Re: [PATCH 2/8] dt-bindings: clock: stm32mp1: describes clocks if "st,stm32mp1-rcc-secure"

[Marek Vasut]

On 4/25/22 21:11, Rob Herring wrote:
> On Fri, Apr 22, 2022 at 06:31:25PM +0200, Marek Vasut wrote:
> > On 4/22/22 17:09, Alexandre Torgue wrote:
> > > In case of "st,stm32mp1-rcc-secure" (stm32mp1 clock driver with RCC
> > > security support hardened), "clocks" and "clock-names" describe oscillators
> > > and are required.
> > >
> > > Signed-off-by: Alexandre Torgue <alexandre.torgue@xxxxxxxxxxx>
> > >
> > > diff --git a/Documentation/devicetree/bindings/clock/st,stm32mp1-rcc.yaml b/Documentation/devicetree/bindings/clock/st,stm32mp1-rcc.yaml
> > > index 7a251264582d..bb0e0b92e907 100644
> > > --- a/Documentation/devicetree/bindings/clock/st,stm32mp1-rcc.yaml
> > > +++ b/Documentation/devicetree/bindings/clock/st,stm32mp1-rcc.yaml
> > > @@ -58,14 +58,8 @@ properties:
> > >              - st,stm32mp1-rcc-secure
> > >              - st,stm32mp1-rcc
> > >          - const: syscon
> > > -
> > > -  clocks:
> > > -    description:
> > > -      Specifies the external RX clock for ethernet MAC.
> > > -    maxItems: 1
> > > -
> > > -  clock-names:
> > > -    const: ETH_RX_CLK/ETH_REF_CLK
> > > +  clocks: true
> > > +  clock-names: true
> >
> > It looks like this should rather be a property than a compatible string --
> > the compatible string is used by the OS to determine which hardware is
> > represented by a node, but here it is the same hardware in either case,
> > "st,stm32mp1-rcc" and "st,stm32mp1-rcc-secure", it is still the same
> > STM32MP1 RCC block, just configured differently by some bootloader stage.
> >
> > So why not just add one-liner property of the RCC block like ?
> > st,rcc-in-secure-configuration
>
> Because using compatible was already decided.

I see ... may I ask why compatible is OK in this case even though this 
is encoding a policy (secure/non-secure configuration of the same clock 
IP) into DT ?