Re: [PATCH] spi: dt-bindings: Move 'rx-sample-delay-ns' to spi-peripheral-props.yaml

[Rob Herring <robh@xxxxxxxxxx>]

On Thu, May 26, 2022 at 11:16:42AM +0530, Pratyush Yadav wrote:
> Hi Rob,
> 
> On 25/05/22 04:00PM, Rob Herring wrote:
> > SPI bus per device properties must be defined in spi-peripheral-props.yaml
> > for unevaluatedProperties checks to work correctly on device nodes.
> > 
> > This has the side effect of promoting 'rx-sample-delay-ns' to be a
> > common property, but functionally it's no different if it was defined in
> > a Synopsys specific schema file.
> 
> Functionally it is no different, but does this property make sense for 
> other controllers? If not then I don't see why we should pollute the 
> common list with controller-specific ones. For one, this now no longer 
> makes it obvious that this property should only be used with the 
> Synopsys controller. And if you keep making small exceptions for other 
> controllers too, soon the common list will be full of controller 
> properties and it will be a mess finding out what belongs to who.

There's at least one other case already:

  cdns,read-delay:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      Delay for read capture logic, in clock cycles.


Too many common properties is not a problem we have. Too many custom 
properties doing the same thing is the problem.

Rob