490                 ret = media_device_enum_links32(dev,
 491                                 (struct media_links_enum32 __user *)arg);
 492                 mutex_unlock(&dev->graph_mutex);
 493                 break;
 494
 495         default:
 496                 ret = -ENOIOCTLCMD;
 497         }
 498
 499         return ret;
 500 }
 501 #endif /* CONFIG_COMPAT */
 502
 503 static const struct media_file_operations media_device_fops = {
 504         .owner = THIS_MODULE,
 505         .open = media_device_open,
 506         .ioctl = media_device_ioctl,
 507 #ifdef CONFIG_COMPAT
 508         .compat_ioctl = media_device_compat_ioctl,
 509 #endif /* CONFIG_COMPAT */
 510         .release = media_device_close,
 511 };
 512
 513 /* -----------------------------------------------------------------------------
 514  * sysfs
 515  */
 516
 517 static ssize_t show_model(struct device *cd,
 518                           struct device_attribute *attr, char *buf)
 519 {
 520         struct media_device *mdev = to_media_device(to_media_devnode(cd));
 521
 522         return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 523 }
 524
 525 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 526
 527 /* -----------------------------------------------------------------------------
 528  * Registration/unregistration
 529  */
 530
 531 static void media_device_release(struct media_devnode *mdev)
 532 {
 533         dev_dbg(mdev->parent, "Media device released\n");
 534 }
 535
 536 /**
 537  * media_device_register_entity - Register an entity with a media device
 538  * @mdev:       The media device
 539  * @entity:     The entity
 540  */
 541 int __must_check media_device_register_entity(struct media_device *mdev,
 542                                               struct media_entity *entity)
 543 {
 544         unsigned int i;
 545         int ret;
 546
 547         if (entity->function == MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN ||
 548             entity->function == MEDIA_ENT_F_UNKNOWN)
 549                 dev_warn(mdev->dev,
 550                          "Entity type for entity %s was not initialized!\n",
 551                          entity->name);
 552
 553         /* Warn if we apparently re-register an entity */
 554         WARN_ON(entity->graph_obj.mdev != NULL);
 555         entity->graph_obj.mdev = mdev;
 556         INIT_LIST_HEAD(&entity->links);
 557         entity->num_links = 0;
 558         entity->num_backlinks = 0;
 559
 560         if (!ida_pre_get(&mdev->entity_internal_idx, GFP_KERNEL))
 561                 return -ENOMEM;
 562
 563         spin_lock(&mdev->lock);
 564
 565         ret = ida_get_new_above(&mdev->entity_internal_idx, 1,
 566                                 &entity->internal_idx);
 567         if (ret < 0) {
 568                 spin_unlock(&mdev->lock);
 569                 return ret;
 570         }
 571
 572         mdev->entity_internal_idx_max =
 573                 max(mdev->entity_internal_idx_max, entity->internal_idx);
 574
 575         /* Initialize media_gobj embedded at the entity */
 576         media_gobj_create(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
 577
 578         /* Initialize objects at the pads */
 579         for (i = 0; i < entity->num_pads; i++)
 580                 media_gobj_create(mdev, MEDIA_GRAPH_PAD,
 581                                &entity->pads[i].graph_obj);
 582
 583         spin_unlock(&mdev->lock);
 584
 585         return 0;
 586 }
 587 EXPORT_SYMBOL_GPL(media_device_register_entity);
 588
 589 static void __media_device_unregister_entity(struct media_entity *entity)
 590 {
 591         struct media_device *mdev = entity->graph_obj.mdev;
 592         struct media_link *link, *tmp;
 593         struct media_interface *intf;
 594         unsigned int i;
 595
 596         ida_simple_remove(&mdev->entity_internal_idx, entity->internal_idx);
 597
 598         /* Remove all interface links pointing to this entity */
 599         list_for_each_entry(intf, &mdev->interfaces, graph_obj.list) {
 600                 list_for_each_entry_safe(link, tmp, &intf->links, list) {
 601                         if (link->entity == entity)
 602                                 __media_remove_intf_link(link);
 603                 }
 604         }
 605
 606         /* Remove all data links that belong to this entity */
 607         __media_entity_remove_links(entity);
 608
 609         /* Remove all pads that belong to this entity */
 610         for (i = 0; i < entity->num_pads; i++)
 611                 media_gobj_destroy(&entity->pads[i].graph_obj);
 612
 613         /* Remove the entity */
 614         media_gobj_destroy(&entity->graph_obj);
 615
 616         entity->graph_obj.mdev = NULL;
 617 }
 618
 619 void media_device_unregister_entity(struct media_entity *entity)
