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 #ifndef _MEDIA_ENTITY_H 12 #define _MEDIA_ENTITY_H 13 14 #include <linux/bitmap.h> 15 #include <linux/bug.h> 16 #include <linux/fwnode.h> 17 #include <linux/kernel.h> 18 #include <linux/list.h> 19 #include <linux/media.h> 20 21 /* Enums used internally at the media controller to represent graphs */ 22 23 /** 24 * enum media_gobj_type - type of a graph object 25 * 26 * @MEDIA_GRAPH_ENTITY: Identify a media entity 27 * @MEDIA_GRAPH_PAD: Identify a media pad 28 * @MEDIA_GRAPH_LINK: Identify a media link 29 * @MEDIA_GRAPH_INTF_DEVNODE: Identify a media Kernel API interface via 30 * a device node 31 */ 32 enum media_gobj_type { 33 MEDIA_GRAPH_ENTITY, 34 MEDIA_GRAPH_PAD, 35 MEDIA_GRAPH_LINK, 36 MEDIA_GRAPH_INTF_DEVNODE, 37 }; 38 39 #define MEDIA_BITS_PER_TYPE 8 40 #define MEDIA_BITS_PER_ID (32 - MEDIA_BITS_PER_TYPE) 41 #define MEDIA_ID_MASK GENMASK_ULL(MEDIA_BITS_PER_ID - 1, 0) 42 43 /* Structs to represent the objects that belong to a media graph */ 44 45 /** 46 * struct media_gobj - Define a graph object. 47 * 48 * @mdev: Pointer to the struct &media_device that owns the object 49 * @id: Non-zero object ID identifier. The ID should be unique 50 * inside a media_device, as it is composed by 51 * %MEDIA_BITS_PER_TYPE to store the type plus 52 * %MEDIA_BITS_PER_ID to store the ID 53 * @list: List entry stored in one of the per-type mdev object lists 54 * 55 * All objects on the media graph should have this struct embedded 56 */ 57 struct media_gobj { 58 struct media_device *mdev; 59 u32 id; 60 struct list_head list; 61 }; 62 63 #define MEDIA_ENTITY_ENUM_MAX_DEPTH 16 64 65 /** 66 * struct media_entity_enum - An enumeration of media entities. 67 * 68 * @bmap: Bit map in which each bit represents one entity at struct 69 * media_entity->internal_idx. 70 * @idx_max: Number of bits in bmap 71 */ 72 struct media_entity_enum { 73 unsigned long *bmap; 74 int idx_max; 75 }; 76 77 /** 78 * struct media_graph - Media graph traversal state 79 * 80 * @stack: Graph traversal stack; the stack contains information 81 * on the path the media entities to be walked and the 82 * links through which they were reached. 83 * @stack.entity: pointer to &struct media_entity at the graph. 84 * @stack.link: pointer to &struct list_head. 85 * @ent_enum: Visited entities 86 * @top: The top of the stack 87 */ 88 struct media_graph { 89 struct { 90 struct media_entity *entity; 91 struct list_head *link; 92 } stack[MEDIA_ENTITY_ENUM_MAX_DEPTH]; 93 94 struct media_entity_enum ent_enum; 95 int top; 96 }; 97 98 /** 99 * struct media_pipeline - Media pipeline related information 100 * 101 * @streaming_count: Streaming start count - streaming stop count 102 * @graph: Media graph walk during pipeline start / stop 103 */ 104 struct media_pipeline { 105 int streaming_count; 106 struct media_graph graph; 107 }; 108 109 /** 110 * struct media_link - A link object part of a media graph. 111 * 112 * @graph_obj: Embedded structure containing the media object common data 113 * @list: Linked list associated with an entity or an interface that 114 * owns the link. 115 * @gobj0: Part of a union. Used to get the pointer for the first 116 * graph_object of the link. 117 * @source: Part of a union. Used only if the first object (gobj0) is 118 * a pad. In that case, it represents the source pad. 119 * @intf: Part of a union. Used only if the first object (gobj0) is 120 * an interface. 121 * @gobj1: Part of a union. Used to get the pointer for the second 122 * graph_object of the link. 123 * @sink: Part of a union. Used only if the second object (gobj1) is 124 * a pad. In that case, it represents the sink pad. 125 * @entity: Part of a union. Used only if the second object (gobj1) is 126 * an entity. 127 * @reverse: Pointer to the link for the reverse direction of a pad to pad 128 * link. 129 * @flags: Link flags, as defined in uapi/media.h (MEDIA_LNK_FL_*) 130 * @is_backlink: Indicate if the link is a backlink. 131 */ 132 struct media_link { 133 struct media_gobj graph_obj; 134 struct list_head list; 135 union { 136 struct media_gobj *gobj0; 137 struct media_pad *source; 138 struct media_interface *intf; 139 }; 140 union { 141 struct media_gobj *gobj1; 142 struct media_pad *sink; 143 struct media_entity *entity; 144 }; 145 struct media_link *reverse; 146 unsigned long flags; 147 bool is_backlink; 148 }; 149 150 /** 151 * enum media_pad_signal_type - type of the signal inside a media pad 152 * 153 * @PAD_SIGNAL_DEFAULT: 154 * Default signal. Use this when all inputs or all outputs are 155 * uniquely identified by the pad number. 156 * @PAD_SIGNAL_ANALOG: 157 * The pad contains an analog signal. It can be Radio Frequency, 158 * Intermediate Frequency, a baseband signal or sub-cariers. 