gpioiic(4) [netbsd man page]

GPIOIIC(4)						   BSD Kernel Interfaces Manual 						GPIOIIC(4)

NAME

     gpioiic -- GPIO I2C controller

SYNOPSIS

     gpioiic* at gpio? offset 0 mask 0x3 flag 0x0
     gpioiic* at gpio?
     iic* at gpioiic?

DESCRIPTION

     The gpioiic driver allows bit-banging an I2C bus as a master using two GPIO pins.	By default the first pin is used as a serial data (SDA)
     signal and the second as a serial clock (SCL).  If the flag locator is set to 0x01, the order of the SDA and SCL signals is reversed.  Both
     GPIO pins must be able to drive an output and the SDA pin must be also able to read an input.

     The pins can be specified in the kernel configuration with the offset and the mask locators.  The offset and mask can also be specified when
     gpioiic is attached at runtime using the GPIOATTACH ioctl(2) on the gpio(4) device.  Each bit in the mask locator defines one pin; the pin
     number is calculated as an addition of the bit position and the offset locator.  For example, offset 17 and mask 0x5 defines pin numbers 17
     and 19.

SEE ALSO

     gpio(4), iic(4), intro(4)

HISTORY

     The gpioiic driver first appeared in OpenBSD 3.9 and NetBSD 5.0.

AUTHORS

     The gpioiic driver was written by Alexander Yurchenko <grange@openbsd.org> and was ported to NetBSD by Marc Balmer <marc@msys.ch>.

CAVEATS

     A gpioiic device can not be detached from the gpio(4) bus at runtime due to the fact that iic(4) busses can not detach once attached.

BSD
								  October 2, 2011							       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