drivers/media/mc/mc-device.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Media device
   4  *
   5  * Copyright (C) 2010 Nokia Corporation
   6  *
   7  * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   8  *           Sakari Ailus <sakari.ailus@iki.fi>
   9  */
  10
  11 #include <linux/compat.h>
  12 #include <linux/export.h>
  13 #include <linux/idr.h>
  14 #include <linux/ioctl.h>
  15 #include <linux/media.h>
  16 #include <linux/slab.h>
  17 #include <linux/types.h>
  18 #include <linux/pci.h>
  19 #include <linux/usb.h>
  20 #include <linux/version.h>
  21
  22 #include <media/media-device.h>
  23 #include <media/media-devnode.h>
  24 #include <media/media-entity.h>
  25 #include <media/media-request.h>
  26
  27 #ifdef CONFIG_MEDIA_CONTROLLER
  28
  29 /*
  30  * Legacy defines from linux/media.h. This is the only place we need this
  31  * so we just define it here. The media.h header doesn't expose it to the
  32  * kernel to prevent it from being used by drivers, but here (and only here!)
  33  * we need it to handle the legacy behavior.
  34  */
  35 #define MEDIA_ENT_SUBTYPE_MASK                  0x0000ffff
  36 #define MEDIA_ENT_T_DEVNODE_UNKNOWN             (MEDIA_ENT_F_OLD_BASE | \
  37                                                  MEDIA_ENT_SUBTYPE_MASK)
  38
  39 /* -----------------------------------------------------------------------------
  40  * Userspace API
  41  */
  42
  43 static inline void __user *media_get_uptr(__u64 arg)
  44 {
  45         return (void __user *)(uintptr_t)arg;
  46 }
  47
  48 static int media_device_open(struct file *filp)
  49 {
  50         return 0;
  51 }
  52
  53 static int media_device_close(struct file *filp)
  54 {
  55         return 0;
  56 }
  57
  58 static long media_device_get_info(struct media_device *dev, void *arg)
  59 {
  60         struct media_device_info *info = arg;
  61
  62         memset(info, 0, sizeof(*info));
  63
  64         if (dev->driver_name[0])
  65                 strscpy(info->driver, dev->driver_name, sizeof(info->driver));
  66         else
  67                 strscpy(info->driver, dev->dev->driver->name,
  68                         sizeof(info->driver));
  69
  70         strscpy(info->model, dev->model, sizeof(info->model));
  71         strscpy(info->serial, dev->serial, sizeof(info->serial));
  72         strscpy(info->bus_info, dev->bus_info, sizeof(info->bus_info));
  73
  74         info->media_version = LINUX_VERSION_CODE;
  75         info->driver_version = info->media_version;
  76         info->hw_revision = dev->hw_revision;
  77
  78         return 0;
  79 }
  80
  81 static struct media_entity *find_entity(struct media_device *mdev, u32 id)
  82 {
  83         struct media_entity *entity;
  84         int next = id & MEDIA_ENT_ID_FLAG_NEXT;
  85
  86         id &= ~MEDIA_ENT_ID_FLAG_NEXT;
  87
  88         media_device_for_each_entity(entity, mdev) {
  89                 if (((media_entity_id(entity) == id) && !next) ||
  90                     ((media_entity_id(entity) > id) && next)) {
  91                         return entity;
  92                 }
  93         }
  94
  95         return NULL;
  96 }
  97
  98 static long media_device_enum_entities(struct media_device *mdev, void *arg)
  99 {
 100         struct media_entity_desc *entd = arg;
 101         struct media_entity *ent;
 102
 103         ent = find_entity(mdev, entd->id);
 104         if (ent == NULL)
 105                 return -EINVAL;
 106
 107         memset(entd, 0, sizeof(*entd));
 108
 109         entd->id = media_entity_id(ent);
 110         if (ent->name)
 111                 strscpy(entd->name, ent->name, sizeof(entd->name));
 112         entd->type = ent->function;
 113         entd->revision = 0;             /* Unused */
 114         entd->flags = ent->flags;
 115         entd->group_id = 0;             /* Unused */
 116         entd->pads = ent->num_pads;
 117         entd->links = ent->num_links - ent->num_backlinks;
 118
 119         /*
 120          * Workaround for a bug at media-ctl <= v1.10 that makes it to
 121          * do the wrong thing if the entity function doesn't belong to
 122          * either MEDIA_ENT_F_OLD_BASE or MEDIA_ENT_F_OLD_SUBDEV_BASE
 123          * Ranges.
