Hi Rob,

Rob Herring [off-list ref] writes:

On Fri, Jul 07, 2023 at 02:07:18PM +0000, Oleksii Moisieiev wrote:

quoted

Gatien Chevallier [off-list ref] writes:

quoted

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).

quoted

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.)

The alternative usages of feature-domains was originally proposed by me
here:
https://lore.kernel.org/lkml/c869d2751125181a55bc8a88c96e3a892b42f37a.1668070216.git.oleksii_moisieiev@epam.com/ (local)

Also I remember Peng Fan also was interested in those bindings.
I think the use-case when one node is protected by firewall and also is
controlled by scmi feature-domain-controller (As was proposed in my
patch series) may take place.

As for the naming maybe you have some thoughts about better name?


-- 
Thanks,
Oleksii