159 * Tuner inputs, IF-PLL demodulators, composite and s-video signals 160 * should use it. 161 * @PAD_SIGNAL_DV: 162 * Contains a digital video signal, with can be a bitstream of samples 163 * taken from an analog TV video source. On such case, it usually 164 * contains the VBI data on it. 165 * @PAD_SIGNAL_AUDIO: 166 * Contains an Intermediate Frequency analog signal from an audio 167 * sub-carrier or an audio bitstream. IF signals are provided by tuners 168 * and consumed by audio AM/FM decoders. Bitstream audio is provided by 169 * an audio decoder. 170 */ 171 enum media_pad_signal_type { 172 PAD_SIGNAL_DEFAULT = 0, 173 PAD_SIGNAL_ANALOG, 174 PAD_SIGNAL_DV, 175 PAD_SIGNAL_AUDIO, 176 }; 177 178 /** 179 * struct media_pad - A media pad graph object. 180 * 181 * @graph_obj: Embedded structure containing the media object common data 182 * @entity: Entity this pad belongs to 183 * @index: Pad index in the entity pads array, numbered from 0 to n 184 * @sig_type: Type of the signal inside a media pad 185 * @flags: Pad flags, as defined in 186 * :ref:`include/uapi/linux/media.h <media_header>` 187 * (seek for ``MEDIA_PAD_FL_*``) 188 */ 189 struct media_pad { 190 struct media_gobj graph_obj; /* must be first field in struct */ 191 struct media_entity *entity; 192 u16 index; 193 enum media_pad_signal_type sig_type; 194 unsigned long flags; 195 }; 196 197 /** 198 * struct media_entity_operations - Media entity operations 199 * @get_fwnode_pad: Return the pad number based on a fwnode endpoint or 200 * a negative value on error. This operation can be used 201 * to map a fwnode to a media pad number. Optional. 202 * @link_setup: Notify the entity of link changes. The operation can 203 * return an error, in which case link setup will be 204 * cancelled. Optional. 205 * @link_validate: Return whether a link is valid from the entity point of 206 * view. The media_pipeline_start() function 207 * validates all links by calling this operation. Optional. 208 * 209 * .. note:: 210 * 211 * Those these callbacks are called with struct &media_device.graph_mutex 212 * mutex held. 213 */ 214 struct media_entity_operations { 215 int (*get_fwnode_pad)(struct media_entity *entity, 216 struct fwnode_endpoint *endpoint); 217 int (*link_setup)(struct media_entity *entity, 218 const struct media_pad *local, 219 const struct media_pad *remote, u32 flags); 220 int (*link_validate)(struct media_link *link); 221 }; 222 223 /** 224 * enum media_entity_type - Media entity type 225 * 226 * @MEDIA_ENTITY_TYPE_BASE: 227 * The entity isn't embedded in another subsystem structure. 228 * @MEDIA_ENTITY_TYPE_VIDEO_DEVICE: 229 * The entity is embedded in a struct video_device instance. 230 * @MEDIA_ENTITY_TYPE_V4L2_SUBDEV: 231 * The entity is embedded in a struct v4l2_subdev instance. 232 * 233 * Media entity objects are often not instantiated directly, but the media 234 * entity structure is inherited by (through embedding) other subsystem-specific 235 * structures. The media entity type identifies the type of the subclass 236 * structure that implements a media entity instance. 237 * 238 * This allows runtime type identification of media entities and safe casting to 239 * the correct object type. For instance, a media entity structure instance 240 * embedded in a v4l2_subdev structure instance will have the type 241 * %MEDIA_ENTITY_TYPE_V4L2_SUBDEV and can safely be cast to a &v4l2_subdev 242 * structure using the container_of() macro. 243 */ 244 enum media_entity_type { 245 MEDIA_ENTITY_TYPE_BASE, 246 MEDIA_ENTITY_TYPE_VIDEO_DEVICE, 247 MEDIA_ENTITY_TYPE_V4L2_SUBDEV, 248 }; 249 250 /** 251 * struct media_entity - A media entity graph object. 252 * 253 * @graph_obj: Embedded structure containing the media object common data. 254 * @name: Entity name. 255 * @obj_type: Type of the object that implements the media_entity. 256 * @function: Entity main function, as defined in 257 * :ref:`include/uapi/linux/media.h <media_header>` 258 * (seek for ``MEDIA_ENT_F_*``) 259 * @flags: Entity flags, as defined in 260 * :ref:`include/uapi/linux/media.h <media_header>` 261 * (seek for ``MEDIA_ENT_FL_*``) 262 * @num_pads: Number of sink and source pads. 263 * @num_links: Total number of links, forward and back, enabled and disabled. 264 * @num_backlinks: Number of backlinks 265 * @internal_idx: An unique internal entity specific number. The numbers are 266 * re-used if entities are unregistered or registered again. 267 * @pads: Pads array with the size defined by @num_pads. 268 * @links: List of data links. 269 * @ops: Entity operations. 270 * @stream_count: Stream count for the entity. 271 * @use_count: Use count for the entity. 272 * @pipe: Pipeline this entity belongs to. 273 * @info: Union with devnode information. Kept just for backward 274 * compatibility. 275 * @info.dev: Contains device major and minor info. 276 * @info.dev.major: device node major, if the device is a devnode. 277 * @info.dev.minor: device node minor, if the device is a devnode. 