 124          *
 125          * Non-subdevices are expected to be at the MEDIA_ENT_F_OLD_BASE,
 126          * or, otherwise, will be silently ignored by media-ctl when
 127          * printing the graphviz diagram. So, map them into the devnode
 128          * old range.
 129          */
 130         if (ent->function < MEDIA_ENT_F_OLD_BASE ||
 131             ent->function > MEDIA_ENT_F_TUNER) {
 132                 if (is_media_entity_v4l2_subdev(ent))
 133                         entd->type = MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN;
 134                 else if (ent->function != MEDIA_ENT_F_IO_V4L)
 135                         entd->type = MEDIA_ENT_T_DEVNODE_UNKNOWN;
 136         }
 137
 138         memcpy(&entd->raw, &ent->info, sizeof(ent->info));
 139
 140         return 0;
 141 }
 142
 143 static void media_device_kpad_to_upad(const struct media_pad *kpad,
 144                                       struct media_pad_desc *upad)
 145 {
 146         upad->entity = media_entity_id(kpad->entity);
 147         upad->index = kpad->index;
 148         upad->flags = kpad->flags;
 149 }
 150
 151 static long media_device_enum_links(struct media_device *mdev, void *arg)
 152 {
 153         struct media_links_enum *links = arg;
 154         struct media_entity *entity;
 155
 156         entity = find_entity(mdev, links->entity);
 157         if (entity == NULL)
 158                 return -EINVAL;
 159
 160         if (links->pads) {
 161                 unsigned int p;
 162
 163                 for (p = 0; p < entity->num_pads; p++) {
 164                         struct media_pad_desc pad;
 165
 166                         memset(&pad, 0, sizeof(pad));
 167                         media_device_kpad_to_upad(&entity->pads[p], &pad);
 168                         if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
 169                                 return -EFAULT;
 170                 }
 171         }
 172
 173         if (links->links) {
 174                 struct media_link *link;
 175                 struct media_link_desc __user *ulink_desc = links->links;
 176
 177                 list_for_each_entry(link, &entity->links, list) {
 178                         struct media_link_desc klink_desc;
 179
 180                         /* Ignore backlinks. */
 181                         if (link->source->entity != entity)
 182                                 continue;
 183                         memset(&klink_desc, 0, sizeof(klink_desc));
 184                         media_device_kpad_to_upad(link->source,
 185                                                   &klink_desc.source);
 186                         media_device_kpad_to_upad(link->sink,
 187                                                   &klink_desc.sink);
 188                         klink_desc.flags = link->flags;
 189                         if (copy_to_user(ulink_desc, &klink_desc,
 190                                          sizeof(*ulink_desc)))
 191                                 return -EFAULT;
 192                         ulink_desc++;
 193                 }
 194         }
 195         memset(links->reserved, 0, sizeof(links->reserved));
 196
 197         return 0;
 198 }
 199
 200 static long media_device_setup_link(struct media_device *mdev, void *arg)
 201 {
 202         struct media_link_desc *linkd = arg;
 203         struct media_link *link = NULL;
 204         struct media_entity *source;
 205         struct media_entity *sink;
 206
 207         /* Find the source and sink entities and link.
