Hi Kenneth, > -----Original Message----- > From: Kenneth Sloat <ksloat@xxxxxxxxxxxxxxxx> > Sent: Thursday, August 20, 2020 2:18 PM > To: Hyun Kwon <hyunk@xxxxxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: Michal Simek <michals@xxxxxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; laurent.pinchart@xxxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > mark.rutland@xxxxxxx > Subject: dt-bindings: display: xlnx: mixer: Inconsistent pixel format terminology > in dt docs > > 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. I agree. The bindings should be in sync with datasheet and not rely on software definitions. Since the driver is only in Xilinx vendor tree, please send directly to git@xxxxxxxxxx. Thanks! -hyun > > Thanks > > Sincerely, > Ken Sloat
