On the 22 of August 2009 an unofficial meeting took place with the purpose to discuss a new
RFC for a new V4L API. Participants were (alphabetically sorted): Hans de Goede, Laurent Pinchart, Hans Verkuil and myself. The main discussion of this API will take place during the
Linux Plumbers Conference, but since not everyone, interested in this development, including the author of these pages, will be able to attend the conference, it has been decided to hold a small unofficial preliminary meeting on this topic. The following implications on the soc-camera migration to v4l2-subdev have been decided upon:
- We will have to remove bus-parameter auto-negotiation and force every board to specify a complete list of bus parameters, like signal polarities and sensing edge.
- Will consider using the .notify() member of struct v4l2_device in sensor drivers, that change their output pixel clock frequency dynamically, e.g., depending on the frame format, instead of using the current sense object.
- Maybe use a list of video subdevices as a parameter to soc-camera host platform device to avoid allocating otherwise "useless" per-source platform devices.
- Use a new enumeration for various pixel data representations on the video source - video host data bus, similar to the current fourcc codes for the in-memory presentation of pixel formats.
We will have to give a bit more thinking to items 2 and 3 though.