 208          */
 209         source = find_entity(mdev, linkd->source.entity);
 210         sink = find_entity(mdev, linkd->sink.entity);
 211
 212         if (source == NULL || sink == NULL)
 213                 return -EINVAL;
 214
 215         if (linkd->source.index >= source->num_pads ||
 216             linkd->sink.index >= sink->num_pads)
 217                 return -EINVAL;
 218
 219         link = media_entity_find_link(&source->pads[linkd->source.index],
 220                                       &sink->pads[linkd->sink.index]);
 221         if (link == NULL)
 222                 return -EINVAL;
 223
 224         memset(linkd->reserved, 0, sizeof(linkd->reserved));
 225
 226         /* Setup the link on both entities. */
 227         return __media_entity_setup_link(link, linkd->flags);
 228 }
 229
 230 static long media_device_get_topology(struct media_device *mdev, void *arg)
 231 {
 232         struct media_v2_topology *topo = arg;
 233         struct media_entity *entity;
 234         struct media_interface *intf;
 235         struct media_pad *pad;
 236         struct media_link *link;
 237         struct media_v2_entity kentity, __user *uentity;
 238         struct media_v2_interface kintf, __user *uintf;
 239         struct media_v2_pad kpad, __user *upad;
 240         struct media_v2_link klink, __user *ulink;
 241         unsigned int i;
 242         int ret = 0;
 243
 244         topo->topology_version = mdev->topology_version;
 245
 246         /* Get entities and number of entities */
 247         i = 0;
 248         uentity = media_get_uptr(topo->ptr_entities);
 249         media_device_for_each_entity(entity, mdev) {
 250                 i++;
 251                 if (ret || !uentity)
 252                         continue;
 253
 254                 if (i > topo->num_entities) {
 255                         ret = -ENOSPC;
 256                         continue;
 257                 }
 258
 259                 /* Copy fields to userspace struct if not error */
 260                 memset(&kentity, 0, sizeof(kentity));
 261                 kentity.id = entity->graph_obj.id;
 262                 kentity.function = entity->function;
 263                 kentity.flags = entity->flags;
 264                 strscpy(kentity.name, entity->name,
 265                         sizeof(kentity.name));
 266
 267                 if (copy_to_user(uentity, &kentity, sizeof(kentity)))
 268                         ret = -EFAULT;
 269                 uentity++;
 270         }
 271         topo->num_entities = i;
 272         topo->reserved1 = 0;
 273
 274         /* Get interfaces and number of interfaces */
 275         i = 0;
 276         uintf = media_get_uptr(topo->ptr_interfaces);
 277         media_device_for_each_intf(intf, mdev) {
 278                 i++;
 279                 if (ret || !uintf)
 280                         continue;
 281
 282                 if (i > topo->num_interfaces) {
 283                         ret = -ENOSPC;
 284                         continue;
 285                 }
 286
 287                 memset(&kintf, 0, sizeof(kintf));
 288
 289                 /* Copy intf fields to userspace struct */
 290                 kintf.id = intf->graph_obj.id;
 291                 kintf.intf_type = intf->type;
 292                 kintf.flags = intf->flags;
 293
 294                 if (media_type(&intf->graph_obj) == MEDIA_GRAPH_INTF_DEVNODE) {
 295                         struct media_intf_devnode *devnode;
 296
 297                         devnode = intf_to_devnode(intf);
 298
 299                         kintf.devnode.major = devnode->major;
 300                         kintf.devnode.minor = devnode->minor;
 301                 }
 302
 303                 if (copy_to_user(uintf, &kintf, sizeof(kintf)))
 304                         ret = -EFAULT;
 305                 uintf++;
 306         }
 307         topo->num_interfaces = i;
 308         topo->reserved2 = 0;
 309
 310         /* Get pads and number of pads */
 311         i = 0;
 312         upad = media_get_uptr(topo->ptr_pads);
 313         media_device_for_each_pad(pad, mdev) {
 314                 i++;
 315                 if (ret || !upad)
 316                         continue;
 317
 318                 if (i > topo->num_pads) {
 319                         ret = -ENOSPC;
