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/container_of.h>
  17#include <linux/fwnode.h>
 
  18#include <linux/list.h>
  19#include <linux/media.h>
  20#include <linux/minmax.h>
  21#include <linux/types.h>
  22
  23/* Enums used internally at the media controller to represent graphs */
  24
  25/**
  26 * enum media_gobj_type - type of a graph object
  27 *
  28 * @MEDIA_GRAPH_ENTITY:		Identify a media entity
  29 * @MEDIA_GRAPH_PAD:		Identify a media pad
  30 * @MEDIA_GRAPH_LINK:		Identify a media link
  31 * @MEDIA_GRAPH_INTF_DEVNODE:	Identify a media Kernel API interface via
  32 *				a device node
  33 */
  34enum media_gobj_type {
  35	MEDIA_GRAPH_ENTITY,
  36	MEDIA_GRAPH_PAD,
  37	MEDIA_GRAPH_LINK,
  38	MEDIA_GRAPH_INTF_DEVNODE,
  39};
  40
  41#define MEDIA_BITS_PER_TYPE		8
  42#define MEDIA_BITS_PER_ID		(32 - MEDIA_BITS_PER_TYPE)
  43#define MEDIA_ID_MASK			 GENMASK_ULL(MEDIA_BITS_PER_ID - 1, 0)
  44
  45/* Structs to represent the objects that belong to a media graph */
  46
  47/**
  48 * struct media_gobj - Define a graph object.
  49 *
  50 * @mdev:	Pointer to the struct &media_device that owns the object
  51 * @id:		Non-zero object ID identifier. The ID should be unique
  52 *		inside a media_device, as it is composed by
  53 *		%MEDIA_BITS_PER_TYPE to store the type plus
  54 *		%MEDIA_BITS_PER_ID to store the ID
  55 * @list:	List entry stored in one of the per-type mdev object lists
  56 *
  57 * All objects on the media graph should have this struct embedded
  58 */
  59struct media_gobj {
  60	struct media_device	*mdev;
  61	u32			id;
  62	struct list_head	list;
  63};
  64
  65#define MEDIA_ENTITY_ENUM_MAX_DEPTH	16
  66
  67/**
  68 * struct media_entity_enum - An enumeration of media entities.
  69 *
  70 * @bmap:	Bit map in which each bit represents one entity at struct
  71 *		media_entity->internal_idx.
  72 * @idx_max:	Number of bits in bmap
  73 */
  74struct media_entity_enum {
  75	unsigned long *bmap;
  76	int idx_max;
  77};
  78
  79/**
  80 * struct media_graph - Media graph traversal state
  81 *
  82 * @stack:		Graph traversal stack; the stack contains information
  83 *			on the path the media entities to be walked and the
  84 *			links through which they were reached.
  85 * @stack.entity:	pointer to &struct media_entity at the graph.
  86 * @stack.link:		pointer to &struct list_head.
  87 * @ent_enum:		Visited entities
  88 * @top:		The top of the stack
  89 */
  90struct media_graph {
  91	struct {
  92		struct media_entity *entity;
  93		struct list_head *link;
  94	} stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];
  95
  96	struct media_entity_enum ent_enum;
  97	int top;
  98};
  99
 100/**
 101 * struct media_pipeline - Media pipeline related information
 102 *
 103 * @allocated:		Media pipeline allocated and freed by the framework
 104 * @mdev:		The media device the pipeline is part of
 105 * @pads:		List of media_pipeline_pad
 106 * @start_count:	Media pipeline start - stop count
 107 */
 108struct media_pipeline {
 109	bool allocated;
 110	struct media_device *mdev;
 111	struct list_head pads;
 112	int start_count;
 113};
 114
 115/**
 116 * struct media_pipeline_pad - A pad part of a media pipeline
 117 *
 118 * @list:		Entry in the media_pad pads list
 119 * @pipe:		The media_pipeline that the pad is part of
 120 * @pad:		The media pad
 121 *
 122 * This structure associate a pad with a media pipeline. Instances of
 123 * media_pipeline_pad are created by media_pipeline_start() when it builds the
 124 * pipeline, and stored in the &media_pad.pads list. media_pipeline_stop()
 125 * removes the entries from the list and deletes them.
 126 */
 127struct media_pipeline_pad {
 128	struct list_head list;
 129	struct media_pipeline *pipe;
 130	struct media_pad *pad;
 131};
 132
 133/**
 134 * struct media_pipeline_pad_iter - Iterator for media_pipeline_for_each_pad
 135 *
 136 * @cursor: The current element
 137 */
 138struct media_pipeline_pad_iter {
 139	struct list_head *cursor;
 140};
 141
 142/**
 143 * struct media_pipeline_entity_iter - Iterator for media_pipeline_for_each_entity
 144 *
 145 * @ent_enum: The entity enumeration tracker
 146 * @cursor: The current element
 147 */
 148struct media_pipeline_entity_iter {
 149	struct media_entity_enum ent_enum;
 150	struct list_head *cursor;
 151};
 152
 153/**
 154 * struct media_link - A link object part of a media graph.
 155 *
 156 * @graph_obj:	Embedded structure containing the media object common data
 157 * @list:	Linked list associated with an entity or an interface that
 158 *		owns the link.
 159 * @gobj0:	Part of a union. Used to get the pointer for the first
 160 *		graph_object of the link.
 161 * @source:	Part of a union. Used only if the first object (gobj0) is
 162 *		a pad. In that case, it represents the source pad.
 163 * @intf:	Part of a union. Used only if the first object (gobj0) is
 164 *		an interface.
 165 * @gobj1:	Part of a union. Used to get the pointer for the second
 166 *		graph_object of the link.
 167 * @sink:	Part of a union. Used only if the second object (gobj1) is
 168 *		a pad. In that case, it represents the sink pad.
 169 * @entity:	Part of a union. Used only if the second object (gobj1) is
 170 *		an entity.
 171 * @reverse:	Pointer to the link for the reverse direction of a pad to pad
 172 *		link.
 173 * @flags:	Link flags, as defined in uapi/media.h (MEDIA_LNK_FL_*)
 174 * @is_backlink: Indicate if the link is a backlink.
 175 */
 176struct media_link {
 177	struct media_gobj graph_obj;
 178	struct list_head list;
 179	union {
 180		struct media_gobj *gobj0;
 181		struct media_pad *source;
 182		struct media_interface *intf;
 183	};
 184	union {
 185		struct media_gobj *gobj1;
 186		struct media_pad *sink;
 187		struct media_entity *entity;
 188	};
 189	struct media_link *reverse;
 190	unsigned long flags;
 191	bool is_backlink;
 192};
 193
 194/**
 195 * enum media_pad_signal_type - type of the signal inside a media pad
 196 *
 197 * @PAD_SIGNAL_DEFAULT:
 198 *	Default signal. Use this when all inputs or all outputs are
 199 *	uniquely identified by the pad number.
 200 * @PAD_SIGNAL_ANALOG:
 201 *	The pad contains an analog signal. It can be Radio Frequency,
 202 *	Intermediate Frequency, a baseband signal or sub-carriers.