278 * @major: Devnode major number (zero if not applicable). Kept just 279 * for backward compatibility. 280 * @minor: Devnode minor number (zero if not applicable). Kept just 281 * for backward compatibility. 282 * 283 * .. note:: 284 * 285 * @stream_count and @use_count reference counts must never be 286 * negative, but are signed integers on purpose: a simple ``WARN_ON(<0)`` 287 * check can be used to detect reference count bugs that would make them 288 * negative. 289 */ 290 struct media_entity { 291 struct media_gobj graph_obj; /* must be first field in struct */ 292 const char *name; 293 enum media_entity_type obj_type; 294 u32 function; 295 unsigned long flags; 296 297 u16 num_pads; 298 u16 num_links; 299 u16 num_backlinks; 300 int internal_idx; 301 302 struct media_pad *pads; 303 struct list_head links; 304 305 const struct media_entity_operations *ops; 306 307 int stream_count; 308 int use_count; 309 310 struct media_pipeline *pipe; 311 312 union { 313 struct { 314 u32 major; 315 u32 minor; 316 } dev; 317 } info; 318 }; 319 320 /** 321 * struct media_interface - A media interface graph object. 322 * 323 * @graph_obj: embedded graph object 324 * @links: List of links pointing to graph entities 325 * @type: Type of the interface as defined in 326 * :ref:`include/uapi/linux/media.h <media_header>` 327 * (seek for ``MEDIA_INTF_T_*``) 328 * @flags: Interface flags as defined in 329 * :ref:`include/uapi/linux/media.h <media_header>` 330 * (seek for ``MEDIA_INTF_FL_*``) 331 * 332 * .. note:: 333 * 334 * Currently, no flags for &media_interface is defined. 335 */ 336 struct media_interface { 337 struct media_gobj graph_obj; 338 struct list_head links; 339 u32 type; 340 u32 flags; 341 }; 342 343 /** 344 * struct media_intf_devnode - A media interface via a device node. 345 * 346 * @intf: embedded interface object 347 * @major: Major number of a device node 348 * @minor: Minor number of a device node 349 */ 350 struct media_intf_devnode { 351 struct media_interface intf; 352 353 /* Should match the fields at media_v2_intf_devnode */ 354 u32 major; 355 u32 minor; 356 }; 357 358 /** 359 * media_entity_id() - return the media entity graph object id 360 * 361 * @entity: pointer to &media_entity 362 */ 363 static inline u32 media_entity_id(struct media_entity *entity) 364 { 365 return entity->graph_obj.id; 366 } 367 368 /** 369 * media_type() - return the media object type 370 * 371 * @gobj: Pointer to the struct &media_gobj graph object 372 */ 373 static inline enum media_gobj_type media_type(struct media_gobj *gobj) 374 { 375 return gobj->id >> MEDIA_BITS_PER_ID; 376 } 377 378 /** 379 * media_id() - return the media object ID 380 * 381 * @gobj: Pointer to the struct &media_gobj graph object 382 */ 383 static inline u32 media_id(struct media_gobj *gobj) 384 { 385 return gobj->id & MEDIA_ID_MASK; 386 } 387 388 /** 389 * media_gobj_gen_id() - encapsulates type and ID on at the object ID 390 * 391 * @type: object type as define at enum &media_gobj_type. 392 * @local_id: next ID, from struct &media_device.id. 393 */ 394 static inline u32 media_gobj_gen_id(enum media_gobj_type type, u64 local_id) 395 { 396 u32 id; 397 398 id = type << MEDIA_BITS_PER_ID; 399 id |= local_id & MEDIA_ID_MASK; 400 401 return id; 402 } 403 404 /** 405 * is_media_entity_v4l2_video_device() - Check if the entity is a video_device 406 * @entity: pointer to entity 407 * 408 * Return: %true if the entity is an instance of a video_device object and can 409 * safely be cast to a struct video_device using the container_of() macro, or 410 * %false otherwise. 411 */ 412 static inline bool is_media_entity_v4l2_video_device(struct media_entity *entity) 413 { 414 return entity && entity->obj_type == MEDIA_ENTITY_TYPE_VIDEO_DEVICE; 415 } 416 417 /** 418 * is_media_entity_v4l2_subdev() - Check if the entity is a v4l2_subdev 419 * @entity: pointer to entity 420 * 421 * Return: %true if the entity is an instance of a &v4l2_subdev object and can 422 * safely be cast to a struct &v4l2_subdev using the container_of() macro, or 423 * %false otherwise. 424 */ 425 static inline bool is_media_entity_v4l2_subdev(struct media_entity *entity) 426 { 427 return entity && entity->obj_type == MEDIA_ENTITY_TYPE_V4L2_SUBDEV; 428 } 429 430 /** 431 * __media_entity_enum_init - Initialise an entity enumeration 432 * 433 * @ent_enum: Entity enumeration to be initialised 434 * @idx_max: Maximum number of entities in the enumeration 435 * 436 * Return: Returns zero on success or a negative error code. 437 */ 438 __must_check int __media_entity_enum_init(struct media_entity_enum *ent_enum, 439 int idx_max); 440 441 /** 442 * media_entity_enum_cleanup - Release resources of an entity enumeration 443 * 444 * @ent_enum: Entity enumeration to be released 445 */ 446 void media_entity_enum_cleanup(struct media_entity_enum *ent_enum); 447 448 /** 449 * media_entity_enum_zero - Clear the entire enum 450 * 451 * @ent_enum: Entity enumeration to be cleared 452 */ 453 static inline void media_entity_enum_zero(struct media_entity_enum *ent_enum) 454 { 455 bitmap_zero(ent_enum->bmap, ent_enum->idx_max); 456 } 457 458 /** 459 * media_entity_enum_set - Mark a single entity in the enum 460 * 461 * @ent_enum: Entity enumeration 462 * @entity: Entity to be marked 463 */ 464 static inline void media_entity_enum_set(struct media_entity_enum *ent_enum, 465 struct media_entity *entity) 466 { 467 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max)) 468 return; 469 470 __set_bit(entity->internal_idx, ent_enum->bmap); 471 } 472 473 /** 474 * media_entity_enum_clear - Unmark a single entity in the enum 475 * 476 * @ent_enum: Entity enumeration 477 * @entity: Entity to be unmarked 478 */ 479 static inline void media_entity_enum_clear(struct media_entity_enum *ent_enum, 480 struct media_entity *entity) 481 { 482 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max)) 483 return; 484 485 __clear_bit(entity->internal_idx, ent_enum->bmap); 486 } 487 488 /** 489 * media_entity_enum_test - Test whether the entity is marked 490 * 491 * @ent_enum: Entity enumeration 492 * @entity: Entity to be tested 493 * 494 * Returns %true if the entity was marked. 495 */ 496 static inline bool media_entity_enum_test(struct media_entity_enum *ent_enum, 497 struct media_entity *entity) 498 { 499 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max)) 500 return true; 501 502 return test_bit(entity->internal_idx, ent_enum->bmap); 503 } 504 505 /** 506 * media_entity_enum_test_and_set - Test whether the entity is marked, 507 * and mark it 508 * 509 * @ent_enum: Entity enumeration 510 * @entity: Entity to be tested 511 * 512 * Returns %true if the entity was marked, and mark it before doing so. 513 */ 514 static inline bool 515 media_entity_enum_test_and_set(struct media_entity_enum *ent_enum, 516 struct media_entity *entity) 517 { 518 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max)) 519 return true; 520 521 return __test_and_set_bit(entity->internal_idx, ent_enum->bmap); 522 } 523 524 /** 525 * media_entity_enum_empty - Test whether the entire enum is empty 526 * 527 * @ent_enum: Entity enumeration 528 * 529 * Return: %true if the entity was empty. 530 */ 531 static inline bool media_entity_enum_empty(struct media_entity_enum *ent_enum) 532 { 533 return bitmap_empty(ent_enum->bmap, ent_enum->idx_max); 534 } 535 536 /** 537 * media_entity_enum_intersects - Test whether two enums intersect 538 * 539 * @ent_enum1: First entity enumeration 540 * @ent_enum2: Second entity enumeration 541 * 542 * Return: %true if entity enumerations @ent_enum1 and @ent_enum2 intersect, 543 * otherwise %false. 544 */ 545 static inline bool media_entity_enum_intersects( 546 struct media_entity_enum *ent_enum1, 547 struct media_entity_enum *ent_enum2) 548 { 549 WARN_ON(ent_enum1->idx_max != ent_enum2->idx_max); 550 551 return bitmap_intersects(ent_enum1->bmap, ent_enum2->bmap, 552 min(ent_enum1->idx_max, ent_enum2->idx_max)); 553 } 554 555 /** 556 * gobj_to_entity - returns the struct &media_entity pointer from the 557 * @gobj contained on it. 558 * 559 * @gobj: Pointer to the struct &media_gobj graph object 560 */ 561 #define gobj_to_entity(gobj) \ 562 container_of(gobj, struct media_entity, graph_obj) 563 564 /** 565 * gobj_to_pad - returns the struct &media_pad pointer from the 566 * @gobj contained on it. 567 * 568 * @gobj: Pointer to the struct &media_gobj graph object 569 */ 570 #define gobj_to_pad(gobj) \ 571 container_of(gobj, struct media_pad, graph_obj) 572 573 /** 574 * gobj_to_link - returns the struct &media_link pointer from the 575 * @gobj contained on it. 576 * 577 * @gobj: Pointer to the struct &media_gobj graph object 578 */ 579 #define gobj_to_link(gobj) \ 580 container_of(gobj, struct media_link, graph_obj) 581 582 /** 583 * gobj_to_intf - returns the struct &media_interface pointer from the 584 * @gobj contained on it. 585 * 586 * @gobj: Pointer to the struct &media_gobj graph object 587 */ 588 #define gobj_to_intf(gobj) \ 589 container_of(gobj, struct media_interface, graph_obj) 590 591 /** 592 * intf_to_devnode - returns the struct media_intf_devnode pointer from the 593 * @intf contained on it. 594 * 595 * @intf: Pointer to struct &media_intf_devnode 596 */ 597 #define intf_to_devnode(intf) \ 598 container_of(intf, struct media_intf_devnode, intf) 599 600 /** 601 * media_gobj_create - Initialize a graph object 602 * 603 * @mdev: Pointer to the &media_device that contains the object 604 * @type: Type of the object 605 * @gobj: Pointer to the struct &media_gobj graph object 606 * 607 * This routine initializes the embedded struct &media_gobj inside a 608 * media graph object. It is called automatically if ``media_*_create`` 609 * function calls are used. However, if the object (entity, link, pad, 610 * interface) is embedded on some other object, this function should be 611 * called before registering the object at the media controller. 