path: root/Documentation/devicetree/bindings/clock
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Diffstat (limited to 'Documentation/devicetree/bindings/clock')
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt
index 2ec489eebe72..b646bbcf7f92 100644
--- a/Documentation/devicetree/bindings/clock/clock-bindings.txt
+++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt
@@ -168,3 +168,19 @@ a shared clock is forbidden.
Configuration of common clocks, which affect multiple consumer devices can
be similarly specified in the clock provider node.
+==Protected clocks==
+Some platforms or firmwares may not fully expose all the clocks to the OS, such
+as in situations where those clks are used by drivers running in ARM secure
+execution levels. Such a configuration can be specified in device tree with the
+protected-clocks property in the form of a clock specifier list. This property should
+only be specified in the node that is providing the clocks being protected:
+ clock-controller@a000f000 {
+ compatible = "vendor,clk95;
+ reg = <0xa000f000 0x1000>
+ #clocks-cells = <1>;
+ ...
+ protected-clocks = <UART3_CLK>, <SPI5_CLK>;
+ };