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

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

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@amd.com>
> > > > > ---
> > > > > 
> > > > >    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.

> 
> Thanks,
> Michal

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com