1*ae1f3df4SWarner Losh.\" 2*ae1f3df4SWarner Losh.\" Copyright (c) 2015 M. Warner Losh 3*ae1f3df4SWarner Losh.\" All rights reserved. 4*ae1f3df4SWarner Losh.\" 5*ae1f3df4SWarner Losh.\" Redistribution and use in source and binary forms, with or without 6*ae1f3df4SWarner Losh.\" modification, are permitted provided that the following conditions 7*ae1f3df4SWarner Losh.\" are met: 8*ae1f3df4SWarner Losh.\" 1. Redistributions of source code must retain the above copyright 9*ae1f3df4SWarner Losh.\" notice, this list of conditions and the following disclaimer. 10*ae1f3df4SWarner Losh.\" 2. The name of the author may not be used to endorse or promote products 11*ae1f3df4SWarner Losh.\" derived from this software without specific prior written permission. 12*ae1f3df4SWarner Losh.\" 13*ae1f3df4SWarner Losh.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14*ae1f3df4SWarner Losh.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15*ae1f3df4SWarner Losh.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16*ae1f3df4SWarner Losh.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17*ae1f3df4SWarner Losh.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18*ae1f3df4SWarner Losh.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19*ae1f3df4SWarner Losh.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20*ae1f3df4SWarner Losh.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21*ae1f3df4SWarner Losh.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22*ae1f3df4SWarner Losh.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23*ae1f3df4SWarner Losh.\" SUCH DAMAGE. 24*ae1f3df4SWarner Losh.\" 25*ae1f3df4SWarner Losh.\" $FreeBSD$ 26*ae1f3df4SWarner Losh.\" 27*ae1f3df4SWarner Losh.Dd July 20, 2015 28*ae1f3df4SWarner Losh.Dt OWC 4 29*ae1f3df4SWarner Losh.Os 30*ae1f3df4SWarner Losh.Sh NAME 31*ae1f3df4SWarner Losh.Nm owc 32*ae1f3df4SWarner Losh.Nd Dallas Semiconductor 1-Wire Controller 33*ae1f3df4SWarner Losh.Sh SYNOPSIS 34*ae1f3df4SWarner Losh.Cd device owc 35*ae1f3df4SWarner Losh.Sh DESCRIPTION 36*ae1f3df4SWarner LoshThe 37*ae1f3df4SWarner Losh.Nm 38*ae1f3df4SWarner Loshmodule implements Dallas Semiconductor 1-Wire signaling. 39*ae1f3df4SWarner LoshIt attaches the 40*ae1f3df4SWarner Losh.Xr ow 4 41*ae1f3df4SWarner Loshdriver 1-Wire bus protocol. 42*ae1f3df4SWarner LoshThe 43*ae1f3df4SWarner Losh.Nm 44*ae1f3df4SWarner Loshdevice implements the Link Layer of the 1-Wire bus protocol stack. 45*ae1f3df4SWarner Losh.Pp 46*ae1f3df4SWarner LoshBit banging a pin on a 47*ae1f3df4SWarner Losh.Xr gpiobus 4 48*ae1f3df4SWarner Loshis the only supported controller. 49*ae1f3df4SWarner LoshBoth standard and overdrive transfer timings are implemented. 50*ae1f3df4SWarner LoshStrong pull-up functionality needed to support parasitic mode is not 51*ae1f3df4SWarner Loshimplemented. 52*ae1f3df4SWarner Losh.Pp 53*ae1f3df4SWarner LoshTo enable 1-Wire for FDT systems requires modifying the DTS for your 54*ae1f3df4SWarner Loshboard to add something like: 55*ae1f3df4SWarner Losh.Bd -literal 56*ae1f3df4SWarner Losh/ { 57*ae1f3df4SWarner Losh ... 58*ae1f3df4SWarner Losh onewire { 59*ae1f3df4SWarner Losh compatible = "w1-gpio"; 60*ae1f3df4SWarner Losh gpios = <&gpio 4 1>; 61*ae1f3df4SWarner Losh }; 62*ae1f3df4SWarner Losh ... 63*ae1f3df4SWarner Losh}; 64*ae1f3df4SWarner Losh.Ed 65*ae1f3df4SWarner Losh.Pp 66*ae1f3df4SWarner LoshThe gpios property describes the GPIO pin the 1-Wire bus is connected 67*ae1f3df4SWarner Loshto. 68*ae1f3df4SWarner LoshFor more details about the 69*ae1f3df4SWarner Losh.Va gpios 70*ae1f3df4SWarner Loshproperty, please consult 71*ae1f3df4SWarner Losh.Pa /usr/src/sys/boot/fdt/dts/bindings-gpio.txt . 72*ae1f3df4SWarner Losh.Sh SEE ALSO 73*ae1f3df4SWarner Losh.Xr gpiobus 4 , 74*ae1f3df4SWarner Losh.Xr ow 4 , 75*ae1f3df4SWarner Losh.Xr ow_temp 4 , 76*ae1f3df4SWarner Losh.Xr owll 9 , 77*ae1f3df4SWarner Losh.Xr own 9 78*ae1f3df4SWarner Losh.Sh LEGAL 79*ae1f3df4SWarner Losh.Tn 1-Wire 80*ae1f3df4SWarner Loshis a registered trademark of Maxim Integrated Products, Inc. 81*ae1f3df4SWarner Losh.Sh HISTORY 82*ae1f3df4SWarner LoshThe 83*ae1f3df4SWarner Losh.Nm 84*ae1f3df4SWarner Loshdriver first appeared in 85*ae1f3df4SWarner Losh.Fx 11.0 . 86*ae1f3df4SWarner Losh.Sh AUTHORS 87*ae1f3df4SWarner LoshThe 88*ae1f3df4SWarner Losh.Nm 89*ae1f3df4SWarner Loshdevice driver and this manual page were written by 90*ae1f3df4SWarner Losh.An Warner Losh . 91*ae1f3df4SWarner Losh.Sh CAVEATS 92*ae1f3df4SWarner LoshThe gpio driver implements timing by busy waiting, which can cause a 93*ae1f3df4SWarner Loshhigh load on slower systems. 94*ae1f3df4SWarner Losh.Sh BUGS 95*ae1f3df4SWarner LoshOverdrive mode has not actually been tested. 96