Re: [PATCH v2 03/15] dt-bindings: memory: snps: Convert the schema to being generic

[Rob Herring]

On Sat, Sep 10, 2022 at 10:56:47PM +0300, Serge Semin wrote:
> At the current state the DW uMCTL2 DDRC DT-schema can't be used as the
> common one for all the IP-core-based devices due to the compatible string
> property constraining the list of the supported device names. In order to
> fix that we suggest to update the compatible property constraints so one
> would permit having any value aside with the generic device names. At the
> same time the generic DT-schema selection must be restricted to the
> denoted generic devices only so not to permit the generic fallback
> compatibles. Finally since the generic schema will be referenced from the
> vendor-specific DT-bindings with possibly non-standard properties defined
> it must permit having additional properties specified.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> 
> ---
> 
> Note alternatively we could drop the "additionalProperties" keyword
> modification since currently there is no actual device available with the
> properties not listed in the generic DT-schema.

Normally, this has required 2 schema files. However, I think you can 
do something like this:

if:
  compatible:
    enum:
      - snps,ddrc-3.80a
      - snps,dw-umctl2-ddrc
      - xlnx,zynqmp-ddrc-2.40a
then:
  unevaluatedProperties: false


But please make sure that actually catches undocumented properties 
because unevaluateProperties under 'then' is not something I've tried.

Rob