612 */ 613 void media_gobj_create(struct media_device *mdev, 614 enum media_gobj_type type, 615 struct media_gobj *gobj); 616 617 /** 618 * media_gobj_destroy - Stop using a graph object on a media device 619 * 620 * @gobj: Pointer to the struct &media_gobj graph object 621 * 622 * This should be called by all routines like media_device_unregister() 623 * that remove/destroy media graph objects. 624 */ 625 void media_gobj_destroy(struct media_gobj *gobj); 626 627 /** 628 * media_entity_pads_init() - Initialize the entity pads 629 * 630 * @entity: entity where the pads belong 631 * @num_pads: total number of sink and source pads 632 * @pads: Array of @num_pads pads. 633 * 634 * The pads array is managed by the entity driver and passed to 635 * media_entity_pads_init() where its pointer will be stored in the 636 * &media_entity structure. 637 * 638 * If no pads are needed, drivers could either directly fill 639 * &media_entity->num_pads with 0 and &media_entity->pads with %NULL or call 640 * this function that will do the same. 641 * 642 * As the number of pads is known in advance, the pads array is not allocated 643 * dynamically but is managed by the entity driver. Most drivers will embed the 644 * pads array in a driver-specific structure, avoiding dynamic allocation. 645 * 646 * Drivers must set the direction of every pad in the pads array before calling 647 * media_entity_pads_init(). The function will initialize the other pads fields. 648 */ 649 int media_entity_pads_init(struct media_entity *entity, u16 num_pads, 650 struct media_pad *pads); 651 652 /** 653 * media_entity_cleanup() - free resources associated with an entity 654 * 655 * @entity: entity where the pads belong 656 * 657 * This function must be called during the cleanup phase after unregistering 658 * the entity (currently, it does nothing). 659 */ 660 #if IS_ENABLED(CONFIG_MEDIA_CONTROLLER) 661 static inline void media_entity_cleanup(struct media_entity *entity) {} 662 #else 663 #define media_entity_cleanup(entity) do { } while (false) 664 #endif 665 666 /** 667 * media_get_pad_index() - retrieves a pad index from an entity 668 * 669 * @entity: entity where the pads belong 670 * @is_sink: true if the pad is a sink, false if it is a source 671 * @sig_type: type of signal of the pad to be search 672 * 673 * This helper function finds the first pad index inside an entity that 674 * satisfies both @is_sink and @sig_type conditions. 675 * 676 * Return: 677 * 678 * On success, return the pad number. If the pad was not found or the media 679 * entity is a NULL pointer, return -EINVAL. 680 */ 681 int media_get_pad_index(struct media_entity *entity, bool is_sink, 682 enum media_pad_signal_type sig_type); 683 684 /** 685 * media_create_pad_link() - creates a link between two entities. 686 * 687 * @source: pointer to &media_entity of the source pad. 688 * @source_pad: number of the source pad in the pads array 689 * @sink: pointer to &media_entity of the sink pad. 690 * @sink_pad: number of the sink pad in the pads array. 691 * @flags: Link flags, as defined in 692 * :ref:`include/uapi/linux/media.h <media_header>` 693 * ( seek for ``MEDIA_LNK_FL_*``) 694 * 695 * Valid values for flags: 696 * 697 * %MEDIA_LNK_FL_ENABLED 698 * Indicates that the link is enabled and can be used to transfer media data. 699 * When two or more links target a sink pad, only one of them can be 700 * enabled at a time. 701 * 702 * %MEDIA_LNK_FL_IMMUTABLE 703 * Indicates that the link enabled state can't be modified at runtime. If 704 * %MEDIA_LNK_FL_IMMUTABLE is set, then %MEDIA_LNK_FL_ENABLED must also be 705 * set, since an immutable link is always enabled. 706 * 707 * .. note:: 708 * 709 * Before calling this function, media_entity_pads_init() and 710 * media_device_register_entity() should be called previously for both ends. 711 */ 712 __must_check int media_create_pad_link(struct media_entity *source, 713 u16 source_pad, struct media_entity *sink, 714 u16 sink_pad, u32 flags); 715 716 /** 717 * media_create_pad_links() - creates a link between two entities. 718 * 719 * @mdev: Pointer to the media_device that contains the object 720 * @source_function: Function of the source entities. Used only if @source is 721 * NULL. 722 * @source: pointer to &media_entity of the source pad. If NULL, it will use 723 * all entities that matches the @sink_function. 724 * @source_pad: number of the source pad in the pads array 725 * @sink_function: Function of the sink entities. Used only if @sink is NULL. 726 * @sink: pointer to &media_entity of the sink pad. If NULL, it will use 727 * all entities that matches the @sink_function. 728 * @sink_pad: number of the sink pad in the pads array. 