1Broadcom BCM2835 GPIO (and pinmux) controller
2
3The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt
4controller, and pinmux/control device.
5
6Required properties:
7- compatible: "brcm,bcm2835-gpio"
8- compatible: should be one of:
9  "brcm,bcm2835-gpio" - BCM2835 compatible pinctrl
10  "brcm,bcm7211-gpio" - BCM7211 compatible pinctrl
11- reg: Should contain the physical address of the GPIO module's registers.
12- gpio-controller: Marks the device node as a GPIO controller.
13- #gpio-cells : Should be two. The first cell is the pin number and the
14  second cell is used to specify optional parameters:
15  - bit 0 specifies polarity (0 for normal, 1 for inverted)
16- interrupts : The interrupt outputs from the controller. One interrupt per
17  individual bank followed by the "all banks" interrupt.
18- interrupt-controller: Marks the device node as an interrupt controller.
19- #interrupt-cells : Should be 2.
20  The first cell is the GPIO number.
21  The second cell is used to specify flags:
22    bits[3:0] trigger type and level flags:
23      1 = low-to-high edge triggered.
24      2 = high-to-low edge triggered.
25      4 = active high level-sensitive.
26      8 = active low level-sensitive.
27    Valid combinations are 1, 2, 3, 4, 8.
28
29Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
30
31Please refer to pinctrl-bindings.txt in this directory for details of the
32common pinctrl bindings used by client devices, including the meaning of the
33phrase "pin configuration node".
34
35Each pin configuration node lists the pin(s) to which it applies, and one or
36more of the mux function to select on those pin(s), and pull-up/down
37configuration. Each subnode only affects those parameters that are explicitly
38listed. In other words, a subnode that lists only a mux function implies no
39information about any pull configuration. Similarly, a subnode that lists only
40a pul parameter implies no information about the mux function.
41
42The BCM2835 pin configuration and multiplexing supports the generic bindings.
43For details on each properties, you can refer to ./pinctrl-bindings.txt.
44
45Required sub-node properties:
46  - pins
47  - function
48
49Optional sub-node properties:
50  - bias-disable
51  - bias-pull-up
52  - bias-pull-down
53  - output-high
54  - output-low
55
56Legacy pin configuration and multiplexing binding:
57*** (Its use is deprecated, use generic multiplexing and configuration
58bindings instead)
59
60Required subnode-properties:
61- brcm,pins: An array of cells. Each cell contains the ID of a pin. Valid IDs
62  are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53.
63
64Optional subnode-properties:
65- brcm,function: Integer, containing the function to mux to the pin(s):
66  0: GPIO in
67  1: GPIO out
68  2: alt5
69  3: alt4
70  4: alt0
71  5: alt1
72  6: alt2
73  7: alt3
74- brcm,pull: Integer, representing the pull-down/up to apply to the pin(s):
75  0: none
76  1: down
77  2: up
78
79Each of brcm,function and brcm,pull may contain either a single value which
80will be applied to all pins in brcm,pins, or 1 value for each entry in
81brcm,pins.
82
83Example:
84
85	gpio: gpio {
86		compatible = "brcm,bcm2835-gpio";
87		reg = <0x2200000 0xb4>;
88		interrupts = <2 17>, <2 19>, <2 18>, <2 20>;
89
90		gpio-controller;
91		#gpio-cells = <2>;
92
93		interrupt-controller;
94		#interrupt-cells = <2>;
95	};
96