drivers/media/mc/mc-entity.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Media entity
   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/bitmap.h>
  12 #include <linux/property.h>
  13 #include <linux/slab.h>
  14 #include <media/media-entity.h>
  15 #include <media/media-device.h>
  16
  17 static inline const char *gobj_type(enum media_gobj_type type)
  18 {
  19         switch (type) {
  20         case MEDIA_GRAPH_ENTITY:
  21                 return "entity";
  22         case MEDIA_GRAPH_PAD:
  23                 return "pad";
  24         case MEDIA_GRAPH_LINK:
  25                 return "link";
  26         case MEDIA_GRAPH_INTF_DEVNODE:
  27                 return "intf-devnode";
  28         default:
  29                 return "unknown";
  30         }
  31 }
  32
  33 static inline const char *intf_type(struct media_interface *intf)
  34 {
  35         switch (intf->type) {
  36         case MEDIA_INTF_T_DVB_FE:
  37                 return "dvb-frontend";
  38         case MEDIA_INTF_T_DVB_DEMUX:
  39                 return "dvb-demux";
  40         case MEDIA_INTF_T_DVB_DVR:
  41                 return "dvb-dvr";
  42         case MEDIA_INTF_T_DVB_CA:
  43                 return  "dvb-ca";
  44         case MEDIA_INTF_T_DVB_NET:
  45                 return "dvb-net";
  46         case MEDIA_INTF_T_V4L_VIDEO:
  47                 return "v4l-video";
  48         case MEDIA_INTF_T_V4L_VBI:
  49                 return "v4l-vbi";
  50         case MEDIA_INTF_T_V4L_RADIO:
  51                 return "v4l-radio";
  52         case MEDIA_INTF_T_V4L_SUBDEV:
  53                 return "v4l-subdev";
  54         case MEDIA_INTF_T_V4L_SWRADIO:
  55                 return "v4l-swradio";
  56         case MEDIA_INTF_T_V4L_TOUCH:
  57                 return "v4l-touch";
  58         default:
  59                 return "unknown-intf";
  60         }
  61 };
  62
  63 __must_check int __media_entity_enum_init(struct media_entity_enum *ent_enum,
  64                                           int idx_max)
  65 {
  66         idx_max = ALIGN(idx_max, BITS_PER_LONG);
  67         ent_enum->bmap = kcalloc(idx_max / BITS_PER_LONG, sizeof(long),
  68                                  GFP_KERNEL);
  69         if (!ent_enum->bmap)
  70                 return -ENOMEM;
  71
  72         bitmap_zero(ent_enum->bmap, idx_max);
  73         ent_enum->idx_max = idx_max;
  74
  75         return 0;
  76 }
  77 EXPORT_SYMBOL_GPL(__media_entity_enum_init);
  78
  79 void media_entity_enum_cleanup(struct media_entity_enum *ent_enum)
  80 {
  81         kfree(ent_enum->bmap);
  82 }
  83 EXPORT_SYMBOL_GPL(media_entity_enum_cleanup);
  84
  85 /**
  86  *  dev_dbg_obj - Prints in debug mode a change on some object
  87  *
  88  * @event_name: Name of the event to report. Could be __func__
  89  * @gobj:       Pointer to the object
  90  *
  91  * Enabled only if DEBUG or CONFIG_DYNAMIC_DEBUG. Otherwise, it
  92  * won't produce any code.
  93  */
  94 static void dev_dbg_obj(const char *event_name,  struct media_gobj *gobj)
  95 {
  96 #if defined(DEBUG) || defined (CONFIG_DYNAMIC_DEBUG)
  97         switch (media_type(gobj)) {
  98         case MEDIA_GRAPH_ENTITY:
  99                 dev_dbg(gobj->mdev->dev,
 100                         "%s id %u: entity '%s'\n",
 101                         event_name, media_id(gobj),
 102                         gobj_to_entity(gobj)->name);
 103                 break;
 104         case MEDIA_GRAPH_LINK:
 105         {
 106                 struct media_link *link = gobj_to_link(gobj);
 107
 108                 dev_dbg(gobj->mdev->dev,
 109                         "%s id %u: %s link id %u ==> id %u\n",
 110                         event_name, media_id(gobj),
 111                         media_type(link->gobj0) == MEDIA_GRAPH_PAD ?