 320                         continue;
 321                 }
 322
 323                 memset(&kpad, 0, sizeof(kpad));
 324
 325                 /* Copy pad fields to userspace struct */
 326                 kpad.id = pad->graph_obj.id;
 327                 kpad.entity_id = pad->entity->graph_obj.id;
 328                 kpad.flags = pad->flags;
 329                 kpad.index = pad->index;
 330
 331                 if (copy_to_user(upad, &kpad, sizeof(kpad)))
 332                         ret = -EFAULT;
 333                 upad++;
 334         }
 335         topo->num_pads = i;
 336         topo->reserved3 = 0;
 337
 338         /* Get links and number of links */
 339         i = 0;
 340         ulink = media_get_uptr(topo->ptr_links);
 341         media_device_for_each_link(link, mdev) {
 342                 if (link->is_backlink)
 343                         continue;
 344
 345                 i++;
 346
 347                 if (ret || !ulink)
 348                         continue;
 349
 350                 if (i > topo->num_links) {
 351                         ret = -ENOSPC;
 352                         continue;
 353                 }
 354
 355                 memset(&klink, 0, sizeof(klink));
 356
 357                 /* Copy link fields to userspace struct */
 358                 klink.id = link->graph_obj.id;
 359                 klink.source_id = link->gobj0->id;
 360                 klink.sink_id = link->gobj1->id;
 361                 klink.flags = link->flags;
 362
 363                 if (copy_to_user(ulink, &klink, sizeof(klink)))
 364                         ret = -EFAULT;
 365                 ulink++;
 366         }
 367         topo->num_links = i;
 368         topo->reserved4 = 0;
 369
 370         return ret;
 371 }
 372
 373 static long media_device_request_alloc(struct media_device *mdev, void *arg)
 374 {
 375 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
 376         int *alloc_fd = arg;
 377
 378         if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
 379                 return -ENOTTY;
 380
 381         return media_request_alloc(mdev, alloc_fd);
 382 #else
 383         return -ENOTTY;
 384 #endif
 385 }
 386
 387 static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
 388 {
 389         if ((_IOC_DIR(cmd) & _IOC_WRITE) &&
 390             copy_from_user(karg, uarg, _IOC_SIZE(cmd)))
 391                 return -EFAULT;
 392
 393         return 0;
 394 }
 395
 396 static long copy_arg_to_user(void __user *uarg, void *karg, unsigned int cmd)
 397 {
 398         if ((_IOC_DIR(cmd) & _IOC_READ) &&
 399             copy_to_user(uarg, karg, _IOC_SIZE(cmd)))
 400                 return -EFAULT;
 401
 402         return 0;
 403 }
 404
 405 /* Do acquire the graph mutex */
 406 #define MEDIA_IOC_FL_GRAPH_MUTEX        BIT(0)
 407
 408 #define MEDIA_IOC_ARG(__cmd, func, fl, from_user, to_user)              \
 409         [_IOC_NR(MEDIA_IOC_##__cmd)] = {                                \
 410                 .cmd = MEDIA_IOC_##__cmd,                               \
 411                 .fn = func,                                             \
 412                 .flags = fl,                                            \
 413                 .arg_from_user = from_user,                             \
 414                 .arg_to_user = to_user,                                 \
 415         }
 416
 417 #define MEDIA_IOC(__cmd, func, fl)                                      \
 418         MEDIA_IOC_ARG(__cmd, func, fl, copy_arg_from_user, copy_arg_to_user)
 419
 420 /* the table is indexed by _IOC_NR(cmd) */
 421 struct media_ioctl_info {
 422         unsigned int cmd;
 423         unsigned short flags;
 424         long (*fn)(struct media_device *dev, void *arg);
 425         long (*arg_from_user)(void *karg, void __user *uarg, unsigned int cmd);
 426         long (*arg_to_user)(void __user *uarg, void *karg, unsigned int cmd);
 427 };
 428
 429 static const struct media_ioctl_info ioctl_info[] = {
 430         MEDIA_IOC(DEVICE_INFO, media_device_get_info, MEDIA_IOC_FL_GRAPH_MUTEX),
 431         MEDIA_IOC(ENUM_ENTITIES, media_device_enum_entities, MEDIA_IOC_FL_GRAPH_MUTEX),
 432         MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
 433         MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
 434         MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