 203 *	Tuner inputs, IF-PLL demodulators, composite and s-video signals
 204 *	should use it.
 205 * @PAD_SIGNAL_DV:
 206 *	Contains a digital video signal, with can be a bitstream of samples
 207 *	taken from an analog TV video source. On such case, it usually
 208 *	contains the VBI data on it.
 209 * @PAD_SIGNAL_AUDIO:
 210 *	Contains an Intermediate Frequency analog signal from an audio
 211 *	sub-carrier or an audio bitstream. IF signals are provided by tuners
 212 *	and consumed by	audio AM/FM decoders. Bitstream audio is provided by
 213 *	an audio decoder.
 214 */
 215enum media_pad_signal_type {
 216	PAD_SIGNAL_DEFAULT = 0,
 217	PAD_SIGNAL_ANALOG,
 218	PAD_SIGNAL_DV,
 219	PAD_SIGNAL_AUDIO,
 220};
 221
 222/**
 223 * struct media_pad - A media pad graph object.
 224 *
 225 * @graph_obj:	Embedded structure containing the media object common data
 226 * @entity:	Entity this pad belongs to
 227 * @index:	Pad index in the entity pads array, numbered from 0 to n
 228 * @num_links:	Number of links connected to this pad
 229 * @sig_type:	Type of the signal inside a media pad
 230 * @flags:	Pad flags, as defined in
 231 *		:ref:`include/uapi/linux/media.h <media_header>`
 232 *		(seek for ``MEDIA_PAD_FL_*``)
 233 * @pipe:	Pipeline this pad belongs to. Use media_entity_pipeline() to
 234 *		access this field.
 235 */
 236struct media_pad {
 237	struct media_gobj graph_obj;	/* must be first field in struct */
 238	struct media_entity *entity;
 239	u16 index;
 240	u16 num_links;
 241	enum media_pad_signal_type sig_type;
 242	unsigned long flags;
 243
 244	/*
 245	 * The fields below are private, and should only be accessed via
 246	 * appropriate functions.
 247	 */
 248	struct media_pipeline *pipe;
 249};
 250
 251/**
 252 * struct media_entity_operations - Media entity operations
 253 * @get_fwnode_pad:	Return the pad number based on a fwnode endpoint or
 254 *			a negative value on error. This operation can be used
 255 *			to map a fwnode to a media pad number. Optional.
 256 * @link_setup:		Notify the entity of link changes. The operation can
 257 *			return an error, in which case link setup will be
 258 *			cancelled. Optional.
 259 * @link_validate:	Return whether a link is valid from the entity point of
 260 *			view. The media_pipeline_start() function
 261 *			validates all links by calling this operation. Optional.
 262 * @has_pad_interdep:	Return whether two pads of the entity are
 263 *			interdependent. If two pads are interdependent they are
 264 *			part of the same pipeline and enabling one of the pads
 265 *			means that the other pad will become "locked" and
 266 *			doesn't allow configuration changes. pad0 and pad1 are
 267 *			guaranteed to not both be sinks or sources. Never call
 268 *			the .has_pad_interdep() operation directly, always use
 269 *			media_entity_has_pad_interdep().
 270 *			Optional: If the operation isn't implemented all pads
 271 *			will be considered as interdependent.
 272 *
 273 * .. note::
 274 *
 275 *    Those these callbacks are called with struct &media_device.graph_mutex
 276 *    mutex held.
 277 */
 278struct media_entity_operations {
 279	int (*get_fwnode_pad)(struct media_entity *entity,
 280			      struct fwnode_endpoint *endpoint);
 281	int (*link_setup)(struct media_entity *entity,
 282			  const struct media_pad *local,
 283			  const struct media_pad *remote, u32 flags);
 284	int (*link_validate)(struct media_link *link);
 285	bool (*has_pad_interdep)(struct media_entity *entity, unsigned int pad0,
 286				 unsigned int pad1);
 287};
 288
 289/**
 290 * enum media_entity_type - Media entity type
 291 *
 292 * @MEDIA_ENTITY_TYPE_BASE:
 293 *	The entity isn't embedded in another subsystem structure.
 294 * @MEDIA_ENTITY_TYPE_VIDEO_DEVICE:
 295 *	The entity is embedded in a struct video_device instance.
 296 * @MEDIA_ENTITY_TYPE_V4L2_SUBDEV:
 297 *	The entity is embedded in a struct v4l2_subdev instance.
 298 *
 299 * Media entity objects are often not instantiated directly, but the media
 300 * entity structure is inherited by (through embedding) other subsystem-specific
 301 * structures. The media entity type identifies the type of the subclass
 302 * structure that implements a media entity instance.
 303 *
 304 * This allows runtime type identification of media entities and safe casting to
 305 * the correct object type. For instance, a media entity structure instance
 306 * embedded in a v4l2_subdev structure instance will have the type
 307 * %MEDIA_ENTITY_TYPE_V4L2_SUBDEV and can safely be cast to a &v4l2_subdev
 308 * structure using the container_of() macro.
 309 */
 310enum media_entity_type {
 311	MEDIA_ENTITY_TYPE_BASE,
 312	MEDIA_ENTITY_TYPE_VIDEO_DEVICE,
 313	MEDIA_ENTITY_TYPE_V4L2_SUBDEV,
 314};
 315
 316/**
 317 * struct media_entity - A media entity graph object.
 318 *
 319 * @graph_obj:	Embedded structure containing the media object common data.
 320 * @name:	Entity name.
 321 * @obj_type:	Type of the object that implements the media_entity.
 322 * @function:	Entity main function, as defined in
 323 *		:ref:`include/uapi/linux/media.h <media_header>`
 324 *		(seek for ``MEDIA_ENT_F_*``)
 325 * @flags:	Entity flags, as defined in
 326 *		:ref:`include/uapi/linux/media.h <media_header>`
 327 *		(seek for ``MEDIA_ENT_FL_*``)
 328 * @num_pads:	Number of sink and source pads.
 329 * @num_links:	Total number of links, forward and back, enabled and disabled.
 330 * @num_backlinks: Number of backlinks
 331 * @internal_idx: An unique internal entity specific number. The numbers are
 332 *		re-used if entities are unregistered or registered again.
 333 * @pads:	Pads array with the size defined by @num_pads.
 334 * @links:	List of data links.
 335 * @ops:	Entity operations.
 
 336 * @use_count:	Use count for the entity.
 
 337 * @info:	Union with devnode information.  Kept just for backward
 338 *		compatibility.
 339 * @info.dev:	Contains device major and minor info.
 340 * @info.dev.major: device node major, if the device is a devnode.
 341 * @info.dev.minor: device node minor, if the device is a devnode.
 
 
 
 
 342 *
 343 * .. note::
 344 *
 345 *    The @use_count reference count must never be negative, but is a signed
 346 *    integer on purpose: a simple ``WARN_ON(<0)`` check can be used to detect
 347 *    reference count bugs that would make it negative.
