xref: /linux/Documentation/devicetree/bindings/pinctrl/brcm,bcm2835-gpio.txt (revision 26fbb4c8c7c3ee9a4c3b4de555a8587b5a19154e) 
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  "brcm,bcm7211-gpio" - BCM7211 compatible pinctrl
13- reg: Should contain the physical address of the GPIO module's registers.
14- gpio-controller: Marks the device node as a GPIO controller.
15- #gpio-cells : Should be two. The first cell is the pin number and the
16  second cell is used to specify optional parameters:
17  - bit 0 specifies polarity (0 for normal, 1 for inverted)
18- interrupts : The interrupt outputs from the controller. One interrupt per
19  individual bank followed by the "all banks" interrupt. For BCM7211, an
20  additional set of per-bank interrupt line and an "all banks" wake-up
21  interrupt may be specified.
22- interrupt-controller: Marks the device node as an interrupt controller.
23- #interrupt-cells : Should be 2.
24  The first cell is the GPIO number.
25  The second cell is used to specify flags:
26    bits[3:0] trigger type and level flags:
27      1 = low-to-high edge triggered.
28      2 = high-to-low edge triggered.
29      4 = active high level-sensitive.
30      8 = active low level-sensitive.
31    Valid combinations are 1, 2, 3, 4, 8.
32
33Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
34
35Please refer to pinctrl-bindings.txt in this directory for details of the
36common pinctrl bindings used by client devices, including the meaning of the
37phrase "pin configuration node".
38
39Each pin configuration node lists the pin(s) to which it applies, and one or
40more of the mux function to select on those pin(s), and pull-up/down
41configuration. Each subnode only affects those parameters that are explicitly
42listed. In other words, a subnode that lists only a mux function implies no
43information about any pull configuration. Similarly, a subnode that lists only
44a pul parameter implies no information about the mux function.
45
46The BCM2835 pin configuration and multiplexing supports the generic bindings.
47For details on each properties, you can refer to ./pinctrl-bindings.txt.
48
49Required sub-node properties:
50  - pins
51  - function
52
53Optional sub-node properties:
54  - bias-disable
55  - bias-pull-up
56  - bias-pull-down
57  - output-high
58  - output-low
59
60Legacy pin configuration and multiplexing binding:
61*** (Its use is deprecated, use generic multiplexing and configuration
62bindings instead)
63
64Required subnode-properties:
65- brcm,pins: An array of cells. Each cell contains the ID of a pin. Valid IDs
66  are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53.
67
68Optional subnode-properties:
69- brcm,function: Integer, containing the function to mux to the pin(s):
70  0: GPIO in
71  1: GPIO out
72  2: alt5
73  3: alt4
74  4: alt0
75  5: alt1
76  6: alt2
77  7: alt3
78- brcm,pull: Integer, representing the pull-down/up to apply to the pin(s):
79  0: none
80  1: down
81  2: up
82
83Each of brcm,function and brcm,pull may contain either a single value which
84will be applied to all pins in brcm,pins, or 1 value for each entry in
85brcm,pins.
86
87Example:
88
89	gpio: gpio {
90		compatible = "brcm,bcm2835-gpio";
91		reg = <0x2200000 0xb4>;
92		interrupts = <2 17>, <2 19>, <2 18>, <2 20>;
93
94		gpio-controller;
95		#gpio-cells = <2>;
96
97		interrupt-controller;
98		#interrupt-cells = <2>;
99	};
100