Re: [Q] Interleaved formats on the media bus

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Sylwester,

On Thursday 02 February 2012 12:14:08 Sylwester Nawrocki wrote:
> On 02/02/2012 10:55 AM, Laurent Pinchart wrote:
> > Do all those sensors interleave the data in the same way ? This sounds
> > quite
> No, each one uses it's own interleaving method.
> 
> > hackish and vendor-specific to me, I'm not sure if we should try to
> > generalize that. Maybe vendor-specific media bus format codes would be
> > the way to go. I don't expect ISPs to understand the format, they will
> > likely be configured in pass-through mode. Instead of adding explicit
> > support for all those weird formats to all ISP drivers, it might make
> > sense to add a "binary blob" media bus code to be used by the ISP.
> 
> This could work, except that there is no way to match a fourcc with media
> bus code. Different fourcc would map to same media bus code, making it
> impossible for the brigde to handle multiple sensors or one sensor
> supporting multiple interleaved formats. Moreover there is a need to map
> media bus code to the MIPI-CSI data ID. What if one sensor sends "binary"
> blob with MIPI-CSI "User Define Data 1" and the other with "User Define
> Data 2" ?

My gut feeling is that the information should be retrieved from the sensor 
driver. This is all pretty vendor-specific, and adding explicit support for 
such sensors to each bridge driver wouldn't be very clean. Could the bridge 
query the sensor using a subdev operation ?

> Maybe we could create e.g. V4L2_MBUS_FMT_USER?, for each MIPI-CSI User
> Defined data identifier, but as I remember it was decided not to map
> MIPI-CSI data codes directly onto media bus pixel codes.

Would setting the format directly on the sensor subdev be an option ?

-- 
Regards,

Laurent Pinchart