ARM: kernel: add device tree init map function

[deliverable/linux.git] / Documentation / devicetree / bindings / arm / cpus.txt

* ARM CPUs binding description

The device tree allows to describe the layout of CPUs in a system through
the "cpus" node, which in turn contains a number of subnodes (ie "cpu")
defining properties for every cpu.

Bindings for CPU nodes follow the ePAPR standard, available from:

http://devicetree.org

For the ARM architecture every CPU node must contain the following properties:

- device_type:	must be "cpu"
- reg:		property matching the CPU MPIDR[23:0] register bits
		reg[31:24] bits must be set to 0
- compatible:	should be one of:
		"arm,arm1020"
		"arm,arm1020e"
		"arm,arm1022"
		"arm,arm1026"
		"arm,arm720"
		"arm,arm740"
		"arm,arm7tdmi"
		"arm,arm920"
		"arm,arm922"
		"arm,arm925"
		"arm,arm926"
		"arm,arm940"
		"arm,arm946"
		"arm,arm9tdmi"
		"arm,cortex-a5"
		"arm,cortex-a7"
		"arm,cortex-a8"
		"arm,cortex-a9"
		"arm,cortex-a15"
		"arm,arm1136"
		"arm,arm1156"
		"arm,arm1176"
		"arm,arm11mpcore"
		"faraday,fa526"
		"intel,sa110"
		"intel,sa1100"
		"marvell,feroceon"
		"marvell,mohawk"
		"marvell,xsc3"
		"marvell,xscale"

Example:

	cpus {
		#size-cells = <0>;
		#address-cells = <1>;

		CPU0: cpu@0 {
			device_type = "cpu";
			compatible = "arm,cortex-a15";
			reg = <0x0>;
		};

		CPU1: cpu@1 {
			device_type = "cpu";
			compatible = "arm,cortex-a15";
			reg = <0x1>;
		};

		CPU2: cpu@100 {
			device_type = "cpu";
			compatible = "arm,cortex-a7";
			reg = <0x100>;
		};

		CPU3: cpu@101 {
			device_type = "cpu";
			compatible = "arm,cortex-a7";
			reg = <0x101>;
		};
	};