Hi Laurent, On 02/04/2012 12:34 PM, Laurent Pinchart wrote: > 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 We have many standard pixel codes in include/linux/v4l2-mediabus.h, yet each bridge driver supports only a subset of them. I wouldn't expect a sudden need for all existing bridge drivers to support some strange interleaved image formats. > query the sensor using a subdev operation ? There is also a MIPI-CSI2 receiver in between that needs to be configured. I.e. it must know that it processes the User Defined Data 1, which implies certain pixel alignment, etc. So far a media bus pixel codes have been a base information to handle such things. >> 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 ? Do you mean setting a MIPI-CSI2 format ? It should work as long as the bridge driver can identify media bus code given a fourcc. I can't recall situation where a reverse lookup is necessary, i.e. struct v4l2_mbus_framefmt::code -> fourcc. This would fail since e.g. JPEG and YUV/JPEG would both correspond to User 1 format. -- Regards, Sylwester -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
