Re: [PATCH] dt-bindings: rtc: zynqmp: Describe power-domains property

[Michal Simek]

On 2/20/24 11:51, Buddhabhatti, Jay wrote:
> Hi Alexandre,
>
> > -----Original Message-----
> > From: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> > Sent: Tuesday, February 20, 2024 1:49 AM
> > To: Simek, Michal <michal.simek@xxxxxxx>
> > Cc: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>; linux-
> > kernel@xxxxxxxxxxxxxxx; monstr@xxxxxxxxx; michal.simek@xxxxxxxxxx;
> > git@xxxxxxxxxx; Conor Dooley <conor+dt@xxxxxxxxxx>; Krzysztof Kozlowski
> > <krzysztof.kozlowski+dt@xxxxxxxxxx>; Rob Herring <robh@xxxxxxxxxx>; open
> > list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS
> > <devicetree@xxxxxxxxxxxxxxx>; moderated list:ARM/ZYNQ ARCHITECTURE
> > <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>; open list:REAL TIME CLOCK (RTC)
> > SUBSYSTEM <linux-rtc@xxxxxxxxxxxxxxx>
> > Subject: Re: [PATCH] dt-bindings: rtc: zynqmp: Describe power-domains
> > property
> >
> > On 19/02/2024 14:11:50+0100, Michal Simek wrote:
> > > On 2/17/24 09:26, Krzysztof Kozlowski wrote:
> > > > On 16/02/2024 10:42, Michal Simek wrote:
> > > > > On 2/16/24 10:19, Krzysztof Kozlowski wrote:
> > > > > > On 16/02/2024 09:51, Michal Simek wrote:
> > > > > > > RTC has its own power domain on Xilinx Versal SOC that's why
> > > > > > > describe it as optional property.
> > > > > > >
> > > > > > > Signed-off-by: Michal Simek <michal.simek@xxxxxxx>
> > > > > > > ---
> > > > > > >
> > > > > > >     Documentation/devicetree/bindings/rtc/xlnx,zynqmp-rtc.yaml | 3
> > +++
> > > > > > >     1 file changed, 3 insertions(+)
> > > > > >
> > > > > > But Versal is not described in this binding, is it? I see only
> > > > > > one compatible.
> > > > >
> > > > > It is the same IP only as is on zynqmp with own power rail.
> > > >
> > > > Then you should have separate compatible, because they are not
> > > > identical. It would also allow you to narrow the domains to versal
> > > > and also require it (on versal).
> > >
> > > I can double check with HW guys but I am quite sure IP itself is
> > > exactly the same. What it is different is that there is own power
> > > domain to it (not shared one as is in zynqmp case).
> > >
> > > Also Linux is non secure sw and if secure firmware won't allow to
> > > change setting of it it can't be required. I am just saying that Linux
> > > doesn't need to be owner of any power domain that's why it shouldn't
> > > be required property.
> >
> > I guess because the integration is different, you still need a differente
> > compatible so you can forbid the property on non-Versal.
>
> [Jay] RTC has its own power domain in case of Versal and ZynqMP both that we double check it.

Thanks Jay for looking into it. I should definitely update my commit message to 
reflect it. Do you still want me to create soc specific property?

Thanks,
Michal