gpioow(4) [netbsd man page]

GPIOOW(4)						   BSD Kernel Interfaces Manual 						 GPIOOW(4)

NAME

     gpioow -- 1-Wire bus bit-banging through GPIO pin

SYNOPSIS

     gpioow* at gpio? offset 0 mask 0x1
     gpioow* at gpio?
     onewire* at gpioow?

DESCRIPTION

     The gpioow driver allows bit-banging a 1-Wire bus as a master using one GPIO pin.	The pin is used as a data signal.  The GPIO pin must be
     able to drive an output and read an input.

     The pin number is specified in the kernel configuration with the offset locator.  The mask locator should always be 0x1.  The offset and mask
     can also be specified when gpioow is attached at runtime using the GPIOATTACH ioctl(2) on the gpio(4) device.

SEE ALSO

     gpio(4), intro(4), onewire(4)

HISTORY

     The gpioow driver first appeared in OpenBSD 4.0 and NetBSD 4.0.

AUTHORS

     The gpioow driver was written by Alexander Yurchenko <grange@openbsd.org> and was ported to NetBSD by Jeff Rizzo <riz@NetBSD.org>.

BSD
								   July 19, 2009							       BSD

GPIOLED(4)						   BSD Kernel Interfaces Manual 						GPIOLED(4)

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

     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:

     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).

     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 restric-
     tion 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).

SEE ALSO

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

HISTORY

     The gpioled manual page first appeared in FreeBSD 10.1.

AUTHORS

     This manual page was written by Luiz Otavio O Souza.

BSD
								   May 14, 2014 							       BSD