cregit-Linux how code gets into the kernel

Release 4.12 include/media/media-entity.h

Directory: include/media
/*
 * Media entity
 *
 * Copyright (C) 2010 Nokia Corporation
 *
 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *           Sakari Ailus <sakari.ailus@iki.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#ifndef _MEDIA_ENTITY_H

#define _MEDIA_ENTITY_H

#include <linux/bitmap.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/media.h>

/* Enums used internally at the media controller to represent graphs */

/**
 * enum media_gobj_type - type of a graph object
 *
 * @MEDIA_GRAPH_ENTITY:         Identify a media entity
 * @MEDIA_GRAPH_PAD:            Identify a media pad
 * @MEDIA_GRAPH_LINK:           Identify a media link
 * @MEDIA_GRAPH_INTF_DEVNODE:   Identify a media Kernel API interface via
 *                              a device node
 */

enum media_gobj_type {
	
MEDIA_GRAPH_ENTITY,
	
MEDIA_GRAPH_PAD,
	
MEDIA_GRAPH_LINK,
	
MEDIA_GRAPH_INTF_DEVNODE,
};


#define MEDIA_BITS_PER_TYPE		8

#define MEDIA_BITS_PER_ID		(32 - MEDIA_BITS_PER_TYPE)

#define MEDIA_ID_MASK			 GENMASK_ULL(MEDIA_BITS_PER_ID - 1, 0)

/* Structs to represent the objects that belong to a media graph */

/**
 * struct media_gobj - Define a graph object.
 *
 * @mdev:       Pointer to the struct &media_device that owns the object
 * @id:         Non-zero object ID identifier. The ID should be unique
 *              inside a media_device, as it is composed by
 *              %MEDIA_BITS_PER_TYPE to store the type plus
 *              %MEDIA_BITS_PER_ID to store the ID
 * @list:       List entry stored in one of the per-type mdev object lists
 *
 * All objects on the media graph should have this struct embedded
 */

struct media_gobj {
	
struct media_device	*mdev;
	
u32			id;
	
struct list_head	list;
};


#define MEDIA_ENTITY_ENUM_MAX_DEPTH	16

/**
 * struct media_entity_enum - An enumeration of media entities.
 *
 * @bmap:       Bit map in which each bit represents one entity at struct
 *              media_entity->internal_idx.
 * @idx_max:    Number of bits in bmap
 */

struct media_entity_enum {
	
unsigned long *bmap;
	
int idx_max;
};

/**
 * struct media_graph - Media graph traversal state
 *
 * @stack:              Graph traversal stack; the stack contains information
 *                      on the path the media entities to be walked and the
 *                      links through which they were reached.
 * @ent_enum:           Visited entities
 * @top:                The top of the stack
 */

struct media_graph {
	struct {
		
struct media_entity *entity;
		
struct list_head *link;
	
} stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];

	
struct media_entity_enum ent_enum;
	
int top;
};

/**
 * struct media_pipeline - Media pipeline related information
 *
 * @streaming_count:    Streaming start count - streaming stop count
 * @graph:              Media graph walk during pipeline start / stop
 */

struct media_pipeline {
	
int streaming_count;
	
struct media_graph graph;
};

/**
 * struct media_link - A link object part of a media graph.
 *
 * @graph_obj:  Embedded structure containing the media object common data
 * @list:       Linked list associated with an entity or an interface that
 *              owns the link.
 * @gobj0:      Part of a union. Used to get the pointer for the first
 *              graph_object of the link.
 * @source:     Part of a union. Used only if the first object (gobj0) is
 *              a pad. In that case, it represents the source pad.
 * @intf:       Part of a union. Used only if the first object (gobj0) is
 *              an interface.
 * @gobj1:      Part of a union. Used to get the pointer for the second
 *              graph_object of the link.
 * @sink:       Part of a union. Used only if the second object (gobj1) is
 *              a pad. In that case, it represents the sink pad.
 * @entity:     Part of a union. Used only if the second object (gobj1) is
 *              an entity.
 * @reverse:    Pointer to the link for the reverse direction of a pad to pad
 *              link.
 * @flags:      Link flags, as defined in uapi/media.h (MEDIA_LNK_FL_*)
 * @is_backlink: Indicate if the link is a backlink.
 */

