Re: [PATCH v5 2/6] dt-bindings: PCI: renesas,pci-rcar-gen2: Add device tree support for r9a06g032

[Rob Herring <robh@kernel.org>]

On Tue, May 03, 2022 at 11:29:53AM +0200, Krzysztof Kozlowski wrote:
> On 03/05/2022 08:51, Geert Uytterhoeven wrote:
> >>>> This should not be a reason why a property is or is not required. Either
> >>>> this is required for device operation or not. If it is required, should
> >>>> be in the bindings. Otherwise what are you going to do in the future?
> >>>> Add a required property breaking the ABI?
> >>>
> >>> The problem is that there are no bindings for the reset controller
> >>> (actually the reset controller feature of the system-controller) yet.
> >>> Yeah, we can just add #reset-cells = <1> to the system-controller
> >>> device node, but we cannot add the actual resets properties to the
> >>> consumers, until the actual cell values are defined.
> >>
> >> Sounds like you should implement providers first. Or just live with the
> >> warning as a reminder to implement the reset provider?
> > 
> > I'd go for the latter. The upstream r9a06g032.dtsi is still under active
> > development. Until very recently, the only device supported was the
> > serial console.
> 
> For clocks we use in such cases fixed-clock placeholders or empty
> phandles. Maybe something like that would work here as well?

IMO, we should move away from doing that for clocks. It's a guaranteed 
ABI break.

Rob