1NVIDIA Tegra GPIO controller
2
3Required properties:
4- compatible : "nvidia,tegra<chip>-gpio"
5- reg : Physical base address and length of the controller's registers.
6- interrupts : The interrupt outputs from the controller. For Tegra20,
7  there should be 7 interrupts specified, and for Tegra30, there should
8  be 8 interrupts specified.
9- #gpio-cells : Should be two. The first cell is the pin number and the
10  second cell is used to specify optional parameters:
11  - bit 0 specifies polarity (0 for normal, 1 for inverted)
12- gpio-controller : Marks the device node as a GPIO controller.
13- #interrupt-cells : Should be 2.
14  The first cell is the GPIO number.
15  The second cell is used to specify flags:
16    bits[3:0] trigger type and level flags:
17      1 = low-to-high edge triggered.
18      2 = high-to-low edge triggered.
19      4 = active high level-sensitive.
20      8 = active low level-sensitive.
21      Valid combinations are 1, 2, 3, 4, 8.
22- interrupt-controller : Marks the device node as an interrupt controller.
23
24Example:
25
26gpio: gpio@6000d000 {
27	compatible = "nvidia,tegra20-gpio";
28	reg = < 0x6000d000 0x1000 >;
29	interrupts = < 0 32 0x04
30		       0 33 0x04
31		       0 34 0x04
32		       0 35 0x04
33		       0 55 0x04
34		       0 87 0x04
35		       0 89 0x04 >;
36	#gpio-cells = <2>;
37	gpio-controller;
38	#interrupt-cells = <2>;
39	interrupt-controller;
40};
41