1.\" $NetBSD: ds2482ow.4,v 1.1 2024/11/04 20:43:37 brad Exp $ 2.\" 3.\" Copyright (c) 2024 Brad Spencer <brad@anduin.eldar.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd October 31, 2024 18.Dt DS2482OW 4 19.Os 20.Sh NAME 21.Nm ds2482ow 22.Nd Driver for Maxim DS2482-100 and DS2482-800 IC2 to 1-Wire bridge 23.Sh SYNOPSIS 24.Cd "ds2482ow* at iic? addr 0x18" 25.Cd "ds2482ow* at iic? addr 0x19" 26.Cd "ds2482ow* at iic? addr 0x1a" 27.Cd "ds2482ow* at iic? addr 0x1b" 28.Cd "ds2482ow* at iic? addr 0x1c" DS2482-800 only 29.Cd "ds2482ow* at iic? addr 0x1d" DS2482-800 only 30.Cd "ds2482ow* at iic? addr 0x1e" DS2482-800 only 31.Cd "ds2482ow* at iic? addr 0x1f" DS2482-800 only 32.Cd "onewire* at ds2482ow?" 33.Sh DESCRIPTION 34The 35.Nm 36driver provides 1 or 8 37.Xr onewire 4 38busses via an I2C interface. 39The 40.Nm 41.Ar addr 42argument selects the address at the 43.Xr iic 4 44bus. 45The chip generates all of the needed 1-Wire pulses on its own 46and provides for the pullup needed on the 1-Wire data line. 47The method that the chip uses for pullup can be changed through 48.Xr sysctl 8 49nodes. 50.Sh SYSCTL VARIABLES 51The following 52.Xr sysctl 3 53variables are provided: 54.Bl -tag -width indent 55.It Li hw.ds2482ow0.pullup.active 56If true, turn on active pullup on all channels supported by the chip. 57.It Li hw.ds2482ow0.pullup.strong 58If true, turn on strong pullup on all channels that the chip supports 59and on the DS2482-100 chip, allow the PCTLZ pin to provide addition 60current to the 1-Wire bus. This mode conflicts with a 1-Wire reset 61and will be disabled if that command is sent to the 1-Wire bus. 62 63.It Li If neither active pullup or strong pullup are enabled the chip will 64use an internal passive resister. 65.It Li hw.ds2482ow0.debug 66If the driver is compiled with 67.Dv DS2482_DEBUG , 68this node will appear and can be used to set the debugging level. 69.El 70.Sh SEE ALSO 71.Xr onewire 4 , 72.Xr iic 4 , 73.Xr sysctl 8 74.Sh HISTORY 75The 76.Nm 77driver first appeared in 78.Nx 11.0 . 79.Sh AUTHORS 80.An -nosplit 81The 82.Nm 83driver was written by 84.An Brad Spencer Aq Mt brad@anduin.eldar.org . 85.Sh BUGS 86The DS2482 chip supports overdrive speed on a 1-Wire bus. 87This driver does not support overdrive speed mode. 88