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-rw-r--r--media.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/media.h b/media.h
index bf5dcb7..80cf976 100644
--- a/media.h
+++ b/media.h
@@ -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