729 * @flags: Link flags, as defined in include/uapi/linux/media.h. 730 * @allow_both_undefined: if %true, then both @source and @sink can be NULL. 731 * In such case, it will create a crossbar between all entities that 732 * matches @source_function to all entities that matches @sink_function. 733 * If %false, it will return 0 and won't create any link if both @source 734 * and @sink are NULL. 735 * 736 * Valid values for flags: 737 * 738 * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be 739 * used to transfer media data. If multiple links are created and this 740 * flag is passed as an argument, only the first created link will have 741 * this flag. 742 * 743 * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't 744 * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then 745 * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is 746 * always enabled. 747 * 748 * It is common for some devices to have multiple source and/or sink entities 749 * of the same type that should be linked. While media_create_pad_link() 750 * creates link by link, this function is meant to allow 1:n, n:1 and even 751 * cross-bar (n:n) links. 752 * 753 * .. note:: 754 * 755 * Before calling this function, media_entity_pads_init() and 756 * media_device_register_entity() should be called previously for the 757 * entities to be linked. 758 */ 759 int media_create_pad_links(const struct media_device *mdev, 760 const u32 source_function, 761 struct media_entity *source, 762 const u16 source_pad, 763 const u32 sink_function, 764 struct media_entity *sink, 765 const u16 sink_pad, 766 u32 flags, 767 const bool allow_both_undefined); 768 769 void __media_entity_remove_links(struct media_entity *entity); 770 771 /** 772 * media_entity_remove_links() - remove all links associated with an entity 773 * 774 * @entity: pointer to &media_entity 775 * 776 * .. note:: 777 * 778 * This is called automatically when an entity is unregistered via 779 * media_device_register_entity(). 780 */ 781 void media_entity_remove_links(struct media_entity *entity); 782 783 /** 784 * __media_entity_setup_link - Configure a media link without locking 785 * @link: The link being configured 786 * @flags: Link configuration flags 787 * 788 * The bulk of link setup is handled by the two entities connected through the 789 * link. This function notifies both entities of the link configuration change. 790 * 791 * If the link is immutable or if the current and new configuration are 792 * identical, return immediately. 793 * 794 * The user is expected to hold link->source->parent->mutex. If not, 795 * media_entity_setup_link() should be used instead. 796 */ 797 int __media_entity_setup_link(struct media_link *link, u32 flags); 798 799 /** 800 * media_entity_setup_link() - changes the link flags properties in runtime 801 * 802 * @link: pointer to &media_link 803 * @flags: the requested new link flags 804 * 805 * The only configurable property is the %MEDIA_LNK_FL_ENABLED link flag 806 * to enable/disable a link. Links marked with the 807 * %MEDIA_LNK_FL_IMMUTABLE link flag can not be enabled or disabled. 808 * 809 * When a link is enabled or disabled, the media framework calls the 810 * link_setup operation for the two entities at the source and sink of the 811 * link, in that order. If the second link_setup call fails, another 812 * link_setup call is made on the first entity to restore the original link 813 * flags. 814 * 815 * Media device drivers can be notified of link setup operations by setting the 816 * &media_device.link_notify pointer to a callback function. If provided, the 817 * notification callback will be called before enabling and after disabling 818 * links. 819 * 820 * Entity drivers must implement the link_setup operation if any of their links 821 * is non-immutable. The operation must either configure the hardware or store 822 * the configuration information to be applied later. 823 * 824 * Link configuration must not have any side effect on other links. If an 825 * enabled link at a sink pad prevents another link at the same pad from 826 * being enabled, the link_setup operation must return %-EBUSY and can't 827 * implicitly disable the first enabled link. 828 * 829 * .. note:: 830 * 831 * The valid values of the flags for the link is the same as described 832 * on media_create_pad_link(), for pad to pad links or the same as described 833 * on media_create_intf_link(), for interface to entity links. 834 */ 835 int media_entity_setup_link(struct media_link *link, u32 flags); 836 837 /** 838 * media_entity_find_link - Find a link between two pads 839 * @source: Source pad 840 * @sink: Sink pad 841 * 842 * Return: returns a pointer to the link between the two entities. If no 843 * such link exists, return %NULL. 844 */ 845 struct media_link *media_entity_find_link(struct media_pad *source, 846 struct media_pad *sink); 847 848 /** 849 * media_entity_remote_pad - Find the pad at the remote end of a link 850 * @pad: Pad at the local end of the link 851 * 852 * Search for a remote pad connected to the given pad by iterating over all 853 * links originating or terminating at that pad until an enabled link is found. 