Describe how clocks property can leverage secure- property prefix
for clocks handled exclusively or shared by secure and non-secure
worlds.
Signed-off-by: Etienne Carriere <etienne.carriere@xxxxxxxxxx>
---
.../devicetree/bindings/arm/secure.txt | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/Documentation/devicetree/bindings/arm/secure.txt b/Documentation/devicetree/bindings/arm/secure.txt
index f27bbff2c780..9bc94921f2a6 100644
--- a/Documentation/devicetree/bindings/arm/secure.txt
+++ b/Documentation/devicetree/bindings/arm/secure.txt
@@ -53,6 +53,25 @@ Valid Secure world properties
status = "disabled"; /* disabled in both */
status = "disabled"; secure-status = "disabled"; /* disabled in both */
+- secure-clocks : specifies the Phandle list secure world shall use
+ for the related clocks whereas property "clocks" specifies the
+ clock Phandle list non-secure shall use for the that clocks.
+ This configuration can apply for example when a hardware clock is
+ shared by the 2 worlds and the hardware implements a specific interface
+ for each world, i.e.:
+
+ clocks = <&clk DMA_NS>; /* NS relies on clock handle DMA_NS */
+ secure-clocks = <&clk DMA_S>; /* S relies on clock handle DMA_S */
+
+ Another example where use of "clocks" and "secure-clocks" can apply
+ is when hardware implements a clock that secure and non-secure must
+ share, as a shared GPIO bank clock, and secure world relies on clock
+ device driver whereas non-secure world relies on a software service
+ exposed by secure world as SCMI clock device. I.e.:
+
+ clocks = <&scmi_clk 2>; /* NS relies on SCMI resources */
+ secure-clocks= <&clk 5>; /* S accesses the SoC reset interfaces */
+
The secure-chosen node
----------------------
--
2.17.1
