On Fri, 28 Jun 2024, John Watts <contact@xxxxxxxxxx> wrote: > Hello there, > > A while ago I added support for the FS035VG158 panel to the kernel, with its > use case being on a Allwinner T113 board. Might be helpful to actually point at the source code or commits or something. > While troubleshooting some other issue (I will be posting about that this > weekend) I found that I need to tell the panel controller to use a bit depth of > 18-bit in order for the panel to work correctly. > > I plan to add another panel to the kernel that also requires setting the bit > depth, but has more configurations than just 24, 18, 16, it also supports > packing 18 of the bits together. > > How all of this is configured depends on how the board and panel are wired > together, it can't be determined at runtime based on pixel formats or anything > like that. It seems to me that this needs to be specified in the device tree. > > My question is: How would I represent this? A property like 'bit-depth'? > 'color-mapping'? Or is there already some subsystem or convention designed for > this? Maybe look at include/uapi/drm/drm_fourcc.h, and how the DRM_FORMAT_* macros are used. Can't help you with device tree, but maybe this gives you pointers to other places for examples. HTH, Jani. -- Jani Nikula, Intel
