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  "brcm,bcm2711-gpio" - BCM2711 compatible pinctrl
12- reg: Should contain the physical address of the GPIO module's registers.
13- gpio-controller: Marks the device node as a GPIO controller.
14- #gpio-cells : Should be two. The first cell is the pin number and the
15  second cell is used to specify optional parameters:
16  - bit 0 specifies polarity (0 for normal, 1 for inverted)
17- interrupts : The interrupt outputs from the controller. One interrupt per
18  individual bank followed by the "all banks" interrupt.
19- interrupt-controller: Marks the device node as an interrupt controller.
20- #interrupt-cells : Should be 2.
21  The first cell is the GPIO number.
22  The second cell is used to specify flags:
23    bits[3:0] trigger type and level flags:
24      1 = low-to-high edge triggered.
25      2 = high-to-low edge triggered.
26      4 = active high level-sensitive.
27      8 = active low level-sensitive.
28    Valid combinations are 1, 2, 3, 4, 8.
29
30Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
31
32Please refer to pinctrl-bindings.txt in this directory for details of the
33common pinctrl bindings used by client devices, including the meaning of the
34phrase "pin configuration node".
35
36Each pin configuration node lists the pin(s) to which it applies, and one or
37more of the mux function to select on those pin(s), and pull-up/down
38configuration. Each subnode only affects those parameters that are explicitly
39listed. In other words, a subnode that lists only a mux function implies no
40information about any pull configuration. Similarly, a subnode that lists only
41a pul parameter implies no information about the mux function.
42
43The BCM2835 pin configuration and multiplexing supports the generic bindings.
44For details on each properties, you can refer to ./pinctrl-bindings.txt.
45
46Required sub-node properties:
47  - pins
48  - function
49
50Optional sub-node properties:
51  - bias-disable
52  - bias-pull-up
53  - bias-pull-down
54  - output-high
55  - output-low
56
57Legacy pin configuration and multiplexing binding:
58*** (Its use is deprecated, use generic multiplexing and configuration
59bindings instead)
60
61Required subnode-properties:
62- brcm,pins: An array of cells. Each cell contains the ID of a pin. Valid IDs
63  are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53.
64
65Optional subnode-properties:
66- brcm,function: Integer, containing the function to mux to the pin(s):
67  0: GPIO in
68  1: GPIO out
69  2: alt5
70  3: alt4
71  4: alt0
72  5: alt1
73  6: alt2
74  7: alt3
75- brcm,pull: Integer, representing the pull-down/up to apply to the pin(s):
76  0: none
77  1: down
78  2: up
79
80Each of brcm,function and brcm,pull may contain either a single value which
81will be applied to all pins in brcm,pins, or 1 value for each entry in
82brcm,pins.
83
84Example:
85
86	gpio: gpio {
87		compatible = "brcm,bcm2835-gpio";
88		reg = <0x2200000 0xb4>;
89		interrupts = <2 17>, <2 19>, <2 18>, <2 20>;
90
91		gpio-controller;
92		#gpio-cells = <2>;
93
94		interrupt-controller;
95		#interrupt-cells = <2>;
96	};
97