Copyright (c) 2012 Bjoern A. Zeeb <bz@FreeBSD.org>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
$FreeBSD$
.Dd December 28, 2012 .Dt wbwd 4 .Os .Sh NAME .Nm wbwd .Nd device driver for watchdog timer found on Winbond Super I/O chips .Sh SYNOPSIS To compile this driver into the kernel, place the following line in your kernel configuration file: d -ragged -offset indent .Cd "device wbwd" .Ed
p Alternatively, to load the driver as a module at boot time, place the following line in .Xr loader.conf 5 : d -literal -offset indent wbwd_load="YES" .Ed .Sh DESCRIPTION The .Nm driver provides .Xr watchdog 4 support for the watchdog interrupt timer present on at least the following Winbond Super I/O chips:
p l -bullet -compact t 83627HF/F/HG/G Rev. G t 83627HF/F/HG/G Rev. J t 83627HF/F/HG/G Rev. UD-A t 83627DHG IC ver. 5 .El .Sh SYSCTL VARIABLES The .Nm driver provides the following options as .Xr sysctl 8 variables. l -tag -width "xxxxxx" t Va dev.wbwd.0.timeout_override This variable allows to program the timer to a value independent on the one provided by the .Xr watchdog 4 framework while still relying on the regular updates from e.g. .Xr watchdogd 8 . This is particularly useful if your system provides multiple watchdogs and you want them to fire in a special sequence to trigger an NMI after a shorter period than the reset timeout for example. The value set must not be lower than the sleep time of .Xr watchdogd 8 . A value of 0 disables this feature and the timeout value provided by .Xr watchdog 4 will be used. t Va dev.wbwd.0.debug_verbose If set this sysctl will tell the driver to log its current state before and after the timer reset on each invocation from .Xr watchdog 9 to the kernel message buffer for debugging. t Va dev.wbwd.0.debug This read-only value gives the state of some registers on last update. .El
p The .Nm driver also provides further sysctl options that are hidden by default. See the source code for more information. .Sh SEE ALSO .Xr watchdog 4 , .Xr device.hints 5 , .Xr watchdog 8 , .Xr watchdogd 8 , .Xr watchdog 9 .Sh HISTORY The .Nm driver first appeared in .Fx 10.0 . .Sh AUTHORS .An -nosplit This manual page was written by .An Bjoern A. Zeeb Aq bz@FreeBSD.org .