Commit | Line | Data |
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d0e45d68 | 1 | * Actions Semi Owl Clock Management Unit (CMU) |
06d42212 | 2 | |
d0e45d68 SS |
3 | The Actions Semi Owl Clock Management Unit generates and supplies clock |
4 | to various controllers within the SoC. The clock binding described here is | |
5 | applicable to S900 and S700 SoC's. | |
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6 | |
7 | Required Properties: | |
8 | ||
d0e45d68 SS |
9 | - compatible: should be one of the following, |
10 | "actions,s900-cmu" | |
11 | "actions,s700-cmu" | |
06d42212 MS |
12 | - reg: physical base address of the controller and length of memory mapped |
13 | region. | |
14 | - clocks: Reference to the parent clocks ("hosc", "losc") | |
15 | - #clock-cells: should be 1. | |
46b5dfab | 16 | - #reset-cells: should be 1. |
06d42212 MS |
17 | |
18 | Each clock is assigned an identifier, and client nodes can use this identifier | |
19 | to specify the clock which they consume. | |
20 | ||
d0e45d68 SS |
21 | All available clocks are defined as preprocessor macros in corresponding |
22 | dt-bindings/clock/actions,s900-cmu.h or actions,s700-cmu.h header and can be | |
23 | used in device tree sources. | |
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24 | |
25 | External clocks: | |
26 | ||
27 | The hosc clock used as input for the plls is generated outside the SoC. It is | |
28 | expected that it is defined using standard clock bindings as "hosc". | |
29 | ||
d0e45d68 | 30 | Actions Semi S900 CMU also requires one more clock: |
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31 | - "losc" - internal low frequency oscillator |
32 | ||
33 | Example: Clock Management Unit node: | |
34 | ||
35 | cmu: clock-controller@e0160000 { | |
36 | compatible = "actions,s900-cmu"; | |
37 | reg = <0x0 0xe0160000 0x0 0x1000>; | |
38 | clocks = <&hosc>, <&losc>; | |
39 | #clock-cells = <1>; | |
46b5dfab | 40 | #reset-cells = <1>; |
06d42212 MS |
41 | }; |
42 | ||
43 | Example: UART controller node that consumes clock generated by the clock | |
44 | management unit: | |
45 | ||
46 | uart: serial@e012a000 { | |
47 | compatible = "actions,s900-uart", "actions,owl-uart"; | |
48 | reg = <0x0 0xe012a000 0x0 0x2000>; | |
49 | interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>; | |
50 | clocks = <&cmu CLK_UART5>; | |
51 | }; |