1.\"- 2.\" Copyright (c) 2012 Bjoern A. Zeeb <bz@FreeBSD.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd March 6, 2012 29.Dt WBWD 4 30.Os 31.Sh NAME 32.Nm wbwd 33.Nd device driver for watchdog timer found on Winbond Super I/O chips 34.Sh SYNOPSIS 35To compile this driver into the kernel, place the following line in your 36kernel configuration file: 37.Bd -ragged -offset indent 38.Cd "device wbwd" 39.Ed 40.Pp 41Alternatively, to load the driver as a module at boot time, place the following 42line in 43.Xr loader.conf 5 : 44.Bd -literal -offset indent 45wbwd_load="YES" 46.Ed 47.Pp 48In 49.Pa /boot/device.hints : 50.Cd hint.wbwd.0.at="isa" 51.Sh DESCRIPTION 52The 53.Nm 54driver provides 55.Xr watchdog 4 56support for the watchdog interrupt timer present on at least the following 57Winbond Super I/O chips: 58.Pp 59.Bl -bullet -compact 60.It 6183627HF/F/HG/G Rev. G 62.It 6383627HF/F/HG/G Rev. J 64.It 6583627HF/F/HG/G Rev. UD-A 66.It 6783627DHG IC ver. 5 68.El 69.Sh SYSCTL VARIABLES 70The 71.Nm 72driver provides the following options as 73.Xr sysctl 8 74variables. 75.Bl -tag -width "xxxxxx" 76.It Va dev.wbwd.0.timeout_override 77This variable allows to program the timer to a value independent on the one 78provided by the 79.Xr watchdog 4 80framework while still relying on the regular updates from e.g. 81.Xr watchdogd 8 . 82This is particularly useful if your system provides multiple watchdogs and 83you want them to fire in a special sequence to trigger an NMI after a shorter 84period than the reset timeout for example. 85The value set must not be lower than the sleep time of 86.Xr watchdogd 8 . 87A value of 0 disables this feature and the timeout value provided by 88.Xr watchdog 4 89will be used. 90.It Va dev.wbwd.0.debug_verbose 91If set this sysctl will tell the driver to log its current state before and 92after the timer reset on each invocation from 93.Xr watchdog 9 94to the kernel message buffer for debugging. 95.It Va dev.wbwd.0.debug 96This read-only value gives the state of some registers on last update. 97.El 98.Pp 99The 100.Nm 101driver also provides further sysctl options that are hidden by default. 102See the source code for more information. 103.Sh SEE ALSO 104.Xr watchdog 4 , 105.Xr device.hints 5 , 106.Xr watchdog 8 , 107.Xr watchdogd 8 , 108.Xr watchdog 9 109.Sh HISTORY 110The 111.Nm 112driver first appeared in 113.Fx 10.0 . 114.Sh AUTHORS 115.An -nosplit 116This manual page was written by 117.An Bjoern A. Zeeb Aq bz@FreeBSD.org . 118