 620 {
 621         struct media_device *mdev = entity->graph_obj.mdev;
 622
 623         if (mdev == NULL)
 624                 return;
 625
 626         spin_lock(&mdev->lock);
 627         __media_device_unregister_entity(entity);
 628         spin_unlock(&mdev->lock);
 629 }
 630 EXPORT_SYMBOL_GPL(media_device_unregister_entity);
 631
 632 /**
 633  * media_device_init() - initialize a media device
 634  * @mdev:       The media device
 635  *
 636  * The caller is responsible for initializing the media device before
 637  * registration. The following fields must be set:
 638  *
 639  * - dev must point to the parent device
 640  * - model must be filled with the device model name
 641  */
 642 void media_device_init(struct media_device *mdev)
 643 {
 644         INIT_LIST_HEAD(&mdev->entities);
 645         INIT_LIST_HEAD(&mdev->interfaces);
 646         INIT_LIST_HEAD(&mdev->pads);
 647         INIT_LIST_HEAD(&mdev->links);
 648         spin_lock_init(&mdev->lock);
 649         mutex_init(&mdev->graph_mutex);
 650         ida_init(&mdev->entity_internal_idx);
 651
 652         dev_dbg(mdev->dev, "Media device initialized\n");
 653 }
 654 EXPORT_SYMBOL_GPL(media_device_init);
 655
 656 void media_device_cleanup(struct media_device *mdev)
 657 {
 658         ida_destroy(&mdev->entity_internal_idx);
 659         mdev->entity_internal_idx_max = 0;
 660         mutex_destroy(&mdev->graph_mutex);
 661 }
 662 EXPORT_SYMBOL_GPL(media_device_cleanup);
 663
 664 int __must_check __media_device_register(struct media_device *mdev,
 665                                          struct module *owner)
 666 {
 667         int ret;
 668
 669         /* Register the device node. */
 670         mdev->devnode.fops = &media_device_fops;
 671         mdev->devnode.parent = mdev->dev;
 672         mdev->devnode.release = media_device_release;
 673
 674         /* Set version 0 to indicate user-space that the graph is static */
 675         mdev->topology_version = 0;
 676
 677         ret = media_devnode_register(&mdev->devnode, owner);
 678         if (ret < 0)
 679                 return ret;
 680
 681         ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
 682         if (ret < 0) {
 683                 media_devnode_unregister(&mdev->devnode);
 684                 return ret;
 685         }
 686
 687         dev_dbg(mdev->dev, "Media device registered\n");
 688
 689         return 0;
 690 }
 691 EXPORT_SYMBOL_GPL(__media_device_register);
 692
 693 void media_device_unregister(struct media_device *mdev)
 694 {
 695         struct media_entity *entity;
 696         struct media_entity *next;
 697         struct media_interface *intf, *tmp_intf;
 698
 699         if (mdev == NULL)
 700                 return;
 701
 702         spin_lock(&mdev->lock);
 703
 704         /* Check if mdev was ever registered at all */
 705         if (!media_devnode_is_registered(&mdev->devnode)) {
 706                 spin_unlock(&mdev->lock);
 707                 return;
 708         }
 709
 710         /* Remove all entities from the media device */
 711         list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
 712                 __media_device_unregister_entity(entity);
 713
 714         /* Remove all interfaces from the media device */
 715         list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
 716                                  graph_obj.list) {
 717                 __media_remove_intf_links(intf);
 718                 media_gobj_destroy(&intf->graph_obj);
 719                 kfree(intf);
 720         }
 721
 722         spin_unlock(&mdev->lock);
 723
 724         device_remove_file(&mdev->devnode.dev, &dev_attr_model);
 725         media_devnode_unregister(&mdev->devnode);
 726
 727         dev_dbg(mdev->dev, "Media device unregistered\n");
 728 }
 729 EXPORT_SYMBOL_GPL(media_device_unregister);
 730
 731 static void media_device_release_devres(struct device *dev, void *res)
 732 {
 733 }
 734
 735 struct media_device *media_device_get_devres(struct device *dev)
 736 {
 737         struct media_device *mdev;
 738
 739         mdev = devres_find(dev, media_device_release_devres, NULL, NULL);
 740         if (mdev)
 741                 return mdev;
 742
 743         mdev = devres_alloc(media_device_release_devres,
 744                                 sizeof(struct media_device), GFP_KERNEL);
 745         if (!mdev)
 746                 return NULL;
 747         return devres_get(dev, mdev, NULL, NULL);
 748 }
 749 EXPORT_SYMBOL_GPL(media_device_get_devres);
 750
 751 struct media_device *media_device_find_devres(struct device *dev)
 752 {
 753         return devres_find(dev, media_device_release_devres, NULL, NULL);
 754 }
 755 EXPORT_SYMBOL_GPL(media_device_find_devres);
 756
 757 #endif /* CONFIG_MEDIA_CONTROLLER */