diff options
Diffstat (limited to 'media.h')
| -rw-r--r-- | media.h | 82 |
1 files changed, 82 insertions, 0 deletions
@@ -56,23 +56,105 @@ struct media_device { __u32 padding[6]; }; +/** + * @brief Open a media device. + * @param name - name (including path) of the device node. + * @param verbose - whether to print verbose information on the standard output. + * + * Open the media device referenced by @a name and enumerate entities, pads and + * links. + * + * @return A pointer to a newly allocated media_device structure instance on + * success and NULL on failure. The returned pointer must be freed with + * media_close when the device isn't needed anymore. + */ struct media_device *media_open(const char *name, int verbose); + +/** + * @brief Close a media device. + * @param media - device instance. + * + * Close the @a media device instance and free allocated resources. Access to the + * device instance is forbidden after this function returns. + */ void media_close(struct media_device *media); +/** + * @brief Locate the pad at the other end of a link. + * @param pad - sink pad at one end of the link. + * + * Locate the source pad connected to @a pad through an enabled link. As only one + * link connected to a sink pad can be enabled at a time, the connected source + * pad is guaranteed to be unique. + * + * @return A pointer to the connected source pad, or NULL if all links connected + * to @a pad are disabled. Return NULL also if @a pad is not a sink pad. + */ struct media_pad *media_entity_remote_source(struct media_pad *pad); +/** + * @brief Get the type of an entity. + * @param entity - the entity. + * + * @return The type of @a entity. + */ static inline unsigned int media_entity_type(struct media_entity *entity) { return entity->info.type & MEDIA_ENTITY_TYPE_MASK; } +/** + * @brief Find an entity by its name. + * @param media - media device. + * @param name - entity name. + * @param length - size of @a name. + * + * Search for an entity with a name equal to @a name. + * + * @return A pointer to the entity if found, or NULL otherwise. + */ struct media_entity *media_get_entity_by_name(struct media_device *media, const char *name, size_t length); + +/** + * @brief Find an entity by its ID. + * @param media - media device. + * @param id - entity ID. + * + * Search for an entity with an ID equal to @a id. + * + * @return A pointer to the entity if found, or NULL otherwise. + */ struct media_entity *media_get_entity_by_id(struct media_device *media, __u32 id); + +/** + * @brief Configure a link. + * @param media - media device. + * @param source - source pad at the link origin. + * @param sink - sink pad at the link target. + * @param flags - configuration flags. + * + * Locate the link between @a source and @a sink, and configure it by applying + * the new @a flags. + * + * Only the MEDIA_LINK_FLAG_ENABLED flag is writable. + * + * @return 0 on success, or a negative error code on failure. + */ int media_setup_link(struct media_device *media, struct media_pad *source, struct media_pad *sink, __u32 flags); + +/** + * @brief Reset all links to the disabled state. + * @param media - media device. + * + * Disable all links in the media device. This function is usually used after + * opening a media device to reset all links to a known state. + * + * @return 0 on success, or a negative error code on failure. + */ int media_reset_links(struct media_device *media); #endif |