NAME
gpioled
—
GPIO LED generic device
driver
SYNOPSIS
To compile this driver into the kernel, place the following lines in your kernel configuration file:
device gpio
device gpioled
DESCRIPTION
Thegpioled
driver provides glue to attach a
led(4) compatible device to a GPIO pin. Each LED in the system has a
name which is used to export a device as
/dev/led/<name>. The GPIO pin can then be
controlled by writing to this device as described in
led(4).
On a
device.hints(5) based system, like
MIPS
, these values are configurable for
gpioled
:
- hint.gpioled.%d.at
- The gpiobus you are attaching to. Normally assigned to gpiobus0.
- hint.gpioled.%d.name
- Arbitrary name of device in /dev/led/ to create for led(4).
- hint.gpioled.%d.pins
- Which pin on the GPIO interface to map to this instance. Please note that this mask should only ever have one bit set (any other bits - i.e., pins - will be ignored).
- hint.gpioled.%d.invert
- If set to 1, the pin will be set to 0 to light the LED, and 1 to clear it.
On a FDT(4) based system, like ARM
, the
DTS part for a gpioled
device usually looks
like:
gpio: gpio { gpio-controller; ... led0 { compatible = "gpioled"; gpios = <&gpio 16 2 0>; /* GPIO pin 16. */ name = "ok"; }; led1 { compatible = "gpioled"; gpios = <&gpio 17 2 0>; /* GPIO pin 17. */ name = "user-led1"; }; };
Optionally, you can choose to combine all the LEDs under a single “gpio-leds” compatible node:
simplebus0 { ... leds { compatible = "gpio-leds"; led0 { gpios = <&gpio 16 2 0>; name = "ok" }; led1 { gpios = <&gpio 17 2 0>; name = "user-led1" }; }; };
Both methods are equally supported and it is possible to have the LEDs defined with any sort of mix between the methods. The only restriction is that a GPIO pin cannot be mapped by two different (gpio)leds.
For more details about the gpios property, please consult /usr/src/sys/dts/bindings-gpio.txt.
The property name is the arbitrary name of the device in /dev/led/ to create for led(4).
SEE ALSO
HISTORY
The gpioled
manual page first appeared in
FreeBSD 10.1.
AUTHORS
This manual page was written by Luiz Otavio O Souza.