 435         MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
 436 };
 437
 438 static long media_device_ioctl(struct file *filp, unsigned int cmd,
 439                                unsigned long __arg)
 440 {
 441         struct media_devnode *devnode = media_devnode_data(filp);
 442         struct media_device *dev = devnode->media_dev;
 443         const struct media_ioctl_info *info;
 444         void __user *arg = (void __user *)__arg;
 445         char __karg[256], *karg = __karg;
 446         long ret;
 447
 448         if (_IOC_NR(cmd) >= ARRAY_SIZE(ioctl_info)
 449             || ioctl_info[_IOC_NR(cmd)].cmd != cmd)
 450                 return -ENOIOCTLCMD;
 451
 452         info = &ioctl_info[_IOC_NR(cmd)];
 453
 454         if (_IOC_SIZE(info->cmd) > sizeof(__karg)) {
 455                 karg = kmalloc(_IOC_SIZE(info->cmd), GFP_KERNEL);
 456                 if (!karg)
 457                         return -ENOMEM;
 458         }
 459
 460         if (info->arg_from_user) {
 461                 ret = info->arg_from_user(karg, arg, cmd);
 462                 if (ret)
 463                         goto out_free;
 464         }
 465
 466         if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
 467                 mutex_lock(&dev->graph_mutex);
 468
 469         ret = info->fn(dev, karg);
 470
 471         if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
 472                 mutex_unlock(&dev->graph_mutex);
 473
 474         if (!ret && info->arg_to_user)
 475                 ret = info->arg_to_user(arg, karg, cmd);
 476
 477 out_free:
 478         if (karg != __karg)
 479                 kfree(karg);
 480
 481         return ret;
 482 }
 483
 484 #ifdef CONFIG_COMPAT
 485
 486 struct media_links_enum32 {
 487         __u32 entity;
 488         compat_uptr_t pads; /* struct media_pad_desc * */
 489         compat_uptr_t links; /* struct media_link_desc * */
 490         __u32 reserved[4];
 491 };
 492
 493 static long media_device_enum_links32(struct media_device *mdev,
 494                                       struct media_links_enum32 __user *ulinks)
 495 {
 496         struct media_links_enum links;
 497         compat_uptr_t pads_ptr, links_ptr;
 498         int ret;
 499
 500         memset(&links, 0, sizeof(links));
 501
 502         if (get_user(links.entity, &ulinks->entity)
 503             || get_user(pads_ptr, &ulinks->pads)
 504             || get_user(links_ptr, &ulinks->links))
 505                 return -EFAULT;
 506
 507         links.pads = compat_ptr(pads_ptr);
 508         links.links = compat_ptr(links_ptr);
 509
 510         ret = media_device_enum_links(mdev, &links);
 511         if (ret)
 512                 return ret;
 513
 514         if (copy_to_user(ulinks->reserved, links.reserved,
 515                          sizeof(ulinks->reserved)))
 516                 return -EFAULT;
 517         return 0;
 518 }
 519
 520 #define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)
 521
 522 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
 523                                       unsigned long arg)
 524 {
 525         struct media_devnode *devnode = media_devnode_data(filp);
 526         struct media_device *dev = devnode->media_dev;
 527         long ret;
 528
 529         switch (cmd) {
 530         case MEDIA_IOC_ENUM_LINKS32:
 531                 mutex_lock(&dev->graph_mutex);
 532                 ret = media_device_enum_links32(dev,
 533                                 (struct media_links_enum32 __user *)arg);
 534                 mutex_unlock(&dev->graph_mutex);
 535                 break;
 536
 537         default:
 538                 return media_device_ioctl(filp, cmd, arg);
 539         }
 540
 541         return ret;
 542 }
 543 #endif /* CONFIG_COMPAT */
 544
 545 static const struct media_file_operations media_device_fops = {
 546         .owner = THIS_MODULE,
 547         .open = media_device_open,
 548         .ioctl = media_device_ioctl,
 549 #ifdef CONFIG_COMPAT
 550         .compat_ioctl = media_device_compat_ioctl,
 551 #endif /* CONFIG_COMPAT */
 552         .release = media_device_close,
 553 };
 554
 555 /* -----------------------------------------------------------------------------
 556  * sysfs
 557  */
 558
 559 static ssize_t show_model(struct device *cd,
