xref: /kernel/linux/linux-5.10/Documentation/devicetree/bindings/clock/amlogic,meson8b-clkc.txt

* Amlogic Meson8, Meson8b and Meson8m2 Clock and Reset Unit

The Amlogic Meson8 / Meson8b / Meson8m2 clock controller generates and
supplies clock to various controllers within the SoC.

Required Properties:

- compatible: must be one of:
	- "amlogic,meson8-clkc" for Meson8 (S802) SoCs
	- "amlogic,meson8b-clkc" for Meson8 (S805) SoCs
	- "amlogic,meson8m2-clkc" for Meson8m2 (S812) SoCs
- #clock-cells: should be 1.
- #reset-cells: should be 1.
- clocks: list of clock phandles, one for each entry in clock-names
- clock-names: should contain the following:
  * "xtal": the 24MHz system oscillator
  * "ddr_pll": the DDR PLL clock
  * "clk_32k": (if present) the 32kHz clock signal from GPIOAO_6 (CLK_32K_IN)

Parent node should have the following properties :
- compatible: "amlogic,meson-hhi-sysctrl", "simple-mfd", "syscon"
- reg: base address and size of the HHI system control register space.

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 the dt-bindings/clock/meson8b-clkc.h header and can be
used in device tree sources.

Similarly a preprocessor macro for each reset line is defined in
dt-bindings/reset/amlogic,meson8b-clkc-reset.h (which can be used from the
device tree sources).


Example: Clock controller node:

	clkc: clock-controller {
		compatible = "amlogic,meson8b-clkc";
		#clock-cells = <1>;
		#reset-cells = <1>;
	};


Example: UART controller node that consumes the clock generated by the clock
  controller:

	uart_AO: serial@c81004c0 {
		compatible = "amlogic,meson-uart";
		reg = <0xc81004c0 0x14>;
		interrupts = <0 90 1>;
		clocks = <&clkc CLKID_CLK81>;
	};