 
 348 */
 349struct media_entity {
 350	struct media_gobj graph_obj;	/* must be first field in struct */
 351	const char *name;
 352	enum media_entity_type obj_type;
 353	u32 function;
 354	unsigned long flags;
 355
 356	u16 num_pads;
 357	u16 num_links;
 358	u16 num_backlinks;
 359	int internal_idx;
 360
 361	struct media_pad *pads;
 362	struct list_head links;
 363
 364	const struct media_entity_operations *ops;
 365
 
 366	int use_count;
 367
 
 
 368	union {
 369		struct {
 370			u32 major;
 371			u32 minor;
 372		} dev;
 373	} info;
 374};
 375
 376/**
 377 * media_entity_for_each_pad - Iterate on all pads in an entity
 378 * @entity: The entity the pads belong to
 379 * @iter: The iterator pad
 380 *
 381 * Iterate on all pads in a media entity.
 382 */
 383#define media_entity_for_each_pad(entity, iter)			\
 384	for (iter = (entity)->pads;				\
 385	     iter < &(entity)->pads[(entity)->num_pads];	\
 386	     ++iter)
 387
 388/**
 389 * struct media_interface - A media interface graph object.
 390 *
 391 * @graph_obj:		embedded graph object
 392 * @links:		List of links pointing to graph entities
 393 * @type:		Type of the interface as defined in
 394 *			:ref:`include/uapi/linux/media.h <media_header>`
 395 *			(seek for ``MEDIA_INTF_T_*``)
 396 * @flags:		Interface flags as defined in
 397 *			:ref:`include/uapi/linux/media.h <media_header>`
 398 *			(seek for ``MEDIA_INTF_FL_*``)
 399 *
 400 * .. note::
 401 *
 402 *    Currently, no flags for &media_interface is defined.
 403 */
 404struct media_interface {
 405	struct media_gobj		graph_obj;
 406	struct list_head		links;
 407	u32				type;
 408	u32				flags;
 409};
 410
 411/**
 412 * struct media_intf_devnode - A media interface via a device node.
 413 *
 414 * @intf:	embedded interface object
 415 * @major:	Major number of a device node
 416 * @minor:	Minor number of a device node
 417 */
 418struct media_intf_devnode {
 419	struct media_interface		intf;
 420
 421	/* Should match the fields at media_v2_intf_devnode */
 422	u32				major;
 423	u32				minor;
 424};
 425
 426/**
 427 * media_entity_id() - return the media entity graph object id
 428 *
 429 * @entity:	pointer to &media_entity
 430 */
 431static inline u32 media_entity_id(struct media_entity *entity)
 432{
 433	return entity->graph_obj.id;
 434}
 435
 436/**
 437 * media_type() - return the media object type
 438 *
 439 * @gobj:	Pointer to the struct &media_gobj graph object
 440 */
 441static inline enum media_gobj_type media_type(struct media_gobj *gobj)
 442{
 443	return gobj->id >> MEDIA_BITS_PER_ID;
 444}
 445
 446/**
 447 * media_id() - return the media object ID
 448 *
 449 * @gobj:	Pointer to the struct &media_gobj graph object
 450 */
 451static inline u32 media_id(struct media_gobj *gobj)
 452{
 453	return gobj->id & MEDIA_ID_MASK;
 454}
 455
 456/**
 457 * media_gobj_gen_id() - encapsulates type and ID on at the object ID
 458 *
 459 * @type:	object type as define at enum &media_gobj_type.
 460 * @local_id:	next ID, from struct &media_device.id.
 461 */
 462static inline u32 media_gobj_gen_id(enum media_gobj_type type, u64 local_id)
 463{
 464	u32 id;
 465
 466	id = type << MEDIA_BITS_PER_ID;
 467	id |= local_id & MEDIA_ID_MASK;
 468
 469	return id;
 470}
 471
 472/**
 473 * is_media_entity_v4l2_video_device() - Check if the entity is a video_device
 474 * @entity:	pointer to entity
 475 *
 476 * Return: %true if the entity is an instance of a video_device object and can
 477 * safely be cast to a struct video_device using the container_of() macro, or
 478 * %false otherwise.
 479 */
 480static inline bool is_media_entity_v4l2_video_device(struct media_entity *entity)
 481{
 482	return entity && entity->obj_type == MEDIA_ENTITY_TYPE_VIDEO_DEVICE;
 483}
 484
 485/**
 486 * is_media_entity_v4l2_subdev() - Check if the entity is a v4l2_subdev
 487 * @entity:	pointer to entity
 488 *
 489 * Return: %true if the entity is an instance of a &v4l2_subdev object and can
 490 * safely be cast to a struct &v4l2_subdev using the container_of() macro, or
 491 * %false otherwise.
 492 */
 493static inline bool is_media_entity_v4l2_subdev(struct media_entity *entity)
 494{
 495	return entity && entity->obj_type == MEDIA_ENTITY_TYPE_V4L2_SUBDEV;
 496}
 497
 498/**
 499 * media_entity_enum_init - Initialise an entity enumeration
 500 *
 501 * @ent_enum: Entity enumeration to be initialised
 502 * @mdev: The related media device
 503 *
 504 * Return: zero on success or a negative error code.
 505 */
 506__must_check int media_entity_enum_init(struct media_entity_enum *ent_enum,
 507					struct media_device *mdev);
 508
 509/**
 510 * media_entity_enum_cleanup - Release resources of an entity enumeration
 511 *
 512 * @ent_enum: Entity enumeration to be released
 513 */
 514void media_entity_enum_cleanup(struct media_entity_enum *ent_enum);
 515
 516/**
 517 * media_entity_enum_zero - Clear the entire enum
 518 *
 519 * @ent_enum: Entity enumeration to be cleared
 520 */
 521static inline void media_entity_enum_zero(struct media_entity_enum *ent_enum)
 522{
 523	bitmap_zero(ent_enum->bmap, ent_enum->idx_max);
 524}
 525
 526/**
 527 * media_entity_enum_set - Mark a single entity in the enum
 528 *
 529 * @ent_enum: Entity enumeration
 530 * @entity: Entity to be marked
 531 */
 532static inline void media_entity_enum_set(struct media_entity_enum *ent_enum,
 533					 struct media_entity *entity)
 534{
 535	if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
 536		return;
 537
 538	__set_bit(entity->internal_idx, ent_enum->bmap);
 539}
 540
 541/**
 542 * media_entity_enum_clear - Unmark a single entity in the enum
 543 *
 544 * @ent_enum: Entity enumeration
 545 * @entity: Entity to be unmarked
 546 */
 547static inline void media_entity_enum_clear(struct media_entity_enum *ent_enum,
 548					   struct media_entity *entity)
 549{
 550	if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
 551		return;
 552
 553	__clear_bit(entity->internal_idx, ent_enum->bmap);
 554}
 555
 556/**
 557 * media_entity_enum_test - Test whether the entity is marked
 558 *
 559 * @ent_enum: Entity enumeration
 560 * @entity: Entity to be tested
 561 *
 562 * Returns %true if the entity was marked.