 112                                 "data" : "interface",
 113                         media_id(link->gobj0),
 114                         media_id(link->gobj1));
 115                 break;
 116         }
 117         case MEDIA_GRAPH_PAD:
 118         {
 119                 struct media_pad *pad = gobj_to_pad(gobj);
 120
 121                 dev_dbg(gobj->mdev->dev,
 122                         "%s id %u: %s%spad '%s':%d\n",
 123                         event_name, media_id(gobj),
 124                         pad->flags & MEDIA_PAD_FL_SINK   ? "sink " : "",
 125                         pad->flags & MEDIA_PAD_FL_SOURCE ? "source " : "",
 126                         pad->entity->name, pad->index);
 127                 break;
 128         }
 129         case MEDIA_GRAPH_INTF_DEVNODE:
 130         {
 131                 struct media_interface *intf = gobj_to_intf(gobj);
 132                 struct media_intf_devnode *devnode = intf_to_devnode(intf);
 133
 134                 dev_dbg(gobj->mdev->dev,
 135                         "%s id %u: intf_devnode %s - major: %d, minor: %d\n",
 136                         event_name, media_id(gobj),
 137                         intf_type(intf),
 138                         devnode->major, devnode->minor);
 139                 break;
 140         }
 141         }
 142 #endif
 143 }
 144
 145 void media_gobj_create(struct media_device *mdev,
 146                            enum media_gobj_type type,
 147                            struct media_gobj *gobj)
 148 {
 149         BUG_ON(!mdev);
 150
 151         gobj->mdev = mdev;
 152
 153         /* Create a per-type unique object ID */
 154         gobj->id = media_gobj_gen_id(type, ++mdev->id);
 155
 156         switch (type) {
 157         case MEDIA_GRAPH_ENTITY:
 158                 list_add_tail(&gobj->list, &mdev->entities);
 159                 break;
 160         case MEDIA_GRAPH_PAD:
 161                 list_add_tail(&gobj->list, &mdev->pads);
 162                 break;
 163         case MEDIA_GRAPH_LINK:
 164                 list_add_tail(&gobj->list, &mdev->links);
 165                 break;
 166         case MEDIA_GRAPH_INTF_DEVNODE:
 167                 list_add_tail(&gobj->list, &mdev->interfaces);
 168                 break;
 169         }
 170
 171         mdev->topology_version++;
 172
 173         dev_dbg_obj(__func__, gobj);
 174 }
 175
 176 void media_gobj_destroy(struct media_gobj *gobj)
 177 {
 178         /* Do nothing if the object is not linked. */
 179         if (gobj->mdev == NULL)
 180                 return;
 181
 182         dev_dbg_obj(__func__, gobj);
 183
 184         gobj->mdev->topology_version++;
 185
 186         /* Remove the object from mdev list */
 187         list_del(&gobj->list);
 188
 189         gobj->mdev = NULL;
 190 }
 191
 192 /*
 193  * TODO: Get rid of this.
 194  */
 195 #define MEDIA_ENTITY_MAX_PADS           512
 196
 197 int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 198                            struct media_pad *pads)
 199 {
 200         struct media_device *mdev = entity->graph_obj.mdev;
 201         unsigned int i;
 202
 203         if (num_pads >= MEDIA_ENTITY_MAX_PADS)
 204                 return -E2BIG;
 205
 206         entity->num_pads = num_pads;
 207         entity->pads = pads;
 208
 209         if (mdev)
 210                 mutex_lock(&mdev->graph_mutex);
 211
 212         for (i = 0; i < num_pads; i++) {
 213                 pads[i].entity = entity;
 214                 pads[i].index = i;
 215                 if (mdev)
 216                         media_gobj_create(mdev, MEDIA_GRAPH_PAD,
 217                                         &entity->pads[i].graph_obj);
 218         }
 219
 220         if (mdev)
 221                 mutex_unlock(&mdev->graph_mutex);
 222
 223         return 0;
 224 }
 225 EXPORT_SYMBOL_GPL(media_entity_pads_init);
 226
 227 /* -----------------------------------------------------------------------------
 228  * Graph traversal
 229  */
 230
 231 static struct media_entity *
 232 media_entity_other(struct media_entity *entity, struct media_link *link)
 233 {
 234         if (link->source->entity == entity)
 235                 return link->sink->entity;
 236         else
 237                 return link->source->entity;
 238 }
 239
 240 /* push an entity to traversal stack */
 241 static void stack_push(struct media_graph *graph,
 242                        struct media_entity *entity)
 243 {
 244         if (graph->top == MEDIA_ENTITY_ENUM_MAX_DEPTH - 1) {
 245                 WARN_ON(1);
 246                 return;
 247         }
 248         graph->top++;
 249         graph->stack[graph->top].link = entity->links.next;
 250         graph->stack[graph->top].entity = entity;
 251 }
 252
 253 static struct media_entity *stack_pop(struct media_graph *graph)
 254 {
 255         struct media_entity *entity;
 256
 257         entity = graph->stack[graph->top].entity;
 258         graph->top--;
 259
 260         return entity;
 261 }
 262
 263 #define link_top(en)    ((en)->stack[(en)->top].link)
 264 #define stack_top(en)   ((en)->stack[(en)->top].entity)
 265
 266 /**
 267  * media_graph_walk_init - Allocate resources for graph walk
 268  * @graph: Media graph structure that will be used to walk the graph
 269  * @mdev: Media device
 270  *
 271  * Reserve resources for graph walk in media device's current
 272  * state. The memory must be released using
 273  * media_graph_walk_free().
