dt-bindings: display: xlnx: mixer: Inconsistent pixel format terminology in dt docs

[Kenneth Sloat <ksloat@designlinxhs.com>]

Hello,

The Xilinx Video mixer IP uses the DRM fourcc string as a device tree binding in order to describe the format for a specific DRM layer/plane. Currently, in the device tree doc in "Documentation/devicetree/bindings/dma/xilinx/xilinx_frmbuf.txt" there is a list called "VIDEO FORMATS" with a table containing "Mixer IP Format" and associated "Driver supported Format String" (fourcc). In general, this table is not helpful, because "Mixer IP Format" does not match the Xilinx IP datasheet terminology for formats but rather some other commonly used nomenclature. This is also inconsistent from other Xilinx dts binding docs which specify the actual correct IP name and at times list other format nomenclature where helpful (i.e. xilinx_frmbuf.txt)

My suggestion is to remove the current "Mixer IP Format" strings in the doc and replace them with the actual IP names in the datasheet (which also match those used in Xilinx's Vivado FPGA tool). Otherwise, the programmer must cross reference other dts documentation or the code in order to figure these out. I am happy to provide a patch for this but wanted to throw out the suggestion first.

Thanks

Sincerely,
Ken Sloat