linux/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt

* Freescale (Enhanced) Configurable Serial Peripheral Interface
  (CSPI/eCSPI) for i.MX

Required properties:
- compatible : Should be "fsl,<soc>-cspi" or "fsl,<soc>-ecspi"
- reg : Offset and length of the register set for the device
- interrupts : Should contain CSPI/eCSPI interrupt
- fsl,spi-num-chipselects : Contains the number of the chipselect
- cs-gpios : Specifies the gpio pins to be used for chipselects.

Example:

ecspi@70010000 {
	#address-cells = <1>;
	#size-cells = <0>;
	compatible = "fsl,imx51-ecspi";
	reg = <0x70010000 0x4000>;
	interrupts = <36>;
	fsl,spi-num-chipselects = <2>;
	cs-gpios = <&gpio3 24 0>, /* GPIO3_24 */
		   <&gpio3 25 0>; /* GPIO3_25 */
};