[PATCH v2 1/7] dt-bindings: display: mxsfb: Convert binding to YAML

[Laurent Pinchart]

Hi Marek,

On Wed, Oct 07, 2020 at 10:55:24AM +0200, Marek Vasut wrote:
> On 10/7/20 10:43 AM, Lucas Stach wrote:
> > 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.
> 
> What in that binding says you should specify compatible =
> "fsl,imx8mq-lcdif", "fsl,imx28-lcdif"; and not e.g. "fsl,imx8mq-lcdif",
> "fsl,imx23-lcdif" or simply "fsl,imx8mq-lcdif" ?

Nothing, until the next patch :-) This patch only handles the YAML
conversion but doesn't fix issues.

-- 
Regards,

Laurent Pinchart