struct media_link {
	
struct media_gobj graph_obj;
	
struct list_head list;
	union {
		
struct media_gobj *gobj0;
		
struct media_pad *source;
		
struct media_interface *intf;
	};
	union {
		
struct media_gobj *gobj1;
		
struct media_pad *sink;
		
struct media_entity *entity;
	};
	
struct media_link *reverse;
	
unsigned long flags;
	
bool is_backlink;
};

/**
 * struct media_pad - A media pad graph object.
 *
 * @graph_obj:  Embedded structure containing the media object common data
 * @entity:     Entity this pad belongs to
 * @index:      Pad index in the entity pads array, numbered from 0 to n
 * @flags:      Pad flags, as defined in
 *              :ref:`include/uapi/linux/media.h <media_header>`
 *              (seek for ``MEDIA_PAD_FL_*``)
 */

struct media_pad {
	
struct media_gobj graph_obj;	/* must be first field in struct */
	
struct media_entity *entity;
	
u16 index;
	
unsigned long flags;
};

/**
 * struct media_entity_operations - Media entity operations
 * @link_setup:         Notify the entity of link changes. The operation can
 *                      return an error, in which case link setup will be
 *                      cancelled. Optional.
 * @link_validate:      Return whether a link is valid from the entity point of
 *                      view. The media_pipeline_start() function
 *                      validates all links by calling this operation. Optional.
 *
 * .. note::
 *
 *    Those these callbacks are called with struct &media_device.graph_mutex
 *    mutex held.
 */

struct media_entity_operations {
	
int (*link_setup)(struct media_entity *entity,
			  const struct media_pad *local,
			  const struct media_pad *remote, u32 flags);
	
int (*link_validate)(struct media_link *link);
};

/**
 * enum media_entity_type - Media entity type
 *
 * @MEDIA_ENTITY_TYPE_BASE:
 *      The entity isn't embedded in another subsystem structure.
 * @MEDIA_ENTITY_TYPE_VIDEO_DEVICE:
 *      The entity is embedded in a struct video_device instance.
 * @MEDIA_ENTITY_TYPE_V4L2_SUBDEV:
 *      The entity is embedded in a struct v4l2_subdev instance.
 *
 * Media entity objects are often not instantiated directly, but the media
 * entity structure is inherited by (through embedding) other subsystem-specific
 * structures. The media entity type identifies the type of the subclass
 * structure that implements a media entity instance.
 *
 * This allows runtime type identification of media entities and safe casting to
 * the correct object type. For instance, a media entity structure instance
 * embedded in a v4l2_subdev structure instance will have the type
 * %MEDIA_ENTITY_TYPE_V4L2_SUBDEV and can safely be cast to a &v4l2_subdev
 * structure using the container_of() macro.
 */

enum media_entity_type {
	
MEDIA_ENTITY_TYPE_BASE,
	
MEDIA_ENTITY_TYPE_VIDEO_DEVICE,
	
MEDIA_ENTITY_TYPE_V4L2_SUBDEV,
};

