13ced1d6a0
o DB-88F5182 o DB-88F5281 o DB-88F6281 o DB-78100 o SheevaPlug This also includes device tree bindings definitions for some newly introduced nodes (mpp, gpio). Reviewed by: imp Sponsored by: The FreeBSD Foundation
102 lines
2.2 KiB
Plaintext
102 lines
2.2 KiB
Plaintext
$FreeBSD$
|
|
|
|
GPIO configuration.
|
|
===================
|
|
|
|
1. Properties for GPIO Controllers
|
|
|
|
1.1 #gpio-cells
|
|
|
|
Property: #gpio-cells
|
|
|
|
Value type: <u32>
|
|
|
|
Description: The #gpio-cells property defines the number of cells required
|
|
to encode a gpio specifier.
|
|
|
|
|
|
1.2 gpio-controller
|
|
|
|
Property: gpio-controller
|
|
|
|
Value type: <empty>
|
|
|
|
Description: The presence of a gpio-controller property defines a node as a
|
|
GPIO controller node.
|
|
|
|
|
|
1.3 pin-count
|
|
|
|
Property: pin-count
|
|
|
|
Value type: <u32>
|
|
|
|
Description: The pin-count property defines the number of GPIO pins.
|
|
|
|
|
|
1.4 Example
|
|
|
|
GPIO: gpio@10100 {
|
|
#gpio-cells = <3>;
|
|
compatible = "mrvl,gpio";
|
|
reg = <0x10100 0x20>;
|
|
gpio-controller;
|
|
interrupts = <6 7 8 9>;
|
|
interrupt-parent = <&PIC>;
|
|
pin-count = <50>
|
|
};
|
|
|
|
2. Properties for GPIO consumer nodes.
|
|
|
|
2.1 gpios
|
|
|
|
Property: gpios
|
|
|
|
Value type: <prop-encoded-array> encoded as arbitrary number of GPIO
|
|
specifiers.
|
|
|
|
Description: The gpios property of a device node defines the GPIO or GPIOs
|
|
that are used by the device. The value of the gpios property
|
|
consists of an arbitrary number of GPIO specifiers.
|
|
|
|
The first cell of the GPIO specifier is phandle of the node's
|
|
parent GPIO controller and remaining cells are defined by the
|
|
binding describing the GPIO parent, typically include
|
|
information like pin number, direction and various flags.
|
|
|
|
Example:
|
|
gpios = <&GPIO 0 1 0 /* GPIO[0]: IN, NONE */
|
|
&GPIO 1 2 0>; /* GPIO[1]: OUT, NONE */
|
|
|
|
|
|
3. "mrvl,gpio" controller GPIO specifier
|
|
|
|
<phandle pin dir flags>
|
|
|
|
|
|
pin: 0-MAX GPIO pin number.
|
|
|
|
dir:
|
|
1 IN Input direction.
|
|
2 OUT Output direction.
|
|
|
|
flags:
|
|
0x0000---- IN_NONE
|
|
0x0001---- IN_POL_LOW Polarity low (inverted input value.
|
|
0x0002---- IN_IRQ_EDGE Interrupt, edge triggered.
|
|
0x0004---- IN_IRQ_LEVEL Interrupt, level triggered.
|
|
|
|
0x----0000 OUT_NONE
|
|
0x----0001 OUT_BLINK Blink on the pin.
|
|
0x----0002 OUT_OPEN_DRAIN Open drain output line.
|
|
0x----0004 OUT_OPEN_SRC Open source output line.
|
|
|
|
|
|
Example:
|
|
gpios = <&GPIO 0 1 0x00000000 /* GPIO[0]: IN */
|
|
&GPIO 1 2 0x00000000 /* GPIO[1]: OUT */
|
|
&GPIO 2 1 0x00020000 /* GPIO[2]: IN, IRQ (edge) */
|
|
&GPIO 3 1 0x00040000 /* GPIO[3]: IN, IRQ (level) */
|
|
...
|
|
&GPIO 10 2 0x00000001>; /* GPIO[10]: OUT, blink */
|