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:
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.
Signed-off-by: Clément Le Goffic <clement.legoffic@xxxxxxxxxxx>
---
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
