1.\" 2.\" Copyright (c) 2012 3.\" The DragonFly Project. 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.\" 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in 13.\" the documentation and/or other materials provided with the 14.\" distribution. 15.\" 3. Neither the name of The DragonFly Project nor the names of its 16.\" contributors may be used to endorse or promote products derived 17.\" from this software without specific, prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 22.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 23.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 24.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 25.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 27.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 28.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 29.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.Dd May 6, 2012 33.Dt WDOG 9 34.Os 35.Sh NAME 36.Nm wdog_register , 37.Nm wdog_unregister 38.Nd watchdog facility 39.Sh SYNOPSIS 40.In sys/wdog.h 41.Bd -literal 42typedef int (wdog_fn)(void *, int); 43.Ed 44.Ft void 45.Fn wdog_register "struct watchdog *wd" 46.Ft void 47.Fn wdog_unregister "struct watchdog *wd" 48.Sh DESCRIPTION 49The 50.Fn wdog_register 51and 52.Fn wdog_unregister 53functions do just what their names indicate. 54.Pp 55The watchdog driver, such as 56.Xr ichwd 4 , 57initializes a 58.Vt struct watchdog 59(see 60.In sys/wdog.h 61for details) and passes a pointer to it to 62.Fn wdog_register . 63The 64.Nm wdog 65framework will then periodically call the function pointed to by the struct's 66.Fa wdog_fn 67member and passes two arguments: a generic pointer specified in 68.Vt struct watchdog Ap s 69.Fa arg 70member and an integer which is the desired period. 71In the function, the driver must tickle the watchdog hardware and return 72the period, which it can adjust if hardware specifics require that. 73.Pp 74Registered watchdogs should be unregistered with 75.Fn wdog_unregister 76upon driver detachment. 77.\".Sh SEE ALSO 78.\".Xr wdog 4 79.Sh HISTORY 80The 81.Nm wdog 82framework appeared in 83.Dx 2.5 . 84.Sh AUTHORS 85.An Alex Hornung 86