Re: [RFC PATCH 1/2] PM / OPP: add support to specify phandle of another node for OPP

[Stephen Warren <swarren@wwwdotorg.org>]

On 08/01/2013 07:54 AM, Mark Rutland wrote:
...
> We seem to be going over two cases, which both feel wrong to me:
> 
> * One SoC used in multiple boards, where on some boards an OPP cannot be
>   used because some requirement is not met. In this case, the board's
>   dts (by including the SoC's dtsi) describes something that's not
>   necessarily usable, and we seem to have no way to describe in the OPP
>   table that the OPP is not usable for that board.

There are probably a lot of examples of this already. For example, for
pinctrl, people often want the SoC .dtsi file to include "pin
configuration nodes" (see
Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt) for many
common pinmux configurations in the SoC .dtsi file, so that board files
can simply refer to the already-existing nodes rather than having to
write everything from scratch. Obviously, not all common configurations
are used by every board.

...
>> Are you suggesting we have OPP tables per board?
> 
> Yes, for the reasons I give above. Common OPP tabless can easily be
> factored into separate include files to allow for arbitrary composition.

Using separate include files sounds like a reasonable idea.