/**
 * struct media_entity - A media entity graph object.
 *
 * @graph_obj:  Embedded structure containing the media object common data.
 * @name:       Entity name.
 * @obj_type:   Type of the object that implements the media_entity.
 * @function:   Entity main function, as defined in
 *              :ref:`include/uapi/linux/media.h <media_header>`
 *              (seek for ``MEDIA_ENT_F_*``)
 * @flags:      Entity flags, as defined in
 *              :ref:`include/uapi/linux/media.h <media_header>`
 *              (seek for ``MEDIA_ENT_FL_*``)
 * @num_pads:   Number of sink and source pads.
 * @num_links:  Total number of links, forward and back, enabled and disabled.
 * @num_backlinks: Number of backlinks
 * @internal_idx: An unique internal entity specific number. The numbers are
 *              re-used if entities are unregistered or registered again.
 * @pads:       Pads array with the size defined by @num_pads.
 * @links:      List of data links.
 * @ops:        Entity operations.
 * @stream_count: Stream count for the entity.
 * @use_count:  Use count for the entity.
 * @pipe:       Pipeline this entity belongs to.
 * @info:       Union with devnode information.  Kept just for backward
 *              compatibility.
 * @major:      Devnode major number (zero if not applicable). Kept just
 *              for backward compatibility.
 * @minor:      Devnode minor number (zero if not applicable). Kept just
 *              for backward compatibility.
 *
 * .. note::
 *
 *    @stream_count and @use_count reference counts must never be
 *    negative, but are signed integers on purpose: a simple ``WARN_ON(<0)``
 *    check can be used to detect reference count bugs that would make them
 *    negative.
 */

struct media_entity {
	
struct media_gobj graph_obj;	/* must be first field in struct */
	
const char *name;
	
enum media_entity_type obj_type;
	
u32 function;
	
unsigned long flags;

	
u16 num_pads;
	
u16 num_links;
	
u16 num_backlinks;
	
int internal_idx;

	
struct media_pad *pads;
	
struct list_head links;

	
const struct media_entity_operations *ops;

	
int stream_count;
	
int use_count;

	
struct media_pipeline *pipe;

	union {
		struct {
			
u32 major;
			
u32 minor;
		
} dev;
	
} info;
};

/**
 * struct media_interface - A media interface graph object.
 *
 * @graph_obj:          embedded graph object
 * @links:              List of links pointing to graph entities
 * @type:               Type of the interface as defined in
 *                      :ref:`include/uapi/linux/media.h <media_header>`
 *                      (seek for ``MEDIA_INTF_T_*``)
 * @flags:              Interface flags as defined in
 *                      :ref:`include/uapi/linux/media.h <media_header>`
 *                      (seek for ``MEDIA_INTF_FL_*``)
 *
 * .. note::
 *
 *    Currently, no flags for &media_interface is defined.
 */

struct media_interface {
	
struct media_gobj		graph_obj;
	
struct list_head		links;
	
u32				type;
	
u32				flags;
};

/**
 * struct media_intf_devnode - A media interface via a device node.
 *
 * @intf:       embedded interface object
 * @major:      Major number of a device node
 * @minor:      Minor number of a device node
 */

struct media_intf_devnode {
	
struct media_interface		intf;

	/* Should match the fields at media_v2_intf_devnode */
	
u32				major;
	
u32				minor;
};

/**
 * media_entity_id() - return the media entity graph object id
 *
 * @entity:     pointer to &media_entity
 */

static inline u32 media_entity_id(struct media_entity *entity) { return entity->graph_obj.id; }

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/** * media_type() - return the media object type * * @gobj: Pointer to the struct &media_gobj graph object */
static inline enum media_gobj_type media_type(struct media_gobj *gobj) { return gobj->id >> MEDIA_BITS_PER_ID; }

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/** * media_id() - return the media object ID * * @gobj: Pointer to the struct &media_gobj graph object */
static inline u32 media_id(struct media_gobj *gobj) { return gobj->id & MEDIA_ID_MASK; }

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/** * media_gobj_gen_id() - encapsulates type and ID on at the object ID * * @type: object type as define at enum &media_gobj_type. * @local_id: next ID, from struct &media_device.id. */
static inline u32 media_gobj_gen_id(enum media_gobj_type type, u64 local_id) { u32 id; id = type << MEDIA_BITS_PER_ID; id |= local_id & MEDIA_ID_MASK; return id; }

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/** * is_media_entity_v4l2_video_device() - Check if the entity is a video_device * @entity: pointer to entity * * Return: %true if the entity is an instance of a video_device object and can * safely be cast to a struct video_device using the container_of() macro, or * %false otherwise. */
static inline bool is_media_entity_v4l2_video_device(struct media_entity *entity) { return entity && entity->obj_type == MEDIA_ENTITY_TYPE_VIDEO_DEVICE; }

