Hi Sylwester, On Saturday 04 February 2012 18:00:10 Sylwester Nawrocki wrote: > 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. Those media bus codes are standard, so implementing explicit support for them in bridge drivers is fine with me. What I want to avoid is adding explicit support for sensor-specific formats to bridges. There should be no dependency between the bridge and the sensor. > > 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. For CSI user-defined data types, I still think that the information required to configure the CSI receiver should come from the sensor. Only the sensor knows what user-defined data type it will generate. > >> 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 ? No, I mean setting the media bus code on the sensor output pad to a vendor- specific value. > 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, Laurent Pinchart -- 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
