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48 lines
1.6 KiB
Plaintext
48 lines
1.6 KiB
Plaintext
* Actions S900 Clock Management Unit (CMU)
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The Actions S900 clock management unit generates and supplies clock to various
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controllers within the SoC. The clock binding described here is applicable to
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S900 SoC.
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Required Properties:
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- compatible: should be "actions,s900-cmu"
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- reg: physical base address of the controller and length of memory mapped
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region.
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- clocks: Reference to the parent clocks ("hosc", "losc")
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- #clock-cells: should be 1.
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Each clock is assigned an identifier, and client nodes can use this identifier
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to specify the clock which they consume.
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All available clocks are defined as preprocessor macros in
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dt-bindings/clock/actions,s900-cmu.h header and can be used in device
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tree sources.
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External clocks:
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The hosc clock used as input for the plls is generated outside the SoC. It is
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expected that it is defined using standard clock bindings as "hosc".
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Actions S900 CMU also requires one more clock:
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- "losc" - internal low frequency oscillator
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Example: Clock Management Unit node:
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cmu: clock-controller@e0160000 {
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compatible = "actions,s900-cmu";
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reg = <0x0 0xe0160000 0x0 0x1000>;
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clocks = <&hosc>, <&losc>;
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#clock-cells = <1>;
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};
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Example: UART controller node that consumes clock generated by the clock
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management unit:
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uart: serial@e012a000 {
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compatible = "actions,s900-uart", "actions,owl-uart";
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reg = <0x0 0xe012a000 0x0 0x2000>;
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interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
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clocks = <&cmu CLK_UART5>;
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};
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