 563 */
 564static inline bool media_entity_enum_test(struct media_entity_enum *ent_enum,
 565					  struct media_entity *entity)
 566{
 567	if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
 568		return true;
 569
 570	return test_bit(entity->internal_idx, ent_enum->bmap);
 571}
 572
 573/**
 574 * media_entity_enum_test_and_set - Test whether the entity is marked,
 575 *	and mark it
 576 *
 577 * @ent_enum: Entity enumeration
 578 * @entity: Entity to be tested
 579 *
 580 * Returns %true if the entity was marked, and mark it before doing so.
 581 */
 582static inline bool
 583media_entity_enum_test_and_set(struct media_entity_enum *ent_enum,
 584			       struct media_entity *entity)
 585{
 586	if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
 587		return true;
 588
 589	return __test_and_set_bit(entity->internal_idx, ent_enum->bmap);
 590}
 591
 592/**
 593 * media_entity_enum_empty - Test whether the entire enum is empty
 594 *
 595 * @ent_enum: Entity enumeration
 596 *
 597 * Return: %true if the entity was empty.
 598 */
 599static inline bool media_entity_enum_empty(struct media_entity_enum *ent_enum)
 600{
 601	return bitmap_empty(ent_enum->bmap, ent_enum->idx_max);
 602}
 603
 604/**
 605 * media_entity_enum_intersects - Test whether two enums intersect
 606 *
 607 * @ent_enum1: First entity enumeration
 608 * @ent_enum2: Second entity enumeration
 609 *
 610 * Return: %true if entity enumerations @ent_enum1 and @ent_enum2 intersect,
 611 * otherwise %false.
 612 */
 613static inline bool media_entity_enum_intersects(
 614	struct media_entity_enum *ent_enum1,
 615	struct media_entity_enum *ent_enum2)
 616{
 617	WARN_ON(ent_enum1->idx_max != ent_enum2->idx_max);
 618
 619	return bitmap_intersects(ent_enum1->bmap, ent_enum2->bmap,
 620				 min(ent_enum1->idx_max, ent_enum2->idx_max));
 621}
 622
 623/**
 624 * gobj_to_entity - returns the struct &media_entity pointer from the
 625 *	@gobj contained on it.
 626 *
 627 * @gobj: Pointer to the struct &media_gobj graph object
 628 */
 629#define gobj_to_entity(gobj) \
 630		container_of(gobj, struct media_entity, graph_obj)
 631
 632/**
 633 * gobj_to_pad - returns the struct &media_pad pointer from the
 634 *	@gobj contained on it.
 635 *
 636 * @gobj: Pointer to the struct &media_gobj graph object
 637 */
 638#define gobj_to_pad(gobj) \
 639		container_of(gobj, struct media_pad, graph_obj)
 640
 641/**
 642 * gobj_to_link - returns the struct &media_link pointer from the
 643 *	@gobj contained on it.
 644 *
 645 * @gobj: Pointer to the struct &media_gobj graph object
 646 */
 647#define gobj_to_link(gobj) \
 648		container_of(gobj, struct media_link, graph_obj)
 649
 650/**
 651 * gobj_to_intf - returns the struct &media_interface pointer from the
 652 *	@gobj contained on it.
 653 *
 654 * @gobj: Pointer to the struct &media_gobj graph object
 655 */
 656#define gobj_to_intf(gobj) \
 657		container_of(gobj, struct media_interface, graph_obj)
 658
 659/**
 660 * intf_to_devnode - returns the struct media_intf_devnode pointer from the
 661 *	@intf contained on it.
 662 *
 663 * @intf: Pointer to struct &media_intf_devnode
 664 */
 665#define intf_to_devnode(intf) \
 666		container_of(intf, struct media_intf_devnode, intf)
 667
 668/**
 669 *  media_gobj_create - Initialize a graph object
 670 *
 671 * @mdev:	Pointer to the &media_device that contains the object
 672 * @type:	Type of the object
 673 * @gobj:	Pointer to the struct &media_gobj graph object
 674 *
 675 * This routine initializes the embedded struct &media_gobj inside a
 676 * media graph object. It is called automatically if ``media_*_create``
 677 * function calls are used. However, if the object (entity, link, pad,
 678 * interface) is embedded on some other object, this function should be
 679 * called before registering the object at the media controller.
 680 */
 681void media_gobj_create(struct media_device *mdev,
 682		    enum media_gobj_type type,
 683		    struct media_gobj *gobj);
 684
 685/**
 686 *  media_gobj_destroy - Stop using a graph object on a media device
 687 *
 688 * @gobj:	Pointer to the struct &media_gobj graph object
 689 *
 690 * This should be called by all routines like media_device_unregister()
 691 * that remove/destroy media graph objects.
 692 */
 693void media_gobj_destroy(struct media_gobj *gobj);
 694
 695/**
 696 * media_entity_pads_init() - Initialize the entity pads
 697 *
 698 * @entity:	entity where the pads belong
 699 * @num_pads:	total number of sink and source pads
 700 * @pads:	Array of @num_pads pads.
 701 *
 702 * The pads array is managed by the entity driver and passed to
 703 * media_entity_pads_init() where its pointer will be stored in the
 704 * &media_entity structure.
 705 *
 706 * If no pads are needed, drivers could either directly fill
 707 * &media_entity->num_pads with 0 and &media_entity->pads with %NULL or call
 708 * this function that will do the same.
 709 *
 710 * As the number of pads is known in advance, the pads array is not allocated
 711 * dynamically but is managed by the entity driver. Most drivers will embed the
 712 * pads array in a driver-specific structure, avoiding dynamic allocation.
 713 *
 714 * Drivers must set the direction of every pad in the pads array before calling
 715 * media_entity_pads_init(). The function will initialize the other pads fields.
 716 */
 717int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 718		      struct media_pad *pads);
 719
 720/**
 721 * media_entity_cleanup() - free resources associated with an entity
 722 *
 723 * @entity:	entity where the pads belong
 724 *
 725 * This function must be called during the cleanup phase after unregistering
 726 * the entity (currently, it does nothing).
 727 *
 728 * Calling media_entity_cleanup() on a media_entity whose memory has been
 729 * zeroed but that has not been initialized with media_entity_pad_init() is
 730 * valid and is a no-op.
 731 */
 732#if IS_ENABLED(CONFIG_MEDIA_CONTROLLER)
 733static inline void media_entity_cleanup(struct media_entity *entity) {}
 734#else
 735#define media_entity_cleanup(entity) do { } while (false)
 736#endif
 737
 738/**
 739 * media_get_pad_index() - retrieves a pad index from an entity
 740 *
 741 * @entity:	entity where the pads belong
 742 * @pad_type:	the type of the pad, one of MEDIA_PAD_FL_* pad types
 743 * @sig_type:	type of signal of the pad to be search
 744 *
 745 * This helper function finds the first pad index inside an entity that
 746 * satisfies both @is_sink and @sig_type conditions.
 747 *
 748 * Return:
 749 *
 750 * On success, return the pad number. If the pad was not found or the media
 751 * entity is a NULL pointer, return -EINVAL.
