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-rw-r--r-- | Documentation/devicetree/bindings/clock/actions,owl-cmu.txt | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/actions,owl-cmu.txt b/Documentation/devicetree/bindings/clock/actions,owl-cmu.txt new file mode 100644 index 000000000..d1e60d297 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/actions,owl-cmu.txt @@ -0,0 +1,49 @@ +* Actions Semi Owl Clock Management Unit (CMU) + +The Actions Semi Owl Clock Management Unit generates and supplies clock +to various controllers within the SoC. The clock binding described here is +applicable to S900 and S700 SoC's. + +Required Properties: + +- compatible: should be one of the following, + "actions,s900-cmu" + "actions,s700-cmu" +- reg: physical base address of the controller and length of memory mapped + region. +- clocks: Reference to the parent clocks ("hosc", "losc") +- #clock-cells: should be 1. + +Each clock is assigned an identifier, and client nodes can use this identifier +to specify the clock which they consume. + +All available clocks are defined as preprocessor macros in corresponding +dt-bindings/clock/actions,s900-cmu.h or actions,s700-cmu.h header and can be +used in device tree sources. + +External clocks: + +The hosc clock used as input for the plls is generated outside the SoC. It is +expected that it is defined using standard clock bindings as "hosc". + +Actions Semi S900 CMU also requires one more clock: + - "losc" - internal low frequency oscillator + +Example: Clock Management Unit node: + + cmu: clock-controller@e0160000 { + compatible = "actions,s900-cmu"; + reg = <0x0 0xe0160000 0x0 0x1000>; + clocks = <&hosc>, <&losc>; + #clock-cells = <1>; + }; + +Example: UART controller node that consumes clock generated by the clock +management unit: + + uart: serial@e012a000 { + compatible = "actions,s900-uart", "actions,owl-uart"; + reg = <0x0 0xe012a000 0x0 0x2000>; + interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&cmu CLK_UART5>; + }; |