 274  *
 275  * Returns error on failure, zero on success.
 276  */
 277 __must_check int media_graph_walk_init(
 278         struct media_graph *graph, struct media_device *mdev)
 279 {
 280         return media_entity_enum_init(&graph->ent_enum, mdev);
 281 }
 282 EXPORT_SYMBOL_GPL(media_graph_walk_init);
 283
 284 /**
 285  * media_graph_walk_cleanup - Release resources related to graph walking
 286  * @graph: Media graph structure that was used to walk the graph
 287  */
 288 void media_graph_walk_cleanup(struct media_graph *graph)
 289 {
 290         media_entity_enum_cleanup(&graph->ent_enum);
 291 }
 292 EXPORT_SYMBOL_GPL(media_graph_walk_cleanup);
 293
 294 void media_graph_walk_start(struct media_graph *graph,
 295                             struct media_entity *entity)
 296 {
 297         media_entity_enum_zero(&graph->ent_enum);
 298         media_entity_enum_set(&graph->ent_enum, entity);
 299
 300         graph->top = 0;
 301         graph->stack[graph->top].entity = NULL;
 302         stack_push(graph, entity);
 303         dev_dbg(entity->graph_obj.mdev->dev,
 304                 "begin graph walk at '%s'\n", entity->name);
 305 }
 306 EXPORT_SYMBOL_GPL(media_graph_walk_start);
 307
 308 static void media_graph_walk_iter(struct media_graph *graph)
 309 {
 310         struct media_entity *entity = stack_top(graph);
 311         struct media_link *link;
 312         struct media_entity *next;
 313
 314         link = list_entry(link_top(graph), typeof(*link), list);
 315
 316         /* The link is not enabled so we do not follow. */
 317         if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
 318                 link_top(graph) = link_top(graph)->next;
 319                 dev_dbg(entity->graph_obj.mdev->dev,
 320                         "walk: skipping disabled link '%s':%u -> '%s':%u\n",
 321                         link->source->entity->name, link->source->index,
 322                         link->sink->entity->name, link->sink->index);
 323                 return;
 324         }
 325
 326         /* Get the entity in the other end of the link . */
 327         next = media_entity_other(entity, link);
 328
 329         /* Has the entity already been visited? */
 330         if (media_entity_enum_test_and_set(&graph->ent_enum, next)) {
 331                 link_top(graph) = link_top(graph)->next;
 332                 dev_dbg(entity->graph_obj.mdev->dev,
 333                         "walk: skipping entity '%s' (already seen)\n",
 334                         next->name);
 335                 return;
 336         }
 337
 338         /* Push the new entity to stack and start over. */
 339         link_top(graph) = link_top(graph)->next;
 340         stack_push(graph, next);
 341         dev_dbg(entity->graph_obj.mdev->dev, "walk: pushing '%s' on stack\n",
 342                 next->name);
 343 }
 344
 345 struct media_entity *media_graph_walk_next(struct media_graph *graph)
 346 {
 347         struct media_entity *entity;
 348
 349         if (stack_top(graph) == NULL)
 350                 return NULL;
 351
 352         /*
 353          * Depth first search. Push entity to stack and continue from
 354          * top of the stack until no more entities on the level can be
 355          * found.