 752 */
 753int media_get_pad_index(struct media_entity *entity, u32 pad_type,
 754			enum media_pad_signal_type sig_type);
 755
 756/**
 757 * media_create_pad_link() - creates a link between two entities.
 758 *
 759 * @source:	pointer to &media_entity of the source pad.
 760 * @source_pad:	number of the source pad in the pads array
 761 * @sink:	pointer to &media_entity of the sink pad.
 762 * @sink_pad:	number of the sink pad in the pads array.
 763 * @flags:	Link flags, as defined in
 764 *		:ref:`include/uapi/linux/media.h <media_header>`
 765 *		( seek for ``MEDIA_LNK_FL_*``)
 766 *
 767 * Valid values for flags:
 768 *
 769 * %MEDIA_LNK_FL_ENABLED
 770 *   Indicates that the link is enabled and can be used to transfer media data.
 771 *   When two or more links target a sink pad, only one of them can be
 772 *   enabled at a time.
 773 *
 774 * %MEDIA_LNK_FL_IMMUTABLE
 775 *   Indicates that the link enabled state can't be modified at runtime. If
 776 *   %MEDIA_LNK_FL_IMMUTABLE is set, then %MEDIA_LNK_FL_ENABLED must also be
 777 *   set, since an immutable link is always enabled.
 778 *
 779 * .. note::
 780 *
 781 *    Before calling this function, media_entity_pads_init() and
 782 *    media_device_register_entity() should be called previously for both ends.
 783 */
 784__must_check int media_create_pad_link(struct media_entity *source,
 785			u16 source_pad, struct media_entity *sink,
 786			u16 sink_pad, u32 flags);
 787
 788/**
 789 * media_create_pad_links() - creates a link between two entities.
 790 *
 791 * @mdev: Pointer to the media_device that contains the object
 792 * @source_function: Function of the source entities. Used only if @source is
 793 *	NULL.
 794 * @source: pointer to &media_entity of the source pad. If NULL, it will use
 795 *	all entities that matches the @sink_function.
 796 * @source_pad: number of the source pad in the pads array
 797 * @sink_function: Function of the sink entities. Used only if @sink is NULL.
 798 * @sink: pointer to &media_entity of the sink pad. If NULL, it will use
 799 *	all entities that matches the @sink_function.
 800 * @sink_pad: number of the sink pad in the pads array.
 801 * @flags: Link flags, as defined in include/uapi/linux/media.h.
 802 * @allow_both_undefined: if %true, then both @source and @sink can be NULL.
 803 *	In such case, it will create a crossbar between all entities that
 804 *	matches @source_function to all entities that matches @sink_function.
 805 *	If %false, it will return 0 and won't create any link if both @source
 806 *	and @sink are NULL.
 807 *
 808 * Valid values for flags:
 809 *
 810 * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be
 811 *	used to transfer media data. If multiple links are created and this
 812 *	flag is passed as an argument, only the first created link will have
 813 *	this flag.
 814 *
 815 * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't
 816 *	be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then
 817 *	%MEDIA_LNK_FL_ENABLED must also be set since an immutable link is
 818 *	always enabled.
 819 *
 820 * It is common for some devices to have multiple source and/or sink entities
 821 * of the same type that should be linked. While media_create_pad_link()
 822 * creates link by link, this function is meant to allow 1:n, n:1 and even
 823 * cross-bar (n:n) links.
 824 *
 825 * .. note::
 826 *
 827 *    Before calling this function, media_entity_pads_init() and
 828 *    media_device_register_entity() should be called previously for the
 829 *    entities to be linked.
 830 */
 831int media_create_pad_links(const struct media_device *mdev,
 832			   const u32 source_function,
 833			   struct media_entity *source,
 834			   const u16 source_pad,
 835			   const u32 sink_function,
 836			   struct media_entity *sink,
 837			   const u16 sink_pad,
 838			   u32 flags,
 839			   const bool allow_both_undefined);
 840
 841void __media_entity_remove_links(struct media_entity *entity);
 842
 843/**
 844 * media_entity_remove_links() - remove all links associated with an entity
 845 *
 846 * @entity:	pointer to &media_entity
 847 *
 848 * .. note::
 849 *
 850 *    This is called automatically when an entity is unregistered via
 851 *    media_device_register_entity().
 852 */
 853void media_entity_remove_links(struct media_entity *entity);
 854
 855/**
 856 * __media_entity_setup_link - Configure a media link without locking
 857 * @link: The link being configured
 858 * @flags: Link configuration flags
 859 *
 860 * The bulk of link setup is handled by the two entities connected through the
 861 * link. This function notifies both entities of the link configuration change.
 862 *
 863 * If the link is immutable or if the current and new configuration are
 864 * identical, return immediately.
 865 *
 866 * The user is expected to hold link->source->parent->mutex. If not,
 867 * media_entity_setup_link() should be used instead.
 868 */
 869int __media_entity_setup_link(struct media_link *link, u32 flags);
 870
 871/**
 872 * media_entity_setup_link() - changes the link flags properties in runtime
 873 *
 874 * @link:	pointer to &media_link
 875 * @flags:	the requested new link flags
 876 *
 877 * The only configurable property is the %MEDIA_LNK_FL_ENABLED link flag
 878 * to enable/disable a link. Links marked with the
 879 * %MEDIA_LNK_FL_IMMUTABLE link flag can not be enabled or disabled.
 880 *
 881 * When a link is enabled or disabled, the media framework calls the
 882 * link_setup operation for the two entities at the source and sink of the
 883 * link, in that order. If the second link_setup call fails, another
 884 * link_setup call is made on the first entity to restore the original link
 885 * flags.
 886 *
 887 * Media device drivers can be notified of link setup operations by setting the
 888 * &media_device.link_notify pointer to a callback function. If provided, the
 889 * notification callback will be called before enabling and after disabling
 890 * links.
 891 *
 892 * Entity drivers must implement the link_setup operation if any of their links
 893 * is non-immutable. The operation must either configure the hardware or store
 894 * the configuration information to be applied later.
 895 *
 896 * Link configuration must not have any side effect on other links. If an
 897 * enabled link at a sink pad prevents another link at the same pad from
 898 * being enabled, the link_setup operation must return %-EBUSY and can't
 899 * implicitly disable the first enabled link.
 900 *
 901 * .. note::
 902 *
 903 *    The valid values of the flags for the link is the same as described
 904 *    on media_create_pad_link(), for pad to pad links or the same as described
 905 *    on media_create_intf_link(), for interface to entity links.
 906 */
 907int media_entity_setup_link(struct media_link *link, u32 flags);
 908
 909/**
 910 * media_entity_find_link - Find a link between two pads
 911 * @source: Source pad
 912 * @sink: Sink pad
 913 *
 914 * Return: returns a pointer to the link between the two entities. If no
 915 * such link exists, return %NULL.
 916 */
 917struct media_link *media_entity_find_link(struct media_pad *source,
 918		struct media_pad *sink);
 919
 920/**
 921 * media_pad_remote_pad_first - Find the first pad at the remote end of a link
 922 * @pad: Pad at the local end of the link
 923 *
 924 * Search for a remote pad connected to the given pad by iterating over all
 925 * links originating or terminating at that pad until an enabled link is found.
