linux-libre/Documentation/devicetree/bindings/arm/al,alpine.txt

Annapurna Labs Alpine Platform Device Tree Bindings
---------------------------------------------------------------

Boards in the Alpine family shall have the following properties:

* Required root node properties:
compatible: must contain "al,alpine"

* Example:

/ {
	model = "Annapurna Labs Alpine Dev Board";
	compatible = "al,alpine";

	...
}

* CPU node:

The Alpine platform includes cortex-a15 cores.
enable-method: must be "al,alpine-smp" to allow smp  [1]

Example:

cpus {
	#address-cells = <1>;
	#size-cells = <0>;
	enable-method = "al,alpine-smp";

	cpu@0 {
		compatible = "arm,cortex-a15";
		device_type = "cpu";
		reg = <0>;
	};

	cpu@1 {
		compatible = "arm,cortex-a15";
		device_type = "cpu";
		reg = <1>;
	};

	cpu@2 {
		compatible = "arm,cortex-a15";
		device_type = "cpu";
		reg = <2>;
	};

	cpu@3 {
		compatible = "arm,cortex-a15";
		device_type = "cpu";
		reg = <3>;
	};
};


* Alpine CPU resume registers

The CPU resume register are used to define required resume address after
reset.

Properties:
- compatible : Should contain "al,alpine-cpu-resume".
- reg : Offset and length of the register set for the device

Example:

cpu_resume {
	compatible = "al,alpine-cpu-resume";
	reg = <0xfbff5ed0 0x30>;
};

* Alpine System-Fabric Service Registers

The System-Fabric Service Registers allow various operation on CPU and
system fabric, like powering CPUs off.

Properties:
- compatible : Should contain "al,alpine-sysfabric-service" and "syscon".
- reg : Offset and length of the register set for the device

Example:

nb_service {
        compatible = "al,alpine-sysfabric-service", "syscon";
        reg = <0xfb070000 0x10000>;
};

[1] arm/cpu-enable-method/al,alpine-smp