 356          */
 357         while (link_top(graph) != &stack_top(graph)->links)
 358                 media_graph_walk_iter(graph);
 359
 360         entity = stack_pop(graph);
 361         dev_dbg(entity->graph_obj.mdev->dev,
 362                 "walk: returning entity '%s'\n", entity->name);
 363
 364         return entity;
 365 }
 366 EXPORT_SYMBOL_GPL(media_graph_walk_next);
 367
 368 int media_entity_get_fwnode_pad(struct media_entity *entity,
 369                                 struct fwnode_handle *fwnode,
 370                                 unsigned long direction_flags)
 371 {
 372         struct fwnode_endpoint endpoint;
 373         unsigned int i;
 374         int ret;
 375
 376         if (!entity->ops || !entity->ops->get_fwnode_pad) {
 377                 for (i = 0; i < entity->num_pads; i++) {
 378                         if (entity->pads[i].flags & direction_flags)
 379                                 return i;
 380                 }
 381
 382                 return -ENXIO;
 383         }
 384
 385         ret = fwnode_graph_parse_endpoint(fwnode, &endpoint);
 386         if (ret)
 387                 return ret;
 388
 389         ret = entity->ops->get_fwnode_pad(&endpoint);
 390         if (ret < 0)
 391                 return ret;
 392
 393         if (ret >= entity->num_pads)
 394                 return -ENXIO;
 395
 396         if (!(entity->pads[ret].flags & direction_flags))
 397                 return -ENXIO;
 398
 399         return ret;
 400 }
 401 EXPORT_SYMBOL_GPL(media_entity_get_fwnode_pad);
 402
 403 /* -----------------------------------------------------------------------------
 404  * Pipeline management
 405  */
 406
 407 __must_check int __media_pipeline_start(struct media_entity *entity,
 408                                         struct media_pipeline *pipe)
 409 {
 410         struct media_device *mdev = entity->graph_obj.mdev;
 411         struct media_graph *graph = &pipe->graph;
 412         struct media_entity *entity_err = entity;
 413         struct media_link *link;
 414         int ret;
 415
 416         if (!pipe->streaming_count++) {
 417                 ret = media_graph_walk_init(&pipe->graph, mdev);
 418                 if (ret)
 419                         goto error_graph_walk_start;
 420         }
 421
 422         media_graph_walk_start(&pipe->graph, entity);
 423
 424         while ((entity = media_graph_walk_next(graph))) {
 425                 DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
 426                 DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
 427
 428                 entity->stream_count++;
 429
 430                 if (entity->pipe && entity->pipe != pipe) {
 431                         pr_err("Pipe active for %s. Can't start for %s\n",
 432                                 entity->name,
 433                                 entity_err->name);
 434                         ret = -EBUSY;
 435                         goto error;
 436                 }
 437
 438                 entity->pipe = pipe;
 439
 440                 /* Already streaming --- no need to check. */
 441                 if (entity->stream_count > 1)
 442                         continue;
 443
 444                 if (!entity->ops || !entity->ops->link_validate)
 445                         continue;
 446
 447                 bitmap_zero(active, entity->num_pads);
 448                 bitmap_fill(has_no_links, entity->num_pads);
 449
 450                 list_for_each_entry(link, &entity->links, list) {
 451                         struct media_pad *pad = link->sink->entity == entity
 452                                                 ? link->sink : link->source;
 453
 454                         /* Mark that a pad is connected by a link. */
 455                         bitmap_clear(has_no_links, pad->index, 1);
 456
 457                         /*
 458                          * Pads that either do not need to connect or
 459                          * are connected through an enabled link are
 460                          * fine.
 461                          */
 462                         if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) ||
 463                             link->flags & MEDIA_LNK_FL_ENABLED)
 464                                 bitmap_set(active, pad->index, 1);
 465
 466                         /*
 467                          * Link validation will only take place for
 468                          * sink ends of the link that are enabled.
 469                          */
 470                         if (link->sink != pad ||
 471                             !(link->flags & MEDIA_LNK_FL_ENABLED))
 472                                 continue;
 473
 474                         ret = entity->ops->link_validate(link);
 475                         if (ret < 0 && ret != -ENOIOCTLCMD) {
 476                                 dev_dbg(entity->graph_obj.mdev->dev,
 477                                         "link validation failed for '%s':%u -> '%s':%u, error %d\n",
 478                                         link->source->entity->name,
 479                                         link->source->index,
 480                                         entity->name, link->sink->index, ret);
 481                                 goto error;
 482                         }
 483                 }
 484
 485                 /* Either no links or validated links are fine. */
 486                 bitmap_or(active, active, has_no_links, entity->num_pads);
 487
 488                 if (!bitmap_full(active, entity->num_pads)) {
 489                         ret = -ENOLINK;
 490                         dev_dbg(entity->graph_obj.mdev->dev,
 491                                 "'%s':%u must be connected by an enabled link\n",
 492                                 entity->name,
 493                                 (unsigned)find_first_zero_bit(
 494                                         active, entity->num_pads));
 495                         goto error;
 496                 }
 497         }
 498
 499         return 0;
 500
 501 error:
 502         /*
 503          * Link validation on graph failed. We revert what we did and
 504          * return the error.