 926 *
 927 * Return: returns a pointer to the pad at the remote end of the first found
 928 * enabled link, or %NULL if no enabled link has been found.
 929 */
 930struct media_pad *media_pad_remote_pad_first(const struct media_pad *pad);
 931
 932/**
 933 * media_pad_remote_pad_unique - Find a remote pad connected to a pad
 934 * @pad: The pad
 935 *
 936 * Search for and return a remote pad connected to @pad through an enabled
 937 * link. If multiple (or no) remote pads are found, an error is returned.
 938 *
 939 * The uniqueness constraint makes this helper function suitable for entities
 940 * that support a single active source at a time on a given pad.
 941 *
 942 * Return: A pointer to the remote pad, or one of the following error pointers
 943 * if an error occurs:
 944 *
 945 * * -ENOTUNIQ - Multiple links are enabled
 946 * * -ENOLINK - No connected pad found
 947 */
 948struct media_pad *media_pad_remote_pad_unique(const struct media_pad *pad);
 949
 950/**
 951 * media_entity_remote_pad_unique - Find a remote pad connected to an entity
 952 * @entity: The entity
 953 * @type: The type of pad to find (MEDIA_PAD_FL_SINK or MEDIA_PAD_FL_SOURCE)
 954 *
 955 * Search for and return a remote pad of @type connected to @entity through an
 956 * enabled link. If multiple (or no) remote pads match these criteria, an error
 957 * is returned.
 958 *
 959 * The uniqueness constraint makes this helper function suitable for entities
 960 * that support a single active source or sink at a time.
 961 *
 962 * Return: A pointer to the remote pad, or one of the following error pointers
 963 * if an error occurs:
 964 *
 965 * * -ENOTUNIQ - Multiple links are enabled
 966 * * -ENOLINK - No connected pad found
 967 */
 968struct media_pad *
 969media_entity_remote_pad_unique(const struct media_entity *entity,
 970			       unsigned int type);
 971
 972/**
 973 * media_entity_remote_source_pad_unique - Find a remote source pad connected to
 974 *	an entity
 975 * @entity: The entity
 976 *
 977 * Search for and return a remote source pad connected to @entity through an
 978 * enabled link. If multiple (or no) remote pads match these criteria, an error
 979 * is returned.
 980 *
 981 * The uniqueness constraint makes this helper function suitable for entities
 982 * that support a single active source at a time.
 983 *
 984 * Return: A pointer to the remote pad, or one of the following error pointers
 985 * if an error occurs:
 986 *
 987 * * -ENOTUNIQ - Multiple links are enabled
 988 * * -ENOLINK - No connected pad found
 989 */
 990static inline struct media_pad *
 991media_entity_remote_source_pad_unique(const struct media_entity *entity)
 992{
 993	return media_entity_remote_pad_unique(entity, MEDIA_PAD_FL_SOURCE);
 994}
 995
 996/**
 997 * media_pad_is_streaming - Test if a pad is part of a streaming pipeline
 998 * @pad: The pad
 999 *
1000 * Return: True if the pad is part of a pipeline started with the
1001 * media_pipeline_start() function, false otherwise.
1002 */
1003static inline bool media_pad_is_streaming(const struct media_pad *pad)
1004{
1005	return pad->pipe;
1006}
1007
1008/**
1009 * media_entity_is_streaming - Test if an entity is part of a streaming pipeline
1010 * @entity: The entity
1011 *
1012 * Return: True if the entity is part of a pipeline started with the
1013 * media_pipeline_start() function, false otherwise.
1014 */
1015static inline bool media_entity_is_streaming(const struct media_entity *entity)
1016{
1017	struct media_pad *pad;
1018
1019	media_entity_for_each_pad(entity, pad) {
1020		if (media_pad_is_streaming(pad))
1021			return true;
1022	}
1023
1024	return false;
1025}
1026
1027/**
1028 * media_entity_pipeline - Get the media pipeline an entity is part of
1029 * @entity: The entity
1030 *
1031 * DEPRECATED: use media_pad_pipeline() instead.
1032 *
1033 * This function returns the media pipeline that an entity has been associated
1034 * with when constructing the pipeline with media_pipeline_start(). The pointer
1035 * remains valid until media_pipeline_stop() is called.
1036 *
1037 * In general, entities can be part of multiple pipelines, when carrying
1038 * multiple streams (either on different pads, or on the same pad using
1039 * multiplexed streams). This function is to be used only for entities that
1040 * do not support multiple pipelines.
1041 *
1042 * Return: The media_pipeline the entity is part of, or NULL if the entity is
1043 * not part of any pipeline.
1044 */
1045struct media_pipeline *media_entity_pipeline(struct media_entity *entity);
1046
1047/**
1048 * media_pad_pipeline - Get the media pipeline a pad is part of
1049 * @pad: The pad
1050 *
1051 * This function returns the media pipeline that a pad has been associated
1052 * with when constructing the pipeline with media_pipeline_start(). The pointer
1053 * remains valid until media_pipeline_stop() is called.
1054 *
1055 * Return: The media_pipeline the pad is part of, or NULL if the pad is
1056 * not part of any pipeline.
1057 */
1058struct media_pipeline *media_pad_pipeline(struct media_pad *pad);
1059
1060/**
1061 * media_entity_get_fwnode_pad - Get pad number from fwnode
1062 *
1063 * @entity: The entity
1064 * @fwnode: Pointer to the fwnode_handle which should be used to find the pad
1065 * @direction_flags: Expected direction of the pad, as defined in
1066 *		     :ref:`include/uapi/linux/media.h <media_header>`
1067 *		     (seek for ``MEDIA_PAD_FL_*``)
1068 *
1069 * This function can be used to resolve the media pad number from
1070 * a fwnode. This is useful for devices which use more complex
1071 * mappings of media pads.
1072 *
1073 * If the entity does not implement the get_fwnode_pad() operation
1074 * then this function searches the entity for the first pad that
1075 * matches the @direction_flags.
1076 *
1077 * Return: returns the pad number on success or a negative error code.
1078 */
1079int media_entity_get_fwnode_pad(struct media_entity *entity,
1080				const struct fwnode_handle *fwnode,
1081				unsigned long direction_flags);
1082
1083/**
1084 * media_graph_walk_init - Allocate resources used by graph walk.
1085 *
1086 * @graph: Media graph structure that will be used to walk the graph
1087 * @mdev: Pointer to the &media_device that contains the object
1088 *
1089 * This function is deprecated, use media_pipeline_for_each_pad() instead.
1090 *
1091 * The caller is required to hold the media_device graph_mutex during the graph
1092 * walk until the graph state is released.
1093 *
1094 * Returns zero on success or a negative error code otherwise.
1095 */
1096__must_check int media_graph_walk_init(
1097	struct media_graph *graph, struct media_device *mdev);
1098
1099/**
1100 * media_graph_walk_cleanup - Release resources used by graph walk.
1101 *
1102 * @graph: Media graph structure that will be used to walk the graph
1103 *
1104 * This function is deprecated, use media_pipeline_for_each_pad() instead.
