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GPIOLED(4)		    Kernel Interfaces Manual		    GPIOLED(4)

NAME
       gpioled -- GPIO led generic device driver

SYNOPSIS
       device gpio
       device gpioled

       This driver attaches a led(4) device to a GPIO pin.

DESCRIPTION
       The gpioled driver provides a glue to attach a led(4) compatible	device
       to  a GPIO pin.	Each led on the	system has a name which	is used	to ex-
       port a device in	/dev/led/<name>.  The GPIO pin can then	be  controlled
       by writing to this device as described on led(4).

       On  a  hint based system, like MIPS, these values are configureable for
       gpioled:

       hint.gpioled.%d.at     The gpiobus you are attaching to.	 Normally  as-
			      signed 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  others  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";
	       };
       };

       And optionally, you can choose 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 device in /dev/led/ to cre-
       ate for led(4).

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

HISTORY
       The gpioled manual page first appeared in FreeBSD 10.1.

AUTHORS
       This manual page	was written by Luiz Otavio O Souza.

FreeBSD	10.3			 May 14, 2014			    GPIOLED(4)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=gpioled&sektion=4&manpath=FreeBSD+10.3-RELEASE>

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