854 * 855 * Return: returns a pointer to the pad at the remote end of the first found 856 * enabled link, or %NULL if no enabled link has been found. 857 */ 858 struct media_pad *media_entity_remote_pad(const struct media_pad *pad); 859 860 /** 861 * media_entity_get_fwnode_pad - Get pad number from fwnode 862 * 863 * @entity: The entity 864 * @fwnode: Pointer to the fwnode_handle which should be used to find the pad 865 * @direction_flags: Expected direction of the pad, as defined in 866 * :ref:`include/uapi/linux/media.h <media_header>` 867 * (seek for ``MEDIA_PAD_FL_*``) 868 * 869 * This function can be used to resolve the media pad number from 870 * a fwnode. This is useful for devices which use more complex 871 * mappings of media pads. 872 * 873 * If the entity does not implement the get_fwnode_pad() operation 874 * then this function searches the entity for the first pad that 875 * matches the @direction_flags. 876 * 877 * Return: returns the pad number on success or a negative error code. 878 */ 879 int media_entity_get_fwnode_pad(struct media_entity *entity, 880 struct fwnode_handle *fwnode, 881 unsigned long direction_flags); 882 883 /** 884 * media_graph_walk_init - Allocate resources used by graph walk. 885 * 886 * @graph: Media graph structure that will be used to walk the graph 887 * @mdev: Pointer to the &media_device that contains the object 888 */ 889 __must_check int media_graph_walk_init( 890 struct media_graph *graph, struct media_device *mdev); 891 892 /** 893 * media_graph_walk_cleanup - Release resources used by graph walk. 894 * 895 * @graph: Media graph structure that will be used to walk the graph 896 */ 897 void media_graph_walk_cleanup(struct media_graph *graph); 898 899 /** 900 * media_graph_walk_start - Start walking the media graph at a 901 * given entity 902 * 903 * @graph: Media graph structure that will be used to walk the graph 904 * @entity: Starting entity 905 * 906 * Before using this function, media_graph_walk_init() must be 907 * used to allocate resources used for walking the graph. This 908 * function initializes the graph traversal structure to walk the 909 * entities graph starting at the given entity. The traversal 910 * structure must not be modified by the caller during graph 911 * traversal. After the graph walk, the resources must be released 912 * using media_graph_walk_cleanup(). 913 */ 914 void media_graph_walk_start(struct media_graph *graph, 915 struct media_entity *entity); 916 917 /** 918 * media_graph_walk_next - Get the next entity in the graph 919 * @graph: Media graph structure 920 * 921 * Perform a depth-first traversal of the given media entities graph. 922 * 923 * The graph structure must have been previously initialized with a call to 924 * media_graph_walk_start(). 925 * 926 * Return: returns the next entity in the graph or %NULL if the whole graph 927 * have been traversed. 928 */ 929 struct media_entity *media_graph_walk_next(struct media_graph *graph); 930 931 /** 932 * media_pipeline_start - Mark a pipeline as streaming 933 * @entity: Starting entity 934 * @pipe: Media pipeline to be assigned to all entities in the pipeline. 935 * 936 * Mark all entities connected to a given entity through enabled links, either 937 * directly or indirectly, as streaming. The given pipeline object is assigned 938 * to every entity in the pipeline and stored in the media_entity pipe field. 939 * 940 * Calls to this function can be nested, in which case the same number of 941 * media_pipeline_stop() calls will be required to stop streaming. The 942 * pipeline pointer must be identical for all nested calls to 943 * media_pipeline_start(). 944 */ 945 __must_check int media_pipeline_start(struct media_entity *entity, 946 struct media_pipeline *pipe); 947 /** 948 * __media_pipeline_start - Mark a pipeline as streaming 949 * 950 * @entity: Starting entity 951 * @pipe: Media pipeline to be assigned to all entities in the pipeline. 952 * 953 * ..note:: This is the non-locking version of media_pipeline_start() 954 */ 955 __must_check int __media_pipeline_start(struct media_entity *entity, 956 struct media_pipeline *pipe); 957 958 /** 959 * media_pipeline_stop - Mark a pipeline as not streaming 960 * @entity: Starting entity 961 * 962 * Mark all entities connected to a given entity through enabled links, either 963 * directly or indirectly, as not streaming. The media_entity pipe field is 964 * reset to %NULL. 965 * 966 * If multiple calls to media_pipeline_start() have been made, the same 967 * number of calls to this function are required to mark the pipeline as not 968 * streaming. 