1105 */
1106void media_graph_walk_cleanup(struct media_graph *graph);
1107
1108/**
1109 * media_graph_walk_start - Start walking the media graph at a
1110 *	given entity
1111 *
1112 * @graph: Media graph structure that will be used to walk the graph
1113 * @entity: Starting entity
1114 *
1115 * This function is deprecated, use media_pipeline_for_each_pad() instead.
1116 *
1117 * Before using this function, media_graph_walk_init() must be
1118 * used to allocate resources used for walking the graph. This
1119 * function initializes the graph traversal structure to walk the
1120 * entities graph starting at the given entity. The traversal
1121 * structure must not be modified by the caller during graph
1122 * traversal. After the graph walk, the resources must be released
1123 * using media_graph_walk_cleanup().
1124 */
1125void media_graph_walk_start(struct media_graph *graph,
1126			    struct media_entity *entity);
1127
1128/**
1129 * media_graph_walk_next - Get the next entity in the graph
1130 * @graph: Media graph structure
1131 *
1132 * This function is deprecated, use media_pipeline_for_each_pad() instead.
1133 *
1134 * Perform a depth-first traversal of the given media entities graph.
1135 *
1136 * The graph structure must have been previously initialized with a call to
1137 * media_graph_walk_start().
1138 *
1139 * Return: returns the next entity in the graph or %NULL if the whole graph
1140 * have been traversed.
1141 */
1142struct media_entity *media_graph_walk_next(struct media_graph *graph);
1143
1144/**
1145 * media_pipeline_start - Mark a pipeline as streaming
1146 * @origin: Starting pad
1147 * @pipe: Media pipeline to be assigned to all pads in the pipeline.
1148 *
1149 * Mark all pads connected to pad @origin through enabled links, either
1150 * directly or indirectly, as streaming. The given pipeline object is assigned
1151 * to every pad in the pipeline and stored in the media_pad pipe field.
1152 *
1153 * Calls to this function can be nested, in which case the same number of
1154 * media_pipeline_stop() calls will be required to stop streaming. The
1155 * pipeline pointer must be identical for all nested calls to
1156 * media_pipeline_start().
1157 */
1158__must_check int media_pipeline_start(struct media_pad *origin,
1159				      struct media_pipeline *pipe);
1160/**
1161 * __media_pipeline_start - Mark a pipeline as streaming
1162 *
1163 * @origin: Starting pad
1164 * @pipe: Media pipeline to be assigned to all pads in the pipeline.
1165 *
1166 * ..note:: This is the non-locking version of media_pipeline_start()
1167 */
1168__must_check int __media_pipeline_start(struct media_pad *origin,
1169					struct media_pipeline *pipe);
1170
1171/**
1172 * media_pipeline_stop - Mark a pipeline as not streaming
1173 * @pad: Starting pad
1174 *
1175 * Mark all pads connected to a given pad through enabled links, either
1176 * directly or indirectly, as not streaming. The media_pad pipe field is
1177 * reset to %NULL.
1178 *
1179 * If multiple calls to media_pipeline_start() have been made, the same
1180 * number of calls to this function are required to mark the pipeline as not
1181 * streaming.
1182 */
1183void media_pipeline_stop(struct media_pad *pad);
1184
1185/**
1186 * __media_pipeline_stop - Mark a pipeline as not streaming
1187 *
1188 * @pad: Starting pad
1189 *
1190 * .. note:: This is the non-locking version of media_pipeline_stop()
1191 */
1192void __media_pipeline_stop(struct media_pad *pad);
1193
1194struct media_pad *
1195__media_pipeline_pad_iter_next(struct media_pipeline *pipe,
1196			       struct media_pipeline_pad_iter *iter,
1197			       struct media_pad *pad);
1198
1199/**
1200 * media_pipeline_for_each_pad - Iterate on all pads in a media pipeline
1201 * @pipe: The pipeline
1202 * @iter: The iterator (struct media_pipeline_pad_iter)
1203 * @pad: The iterator pad
1204 *
1205 * Iterate on all pads in a media pipeline. This is only valid after the
1206 * pipeline has been built with media_pipeline_start() and before it gets
1207 * destroyed with media_pipeline_stop().
1208 */
1209#define media_pipeline_for_each_pad(pipe, iter, pad)			\
1210	for (pad = __media_pipeline_pad_iter_next((pipe), iter, NULL);	\
1211	     pad != NULL;						\
1212	     pad = __media_pipeline_pad_iter_next((pipe), iter, pad))
1213
1214/**
1215 * media_pipeline_entity_iter_init - Initialize a pipeline entity iterator
1216 * @pipe: The pipeline
1217 * @iter: The iterator
1218 *
1219 * This function must be called to initialize the iterator before using it in a
1220 * media_pipeline_for_each_entity() loop. The iterator must be destroyed by a
1221 * call to media_pipeline_entity_iter_cleanup after the loop (including in code
1222 * paths that break from the loop).
1223 *
1224 * The same iterator can be used in multiple consecutive loops without being
1225 * destroyed and reinitialized.
1226 *
1227 * Return: 0 on success or a negative error code otherwise.
1228 */
1229int media_pipeline_entity_iter_init(struct media_pipeline *pipe,
1230				    struct media_pipeline_entity_iter *iter);
1231
1232/**
1233 * media_pipeline_entity_iter_cleanup - Destroy a pipeline entity iterator
1234 * @iter: The iterator
1235 *
1236 * This function must be called to destroy iterators initialized with
1237 * media_pipeline_entity_iter_init().
1238 */
1239void media_pipeline_entity_iter_cleanup(struct media_pipeline_entity_iter *iter);
1240
1241struct media_entity *
1242__media_pipeline_entity_iter_next(struct media_pipeline *pipe,
1243				  struct media_pipeline_entity_iter *iter,
1244				  struct media_entity *entity);
1245
1246/**
1247 * media_pipeline_for_each_entity - Iterate on all entities in a media pipeline
1248 * @pipe: The pipeline
1249 * @iter: The iterator (struct media_pipeline_entity_iter)
1250 * @entity: The iterator entity
1251 *
1252 * Iterate on all entities in a media pipeline. This is only valid after the
1253 * pipeline has been built with media_pipeline_start() and before it gets
1254 * destroyed with media_pipeline_stop(). The iterator must be initialized with
1255 * media_pipeline_entity_iter_init() before iteration, and destroyed with
1256 * media_pipeline_entity_iter_cleanup() after (including in code paths that
1257 * break from the loop).
1258 */
1259#define media_pipeline_for_each_entity(pipe, iter, entity)			\
1260	for (entity = __media_pipeline_entity_iter_next((pipe), iter, NULL);	\
1261	     entity != NULL;							\
1262	     entity = __media_pipeline_entity_iter_next((pipe), iter, entity))
1263
1264/**
1265 * media_pipeline_alloc_start - Mark a pipeline as streaming
1266 * @pad: Starting pad
1267 *
1268 * media_pipeline_alloc_start() is similar to media_pipeline_start() but instead
1269 * of working on a given pipeline the function will use an existing pipeline if
1270 * the pad is already part of a pipeline, or allocate a new pipeline.
