1eb8752d5SNicolas Souchu.\" Copyright (c) 1998, Nicolas Souchu 2eb8752d5SNicolas Souchu.\" All rights reserved. 3eb8752d5SNicolas Souchu.\" 4eb8752d5SNicolas Souchu.\" Redistribution and use in source and binary forms, with or without 5eb8752d5SNicolas Souchu.\" modification, are permitted provided that the following conditions 6eb8752d5SNicolas Souchu.\" are met: 7eb8752d5SNicolas Souchu.\" 1. Redistributions of source code must retain the above copyright 8eb8752d5SNicolas Souchu.\" notice, this list of conditions and the following disclaimer. 9eb8752d5SNicolas Souchu.\" 2. Redistributions in binary form must reproduce the above copyright 10eb8752d5SNicolas Souchu.\" notice, this list of conditions and the following disclaimer in the 11eb8752d5SNicolas Souchu.\" documentation and/or other materials provided with the distribution. 12eb8752d5SNicolas Souchu.\" 13eb8752d5SNicolas Souchu.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14eb8752d5SNicolas Souchu.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15eb8752d5SNicolas Souchu.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16eb8752d5SNicolas Souchu.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17eb8752d5SNicolas Souchu.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18eb8752d5SNicolas Souchu.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19eb8752d5SNicolas Souchu.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20eb8752d5SNicolas Souchu.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21eb8752d5SNicolas Souchu.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22eb8752d5SNicolas Souchu.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23eb8752d5SNicolas Souchu.\" SUCH DAMAGE. 24eb8752d5SNicolas Souchu.\" 257f3dea24SPeter Wemm.\" $FreeBSD$ 26eb8752d5SNicolas Souchu.\" 27eb8752d5SNicolas Souchu.Dd August 10, 1998 283c7f758bSBruce Evans.Dt SMBUS 4 29eb8752d5SNicolas Souchu.Os FreeBSD 30eb8752d5SNicolas Souchu.Sh NAME 31eb8752d5SNicolas Souchu.Nm smbus 32eb8752d5SNicolas Souchu.Nd 33eb8752d5SNicolas SouchuSystem Management Bus 34eb8752d5SNicolas Souchu.Sh SYNOPSIS 35b9781e20SJeroen Ruigrok van der Werven.Cd "device smbus" 36eb8752d5SNicolas Souchu.Pp 37b9781e20SJeroen Ruigrok van der Werven.Cd "device iicsmb" 38b9781e20SJeroen Ruigrok van der Werven.Cd "device bktr" 39eb8752d5SNicolas Souchu.Sh DESCRIPTION 40eb8752d5SNicolas SouchuThe 41eb8752d5SNicolas Souchu.Em smbus 42eb8752d5SNicolas Souchusystem provides a uniform, modular and architecture-independent 43eb8752d5SNicolas Souchusystem for the implementation of drivers to control various SMB devices 44eb8752d5SNicolas Souchuand to utilize different SMB controllers (I2C, PIIX4, Brooktree848, vm86...). 45eb8752d5SNicolas Souchu.Sh System Management Bus 46eb8752d5SNicolas SouchuThe 47eb8752d5SNicolas Souchu.Em System Management Bus 48eb8752d5SNicolas Souchuis a two-wire interface through which simple power-related chips can communicate 496d249eeeSSheldon Hearnwith rest of the system. 506d249eeeSSheldon HearnIt uses I2C as its backbone (see 51eb8752d5SNicolas Souchu.Xr iicbus 4 ). 523136363fSRuslan Ermilov.Pp 53eb8752d5SNicolas SouchuA system using SMB passes messages to and from devices instead of tripping 54eb8752d5SNicolas Souchuindividual control lines. 553136363fSRuslan Ermilov.Pp 56eb8752d5SNicolas SouchuWith the SMBus, a device can provide manufacturer information, tell the 57eb8752d5SNicolas Souchusystem what its model/part number is, save its state for a suspend event, 58eb8752d5SNicolas Souchureport different types of errors, accept control parameters, and return its 59eb8752d5SNicolas Souchustatus. 603136363fSRuslan Ermilov.Pp 6156b1692aSJean-Marc ZucconiThe SMBus may share the same host device and physical bus as ACCESS bus 6256b1692aSJean-Marc Zucconicomponents provided that an appropriate electrical bridge is provided 6356b1692aSJean-Marc Zucconibetween the internal SMB devices and external ACCESS bus devices. 64eb8752d5SNicolas Souchu.Sh SEE ALSO 65def37e7cSMike Pritchard.Xr bktr 4 , 66eb8752d5SNicolas Souchu.Xr iicbus 4 , 67eb8752d5SNicolas Souchu.Xr iicsmb 4 , 68eb8752d5SNicolas Souchu.Xr smb 4 69eb8752d5SNicolas Souchu.Sh HISTORY 70eb8752d5SNicolas SouchuThe 71eb8752d5SNicolas Souchu.Nm 72eb8752d5SNicolas Souchumanual page first appeared in 73eb8752d5SNicolas Souchu.Fx 3.0 . 74def37e7cSMike Pritchard.Sh AUTHORS 75eb8752d5SNicolas SouchuThis 76eb8752d5SNicolas Souchumanual page was written by 77eb8752d5SNicolas Souchu.An Nicolas Souchu . 78