Messages in this thread Patch in this message | | | From | Etienne Carriere <> | Subject | [RFC PATCH 1/2] dt-bindings: arm: Add secure-clocks binding description | Date | Thu, 23 Apr 2020 08:48:07 +0200 |
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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@linaro.org> --- .../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
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