 560                           struct device_attribute *attr, char *buf)
 561 {
 562         struct media_devnode *devnode = to_media_devnode(cd);
 563         struct media_device *mdev = devnode->media_dev;
 564
 565         return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 566 }
 567
 568 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 569
 570 /* -----------------------------------------------------------------------------
 571  * Registration/unregistration
 572  */
 573
 574 static void media_device_release(struct media_devnode *devnode)
 575 {
 576         dev_dbg(devnode->parent, "Media device released\n");
 577 }
 578
 579 static void __media_device_unregister_entity(struct media_entity *entity)
 580 {
 581         struct media_device *mdev = entity->graph_obj.mdev;
 582         struct media_link *link, *tmp;
 583         struct media_interface *intf;
 584         unsigned int i;
 585
 586         ida_free(&mdev->entity_internal_idx, entity->internal_idx);
 587
 588         /* Remove all interface links pointing to this entity */
 589         list_for_each_entry(intf, &mdev->interfaces, graph_obj.list) {
 590                 list_for_each_entry_safe(link, tmp, &intf->links, list) {
 591                         if (link->entity == entity)
 592                                 __media_remove_intf_link(link);
 593                 }
 594         }
 595
 596         /* Remove all data links that belong to this entity */
 597         __media_entity_remove_links(entity);
 598
 599         /* Remove all pads that belong to this entity */
 600         for (i = 0; i < entity->num_pads; i++)
 601                 media_gobj_destroy(&entity->pads[i].graph_obj);
 602
 603         /* Remove the entity */
 604         media_gobj_destroy(&entity->graph_obj);
 605
 606         /* invoke entity_notify callbacks to handle entity removal?? */
 607
 608         entity->graph_obj.mdev = NULL;
 609 }
 610
 611 /**
 612  * media_device_register_entity - Register an entity with a media device
 613  * @mdev:       The media device
 614  * @entity:     The entity
 615  */
 616 int __must_check media_device_register_entity(struct media_device *mdev,
 617                                               struct media_entity *entity)
 618 {
 619         struct media_entity_notify *notify, *next;
 620         unsigned int i;
 621         int ret;
 622
 623         if (entity->function == MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN ||
 624             entity->function == MEDIA_ENT_F_UNKNOWN)
 625                 dev_warn(mdev->dev,
 626                          "Entity type for entity %s was not initialized!\n",
 627                          entity->name);
 628
 629         /* Warn if we apparently re-register an entity */
 630         WARN_ON(entity->graph_obj.mdev != NULL);
 631         entity->graph_obj.mdev = mdev;
 632         INIT_LIST_HEAD(&entity->links);
 633         entity->num_links = 0;
 634         entity->num_backlinks = 0;
 635
 636         ret = ida_alloc_min(&mdev->entity_internal_idx, 1, GFP_KERNEL);
 637         if (ret < 0)
 638                 return ret;
 639         entity->internal_idx = ret;
 640
 641         mutex_lock(&mdev->graph_mutex);
 642         mdev->entity_internal_idx_max =
 643                 max(mdev->entity_internal_idx_max, entity->internal_idx);
 644
 645         /* Initialize media_gobj embedded at the entity */
 646         media_gobj_create(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
 647
 648         /* Initialize objects at the pads */
 649         for (i = 0; i < entity->num_pads; i++)
 650                 media_gobj_create(mdev, MEDIA_GRAPH_PAD,
 651                                &entity->pads[i].graph_obj);
 652
 653         /* invoke entity_notify callbacks */
 654         list_for_each_entry_safe(notify, next, &mdev->entity_notify, list)
 655                 notify->notify(entity, notify->notify_data);
 656
 657         if (mdev->entity_internal_idx_max
 658             >= mdev->pm_count_walk.ent_enum.idx_max) {
 659                 struct media_graph new = { .top = 0 };
 660
 661                 /*
 662                  * Initialise the new graph walk before cleaning up
 663                  * the old one in order not to spoil the graph walk
 664                  * object of the media device if graph walk init fails.
