On Mi, 2020-10-07 at 10:32 +0200, Marek Vasut wrote: > On 10/7/20 3:24 AM, Laurent Pinchart wrote: > [...] > > +properties: > > + compatible: > > + enum: > > + - fsl,imx23-lcdif > > + - fsl,imx28-lcdif > > + - fsl,imx6sx-lcdif > > + - fsl,imx8mq-lcdif > > There is no fsl,imx8mq-lcdif in drivers/gpu/drm/mxsfb/mxsfb_drv.c, > so the DT must specify compatible = "fsl,imx8mq-lcdif", > "fsl,imx28-lcdif" (since imx28 is the oldest SoC with LCDIF V4). > > Should the compatible be added to drivers/gpu/drm/mxsfb/mxsfb_drv.c or > dropped from the YAML file or neither ? Neither. As far as we know the block is compatible, so the DT should claim that it's compatible to "fsl,imx28-lcdif". However we don't know if there are any surprises, so we add the SoC specific compatible to be able to change the driver matching later without changing the DT if the need arises. For the DT validation to pass the SoC specific compatible needs to be documented, even if it currently unused by the driver. Regards, Lucas