1 Broadcom BCM2835 GPIO (and pinmux) controller 1 Broadcom BCM2835 GPIO (and pinmux) controller
2 2
3 The BCM2835 GPIO module is a combined GPIO con 3 The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt
4 controller, and pinmux/control device. 4 controller, and pinmux/control device.
5 5
6 Required properties: 6 Required properties:
7 - compatible: "brcm,bcm2835-gpio" 7 - compatible: "brcm,bcm2835-gpio"
8 - compatible: should be one of: <<
9 "brcm,bcm2835-gpio" - BCM2835 compatible pin <<
10 "brcm,bcm7211-gpio" - BCM7211 compatible pin <<
11 "brcm,bcm2711-gpio" - BCM2711 compatible pin <<
12 "brcm,bcm7211-gpio" - BCM7211 compatible pin <<
13 - reg: Should contain the physical address of 8 - reg: Should contain the physical address of the GPIO module's registers.
14 - gpio-controller: Marks the device node as a 9 - gpio-controller: Marks the device node as a GPIO controller.
15 - #gpio-cells : Should be two. The first cell 10 - #gpio-cells : Should be two. The first cell is the pin number and the
16 second cell is used to specify optional para 11 second cell is used to specify optional parameters:
17 - bit 0 specifies polarity (0 for normal, 1 12 - bit 0 specifies polarity (0 for normal, 1 for inverted)
18 - interrupts : The interrupt outputs from the 13 - interrupts : The interrupt outputs from the controller. One interrupt per
19 individual bank followed by the "all banks" !! 14 individual bank followed by the "all banks" interrupt.
20 additional set of per-bank interrupt line an <<
21 interrupt may be specified. <<
22 - interrupt-controller: Marks the device node 15 - interrupt-controller: Marks the device node as an interrupt controller.
23 - #interrupt-cells : Should be 2. 16 - #interrupt-cells : Should be 2.
24 The first cell is the GPIO number. 17 The first cell is the GPIO number.
25 The second cell is used to specify flags: 18 The second cell is used to specify flags:
26 bits[3:0] trigger type and level flags: 19 bits[3:0] trigger type and level flags:
27 1 = low-to-high edge triggered. 20 1 = low-to-high edge triggered.
28 2 = high-to-low edge triggered. 21 2 = high-to-low edge triggered.
29 4 = active high level-sensitive. 22 4 = active high level-sensitive.
30 8 = active low level-sensitive. 23 8 = active low level-sensitive.
31 Valid combinations are 1, 2, 3, 4, 8. 24 Valid combinations are 1, 2, 3, 4, 8.
32 25
33 Please refer to ../gpio/gpio.txt for a general 26 Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
34 27
35 Please refer to pinctrl-bindings.txt in this d 28 Please refer to pinctrl-bindings.txt in this directory for details of the
36 common pinctrl bindings used by client devices 29 common pinctrl bindings used by client devices, including the meaning of the
37 phrase "pin configuration node". 30 phrase "pin configuration node".
38 31
39 Each pin configuration node lists the pin(s) t 32 Each pin configuration node lists the pin(s) to which it applies, and one or
40 more of the mux function to select on those pi 33 more of the mux function to select on those pin(s), and pull-up/down
41 configuration. Each subnode only affects those 34 configuration. Each subnode only affects those parameters that are explicitly
42 listed. In other words, a subnode that lists o 35 listed. In other words, a subnode that lists only a mux function implies no
43 information about any pull configuration. Simi 36 information about any pull configuration. Similarly, a subnode that lists only
44 a pul parameter implies no information about t 37 a pul parameter implies no information about the mux function.
45 <<
46 The BCM2835 pin configuration and multiplexing <<
47 For details on each properties, you can refer <<
48 <<
49 Required sub-node properties: <<
50 - pins <<
51 - function <<
52 <<
53 Optional sub-node properties: <<
54 - bias-disable <<
55 - bias-pull-up <<
56 - bias-pull-down <<
57 - output-high <<
58 - output-low <<
59 <<
60 Legacy pin configuration and multiplexing bind <<
61 *** (Its use is deprecated, use generic multip <<
62 bindings instead) <<
63 38
64 Required subnode-properties: 39 Required subnode-properties:
65 - brcm,pins: An array of cells. Each cell cont 40 - 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 41 are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53.
67 42
68 Optional subnode-properties: 43 Optional subnode-properties:
69 - brcm,function: Integer, containing the funct 44 - brcm,function: Integer, containing the function to mux to the pin(s):
70 0: GPIO in 45 0: GPIO in
71 1: GPIO out 46 1: GPIO out
72 2: alt5 47 2: alt5
73 3: alt4 48 3: alt4
74 4: alt0 49 4: alt0
75 5: alt1 50 5: alt1
76 6: alt2 51 6: alt2
77 7: alt3 52 7: alt3
78 - brcm,pull: Integer, representing the pull-do 53 - brcm,pull: Integer, representing the pull-down/up to apply to the pin(s):
79 0: none 54 0: none
80 1: down 55 1: down
81 2: up 56 2: up
82 57
83 Each of brcm,function and brcm,pull may contai 58 Each of brcm,function and brcm,pull may contain either a single value which
84 will be applied to all pins in brcm,pins, or 1 59 will be applied to all pins in brcm,pins, or 1 value for each entry in
85 brcm,pins. 60 brcm,pins.
86 61
87 Example: 62 Example:
88 63
89 gpio: gpio { 64 gpio: gpio {
90 compatible = "brcm,bcm2835-gpi 65 compatible = "brcm,bcm2835-gpio";
91 reg = <0x2200000 0xb4>; 66 reg = <0x2200000 0xb4>;
92 interrupts = <2 17>, <2 19>, < 67 interrupts = <2 17>, <2 19>, <2 18>, <2 20>;
93 68
94 gpio-controller; 69 gpio-controller;
95 #gpio-cells = <2>; 70 #gpio-cells = <2>;
96 71
97 interrupt-controller; 72 interrupt-controller;
98 #interrupt-cells = <2>; 73 #interrupt-cells = <2>;
99 }; 74 };
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