1ae1f3df4SWarner Losh.\" 2ae1f3df4SWarner Losh.\" Copyright (c) 2015 M. Warner Losh 3ae1f3df4SWarner Losh.\" All rights reserved. 4ae1f3df4SWarner Losh.\" 5ae1f3df4SWarner Losh.\" Redistribution and use in source and binary forms, with or without 6ae1f3df4SWarner Losh.\" modification, are permitted provided that the following conditions 7ae1f3df4SWarner Losh.\" are met: 8ae1f3df4SWarner Losh.\" 1. Redistributions of source code must retain the above copyright 9ae1f3df4SWarner Losh.\" notice, this list of conditions and the following disclaimer. 10ae1f3df4SWarner Losh.\" 2. The name of the author may not be used to endorse or promote products 11ae1f3df4SWarner Losh.\" derived from this software without specific prior written permission. 12ae1f3df4SWarner Losh.\" 13ae1f3df4SWarner Losh.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14ae1f3df4SWarner Losh.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15ae1f3df4SWarner Losh.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16ae1f3df4SWarner Losh.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17ae1f3df4SWarner Losh.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18ae1f3df4SWarner Losh.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19ae1f3df4SWarner Losh.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20ae1f3df4SWarner Losh.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21ae1f3df4SWarner Losh.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22ae1f3df4SWarner Losh.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23ae1f3df4SWarner Losh.\" SUCH DAMAGE. 24ae1f3df4SWarner Losh.\" 25ae1f3df4SWarner Losh.\" $FreeBSD$ 26ae1f3df4SWarner Losh.\" 27ae1f3df4SWarner Losh.Dd July 20, 2015 28ae1f3df4SWarner Losh.Dt OWC 4 29ae1f3df4SWarner Losh.Os 30ae1f3df4SWarner Losh.Sh NAME 31ae1f3df4SWarner Losh.Nm owc 32ae1f3df4SWarner Losh.Nd Dallas Semiconductor 1-Wire Controller 33ae1f3df4SWarner Losh.Sh SYNOPSIS 34ae1f3df4SWarner Losh.Cd device owc 35ae1f3df4SWarner Losh.Sh DESCRIPTION 36ae1f3df4SWarner LoshThe 37ae1f3df4SWarner Losh.Nm 38ae1f3df4SWarner Loshmodule implements Dallas Semiconductor 1-Wire signaling. 39ae1f3df4SWarner LoshIt attaches the 40ae1f3df4SWarner Losh.Xr ow 4 41ae1f3df4SWarner Loshdriver 1-Wire bus protocol. 42ae1f3df4SWarner LoshThe 43ae1f3df4SWarner Losh.Nm 44ae1f3df4SWarner Loshdevice implements the Link Layer of the 1-Wire bus protocol stack. 45ae1f3df4SWarner Losh.Pp 46ae1f3df4SWarner LoshBit banging a pin on a 47ae1f3df4SWarner Losh.Xr gpiobus 4 48ae1f3df4SWarner Loshis the only supported controller. 49ae1f3df4SWarner LoshBoth standard and overdrive transfer timings are implemented. 50ae1f3df4SWarner LoshStrong pull-up functionality needed to support parasitic mode is not 51ae1f3df4SWarner Loshimplemented. 52ae1f3df4SWarner Losh.Pp 53ae1f3df4SWarner LoshTo enable 1-Wire for FDT systems requires modifying the DTS for your 54ae1f3df4SWarner Loshboard to add something like: 55ae1f3df4SWarner Losh.Bd -literal 56ae1f3df4SWarner Losh/ { 57ae1f3df4SWarner Losh ... 58ae1f3df4SWarner Losh onewire { 59ae1f3df4SWarner Losh compatible = "w1-gpio"; 60ae1f3df4SWarner Losh gpios = <&gpio 4 1>; 61ae1f3df4SWarner Losh }; 62ae1f3df4SWarner Losh ... 63ae1f3df4SWarner Losh}; 64ae1f3df4SWarner Losh.Ed 65ae1f3df4SWarner Losh.Pp 66ae1f3df4SWarner LoshThe gpios property describes the GPIO pin the 1-Wire bus is connected 67ae1f3df4SWarner Loshto. 68ae1f3df4SWarner LoshFor more details about the 69ae1f3df4SWarner Losh.Va gpios 70ae1f3df4SWarner Loshproperty, please consult 71*2e36db14SWarner Losh.Pa /usr/src/sys/dts/bindings-gpio.txt . 72ae1f3df4SWarner Losh.Sh SEE ALSO 73ae1f3df4SWarner Losh.Xr gpiobus 4 , 74ae1f3df4SWarner Losh.Xr ow 4 , 75ae1f3df4SWarner Losh.Xr ow_temp 4 , 76ae1f3df4SWarner Losh.Xr owll 9 , 77ae1f3df4SWarner Losh.Xr own 9 78ae1f3df4SWarner Losh.Sh LEGAL 79ae1f3df4SWarner Losh.Tn 1-Wire 80ae1f3df4SWarner Loshis a registered trademark of Maxim Integrated Products, Inc. 81ae1f3df4SWarner Losh.Sh HISTORY 82ae1f3df4SWarner LoshThe 83ae1f3df4SWarner Losh.Nm 84ae1f3df4SWarner Loshdriver first appeared in 85ae1f3df4SWarner Losh.Fx 11.0 . 86ae1f3df4SWarner Losh.Sh AUTHORS 87ae1f3df4SWarner LoshThe 88ae1f3df4SWarner Losh.Nm 89ae1f3df4SWarner Loshdevice driver and this manual page were written by 90ae1f3df4SWarner Losh.An Warner Losh . 91ae1f3df4SWarner Losh.Sh CAVEATS 92ae1f3df4SWarner LoshThe gpio driver implements timing by busy waiting, which can cause a 93ae1f3df4SWarner Loshhigh load on slower systems. 94ae1f3df4SWarner Losh.Sh BUGS 95ae1f3df4SWarner LoshOverdrive mode has not actually been tested. 96