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OWC(4)			    Kernel Interfaces Manual			OWC(4)

NAME
       owc -- Dallas Semiconductor 1-Wire Controller

SYNOPSIS
       device owc

DESCRIPTION
       The  owc	 module	 implements Dallas Semiconductor 1-Wire	signaling.  It
       attaches	the ow(4) driver 1-Wire	bus protocol.  The owc	device	imple-
       ments the Link Layer of the 1-Wire bus protocol stack.

       Bit  banging  a	pin  on	a gpiobus(4) is	the only supported controller.
       Both standard and overdrive transfer timings are	 implemented.	Strong
       pull-up	functionality  needed  to support parasitic mode is not	imple-
       mented.

       To enable 1-Wire	for FDT	systems	requires modifying the	DTS  for  your
       board to	add something like:

       / {
	       ...
	       onewire {
		       compatible = "w1-gpio";
		       gpios = <&gpio 4	1>;
	       };
	       ...
       };

       The  gpios  property describes the GPIO pin the 1-Wire bus is connected
       to.   For  more	details	 about	the  gpios  property,  please  consult
       /usr/src/sys/dts/bindings-gpio.txt.

       On  a  device.hints(5)  based  system these values are required for the
       owc:

       hint.owc.%d.at	  The gpiobus you are attaching	to.

       hint.owc.%d.pins	  This is a bitmask that defines a pin on the  gpiobus
			  that	is  to	be  used  for the 1-Wire bus.  For in-
			  stance, to configure pin  10,	 use  the  bitmask  of
			  0x400.   Please note that this mask should have only
			  one bit set (any other bits -	i.e., pins -  will  be
			  ignored).

SEE ALSO
       gpiobus(4), ow(4), ow_temp(4), owll(9), own(9)

LEGAL
       1-Wire is a registered trademark	of Maxim Integrated Products, Inc.

HISTORY
       The owc driver first appeared in	FreeBSD	11.0.

AUTHORS
       The owc device driver and this manual page were written by Warner Losh.

CAVEATS
       The  gpio  driver  implements timing by busy waiting, which can cause a
       high load on slower systems.

BUGS
       Overdrive mode has not actually been tested.

FreeBSD	14.3			 June 26, 2019				OWC(4)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=owc&sektion=4&manpath=FreeBSD+14.3-RELEASE+and+Ports>

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