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e1b2dc70 SA |
1 | Broadcom BCM2835 GPIO (and pinmux) controller |
2 | ||
3 | The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt | |
4 | controller, and pinmux/control device. | |
5 | ||
6 | Required properties: | |
7 | - compatible: "brcm,bcm2835-gpio" | |
8 | - reg: Should contain the physical address of the GPIO module's registes. | |
9 | - gpio-controller: Marks the device node as a GPIO controller. | |
10 | - #gpio-cells : Should be two. The first cell is the pin number and the | |
11 | second cell is used to specify optional parameters: | |
12 | - bit 0 specifies polarity (0 for normal, 1 for inverted) | |
13 | - interrupts : The interrupt outputs from the controller. One interrupt per | |
14 | individual bank followed by the "all banks" interrupt. | |
15 | - interrupt-controller: Marks the device node as an interrupt controller. | |
16 | - #interrupt-cells : Should be 2. | |
17 | The first cell is the GPIO number. | |
18 | The second cell is used to specify flags: | |
19 | bits[3:0] trigger type and level flags: | |
20 | 1 = low-to-high edge triggered. | |
21 | 2 = high-to-low edge triggered. | |
22 | 4 = active high level-sensitive. | |
23 | 8 = active low level-sensitive. | |
24 | Valid combinations are 1, 2, 3, 4, 8. | |
25 | ||
26 | Please refer to ../gpio/gpio.txt for a general description of GPIO bindings. | |
27 | ||
28 | Please refer to pinctrl-bindings.txt in this directory for details of the | |
29 | common pinctrl bindings used by client devices, including the meaning of the | |
30 | phrase "pin configuration node". | |
31 | ||
32 | Each pin configuration node lists the pin(s) to which it applies, and one or | |
33 | more of the mux function to select on those pin(s), and pull-up/down | |
34 | configuration. Each subnode only affects those parameters that are explicitly | |
35 | listed. In other words, a subnode that lists only a mux function implies no | |
36 | information about any pull configuration. Similarly, a subnode that lists only | |
37 | a pul parameter implies no information about the mux function. | |
38 | ||
39 | Required subnode-properties: | |
40 | - brcm,pins: An array of cells. Each cell contains the ID of a pin. Valid IDs | |
41 | are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53. | |
42 | ||
43 | Optional subnode-properties: | |
44 | - brcm,function: Integer, containing the function to mux to the pin(s): | |
45 | 0: GPIO in | |
46 | 1: GPIO out | |
47 | 2: alt5 | |
48 | 3: alt4 | |
49 | 4: alt0 | |
50 | 5: alt1 | |
51 | 6: alt2 | |
52 | 7: alt3 | |
53 | - brcm,pull: Integer, representing the pull-down/up to apply to the pin(s): | |
54 | 0: none | |
55 | 1: down | |
56 | 2: up | |
57 | ||
58 | Each of brcm,function and brcm,pull may contain either a single value which | |
59 | will be applied to all pins in brcm,pins, or 1 value for each entry in | |
60 | brcm,pins. | |
61 | ||
62 | Example: | |
63 | ||
64 | gpio: gpio { | |
65 | compatible = "brcm,bcm2835-gpio"; | |
66 | reg = <0x2200000 0xb4>; | |
67 | interrupts = <2 17>, <2 19>, <2 18>, <2 20>; | |
68 | ||
69 | gpio-controller; | |
70 | #gpio-cells = <2>; | |
71 | ||
72 | interrupt-controller; | |
73 | #interrupt-cells = <2>; | |
74 | }; |