Add doxygen comments

Add doxygen format comments to header files.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Todor Tomov <ttomov@mm-sol.com>

3 files changed, 182 insertions, 18 deletions

diff --git a/media.c b/media.c
index 5508775..456b882 100644
--- a/media.c
+++ b/media.c
@@ -34,9 +34,6 @@
 #include "media.h"
 #include "tools.h"
 
-/*
- * media_entity_remote_pad -
- */
 struct media_pad *media_entity_remote_source(struct media_pad *pad)
 {
 	unsigned int i;
@@ -57,9 +54,6 @@ struct media_pad *media_entity_remote_source(struct media_pad *pad)
 	return NULL;
 }
 
-/*
- * media_get_entity_by_name -
- */
 struct media_entity *media_get_entity_by_name(struct media_device *media,
 					      const char *name, size_t length)
 {
@@ -75,9 +69,6 @@ struct media_entity *media_get_entity_by_name(struct media_device *media,
 	return NULL;
 }
 
-/*
- * media_get_entity_by_id -
- */
 struct media_entity *media_get_entity_by_id(struct media_device *media,
 					    __u32 id)
 {
@@ -93,9 +84,6 @@ struct media_entity *media_get_entity_by_id(struct media_device *media,
 	return NULL;
 }
 
-/*
- * media_setup_link -
- */
 int media_setup_link(struct media_device *media,
 		     struct media_pad *source,
 		     struct media_pad *sink,
@@ -330,9 +318,6 @@ static int media_enum_entities(struct media_device *media)
 	return 0;
 }
 
-/*
- * media_open -
- */
 struct media_device *media_open(const char *name, int verbose)
 {
 	struct media_device *media;
@@ -381,9 +366,6 @@ struct media_device *media_open(const char *name, int verbose)
 	return media;
 }
 
-/*
- * media_close -
- */
 void media_close(struct media_device *media)
 {
 	unsigned int i;
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
diff --git a/subdev.h b/subdev.h
index 976d066..9451b12 100644
--- a/subdev.h
+++ b/subdev.h
@@ -24,20 +24,120 @@
 
 struct media_entity;
 
+/**
+ * @brief Open a sub-device.
+ * @param entity - sub-device media entity.
+ *
+ * Open the V4L2 subdev device node associated with @a entity. The file
+ * descriptor is stored in the media_entity structure.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
 int v4l2_subdev_open(struct media_entity *entity);
 
+/**
+ * @brief Close a sub-device.
+ * @param entity - sub-device media entity.
+ *
+ * Close the V4L2 subdev device node associated with the @a entity and opened by
+ * a previous call to v4l2_subdev_open() (either explicit or implicit).
+ */
 void v4l2_subdev_close(struct media_entity *entity);
 
+/**
+ * @brief Retrieve the format on a pad.
+ * @param entity - subdev-device media entity.
+ * @param format - format to be filled.
+ * @param pad - pad number.
+ * @param which - identifier of the format to get.
+ *
+ * Retrieve the current format on the @a entity @a pad and store it in the
+ * @a format structure.
+ *
+ * @a which is set to V4L2_SUBDEV_FORMAT_TRY to retrieve the try format stored
+ * in the file handle, of V4L2_SUBDEV_FORMAT_ACTIVE to retrieve the current
+ * active format.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
 int v4l2_subdev_get_format(struct media_entity *entity,
 	struct v4l2_mbus_framefmt *format, unsigned int pad,
 	enum v4l2_subdev_format_whence which);
+
+/**
+ * @brief Set the format on a pad.
+ * @param entity - subdev-device media entity.
+ * @param format - format.
+ * @param pad - pad number.
+ * @param which - identifier of the format to set.
+ *
+ * Set the format on the @a entity @a pad to @a format. The driver is allowed to
+ * modify the requested format, in which case @a format is updated with the
+ * modifications.
+ *
+ * @a which is set to V4L2_SUBDEV_FORMAT_TRY to set the try format stored in the
+ * file handle, of V4L2_SUBDEV_FORMAT_ACTIVE to configure the device with an
+ * active format.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
 int v4l2_subdev_set_format(struct media_entity *entity,
 	struct v4l2_mbus_framefmt *format, unsigned int pad,
 	enum v4l2_subdev_format_whence which);
+
+/**
+ * @brief Retrieve the crop rectangle on a pad.
+ * @param entity - subdev-device media entity.
+ * @param rect - crop rectangle to be filled.
+ * @param pad - pad number.
+ * @param which - identifier of the format to get.
+ *
+ * Retrieve the current crop rectangleon the @a entity @a pad and store it in
+ * the @a rect structure.
+ *
+ * @a which is set to V4L2_SUBDEV_FORMAT_TRY to retrieve the try crop rectangle
+ * stored in the file handle, of V4L2_SUBDEV_FORMAT_ACTIVE to retrieve the
+ * current active crop rectangle.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
 int v4l2_subdev_get_crop(struct media_entity *entity, struct v4l2_rect *rect,
 	unsigned int pad, enum v4l2_subdev_format_whence which);
+
+/**
+ * @brief Set the crop rectangle on a pad.
+ * @param entity - subdev-device media entity.
+ * @param rect - crop rectangle.
+ * @param pad - pad number.
+ * @param which - identifier of the format to set.
+ *
+ * Set the crop rectangle on the @a entity @a pad to @a rect. The driver is
+ * allowed to modify the requested rectangle, in which case @a rect is updated
+ * with the modifications.
+ *
+ * @a which is set to V4L2_SUBDEV_FORMAT_TRY to set the try crop rectangle
+ * stored in the file handle, of V4L2_SUBDEV_FORMAT_ACTIVE to configure the
+ * device with an active crop rectangle.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
 int v4l2_subdev_set_crop(struct media_entity *entity, struct v4l2_rect *rect,
 	unsigned int pad, enum v4l2_subdev_format_whence which);
+
+/**
+ * @brief Set the frame interval on a sub-device.
+ * @param entity - subdev-device media entity.
+ * @param interval - frame interval.
+ *
+ * Set the frame interval on subdev @a entity to @a interval. The driver is
+ * allowed to modify the requested frame interval, in which case @a interval is
+ * updated with the modifications.
+ *
+ * Frame interval setting is usually supported only on devices at the beginning
+ * of video pipelines, such as sensors.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
 int v4l2_subdev_set_frame_interval(struct media_entity *entity,
 	struct v4l2_fract *interval);