1271 *
1272 * Calls to media_pipeline_alloc_start() must be matched with
1273 * media_pipeline_stop().
1274 */
1275__must_check int media_pipeline_alloc_start(struct media_pad *pad);
1276
1277/**
1278 * media_devnode_create() - creates and initializes a device node interface
1279 *
1280 * @mdev:	pointer to struct &media_device
1281 * @type:	type of the interface, as given by
1282 *		:ref:`include/uapi/linux/media.h <media_header>`
1283 *		( seek for ``MEDIA_INTF_T_*``) macros.
1284 * @flags:	Interface flags, as defined in
1285 *		:ref:`include/uapi/linux/media.h <media_header>`
1286 *		( seek for ``MEDIA_INTF_FL_*``)
1287 * @major:	Device node major number.
1288 * @minor:	Device node minor number.
1289 *
1290 * Return: if succeeded, returns a pointer to the newly allocated
1291 *	&media_intf_devnode pointer.
1292 *
1293 * .. note::
1294 *
1295 *    Currently, no flags for &media_interface is defined.
1296 */
1297struct media_intf_devnode *
1298__must_check media_devnode_create(struct media_device *mdev,
1299				  u32 type, u32 flags,
1300				  u32 major, u32 minor);
1301/**
1302 * media_devnode_remove() - removes a device node interface
1303 *
1304 * @devnode:	pointer to &media_intf_devnode to be freed.
1305 *
1306 * When a device node interface is removed, all links to it are automatically
1307 * removed.
1308 */
1309void media_devnode_remove(struct media_intf_devnode *devnode);
 
1310
1311/**
1312 * media_create_intf_link() - creates a link between an entity and an interface
1313 *
1314 * @entity:	pointer to %media_entity
1315 * @intf:	pointer to %media_interface
1316 * @flags:	Link flags, as defined in
1317 *		:ref:`include/uapi/linux/media.h <media_header>`
1318 *		( seek for ``MEDIA_LNK_FL_*``)
1319 *
1320 *
1321 * Valid values for flags:
1322 *
1323 * %MEDIA_LNK_FL_ENABLED
1324 *   Indicates that the interface is connected to the entity hardware.
1325 *   That's the default value for interfaces. An interface may be disabled if
1326 *   the hardware is busy due to the usage of some other interface that it is
1327 *   currently controlling the hardware.
1328 *
1329 *   A typical example is an hybrid TV device that handle only one type of
1330 *   stream on a given time. So, when the digital TV is streaming,
1331 *   the V4L2 interfaces won't be enabled, as such device is not able to
1332 *   also stream analog TV or radio.
1333 *
1334 * .. note::
1335 *
1336 *    Before calling this function, media_devnode_create() should be called for
1337 *    the interface and media_device_register_entity() should be called for the
1338 *    interface that will be part of the link.
1339 */
1340struct media_link *
1341__must_check media_create_intf_link(struct media_entity *entity,
1342				    struct media_interface *intf,
1343				    u32 flags);
1344/**
1345 * __media_remove_intf_link() - remove a single interface link
1346 *
1347 * @link:	pointer to &media_link.
1348 *
1349 * .. note:: This is an unlocked version of media_remove_intf_link()
1350 */
1351void __media_remove_intf_link(struct media_link *link);
1352
1353/**
1354 * media_remove_intf_link() - remove a single interface link
1355 *
1356 * @link:	pointer to &media_link.
1357 *
1358 * .. note:: Prefer to use this one, instead of __media_remove_intf_link()
1359 */
1360void media_remove_intf_link(struct media_link *link);
1361
1362/**
1363 * __media_remove_intf_links() - remove all links associated with an interface
1364 *
1365 * @intf:	pointer to &media_interface
1366 *
1367 * .. note:: This is an unlocked version of media_remove_intf_links().
1368 */
1369void __media_remove_intf_links(struct media_interface *intf);
1370
1371/**
1372 * media_remove_intf_links() - remove all links associated with an interface
1373 *
1374 * @intf:	pointer to &media_interface
1375 *
1376 * .. note::
1377 *
1378 *   #) This is called automatically when an entity is unregistered via
1379 *      media_device_register_entity() and by media_devnode_remove().
1380 *
1381 *   #) Prefer to use this one, instead of __media_remove_intf_links().
1382 */
1383void media_remove_intf_links(struct media_interface *intf);
1384
1385/**
1386 * media_entity_call - Calls a struct media_entity_operations operation on
1387 *	an entity
1388 *
1389 * @entity: entity where the @operation will be called
1390 * @operation: type of the operation. Should be the name of a member of
1391 *	struct &media_entity_operations.
1392 *
1393 * This helper function will check if @operation is not %NULL. On such case,
1394 * it will issue a call to @operation\(@entity, @args\).
1395 */
1396
1397#define media_entity_call(entity, operation, args...)			\
1398	(((entity)->ops && (entity)->ops->operation) ?			\
1399	 (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)
1400
1401/**
1402 * media_create_ancillary_link() - create an ancillary link between two
1403 *				   instances of &media_entity
1404 *
1405 * @primary:	pointer to the primary &media_entity
1406 * @ancillary:	pointer to the ancillary &media_entity
1407 *
1408 * Create an ancillary link between two entities, indicating that they
1409 * represent two connected pieces of hardware that form a single logical unit.
1410 * A typical example is a camera lens controller being linked to the sensor that
1411 * it is supporting.
1412 *
1413 * The function sets both MEDIA_LNK_FL_ENABLED and MEDIA_LNK_FL_IMMUTABLE for
1414 * the new link.
1415 */
1416struct media_link *
1417media_create_ancillary_link(struct media_entity *primary,
1418			    struct media_entity *ancillary);
1419
1420/**
1421 * __media_entity_next_link() - Iterate through a &media_entity's links
1422 *
1423 * @entity:	pointer to the &media_entity
1424 * @link:	pointer to a &media_link to hold the iterated values
1425 * @link_type:	one of the MEDIA_LNK_FL_LINK_TYPE flags
1426 *
1427 * Return the next link against an entity matching a specific link type. This
1428 * allows iteration through an entity's links whilst guaranteeing all of the
1429 * returned links are of the given type.
1430 */
1431struct media_link *__media_entity_next_link(struct media_entity *entity,
1432					    struct media_link *link,
1433					    unsigned long link_type);
1434
1435/**
1436 * for_each_media_entity_data_link() - Iterate through an entity's data links
1437 *
1438 * @entity:	pointer to the &media_entity
1439 * @link:	pointer to a &media_link to hold the iterated values
1440 *
1441 * Iterate over a &media_entity's data links
1442 */
1443#define for_each_media_entity_data_link(entity, link)			\
1444	for (link = __media_entity_next_link(entity, NULL,		\
1445					     MEDIA_LNK_FL_DATA_LINK);	\
1446	     link;							\
1447	     link = __media_entity_next_link(entity, link,		\
1448					     MEDIA_LNK_FL_DATA_LINK))
1449
1450#endif