[libcamera-devel] [PATCH v3 0/5] Introduce ancillary links

[Daniel Scally]

Hello everyone


Any more comments on this series?


Thanks

Dan

On 02/03/2022 22:02, Daniel Scally wrote:
> Hello all
>
> At present there's no means in the kernel of describing the supporting
> relationship between subdevices that work together to form an effective single
> unit - the type example in this case being a camera sensor and its
> corresponding vcm. To attempt to solve that, this series adds a new type of
> media link called MEDIA_LNK_FL_ANCILLARY_LINK, which connects two instances of
> struct media_entity.
>
> The mechanism of connection I have modelled as a notifier and async subdev,
> which seemed the best route since sensor drivers already typically will call
> v4l2_async_register_subdev_sensor() on probe, and that function already looks
> for a reference to a firmware node with the reference named "lens-focus". To
> avoid boilerplate in the sensor drivers, I added some new functions in
> v4l2-async that are called in v4l2_async_match_notify() to create the ancillary
> links. I haven't gone further than that yet, but I suspect we could cut down on
> code elsewhere by, for example, also creating pad-to-pad links in the same place
>
> Series level changes since v2:
>
>   - Squashed #2 and #3
>
> Series-level changes since v1:
>
> 	- New patch adding some documentation to the uAPI pages.
>
> Dan
>
>
> Daniel Scally (5):
>   media: entity: Skip non-data links in graph iteration
>   media: media.h: Add new media link type
>   media: entity: Add link_type_name() helper
>   media: entity: Add support for ancillary links
>   media: v4l2-async: Create links during v4l2_async_match_notify()
>
>  .../media/mediactl/media-controller-model.rst |  6 +++
>  .../media/mediactl/media-types.rst            | 17 +++++--
>  drivers/media/mc/mc-entity.c                  | 46 +++++++++++++++++--
>  drivers/media/v4l2-core/v4l2-async.c          | 31 +++++++++++++
>  include/media/media-entity.h                  | 19 ++++++++
>  include/uapi/linux/media.h                    |  1 +
>  6 files changed, 112 insertions(+), 8 deletions(-)
>