.\" $NetBSD: ds2482ow.4,v 1.1 2024/11/04 20:43:37 brad Exp $
.\"
.\" Copyright (c) 2024 Brad Spencer <brad@anduin.eldar.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd October 31, 2024
.Dt DS2482OW 4
.Os
.Sh NAME
.Nm ds2482ow
.Nd Driver for Maxim DS2482-100 and DS2482-800 IC2 to 1-Wire bridge
.Sh SYNOPSIS
.Cd "ds2482ow* at iic? addr 0x18"
.Cd "ds2482ow* at iic? addr 0x19"
.Cd "ds2482ow* at iic? addr 0x1a"
.Cd "ds2482ow* at iic? addr 0x1b"
.Cd "ds2482ow* at iic? addr 0x1c" DS2482-800 only
.Cd "ds2482ow* at iic? addr 0x1d" DS2482-800 only
.Cd "ds2482ow* at iic? addr 0x1e" DS2482-800 only
.Cd "ds2482ow* at iic? addr 0x1f" DS2482-800 only
.Cd "onewire* at ds2482ow?"
.Sh DESCRIPTION
The
.Nm
driver provides 1 or 8
.Xr onewire 4
busses via an I2C interface.
The
.Nm
.Ar addr
argument selects the address at the
.Xr iic 4
bus.
The chip generates all of the needed 1-Wire pulses on its own
and provides for the pullup needed on the 1-Wire data line.
The method that the chip uses for pullup can be changed through
.Xr sysctl 8
nodes.
.Sh SYSCTL VARIABLES
The following
.Xr sysctl 3
variables are provided:
.Bl -tag -width indent
.It Li hw.ds2482ow0.pullup.active
If true, turn on active pullup on all channels supported by the chip.
.It Li hw.ds2482ow0.pullup.strong
If true, turn on strong pullup on all channels that the chip supports
and on the DS2482-100 chip, allow the PCTLZ pin to provide addition
current to the 1-Wire bus.  This mode conflicts with a 1-Wire reset
and will be disabled if that command is sent to the 1-Wire bus.

.It Li If neither active pullup or strong pullup are enabled the chip will
use an internal passive resister.
.It Li hw.ds2482ow0.debug
If the driver is compiled with
.Dv DS2482_DEBUG ,
this node will appear and can be used to set the debugging level.
.El
.Sh SEE ALSO
.Xr onewire 4 ,
.Xr iic 4 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 11.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Brad Spencer Aq Mt brad@anduin.eldar.org .
.Sh BUGS
The DS2482 chip supports overdrive speed on a 1-Wire bus.
This driver does not support overdrive speed mode.