GPIOLED(4FREEBSD) - Linux man page online | Special files

GPIO LED generic device driver.

May 14, 2014
GPIOLED(4) BSD Kernel Interfaces Manual GPIOLED(4)


gpioled — GPIO LED generic device driver


To compile this driver into the kernel, place the following lines in your kernel configura‐ tion file: device gpio device gpioled


The gpioled 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: The gpiobus you are attaching to. Normally assigned to gpiobus0. 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). 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/boot/fdt/dts/bindings-gpio.txt. The property name is the arbitrary name of the device in /dev/led/ to create for led(4).


fdt(4), gpio(4), gpioiic(4), led(4)


The gpioled manual page first appeared in FreeBSD 10.1.


This manual page was written by Luiz Otavio O Souza.
BSD May 14, 2014 BSD
This manual Reference Other manuals
gpioled(4freebsd) referred by gpio(4freebsd) | gpiobus(4freebsd) | gpioiic(4freebsd)
refer to gpio(4freebsd) | gpioiic(4freebsd) | led(4freebsd)
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