50 lines
1.7 KiB
Plaintext
Executable file
50 lines
1.7 KiB
Plaintext
Executable file
* 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>;
|
|
};
|