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/** * is_media_entity_v4l2_subdev() - Check if the entity is a v4l2_subdev * @entity: pointer to entity * * Return: %true if the entity is an instance of a &v4l2_subdev object and can * safely be cast to a struct &v4l2_subdev using the container_of() macro, or * %false otherwise. */
static inline bool is_media_entity_v4l2_subdev(struct media_entity *entity) { return entity && entity->obj_type == MEDIA_ENTITY_TYPE_V4L2_SUBDEV; }

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/** * __media_entity_enum_init - Initialise an entity enumeration * * @ent_enum: Entity enumeration to be initialised * @idx_max: Maximum number of entities in the enumeration * * Return: Returns zero on success or a negative error code. */ __must_check int __media_entity_enum_init(struct media_entity_enum *ent_enum, int idx_max); /** * media_entity_enum_cleanup - Release resources of an entity enumeration * * @ent_enum: Entity enumeration to be released */ void media_entity_enum_cleanup(struct media_entity_enum *ent_enum); /** * media_entity_enum_zero - Clear the entire enum * * @ent_enum: Entity enumeration to be cleared */
static inline void media_entity_enum_zero(struct media_entity_enum *ent_enum) { bitmap_zero(ent_enum->bmap, ent_enum->idx_max); }

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/** * media_entity_enum_set - Mark a single entity in the enum * * @ent_enum: Entity enumeration * @entity: Entity to be marked */
static inline void media_entity_enum_set(struct media_entity_enum *ent_enum, struct media_entity *entity) { if (WARN_ON(entity->internal_idx >= ent_enum->idx_max)) return; __set_bit(entity->internal_idx, ent_enum->bmap); }

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/** * media_entity_enum_clear - Unmark a single entity in the enum * * @ent_enum: Entity enumeration * @entity: Entity to be unmarked */
static inline void media_entity_enum_clear(struct media_entity_enum *ent_enum, struct media_entity *entity) { if (WARN_ON(entity->internal_idx >= ent_enum->idx_max)) return; __clear_bit(entity->internal_idx, ent_enum->bmap); }

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/** * media_entity_enum_test - Test whether the entity is marked * * @ent_enum: Entity enumeration * @entity: Entity to be tested * * Returns %true if the entity was marked. */
static inline bool media_entity_enum_test(struct media_entity_enum *ent_enum, struct media_entity *entity) { if (WARN_ON(entity->internal_idx >= ent_enum->idx_max)) return true; return test_bit(entity->internal_idx, ent_enum->bmap); }

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/** * media_entity_enum_test_and_set - Test whether the entity is marked, * and mark it * * @ent_enum: Entity enumeration * @entity: Entity to be tested * * Returns %true if the entity was marked, and mark it before doing so. */
static inline bool media_entity_enum_test_and_set(struct media_entity_enum *ent_enum, struct media_entity *entity) { if (WARN_ON(entity->internal_idx >= ent_enum->idx_max)) return true; return __test_and_set_bit(entity->internal_idx, ent_enum->bmap); }

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/** * media_entity_enum_empty - Test whether the entire enum is empty * * @ent_enum: Entity enumeration * * Return: %true if the entity was empty. */
static inline bool media_entity_enum_empty(struct media_entity_enum *ent_enum) { return bitmap_empty(ent_enum->bmap, ent_enum->idx_max); }

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/** * media_entity_enum_intersects - Test whether two enums intersect * * @ent_enum1: First entity enumeration * @ent_enum2: Second entity enumeration * * Return: %true if entity enumerations @ent_enum1 and @ent_enum2 intersect, * otherwise %false. */
static inline bool media_entity_enum_intersects( struct media_entity_enum *ent_enum1, struct media_entity_enum *ent_enum2) { WARN_ON(ent_enum1->idx_max != ent_enum2->idx_max); return bitmap_intersects(ent_enum1->bmap, ent_enum2->bmap, min(ent_enum1->idx_max, ent_enum2->idx_max)); }

