Re: [PATCH 04/10] dt-bindings: treewide: add feature-domains description in binding files

[Rob Herring <robh@kernel.org>]

On Fri, Jul 07, 2023 at 02:07:18PM +0000, Oleksii Moisieiev wrote:
> 
> Gatien Chevallier <gatien.chevallier@foss.st.com> writes:
> 
> > feature-domains is an optional property that allows a peripheral to
> > refer to one or more feature domain controller(s).
> >
> > Description of this property is added to all peripheral binding files of
> > the peripheral under the STM32 firewall controllers. It allows an accurate
> > representation of the hardware, where various peripherals are connected
> > to this firewall bus. The firewall can then check the peripheral accesses
> > before allowing it to probe.
> >
> > Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
> > ---
> >
> > Disclaimer: Some error with dtbs_check will be observed as I've
> > considered the property to be generic, as Rob asked
> >
> >  Documentation/devicetree/bindings/crypto/st,stm32-hash.yaml  | 4 ++++
> >  Documentation/devicetree/bindings/dma/st,stm32-dma.yaml      | 4 ++++
> >  Documentation/devicetree/bindings/dma/st,stm32-dmamux.yaml   | 4 ++++
> >  Documentation/devicetree/bindings/i2c/st,stm32-i2c.yaml      | 4 ++++
> >  Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml  | 4 ++++
> >  .../devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml      | 4 ++++
> >  Documentation/devicetree/bindings/iio/dac/st,stm32-dac.yaml  | 4 ++++
> >  .../devicetree/bindings/media/cec/st,stm32-cec.yaml          | 4 ++++
> >  Documentation/devicetree/bindings/media/st,stm32-dcmi.yaml   | 4 ++++
> >  .../bindings/memory-controllers/st,stm32-fmc2-ebi.yaml       | 4 ++++
> >  Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml  | 4 ++++
> >  Documentation/devicetree/bindings/mfd/st,stm32-timers.yaml   | 5 +++++
> >  Documentation/devicetree/bindings/mmc/arm,pl18x.yaml         | 4 ++++
> >  Documentation/devicetree/bindings/net/stm32-dwmac.yaml       | 4 ++++
> >  Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml | 4 ++++
> >  .../devicetree/bindings/regulator/st,stm32-vrefbuf.yaml      | 4 ++++
> >  Documentation/devicetree/bindings/rng/st,stm32-rng.yaml      | 4 ++++
> >  Documentation/devicetree/bindings/serial/st,stm32-uart.yaml  | 4 ++++
> >  Documentation/devicetree/bindings/sound/st,stm32-i2s.yaml    | 4 ++++
> >  Documentation/devicetree/bindings/sound/st,stm32-sai.yaml    | 4 ++++
> >  .../devicetree/bindings/sound/st,stm32-spdifrx.yaml          | 4 ++++
> >  Documentation/devicetree/bindings/spi/st,stm32-qspi.yaml     | 4 ++++
> >  Documentation/devicetree/bindings/spi/st,stm32-spi.yaml      | 4 ++++
> >  Documentation/devicetree/bindings/usb/dwc2.yaml              | 4 ++++
> >  24 files changed, 97 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/crypto/st,stm32-hash.yaml b/Documentation/devicetree/bindings/crypto/st,stm32-hash.yaml
> > index b767ec72a999..daf8dcaef627 100644
> > --- a/Documentation/devicetree/bindings/crypto/st,stm32-hash.yaml
> > +++ b/Documentation/devicetree/bindings/crypto/st,stm32-hash.yaml
> > @@ -50,6 +50,10 @@ properties:
> >    power-domains:
> >      maxItems: 1
> >  
> > +  feature-domains:
> > +    minItems: 1
> > +    maxItems: 3
> > +
> 
> I beliewe feature-domains is generic binding. This means that maxItems
> can be implementation dependend. I would rather drop maxItems so the
> following format will be possible:
> 
>           feature-domains = <&etzpc 1>, <&etzpc 2>, <&some_other_domain 1 2 3 4>
>           feature-domain-names = "firewall 1", "firewall 2", "other_domain"

The above already allows this (not -names, but the number of entries).
> 
> Also I beliewe driver will handle feature-domain-names property so it
> will parse feature-domains only related to the firewall.

Now I'm curious. What's an example that's not a firewall?

(Note I'm still not happy with the naming of 'feature' as anything is a 
feature, but that's the least of the issues really.)

Rob