bindings-gpio.txt revision 266105 
1$FreeBSD: stable/10/sys/boot/fdt/dts/bindings-gpio.txt 266105 2014-05-15 01:27:53Z loos $
2
3GPIO configuration.
4===================
5
61. Properties for GPIO Controllers
7
81.1 #gpio-cells
9
10Property:	#gpio-cells
11
12Value type:	<u32>
13
14Description:	The #gpio-cells property defines the number of cells required
15		to encode a gpio specifier.
16
17
181.2 gpio-controller
19
20Property:	gpio-controller
21
22Value type:	<empty>
23
24Description:	The presence of a gpio-controller property defines a node as a
25		GPIO controller node.
26
27
281.3 pin-count
29
30Property:	pin-count
31
32Value type:	<u32>
33
34Description:	The pin-count property defines the number of GPIO pins.
35
36
371.4 Example
38
39	GPIO: gpio@10100 {
40		#gpio-cells = <3>;
41		compatible = "mrvl,gpio";
42		reg = <0x10100 0x20>;
43		gpio-controller;
44		interrupts = <6 7 8 9>;
45		interrupt-parent = <&PIC>;
46		pin-count = <50>
47	};
48
492. Properties for GPIO consumer nodes.
50
512.1 gpios
52
53Property:	gpios
54
55Value type:	<prop-encoded-array> encoded as arbitrary number of GPIO
56		specifiers.
57
58Description:	The gpios property of a device node defines the GPIO or GPIOs
59		that are used by the device. The value of the gpios property
60		consists of an arbitrary number of GPIO specifiers.
61		
62		The first cell of the GPIO specifier is phandle of the node's
63		parent GPIO controller and remaining cells are defined by the
64		binding describing the GPIO parent, typically include
65		information like pin number, direction and various flags.
66
67Example:
68		gpios = <&GPIO 0 1 0		/* GPIO[0]:  IN,  NONE */
69			 &GPIO 1 2 0>;		/* GPIO[1]:  OUT, NONE */
70
71
723. "mrvl,gpio" controller GPIO specifier
73
74	<phandle pin dir flags>
75
76
77pin:	0-MAX				GPIO pin number.
78
79dir:
80	1		IN		Input direction.
81	2		OUT		Output direction.
82
83flags:
84	0x0000----	IN_NONE
85	0x0001----	IN_POL_LOW	Polarity low (active-low).
86	0x0002----	IN_IRQ_EDGE	Interrupt, edge triggered.
87	0x0004----	IN_IRQ_LEVEL	Interrupt, level triggered.
88	
89	0x----0000	OUT_NONE
90	0x----0001	OUT_BLINK	Blink on the pin.
91	0x----0002	OUT_OPEN_DRAIN	Open drain output line.
92	0x----0004	OUT_OPEN_SRC	Open source output line.
93
94
95Example:
96	gpios = <&GPIO 0  1 0x00000000		/* GPIO[0]:   IN */
97		 &GPIO 1  2 0x00000000		/* GPIO[1]:   OUT */
98		 &GPIO 2  1 0x00020000		/* GPIO[2]:   IN, IRQ (edge) */
99		 &GPIO 3  1 0x00040000		/* GPIO[3]:   IN, IRQ (level) */
100		 ...
101		 &GPIO 10 2 0x00000001>;	/* GPIO[10]:  OUT, blink */
102