 665                  */
 666                 ret = media_graph_walk_init(&new, mdev);
 667                 if (ret) {
 668                         __media_device_unregister_entity(entity);
 669                         mutex_unlock(&mdev->graph_mutex);
 670                         return ret;
 671                 }
 672                 media_graph_walk_cleanup(&mdev->pm_count_walk);
 673                 mdev->pm_count_walk = new;
 674         }
 675         mutex_unlock(&mdev->graph_mutex);
 676
 677         return 0;
 678 }
 679 EXPORT_SYMBOL_GPL(media_device_register_entity);
 680
 681 void media_device_unregister_entity(struct media_entity *entity)
 682 {
 683         struct media_device *mdev = entity->graph_obj.mdev;
 684
 685         if (mdev == NULL)
 686                 return;
 687
 688         mutex_lock(&mdev->graph_mutex);
 689         __media_device_unregister_entity(entity);
 690         mutex_unlock(&mdev->graph_mutex);
 691 }
 692 EXPORT_SYMBOL_GPL(media_device_unregister_entity);
 693
 694 /**
 695  * media_device_init() - initialize a media device
 696  * @mdev:       The media device
 697  *
 698  * The caller is responsible for initializing the media device before
 699  * registration. The following fields must be set:
 700  *
 701  * - dev must point to the parent device
 702  * - model must be filled with the device model name
 703  */
 704 void media_device_init(struct media_device *mdev)
 705 {
 706         INIT_LIST_HEAD(&mdev->entities);
 707         INIT_LIST_HEAD(&mdev->interfaces);
 708         INIT_LIST_HEAD(&mdev->pads);
 709         INIT_LIST_HEAD(&mdev->links);
 710         INIT_LIST_HEAD(&mdev->entity_notify);
 711
 712         mutex_init(&mdev->req_queue_mutex);
 713         mutex_init(&mdev->graph_mutex);
 714         ida_init(&mdev->entity_internal_idx);
 715
 716         atomic_set(&mdev->request_id, 0);
 717
 718         dev_dbg(mdev->dev, "Media device initialized\n");
 719 }
 720 EXPORT_SYMBOL_GPL(media_device_init);
 721
 722 void media_device_cleanup(struct media_device *mdev)
 723 {
 724         ida_destroy(&mdev->entity_internal_idx);
 725         mdev->entity_internal_idx_max = 0;
 726         media_graph_walk_cleanup(&mdev->pm_count_walk);
 727         mutex_destroy(&mdev->graph_mutex);
 728         mutex_destroy(&mdev->req_queue_mutex);
 729 }
 730 EXPORT_SYMBOL_GPL(media_device_cleanup);
 731
 732 int __must_check __media_device_register(struct media_device *mdev,
 733                                          struct module *owner)
 734 {
 735         struct media_devnode *devnode;
 736         int ret;
 737
 738         devnode = kzalloc(sizeof(*devnode), GFP_KERNEL);
 739         if (!devnode)
 740                 return -ENOMEM;
 741
 742         /* Register the device node. */
 743         mdev->devnode = devnode;
 744         devnode->fops = &media_device_fops;
 745         devnode->parent = mdev->dev;
 746         devnode->release = media_device_release;
 747
 748         /* Set version 0 to indicate user-space that the graph is static */
 749         mdev->topology_version = 0;
 750
 751         ret = media_devnode_register(mdev, devnode, owner);
 752         if (ret < 0) {
 753                 /* devnode free is handled in media_devnode_*() */
 754                 mdev->devnode = NULL;
 755                 return ret;
 756         }
 757
 758         ret = device_create_file(&devnode->dev, &dev_attr_model);
 759         if (ret < 0) {
 760                 /* devnode free is handled in media_devnode_*() */
 761                 mdev->devnode = NULL;
 762                 media_devnode_unregister_prepare(devnode);
 763                 media_devnode_unregister(devnode);
 764                 return ret;
 765         }
 766
 767         dev_dbg(mdev->dev, "Media device registered\n");
 768
 769         return 0;
 770 }
 771 EXPORT_SYMBOL_GPL(__media_device_register);
 772
 773 int __must_check media_device_register_entity_notify(struct media_device *mdev,
 774                                         struct media_entity_notify *nptr)
 775 {
 776         mutex_lock(&mdev->graph_mutex);
 777         list_add_tail(&nptr->list, &mdev->entity_notify);
 778         mutex_unlock(&mdev->graph_mutex);
 779         return 0;
 780 }
 781 EXPORT_SYMBOL_GPL(media_device_register_entity_notify);
 782
 783 /*
 784  * Note: Should be called with mdev->lock held.
