2 .\" Copyright (c) 2012 Bjoern A. Zeeb <bz@FreeBSD.org>
3 .\" All rights reserved.
5 .\" Redistribution and use in source and binary forms, with or without
6 .\" modification, are permitted provided that the following conditions
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.
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
33 .Nd device driver for watchdog timer found on Winbond Super I/O chips
35 To compile this driver into the kernel, place the following line in your
36 kernel configuration file:
37 .Bd -ragged -offset indent
41 Alternatively, to load the driver as a module at boot time, place the following
44 .Bd -literal -offset indent
49 .Pa /boot/device.hints :
50 .Cd hint.wbwd.0.at="isa"
56 support for the watchdog interrupt timer present on at least the following
57 Winbond Super I/O chips:
65 83627HF/F/HG/G Rev. UD-A
72 driver provides the following options as
75 .Bl -tag -width "xxxxxx"
76 .It Va dev.wbwd.0.timeout_override
77 This variable allows to program the timer to a value independent on the one
80 framework while still relying on the regular updates from e.g.
82 This is particularly useful if your system provides multiple watchdogs and
83 you want them to fire in a special sequence to trigger an NMI after a shorter
84 period than the reset timeout for example.
85 The value set must not be lower than the sleep time of
87 A value of 0 disables this feature and the timeout value provided by
90 .It Va dev.wbwd.0.debug_verbose
91 If set this sysctl will tell the driver to log its current state before and
92 after the timer reset on each invocation from
94 to the kernel message buffer for debugging.
95 .It Va dev.wbwd.0.debug
96 This read-only value gives the state of some registers on last update.
101 driver also provides further sysctl options that are hidden by default.
102 See the source code for more information.
112 driver first appeared in
116 This manual page was written by
117 .An Bjoern A. Zeeb Aq bz@FreeBSD.org .