969 */ 970 void media_pipeline_stop(struct media_entity *entity); 971 972 /** 973 * __media_pipeline_stop - Mark a pipeline as not streaming 974 * 975 * @entity: Starting entity 976 * 977 * .. note:: This is the non-locking version of media_pipeline_stop() 978 */ 979 void __media_pipeline_stop(struct media_entity *entity); 980 981 /** 982 * media_devnode_create() - creates and initializes a device node interface 983 * 984 * @mdev: pointer to struct &media_device 985 * @type: type of the interface, as given by 986 * :ref:`include/uapi/linux/media.h <media_header>` 987 * ( seek for ``MEDIA_INTF_T_*``) macros. 988 * @flags: Interface flags, as defined in 989 * :ref:`include/uapi/linux/media.h <media_header>` 990 * ( seek for ``MEDIA_INTF_FL_*``) 991 * @major: Device node major number. 992 * @minor: Device node minor number. 993 * 994 * Return: if succeeded, returns a pointer to the newly allocated 995 * &media_intf_devnode pointer. 996 * 997 * .. note:: 998 * 999 * Currently, no flags for &media_interface is defined. 1000 */ 1001 struct media_intf_devnode * 1002 __must_check media_devnode_create(struct media_device *mdev, 1003 u32 type, u32 flags, 1004 u32 major, u32 minor); 1005 /** 1006 * media_devnode_remove() - removes a device node interface 1007 * 1008 * @devnode: pointer to &media_intf_devnode to be freed. 1009 * 1010 * When a device node interface is removed, all links to it are automatically 1011 * removed. 1012 */ 1013 void media_devnode_remove(struct media_intf_devnode *devnode); 1014 struct media_link * 1015 1016 /** 1017 * media_create_intf_link() - creates a link between an entity and an interface 1018 * 1019 * @entity: pointer to %media_entity 1020 * @intf: pointer to %media_interface 1021 * @flags: Link flags, as defined in 1022 * :ref:`include/uapi/linux/media.h <media_header>` 1023 * ( seek for ``MEDIA_LNK_FL_*``) 1024 * 1025 * 1026 * Valid values for flags: 1027 * 1028 * %MEDIA_LNK_FL_ENABLED 1029 * Indicates that the interface is connected to the entity hardware. 1030 * That's the default value for interfaces. An interface may be disabled if 1031 * the hardware is busy due to the usage of some other interface that it is 1032 * currently controlling the hardware. 1033 * 1034 * A typical example is an hybrid TV device that handle only one type of 1035 * stream on a given time. So, when the digital TV is streaming, 1036 * the V4L2 interfaces won't be enabled, as such device is not able to 1037 * also stream analog TV or radio. 1038 * 1039 * .. note:: 1040 * 1041 * Before calling this function, media_devnode_create() should be called for 1042 * the interface and media_device_register_entity() should be called for the 1043 * interface that will be part of the link. 1044 */ 1045 __must_check media_create_intf_link(struct media_entity *entity, 1046 struct media_interface *intf, 1047 u32 flags); 1048 /** 1049 * __media_remove_intf_link() - remove a single interface link 1050 * 1051 * @link: pointer to &media_link. 1052 * 1053 * .. note:: This is an unlocked version of media_remove_intf_link() 1054 */ 1055 void __media_remove_intf_link(struct media_link *link); 1056 1057 /** 1058 * media_remove_intf_link() - remove a single interface link 1059 * 1060 * @link: pointer to &media_link. 1061 * 1062 * .. note:: Prefer to use this one, instead of __media_remove_intf_link() 1063 */ 1064 void media_remove_intf_link(struct media_link *link); 1065 1066 /** 1067 * __media_remove_intf_links() - remove all links associated with an interface 1068 * 1069 * @intf: pointer to &media_interface 1070 * 1071 * .. note:: This is an unlocked version of media_remove_intf_links(). 1072 */ 1073 void __media_remove_intf_links(struct media_interface *intf); 1074 1075 /** 1076 * media_remove_intf_links() - remove all links associated with an interface 1077 * 1078 * @intf: pointer to &media_interface 1079 * 1080 * .. note:: 1081 * 1082 * #) This is called automatically when an entity is unregistered via 1083 * media_device_register_entity() and by media_devnode_remove(). 1084 * 1085 * #) Prefer to use this one, instead of __media_remove_intf_links(). 1086 */ 1087 void media_remove_intf_links(struct media_interface *intf); 1088 1089 /** 1090 * media_entity_call - Calls a struct media_entity_operations operation on 1091 * an entity 1092 * 1093 * @entity: entity where the @operation will be called 1094 * @operation: type of the operation. Should be the name of a member of 1095 * struct &media_entity_operations. 1096 * 1097 * This helper function will check if @operation is not %NULL. On such case, 1098 * it will issue a call to @operation\(@entity, @args\). 1099 */ 1100 1101 #define media_entity_call(entity, operation, args...) \ 1102 (((entity)->ops && (entity)->ops->operation) ? \ 1103 (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD) 1104 1105 #endif 1106