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/** * gobj_to_entity - returns the struct &media_entity pointer from the * @gobj contained on it. * * @gobj: Pointer to the struct &media_gobj graph object */ #define gobj_to_entity(gobj) \ container_of(gobj, struct media_entity, graph_obj) /** * gobj_to_pad - returns the struct &media_pad pointer from the * @gobj contained on it. * * @gobj: Pointer to the struct &media_gobj graph object */ #define gobj_to_pad(gobj) \ container_of(gobj, struct media_pad, graph_obj) /** * gobj_to_link - returns the struct &media_link pointer from the * @gobj contained on it. * * @gobj: Pointer to the struct &media_gobj graph object */ #define gobj_to_link(gobj) \ container_of(gobj, struct media_link, graph_obj) /** * gobj_to_intf - returns the struct &media_interface pointer from the * @gobj contained on it. * * @gobj: Pointer to the struct &media_gobj graph object */ #define gobj_to_intf(gobj) \ container_of(gobj, struct media_interface, graph_obj) /** * intf_to_devnode - returns the struct media_intf_devnode pointer from the * @intf contained on it. * * @intf: Pointer to struct &media_intf_devnode */ #define intf_to_devnode(intf) \ container_of(intf, struct media_intf_devnode, intf) /** * media_gobj_create - Initialize a graph object * * @mdev: Pointer to the &media_device that contains the object * @type: Type of the object * @gobj: Pointer to the struct &media_gobj graph object * * This routine initializes the embedded struct &media_gobj inside a * media graph object. It is called automatically if ``media_*_create`` * function calls are used. However, if the object (entity, link, pad, * interface) is embedded on some other object, this function should be * called before registering the object at the media controller. */ void media_gobj_create(struct media_device *mdev, enum media_gobj_type type, struct media_gobj *gobj); /** * media_gobj_destroy - Stop using a graph object on a media device * * @gobj: Pointer to the struct &media_gobj graph object * * This should be called by all routines like media_device_unregister() * that remove/destroy media graph objects. */ void media_gobj_destroy(struct media_gobj *gobj); /** * media_entity_pads_init() - Initialize the entity pads * * @entity: entity where the pads belong * @num_pads: total number of sink and source pads * @pads: Array of @num_pads pads. * * The pads array is managed by the entity driver and passed to * media_entity_pads_init() where its pointer will be stored in the * &media_entity structure. * * If no pads are needed, drivers could either directly fill * &media_entity->num_pads with 0 and &media_entity->pads with %NULL or call * this function that will do the same. * * As the number of pads is known in advance, the pads array is not allocated * dynamically but is managed by the entity driver. Most drivers will embed the * pads array in a driver-specific structure, avoiding dynamic allocation. * * Drivers must set the direction of every pad in the pads array before calling * media_entity_pads_init(). The function will initialize the other pads fields. */ int media_entity_pads_init(struct media_entity *entity, u16 num_pads, struct media_pad *pads); /** * media_entity_cleanup() - free resources associated with an entity * * @entity: entity where the pads belong * * This function must be called during the cleanup phase after unregistering * the entity (currently, it does nothing). */
static inline void media_entity_cleanup(struct media_entity *entity) {}