 505          */
 506         media_graph_walk_start(graph, entity_err);
 507
 508         while ((entity_err = media_graph_walk_next(graph))) {
 509                 /* Sanity check for negative stream_count */
 510                 if (!WARN_ON_ONCE(entity_err->stream_count <= 0)) {
 511                         entity_err->stream_count--;
 512                         if (entity_err->stream_count == 0)
 513                                 entity_err->pipe = NULL;
 514                 }
 515
 516                 /*
 517                  * We haven't increased stream_count further than this
 518                  * so we quit here.
 519                  */
 520                 if (entity_err == entity)
 521                         break;
 522         }
 523
 524 error_graph_walk_start:
 525         if (!--pipe->streaming_count)
 526                 media_graph_walk_cleanup(graph);
 527
 528         return ret;
 529 }
 530 EXPORT_SYMBOL_GPL(__media_pipeline_start);
 531
 532 __must_check int media_pipeline_start(struct media_entity *entity,
 533                                       struct media_pipeline *pipe)
 534 {
 535         struct media_device *mdev = entity->graph_obj.mdev;
 536         int ret;
 537
 538         mutex_lock(&mdev->graph_mutex);
 539         ret = __media_pipeline_start(entity, pipe);
 540         mutex_unlock(&mdev->graph_mutex);
 541         return ret;
 542 }
 543 EXPORT_SYMBOL_GPL(media_pipeline_start);
 544
 545 void __media_pipeline_stop(struct media_entity *entity)
 546 {
 547         struct media_graph *graph = &entity->pipe->graph;
 548         struct media_pipeline *pipe = entity->pipe;
 549
 550         /*
 551          * If the following check fails, the driver has performed an
 552          * unbalanced call to media_pipeline_stop()
 553          */
 554         if (WARN_ON(!pipe))
 555                 return;
 556
 557         media_graph_walk_start(graph, entity);
 558
 559         while ((entity = media_graph_walk_next(graph))) {
 560                 /* Sanity check for negative stream_count */
 561                 if (!WARN_ON_ONCE(entity->stream_count <= 0)) {
 562                         entity->stream_count--;
 563                         if (entity->stream_count == 0)
 564                                 entity->pipe = NULL;
 565                 }
 566         }
 567
 568         if (!--pipe->streaming_count)
 569                 media_graph_walk_cleanup(graph);
 570
 571 }
 572 EXPORT_SYMBOL_GPL(__media_pipeline_stop);
 573
 574 void media_pipeline_stop(struct media_entity *entity)
 575 {
 576         struct media_device *mdev = entity->graph_obj.mdev;
 577
 578         mutex_lock(&mdev->graph_mutex);
 579         __media_pipeline_stop(entity);
 580         mutex_unlock(&mdev->graph_mutex);
 581 }
 582 EXPORT_SYMBOL_GPL(media_pipeline_stop);
 583
 584 /* -----------------------------------------------------------------------------
 585  * Links management
 586  */
 587
 588 static struct media_link *media_add_link(struct list_head *head)
 589 {
 590         struct media_link *link;
 591
 592         link = kzalloc(sizeof(*link), GFP_KERNEL);
 593         if (link == NULL)
 594                 return NULL;
 595
 596         list_add_tail(&link->list, head);
 597
 598         return link;
 599 }
 600
 601 static void __media_entity_remove_link(struct media_entity *entity,
 602                                        struct media_link *link)
 603 {
 604         struct media_link *rlink, *tmp;
 605         struct media_entity *remote;
 606
 607         if (link->source->entity == entity)
 608                 remote = link->sink->entity;
 609         else
 610                 remote = link->source->entity;
 611
 612         list_for_each_entry_safe(rlink, tmp, &remote->links, list) {
 613                 if (rlink != link->reverse)
 614                         continue;
 615
 616                 if (link->source->entity == entity)
 617                         remote->num_backlinks--;
 618
 619                 /* Remove the remote link */
 620                 list_del(&rlink->list);
 621                 media_gobj_destroy(&rlink->graph_obj);
 622                 kfree(rlink);
 623
 624                 if (--remote->num_links == 0)
 625                         break;
 626         }
 627         list_del(&link->list);
 628         media_gobj_destroy(&link->graph_obj);
 629         kfree(link);
 630 }
 631
 632 int media_get_pad_index(struct media_entity *entity, bool is_sink,
 633                         enum media_pad_signal_type sig_type)
 634 {
 635         int i;
 636         bool pad_is_sink;
 637
 638         if (!entity)
 639                 return -EINVAL;
 640
 641         for (i = 0; i < entity->num_pads; i++) {
 642                 if (entity->pads[i].flags & MEDIA_PAD_FL_SINK)
