Hello Rob,

On 7/15/25 05:17, Rob Herring wrote:

On Fri, Jul 11, 2025 at 04:48:54PM +0200, Clément Le Goffic wrote:

quoted

RCC is able to check the availability of a clock.
Allow to query the RCC with a firewall ID.

If it is tied to a clock, do we need another provider? We have the
"protected clocks" thing, but that might be a bit different.

I couldn't find any reference to "protected-clocks" outside of qcom
related code, is there a documentation? (Couldn't find it in
clocks.yaml).

The RCC is firewall-aware and has it's own firewall configuration at
RCC level for some system resources. When checking access to a clock,
or a reset, we're reading RCC registers, hence declaring it as an
access-controller.

A RCC resource's firewall configuration usually covers more than a
clock.

quoted

Signed-off-by: Clément Le Goffic <redacted>
---
  Documentation/devicetree/bindings/clock/st,stm32mp25-rcc.yaml | 7 +++++++
  1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/st,stm32mp25-rcc.yaml b/Documentation/devicetree/bindings/clock/st,stm32mp25-rcc.yaml
index 88e52f10d1ec..4d471e3d89bc 100644
--- a/Documentation/devicetree/bindings/clock/st,stm32mp25-rcc.yaml
+++ b/Documentation/devicetree/bindings/clock/st,stm32mp25-rcc.yaml

@@ -31,6 +31,11 @@ properties:
    '#reset-cells':
      const: 1
  
+  '#access-controller-cells':
+    const: 1
+    description:
+      Contains the firewall ID associated to the peripheral.
+
    clocks:
      items:
        - description: CK_SCMI_HSE High Speed External oscillator (8 to 48 MHz)

@@ -123,6 +128,7 @@ required:
    - reg
    - '#clock-cells'
    - '#reset-cells'
+  - '#access-controller-cells'
    - clocks
  
  additionalProperties: false

@@ -136,6 +142,7 @@ examples:
          reg = <0x44200000 0x10000>;
          #clock-cells = <1>;
          #reset-cells = <1>;
+        #access-controller-cells = <1>;
          clocks =  <&scmi_clk CK_SCMI_HSE>,
                    <&scmi_clk CK_SCMI_HSI>,
                    <&scmi_clk CK_SCMI_MSI>,

-- 
2.43.0

Best regards,
Gatien