linux-arkmicro/linux/Documentation/devicetree/bindings/misc/ge-achc.txt

* GE Healthcare USB Management Controller

A device which handles data aquisition from compatible USB based peripherals.
SPI is used for device management.

Note: This device does not expose the peripherals as USB devices.

Required properties:

- compatible : Should be "ge,achc"

Required SPI properties:

- reg : Should be address of the device chip select within
  the controller.

- spi-max-frequency : Maximum SPI clocking speed of device in Hz, should be
  1MHz for the GE ACHC.

Example:

spidev0: spi@0 {
	compatible = "ge,achc";
	reg = <0>;
	spi-max-frequency = <1000000>;
};