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52 lines
1.8 KiB
52 lines
1.8 KiB
* Actions Semi Owl Clock Management Unit (CMU) |
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The Actions Semi Owl Clock Management Unit generates and supplies clock |
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to various controllers within the SoC. The clock binding described here is |
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applicable to S900, S700 and S500 SoC's. |
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Required Properties: |
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- compatible: should be one of the following, |
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"actions,s900-cmu" |
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"actions,s700-cmu" |
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"actions,s500-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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- #reset-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 corresponding |
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dt-bindings/clock/actions,s900-cmu.h or actions,s700-cmu.h or |
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actions,s500-cmu.h header and can be used in device 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 Semi 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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#reset-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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