 643                         pad_is_sink = true;
 644                 else if (entity->pads[i].flags & MEDIA_PAD_FL_SOURCE)
 645                         pad_is_sink = false;
 646                 else
 647                         continue;       /* This is an error! */
 648
 649                 if (pad_is_sink != is_sink)
 650                         continue;
 651                 if (entity->pads[i].sig_type == sig_type)
 652                         return i;
 653         }
 654         return -EINVAL;
 655 }
 656 EXPORT_SYMBOL_GPL(media_get_pad_index);
 657
 658 int
 659 media_create_pad_link(struct media_entity *source, u16 source_pad,
 660                          struct media_entity *sink, u16 sink_pad, u32 flags)
 661 {
 662         struct media_link *link;
 663         struct media_link *backlink;
 664
 665         BUG_ON(source == NULL || sink == NULL);
 666         BUG_ON(source_pad >= source->num_pads);
 667         BUG_ON(sink_pad >= sink->num_pads);
 668
 669         link = media_add_link(&source->links);
 670         if (link == NULL)
 671                 return -ENOMEM;
 672
 673         link->source = &source->pads[source_pad];
 674         link->sink = &sink->pads[sink_pad];
 675         link->flags = flags & ~MEDIA_LNK_FL_INTERFACE_LINK;
 676
 677         /* Initialize graph object embedded at the new link */
 678         media_gobj_create(source->graph_obj.mdev, MEDIA_GRAPH_LINK,
 679                         &link->graph_obj);
 680
 681         /* Create the backlink. Backlinks are used to help graph traversal and
 682          * are not reported to userspace.
 683          */
 684         backlink = media_add_link(&sink->links);
 685         if (backlink == NULL) {
 686                 __media_entity_remove_link(source, link);
 687                 return -ENOMEM;
 688         }
 689
 690         backlink->source = &source->pads[source_pad];
 691         backlink->sink = &sink->pads[sink_pad];
 692         backlink->flags = flags;
 693         backlink->is_backlink = true;
 694
 695         /* Initialize graph object embedded at the new link */
 696         media_gobj_create(sink->graph_obj.mdev, MEDIA_GRAPH_LINK,
 697                         &backlink->graph_obj);
 698
 699         link->reverse = backlink;
 700         backlink->reverse = link;
 701
 702         sink->num_backlinks++;
 703         sink->num_links++;
 704         source->num_links++;
 705
 706         return 0;
 707 }
 708 EXPORT_SYMBOL_GPL(media_create_pad_link);
 709
 710 int media_create_pad_links(const struct media_device *mdev,
 711                            const u32 source_function,
 712                            struct media_entity *source,
 713                            const u16 source_pad,
 714                            const u32 sink_function,
 715                            struct media_entity *sink,
 716                            const u16 sink_pad,
 717                            u32 flags,
 718                            const bool allow_both_undefined)
 719 {
 720         struct media_entity *entity;
 721         unsigned function;
 722         int ret;
 723
 724         /* Trivial case: 1:1 relation */
 725         if (source && sink)
 726                 return media_create_pad_link(source, source_pad,
 727                                              sink, sink_pad, flags);
 728
 729         /* Worse case scenario: n:n relation */
 730         if (!source && !sink) {
 731                 if (!allow_both_undefined)
 732                         return 0;
 733                 media_device_for_each_entity(source, mdev) {
 734                         if (source->function != source_function)
 735                                 continue;
 736                         media_device_for_each_entity(sink, mdev) {
 737                                 if (sink->function != sink_function)
 738                                         continue;
 739                                 ret = media_create_pad_link(source, source_pad,
 740                                                             sink, sink_pad,
 741                                                             flags);
 742                                 if (ret)
 743                                         return ret;
 744                                 flags &= ~(MEDIA_LNK_FL_ENABLED |
 745                                            MEDIA_LNK_FL_IMMUTABLE);
 746                         }
 747                 }
 748                 return 0;
 749         }
 750
 751         /* Handle 1:n and n:1 cases */
 752         if (source)
 753                 function = sink_function;
 754         else
 755                 function = source_function;
 756
 757         media_device_for_each_entity(entity, mdev) {
