1. 根目录:
2. Documentation
3. devicetree
4. bindings
5. gpio
6. gpio-zynq.txt

Xilinx Zynq GPIO controller Device Tree Bindings
-------------------------------------------

Required properties:
- #gpio-cells 		: Should be two
			  - First cell is the GPIO line number
			  - Second cell is used to specify optional
			    parameters (unused)
- compatible		: Should be "xlnx,zynq-gpio-1.0" or "xlnx,zynqmp-gpio-1.0"
- clocks		: Clock specifier (see clock bindings for details)
- gpio-controller	: Marks the device node as a GPIO controller.
- interrupts		: Interrupt specifier (see interrupt bindings for
			  details)
- interrupt-parent	: Must be core interrupt controller
- interrupt-controller	: Marks the device node as an interrupt controller.
- #interrupt-cells 	: Should be 2.  The first cell is the GPIO number.
			  The second cell bits[3:0] is used to specify trigger type and level flags:
			      1 = low-to-high edge triggered.
			      2 = high-to-low edge triggered.
			      4 = active high level-sensitive.
			      8 = active low level-sensitive.
- reg			: Address and length of the register set for the device

Example:
	gpio@e000a000 {
		#gpio-cells = <2>;
		compatible = "xlnx,zynq-gpio-1.0";
		clocks = <&clkc 42>;
		gpio-controller;
		interrupt-parent = <&intc>;
		interrupts = <0 20 4>;
		interrupt-controller;
		#interrupt-cells = <2>;
		reg = <0xe000a000 0x1000>;
	};