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Diffstat (limited to 'include/media/media-entity.h')
| -rw-r--r-- | include/media/media-entity.h | 1088 |
1 files changed, 1088 insertions, 0 deletions
diff --git a/include/media/media-entity.h b/include/media/media-entity.h new file mode 100644 index 000000000..3aa3d58d1 --- /dev/null +++ b/include/media/media-entity.h @@ -0,0 +1,1088 @@ +/* + * 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/fwnode.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. + * @stack.entity: pointer to &struct media_entity at the graph. + * @stack.link: pointer to &struct list_head. + * @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 + * @get_fwnode_pad: Return the pad number based on a fwnode endpoint or + * a negative value on error. This operation can be used + * to map a fwnode to a media pad number. Optional. + * @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 (*get_fwnode_pad)(struct fwnode_endpoint *endpoint); + 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. + * @info.dev: Contains device major and minor info. + * @info.dev.major: device node major, if the device is a devnode. + * @info.dev.minor: device node minor, if the device is a devnode. + * @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; +} + +/** + * 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; +} + +/** + * 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; +} + +/** + * 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; +} + +/** + * 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; +} + +/** + * 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; +} + +/** + * __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); +} + +/** + * 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); +} + +/** + * 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); +} + +/** + * 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); +} + +/** + * 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); +} + +/** + * 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); +} + +/** + * 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)); +} + +/** + * 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). + */ +#if IS_ENABLED(CONFIG_MEDIA_CONTROLLER) +static inline void media_entity_cleanup(struct media_entity *entity) {} +#else +#define media_entity_cleanup(entity) do { } while (false) +#endif + +/** + * 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(const 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_entity_get_fwnode_pad - Get pad number from fwnode + * + * @entity: The entity + * @fwnode: Pointer to the fwnode_handle which should be used to find the pad + * @direction_flags: Expected direction of the pad, as defined in + * :ref:`include/uapi/linux/media.h <media_header>` + * (seek for ``MEDIA_PAD_FL_*``) + * + * This function can be used to resolve the media pad number from + * a fwnode. This is useful for devices which use more complex + * mappings of media pads. + * + * If the entity does not implement the get_fwnode_pad() operation + * then this function searches the entity for the first pad that + * matches the @direction_flags. + * + * Return: returns the pad number on success or a negative error code. + */ +int media_entity_get_fwnode_pad(struct media_entity *entity, + struct fwnode_handle *fwnode, + unsigned long direction_flags); + +/** + * 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 |