On Wednesday 21 July 2010 16:35:28 Laurent Pinchart wrote:
<snip>
> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> new file mode 100644
> index 0000000..fd44647
> --- /dev/null
> +++ b/include/media/media-entity.h
> @@ -0,0 +1,79 @@
> +#ifndef _MEDIA_ENTITY_H
> +#define _MEDIA_ENTITY_H
> +
> +#include <linux/list.h>
> +
> +#define MEDIA_ENTITY_TYPE_NODE 1
> +#define MEDIA_ENTITY_TYPE_SUBDEV 2
> +
> +#define MEDIA_ENTITY_SUBTYPE_NODE_V4L 1
> +#define MEDIA_ENTITY_SUBTYPE_NODE_FB 2
> +#define MEDIA_ENTITY_SUBTYPE_NODE_ALSA 3
> +#define MEDIA_ENTITY_SUBTYPE_NODE_DVB 4
> +
> +#define MEDIA_ENTITY_SUBTYPE_SUBDEV_VID_DECODER 1
> +#define MEDIA_ENTITY_SUBTYPE_SUBDEV_VID_ENCODER 2
> +#define MEDIA_ENTITY_SUBTYPE_SUBDEV_MISC 3
These names are too awkward.
I see two options:
1) Rename the type field to 'entity' and the macros to MEDIA_ENTITY_NODE/SUBDEV.
Also rename subtype to type and the macros to MEDIA_ENTITY_TYPE_NODE_V4L
and MEDIA_ENTITY_TYPE_SUBDEV_VID_DECODER. We might even get away with dropping
_TYPE from the macro name.
2) Merge type and subtype to a single entity field. The top 16 bits are the entity
type, the bottom 16 bits are the subtype. That way you end up with:
#define MEDIA_ENTITY_NODE (1 << 16)
#define MEDIA_ENTITY_SUBDEV (2 << 16)
#define MEDIA_ENTITY_NODE_V4L (MEDIA_ENTITY_NODE + 1)
#define MEDIA_ENTITY_SUBDEV_VID_DECODER (MEDIA_ENTITY_SUBDEV + 1)
I rather like this option myself.
> +
> +#define MEDIA_LINK_FLAG_ACTIVE (1 << 0)
> +#define MEDIA_LINK_FLAG_IMMUTABLE (1 << 1)
> +
> +#define MEDIA_PAD_DIR_INPUT 1
> +#define MEDIA_PAD_DIR_OUTPUT 2
> +
> +struct media_entity_link {
> + struct media_entity_pad *source;/* Source pad */
> + struct media_entity_pad *sink; /* Sink pad */
> + struct media_entity_link *other;/* Link in the reverse direction */
> + u32 flags; /* Link flags (MEDIA_LINK_FLAG_*) */
> +};
> +
> +struct media_entity_pad {
> + struct media_entity *entity; /* Entity this pad belongs to */
> + u32 direction; /* Pad direction (MEDIA_PAD_DIR_*) */
> + u8 index; /* Pad index in the entity pads array */
We can use bitfields for direction and index. That way we can also easily add
other flags/attributes.
> +};
> +
> +struct media_entity {
> + struct list_head list;
> + struct media_device *parent; /* Media device this entity belongs to*/
> + u32 id; /* Entity ID, unique in the parent media
> + * device context */
> + const char *name; /* Entity name */
> + u32 type; /* Entity type (MEDIA_ENTITY_TYPE_*) */
> + u32 subtype; /* Entity subtype (type-specific) */
> +
> + u8 num_pads; /* Number of input and output pads */
> + u8 num_links; /* Number of existing links, both active
> + * and inactive */
> + u8 num_backlinks; /* Number of backlinks */
> + u8 max_links; /* Maximum number of links */
> +
> + struct media_entity_pad *pads; /* Array of pads (num_pads elements) */
> + struct media_entity_link *links;/* Array of links (max_links elements)*/
> +
> + union {
> + /* Node specifications */
> + struct {
> + u32 major;
> + u32 minor;
> + } v4l;
> + struct {
> + u32 major;
> + u32 minor;
> + } fb;
> + int alsa;
> + int dvb;
> +
> + /* Sub-device specifications */
> + /* Nothing needed yet */
> + };
> +};
> +
> +int media_entity_init(struct media_entity *entity, u8 num_pads,
> + struct media_entity_pad *pads, u8 extra_links);
> +void media_entity_cleanup(struct media_entity *entity);
> +int media_entity_create_link(struct media_entity *source, u8 source_pad,
> + struct media_entity *sink, u8 sink_pad, u32 flags);
> +
> +#endif
>
Regards,
Hans
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of Cisco
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