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; /** * media_create_pad_link() - creates a link between two entities. * * @source: pointer to &media_entity of the source pad. * @source_pad: number of the source pad in the pads array * @sink: pointer to &media_entity of the sink pad. * @sink_pad: number of the sink pad in the pads array. * @flags: Link flags, as defined in * :ref:`include/uapi/linux/media.h <media_header>` * ( seek for ``MEDIA_LNK_FL_*``) * * Valid values for flags: * * %MEDIA_LNK_FL_ENABLED * Indicates that the link is enabled and can be used to transfer media data. * When two or more links target a sink pad, only one of them can be * enabled at a time. * * %MEDIA_LNK_FL_IMMUTABLE * Indicates that the link enabled state can't be modified at runtime. If * %MEDIA_LNK_FL_IMMUTABLE is set, then %MEDIA_LNK_FL_ENABLED must also be * set, since an immutable link is always enabled. * * .. note:: * * Before calling this function, media_entity_pads_init() and * media_device_register_entity() should be called previously for both ends. */ __must_check int media_create_pad_link(struct media_entity *source, u16 source_pad, struct media_entity *sink, u16 sink_pad, u32 flags); /** * media_create_pad_links() - creates a link between two entities. * * @mdev: Pointer to the media_device that contains the object * @source_function: Function of the source entities. Used only if @source is * NULL. * @source: pointer to &media_entity of the source pad. If NULL, it will use * all entities that matches the @sink_function. * @source_pad: number of the source pad in the pads array * @sink_function: Function of the sink entities. Used only if @sink is NULL. * @sink: pointer to &media_entity of the sink pad. If NULL, it will use * all entities that matches the @sink_function. * @sink_pad: number of the sink pad in the pads array. * @flags: Link flags, as defined in include/uapi/linux/media.h. * @allow_both_undefined: if %true, then both @source and @sink can be NULL. * In such case, it will create a crossbar between all entities that * matches @source_function to all entities that matches @sink_function. * If %false, it will return 0 and won't create any link if both @source * and @sink are NULL. * * Valid values for flags: * * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be * used to transfer media data. If multiple links are created and this * flag is passed as an argument, only the first created link will have * this flag. * * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is * always enabled. * * It is common for some devices to have multiple source and/or sink entities * of the same type that should be linked. While media_create_pad_link() * creates link by link, this function is meant to allow 1:n, n:1 and even * cross-bar (n:n) links. * * .. note:: * * Before calling this function, media_entity_pads_init() and * media_device_register_entity() should be called previously for the * entities to be linked. */ int media_create_pad_links(const struct media_device *mdev, const u32 source_function, struct media_entity *source, const u16 source_pad, const u32 sink_function, struct media_entity *sink, const u16 sink_pad, u32 flags, const bool allow_both_undefined); void __media_entity_remove_links(struct media_entity *entity); /** * media_entity_remove_links() - remove all links associated with an entity * * @entity: pointer to &media_entity * * .. note:: * * This is called automatically when an entity is unregistered via * media_device_register_entity(). */ void media_entity_remove_links(struct media_entity *entity); /** * __media_entity_setup_link - Configure a media link without locking * @link: The link being configured * @flags: Link configuration flags * * The bulk of link setup is handled by the two entities connected through the * link. This function notifies both entities of the link configuration change. * * If the link is immutable or if the current and new configuration are * identical, return immediately. * * The user is expected to hold link->source->parent->mutex. If not, * media_entity_setup_link() should be used instead. */ int __media_entity_setup_link(struct media_link *link, u32 flags); /** * media_entity_setup_link() - changes the link flags properties in runtime * * @link: pointer to &media_link * @flags: the requested new link flags * * The only configurable property is the %MEDIA_LNK_FL_ENABLED link flag * flag to enable/disable a link. Links marked with the * %MEDIA_LNK_FL_IMMUTABLE link flag can not be enabled or disabled. * * When a link is enabled or disabled, the media framework calls the * link_setup operation for the two entities at the source and sink of the * link, in that order. If the second link_setup call fails, another * link_setup call is made on the first entity to restore the original link * flags. * * Media device drivers can be notified of link setup operations by setting the * &media_device.link_notify pointer to a callback function. If