 758                 if (entity->function != function)
 759                         continue;
 760
 761                 if (source)
 762                         ret = media_create_pad_link(source, source_pad,
 763                                                     entity, sink_pad, flags);
 764                 else
 765                         ret = media_create_pad_link(entity, source_pad,
 766                                                     sink, sink_pad, flags);
 767                 if (ret)
 768                         return ret;
 769                 flags &= ~(MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
 770         }
 771         return 0;
 772 }
 773 EXPORT_SYMBOL_GPL(media_create_pad_links);
 774
 775 void __media_entity_remove_links(struct media_entity *entity)
 776 {
 777         struct media_link *link, *tmp;
 778
 779         list_for_each_entry_safe(link, tmp, &entity->links, list)
 780                 __media_entity_remove_link(entity, link);
 781
 782         entity->num_links = 0;
 783         entity->num_backlinks = 0;
 784 }
 785 EXPORT_SYMBOL_GPL(__media_entity_remove_links);
 786
 787 void media_entity_remove_links(struct media_entity *entity)
 788 {
 789         struct media_device *mdev = entity->graph_obj.mdev;
 790
 791         /* Do nothing if the entity is not registered. */
 792         if (mdev == NULL)
 793                 return;
 794
 795         mutex_lock(&mdev->graph_mutex);
 796         __media_entity_remove_links(entity);
 797         mutex_unlock(&mdev->graph_mutex);
 798 }
 799 EXPORT_SYMBOL_GPL(media_entity_remove_links);
 800
 801 static int __media_entity_setup_link_notify(struct media_link *link, u32 flags)
 802 {
 803         int ret;
 804
 805         /* Notify both entities. */
 806         ret = media_entity_call(link->source->entity, link_setup,
 807                                 link->source, link->sink, flags);
 808         if (ret < 0 && ret != -ENOIOCTLCMD)
 809                 return ret;
 810
 811         ret = media_entity_call(link->sink->entity, link_setup,
 812                                 link->sink, link->source, flags);
 813         if (ret < 0 && ret != -ENOIOCTLCMD) {
 814                 media_entity_call(link->source->entity, link_setup,
 815                                   link->source, link->sink, link->flags);
 816                 return ret;
 817         }
 818
 819         link->flags = flags;
 820         link->reverse->flags = link->flags;
 821
 822         return 0;
 823 }
 824
 825 int __media_entity_setup_link(struct media_link *link, u32 flags)
 826 {
 827         const u32 mask = MEDIA_LNK_FL_ENABLED;
 828         struct media_device *mdev;
 829         struct media_entity *source, *sink;
 830         int ret = -EBUSY;
 831
 832         if (link == NULL)
 833                 return -EINVAL;
 834
 835         /* The non-modifiable link flags must not be modified. */
 836         if ((link->flags & ~mask) != (flags & ~mask))
 837                 return -EINVAL;
 838
 839         if (link->flags & MEDIA_LNK_FL_IMMUTABLE)
 840                 return link->flags == flags ? 0 : -EINVAL;
 841
 842         if (link->flags == flags)
 843                 return 0;
 844
 845         source = link->source->entity;
 846         sink = link->sink->entity;
 847
 848         if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) &&
 849             (source->stream_count || sink->stream_count))
 850                 return -EBUSY;
 851
 852         mdev = source->graph_obj.mdev;
 853
 854         if (mdev->ops && mdev->ops->link_notify) {
 855                 ret = mdev->ops->link_notify(link, flags,
 856                                              MEDIA_DEV_NOTIFY_PRE_LINK_CH);
 857                 if (ret < 0)
 858                         return ret;
 859         }
 860
 861         ret = __media_entity_setup_link_notify(link, flags);
 862
 863         if (mdev->ops && mdev->ops->link_notify)
 864                 mdev->ops->link_notify(link, flags,
 865                                        MEDIA_DEV_NOTIFY_POST_LINK_CH);
 866
 867         return ret;
 868 }
 869 EXPORT_SYMBOL_GPL(__media_entity_setup_link);
 870
 871 int media_entity_setup_link(struct media_link *link, u32 flags)
 872 {
 873         int ret;
 874
 875         mutex_lock(&link->graph_obj.mdev->graph_mutex);
 876         ret = __media_entity_setup_link(link, flags);
 877         mutex_unlock(&link->graph_obj.mdev->graph_mutex);
 878
 879         return ret;
 880 }
 881 EXPORT_SYMBOL_GPL(media_entity_setup_link);
 882
 883 struct media_link *
 884 media_entity_find_link(struct media_pad *source, struct media_pad *sink)
 885 {
 886         struct media_link *link;
 887
 888         list_for_each_entry(link, &source->entity->links, list) {