 785  */
 786 static void __media_device_unregister_entity_notify(struct media_device *mdev,
 787                                         struct media_entity_notify *nptr)
 788 {
 789         list_del(&nptr->list);
 790 }
 791
 792 void media_device_unregister_entity_notify(struct media_device *mdev,
 793                                         struct media_entity_notify *nptr)
 794 {
 795         mutex_lock(&mdev->graph_mutex);
 796         __media_device_unregister_entity_notify(mdev, nptr);
 797         mutex_unlock(&mdev->graph_mutex);
 798 }
 799 EXPORT_SYMBOL_GPL(media_device_unregister_entity_notify);
 800
 801 void media_device_unregister(struct media_device *mdev)
 802 {
 803         struct media_entity *entity;
 804         struct media_entity *next;
 805         struct media_interface *intf, *tmp_intf;
 806         struct media_entity_notify *notify, *nextp;
 807
 808         if (mdev == NULL)
 809                 return;
 810
 811         mutex_lock(&mdev->graph_mutex);
 812
 813         /* Check if mdev was ever registered at all */
 814         if (!media_devnode_is_registered(mdev->devnode)) {
 815                 mutex_unlock(&mdev->graph_mutex);
 816                 return;
 817         }
 818
 819         /* Clear the devnode register bit to avoid races with media dev open */
 820         media_devnode_unregister_prepare(mdev->devnode);
 821
 822         /* Remove all entities from the media device */
 823         list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
 824                 __media_device_unregister_entity(entity);
 825
 826         /* Remove all entity_notify callbacks from the media device */
 827         list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list)
 828                 __media_device_unregister_entity_notify(mdev, notify);
 829
 830         /* Remove all interfaces from the media device */
 831         list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
 832                                  graph_obj.list) {
 833                 /*
 834                  * Unlink the interface, but don't free it here; the
 835                  * module which created it is responsible for freeing
 836                  * it
 837                  */
 838                 __media_remove_intf_links(intf);
 839                 media_gobj_destroy(&intf->graph_obj);
 840         }
 841
 842         mutex_unlock(&mdev->graph_mutex);
 843
 844         dev_dbg(mdev->dev, "Media device unregistered\n");
 845
 846         device_remove_file(&mdev->devnode->dev, &dev_attr_model);
 847         media_devnode_unregister(mdev->devnode);
 848         /* devnode free is handled in media_devnode_*() */
 849         mdev->devnode = NULL;
 850 }
 851 EXPORT_SYMBOL_GPL(media_device_unregister);
 852
 853 #if IS_ENABLED(CONFIG_PCI)
 854 void media_device_pci_init(struct media_device *mdev,
 855                            struct pci_dev *pci_dev,
 856                            const char *name)
 857 {
 858         mdev->dev = &pci_dev->dev;
 859
 860         if (name)
 861                 strscpy(mdev->model, name, sizeof(mdev->model));
 862         else
 863                 strscpy(mdev->model, pci_name(pci_dev), sizeof(mdev->model));
 864
 865         sprintf(mdev->bus_info, "PCI:%s", pci_name(pci_dev));
 866
 867         mdev->hw_revision = (pci_dev->subsystem_vendor << 16)
 868                             | pci_dev->subsystem_device;
 869
 870         media_device_init(mdev);
 871 }
 872 EXPORT_SYMBOL_GPL(media_device_pci_init);
 873 #endif
 874
 875 #if IS_ENABLED(CONFIG_USB)
 876 void __media_device_usb_init(struct media_device *mdev,
 877                              struct usb_device *udev,
 878                              const char *board_name,
 879                              const char *driver_name)
 880 {
 881         mdev->dev = &udev->dev;
 882
 883         if (driver_name)
 884                 strscpy(mdev->driver_name, driver_name,
 885                         sizeof(mdev->driver_name));
 886
 887         if (board_name)
 888                 strscpy(mdev->model, board_name, sizeof(mdev->model));
 889         else if (udev->product)
 890                 strscpy(mdev->model, udev->product, sizeof(mdev->model));
 891         else
 892                 strscpy(mdev->model, "unknown model", sizeof(mdev->model));
 893         if (udev->serial)
 894                 strscpy(mdev->serial, udev->serial, sizeof(mdev->serial));
 895         usb_make_path(udev, mdev->bus_info, sizeof(mdev->bus_info));
 896         mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
 897
 898         media_device_init(mdev);
 899 }
 900 EXPORT_SYMBOL_GPL(__media_device_usb_init);
 901 #endif
 902
 903
 904 #endif /* CONFIG_MEDIA_CONTROLLER */