provided, the * notification callback will be called before enabling and after disabling * links. * * Entity drivers must implement the link_setup operation if any of their links * is non-immutable. The operation must either configure the hardware or store * the configuration information to be applied later. * * Link configuration must not have any side effect on other links. If an * enabled link at a sink pad prevents another link at the same pad from * being enabled, the link_setup operation must return %-EBUSY and can't * implicitly disable the first enabled link. * * .. note:: * * The valid values of the flags for the link is the same as described * on media_create_pad_link(), for pad to pad links or the same as described * on media_create_intf_link(), for interface to entity links. */ int media_entity_setup_link(struct media_link *link, u32 flags); /** * media_entity_find_link - Find a link between two pads * @source: Source pad * @sink: Sink pad * * Return: returns a pointer to the link between the two entities. If no * such link exists, return %NULL. */ struct media_link *media_entity_find_link(struct media_pad *source, struct media_pad *sink); /** * media_entity_remote_pad - Find the pad at the remote end of a link * @pad: Pad at the local end of the link * * Search for a remote pad connected to the given pad by iterating over all * links originating or terminating at that pad until an enabled link is found. * * Return: returns a pointer to the pad at the remote end of the first found * enabled link, or %NULL if no enabled link has been found. */ struct media_pad *media_entity_remote_pad(struct media_pad *pad); /** * media_entity_get - Get a reference to the parent module * * @entity: The entity * * Get a reference to the parent media device module. * * The function will return immediately if @entity is %NULL. * * Return: returns a pointer to the entity on success or %NULL on failure. */ struct media_entity *media_entity_get(struct media_entity *entity); /** * media_graph_walk_init - Allocate resources used by graph walk. * * @graph: Media graph structure that will be used to walk the graph * @mdev: Pointer to the &media_device that contains the object */ __must_check int media_graph_walk_init( struct media_graph *graph, struct media_device *mdev); /** * media_graph_walk_cleanup - Release resources used by graph walk. * * @graph: Media graph structure that will be used to walk the graph */ void media_graph_walk_cleanup(struct media_graph *graph); /** * media_entity_put - Release the reference to the parent module * * @entity: The entity * * Release the reference count acquired by media_entity_get(). * * The function will return immediately if @entity is %NULL. */ void media_entity_put(struct media_entity *entity); /** * media_graph_walk_start - Start walking the media graph at a * given entity * * @graph: Media graph structure that will be used to walk the graph * @entity: Starting entity * * Before using this function, media_graph_walk_init() must be * used to allocate resources used for walking the graph. This * function initializes the graph traversal structure to walk the * entities graph starting at the given entity. The traversal * structure must not be modified by the caller during graph * traversal. After the graph walk, the resources must be released * using media_graph_walk_cleanup(). */ void media_graph_walk_start(struct media_graph *graph, struct media_entity *entity); /** * media_graph_walk_next - Get the next entity in the graph * @graph: Media graph structure * * Perform a depth-first traversal of the given media entities graph. * * The graph structure must have been previously initialized with a call to * media_graph_walk_start(). * * Return: returns the next entity in the graph or %NULL if the whole graph * have been traversed. */ struct media_entity *media_graph_walk_next(struct media_graph *graph); /** * media_pipeline_start - Mark a pipeline as streaming * @entity: Starting entity * @pipe: Media pipeline to be assigned to all entities in the pipeline. * * Mark all entities connected to a given entity through enabled links, either * directly or indirectly, as streaming. The given pipeline object is assigned * to every entity in the pipeline and stored in the media_entity pipe field. * * Calls to this function can be nested, in which case the same number of * media_pipeline_stop() calls will be required to stop streaming. The * pipeline pointer must be identical for all nested calls to * media_pipeline_start(). */ __must_check int media_pipeline_start(struct media_entity *entity, struct media_pipeline *pipe); /** * __media_pipeline_start - Mark a pipeline as streaming * * @entity: Starting entity * @pipe: Media pipeline to be assigned to all entities in the pipeline. * * ..note:: This is the non-locking version of media_pipeline_start() */ __must_check int __media_pipeline_start(struct media_entity *entity, struct media_pipeline *pipe); /** * media_pipeline_stop - Mark a pipeline as not streaming * @entity: Starting entity * * Mark all entities connected to a given entity through enabled links, either * directly or indirectly, as not streaming. The media_entity pipe field is * reset to %NULL. * * If multiple calls to media_pipeline_start() have been made, the same * number of calls to this function are required to mark the pipeline as not * streaming. */ void media_pipeline_stop(struct media_entity *entity); /** * __media_pipeline_stop - Mark a pipeline as not streaming * * @entity: Starting entity * * .. note:: This is the non-locking version of media_pipeline_stop() */ void __media_pipeline_stop(struct media_entity *entity); /** * media_devnode_create() - creates and initializes a device node interface * * @mdev: pointer to struct &media_device * @type: type of the interface, as given by * :ref:`include/uapi/linux/media.h <media_header>` * ( seek for ``MEDIA_INTF_T_*``) macros. * @flags: Interface flags, as defined in * :ref:`include/uapi/linux/media.h <media_header>` * ( seek for ``MEDIA_INTF_FL_*``) * @major: Device node major number. * @minor: Device node minor number. * * Return: if succeeded, returns a pointer to the newly allocated * &media_intf_devnode pointer. * * .. note:: * * Currently, no flags for &media_interface is defined. */ struct media_intf_devnode * __must_check media_devnode_create(struct media_device *mdev, u32 type, u32 flags, u32 major, u32 minor); /** * media_devnode_remove() - removes a device node interface * * @devnode: pointer to &media_intf_devnode to be freed. * * When a device node interface is removed, all links to it are automatically * removed. */ void media_devnode_remove(struct media_intf_devnode *devnode); struct media_link * /** * media_create_intf_link() - creates a link between an entity and an interface * * @entity: pointer to %media_entity * @intf: pointer to %media_interface * @flags: Link flags, as defined in * :ref:`include/uapi/linux/media.h <media_header>` * ( seek for ``MEDIA_LNK_FL_*``) * * * Valid values for flags: * * %MEDIA_LNK_FL_ENABLED * Indicates that the interface is connected to the entity hardware. * That's the default value for interfaces. An interface may be disabled if * the hardware is busy due to the usage of some other interface that it is * currently controlling the hardware. * * A typical example is an hybrid TV device that handle only one type of * stream on a given time. So, when the digital TV is streaming, * the V4L2 interfaces won't be enabled, as such device is not able to * also stream analog TV or radio. * * .. note:: * * Before calling this function, media_devnode_create() should be called for * the interface and media_device_register_entity() should be called for the * interface that will be part of the link. */ __must_check media_create_intf_link(struct media_entity *entity, struct media_interface *intf, u32 flags); /** * __media_remove_intf_link() - remove a single interface link * * @link: pointer to &media_link. * * .. note:: This is an unlocked version of media_remove_intf_link() */ void __media_remove_intf_link(struct media_link *link); /** * media_remove_intf_link() - remove a single interface link * * @link: pointer to &media_link. * * .. note:: Prefer to use this one, instead of __media_remove_intf_link() */ void media_remove_intf_link(struct media_link *link); /** * __media_remove_intf_links() - remove all links associated with an interface * * @intf: pointer to &media_interface * * .. note:: This is an unlocked version of media_remove_intf_links(). */ void __media_remove_intf_links(struct media_interface *intf); /** * media_remove_intf_links() - remove all links associated with an interface * * @intf: pointer to &media_interface * * .. note:: * * #) This is called automatically when an entity is unregistered via * media_device_register_entity() and by media_devnode_remove(). * * #) Prefer to use this one, instead of __media_remove_intf_links(). */ void media_remove_intf_links(struct media_interface *intf); /** * media_entity_call - Calls a struct media_entity_operations operation on * an entity * * @entity: entity where the @operation will be called * @operation: type of the operation. Should be the name of a member of * struct &media_entity_operations. * * This helper function will check if @operation is not %NULL. On such case, * it will issue a call to @operation\(@entity, @args\). */ #define media_entity_call(entity, operation, args...) \ (((entity)->ops && (entity)->ops->operation) ? \ (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD) #endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Mauro Carvalho Chehab50838.54%3557.38%
Sakari Ailus43533.00%1321.31%
Laurent Pinchart33025.04%813.11%
Shuah Khan221.67%11.64%
Sylwester Nawrocki181.37%11.64%
Philipp Zabel30.23%11.64%
Clemens Ladisch10.08%11.64%
Andrzej Hajda10.08%11.64%
Total1318100.00%61100.00%
Directory: include/media
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