 889                 if (link->source->entity == source->entity &&
 890                     link->source->index == source->index &&
 891                     link->sink->entity == sink->entity &&
 892                     link->sink->index == sink->index)
 893                         return link;
 894         }
 895
 896         return NULL;
 897 }
 898 EXPORT_SYMBOL_GPL(media_entity_find_link);
 899
 900 struct media_pad *media_entity_remote_pad(const struct media_pad *pad)
 901 {
 902         struct media_link *link;
 903
 904         list_for_each_entry(link, &pad->entity->links, list) {
 905                 if (!(link->flags & MEDIA_LNK_FL_ENABLED))
 906                         continue;
 907
 908                 if (link->source == pad)
 909                         return link->sink;
 910
 911                 if (link->sink == pad)
 912                         return link->source;
 913         }
 914
 915         return NULL;
 916
 917 }
 918 EXPORT_SYMBOL_GPL(media_entity_remote_pad);
 919
 920 static void media_interface_init(struct media_device *mdev,
 921                                  struct media_interface *intf,
 922                                  u32 gobj_type,
 923                                  u32 intf_type, u32 flags)
 924 {
 925         intf->type = intf_type;
 926         intf->flags = flags;
 927         INIT_LIST_HEAD(&intf->links);
 928
 929         media_gobj_create(mdev, gobj_type, &intf->graph_obj);
 930 }
 931
 932 /* Functions related to the media interface via device nodes */
 933
 934 struct media_intf_devnode *media_devnode_create(struct media_device *mdev,
 935                                                 u32 type, u32 flags,
 936                                                 u32 major, u32 minor)
 937 {
 938         struct media_intf_devnode *devnode;
 939
 940         devnode = kzalloc(sizeof(*devnode), GFP_KERNEL);
 941         if (!devnode)
 942                 return NULL;
 943
 944         devnode->major = major;
 945         devnode->minor = minor;
 946
 947         media_interface_init(mdev, &devnode->intf, MEDIA_GRAPH_INTF_DEVNODE,
 948                              type, flags);
 949
 950         return devnode;
 951 }
 952 EXPORT_SYMBOL_GPL(media_devnode_create);
 953
 954 void media_devnode_remove(struct media_intf_devnode *devnode)
 955 {
 956         media_remove_intf_links(&devnode->intf);
 957         media_gobj_destroy(&devnode->intf.graph_obj);
 958         kfree(devnode);
 959 }
 960 EXPORT_SYMBOL_GPL(media_devnode_remove);
 961
 962 struct media_link *media_create_intf_link(struct media_entity *entity,
 963                                             struct media_interface *intf,
 964                                             u32 flags)
 965 {
 966         struct media_link *link;
 967
 968         link = media_add_link(&intf->links);
 969         if (link == NULL)
 970                 return NULL;
 971
 972         link->intf = intf;
 973         link->entity = entity;
 974         link->flags = flags | MEDIA_LNK_FL_INTERFACE_LINK;
 975
 976         /* Initialize graph object embedded at the new link */
 977         media_gobj_create(intf->graph_obj.mdev, MEDIA_GRAPH_LINK,
 978                         &link->graph_obj);
 979
 980         return link;
 981 }
 982 EXPORT_SYMBOL_GPL(media_create_intf_link);
 983
 984 void __media_remove_intf_link(struct media_link *link)
 985 {
 986         list_del(&link->list);
 987         media_gobj_destroy(&link->graph_obj);
 988         kfree(link);
 989 }
 990 EXPORT_SYMBOL_GPL(__media_remove_intf_link);
 991
 992 void media_remove_intf_link(struct media_link *link)
 993 {
 994         struct media_device *mdev = link->graph_obj.mdev;
 995
 996         /* Do nothing if the intf is not registered. */
 997         if (mdev == NULL)
 998                 return;
 999
1000         mutex_lock(&mdev->graph_mutex);
1001         __media_remove_intf_link(link);
1002         mutex_unlock(&mdev->graph_mutex);
1003 }
1004 EXPORT_SYMBOL_GPL(media_remove_intf_link);
1005
1006 void __media_remove_intf_links(struct media_interface *intf)
1007 {
1008         struct media_link *link, *tmp;
1009
1010         list_for_each_entry_safe(link, tmp, &intf->links, list)
1011                 __media_remove_intf_link(link);
1012
1013 }
1014 EXPORT_SYMBOL_GPL(__media_remove_intf_links);
1015
1016 void media_remove_intf_links(struct media_interface *intf)
1017 {
1018         struct media_device *mdev = intf->graph_obj.mdev;
1019
1020         /* Do nothing if the intf is not registered. */
1021         if (mdev == NULL)
1022                 return;
1023
1024         mutex_lock(&mdev->graph_mutex);
1025         __media_remove_intf_links(intf);
1026         mutex_unlock(&mdev->graph_mutex);
1027 }
1028 EXPORT_SYMBOL_GPL(media_remove_intf_links);