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.\" 25*fbf8e324SMark Murray.Dd March 7, 2021 263c7f758bSBruce Evans.Dt SMBUS 4 273d45e180SRuslan Ermilov.Os 28eb8752d5SNicolas Souchu.Sh NAME 29eb8752d5SNicolas Souchu.Nm smbus 30eb083802SRuslan Ermilov.Nd System Management Bus 31eb8752d5SNicolas Souchu.Sh SYNOPSIS 32b9781e20SJeroen Ruigrok van der Werven.Cd "device smbus" 33eb8752d5SNicolas Souchu.Pp 34b9781e20SJeroen Ruigrok van der Werven.Cd "device iicsmb" 35eb8752d5SNicolas Souchu.Sh DESCRIPTION 36eb8752d5SNicolas SouchuThe 37eb8752d5SNicolas Souchu.Em smbus 38eb8752d5SNicolas Souchusystem provides a uniform, modular and architecture-independent 39eb8752d5SNicolas Souchusystem for the implementation of drivers to control various SMB devices 40*fbf8e324SMark Murrayand to utilize different SMB controllers (I2C, PIIX4, vm86...). 41eb8752d5SNicolas Souchu.Sh System Management Bus 42eb8752d5SNicolas SouchuThe 43eb8752d5SNicolas Souchu.Em System Management Bus 44eb8752d5SNicolas Souchuis a two-wire interface through which simple power-related chips can communicate 456d249eeeSSheldon Hearnwith rest of the system. 466d249eeeSSheldon HearnIt uses I2C as its backbone (see 47eb8752d5SNicolas Souchu.Xr iicbus 4 ) . 483136363fSRuslan Ermilov.Pp 49eb8752d5SNicolas SouchuA system using SMB passes messages to and from devices instead of tripping 50eb8752d5SNicolas Souchuindividual control lines. 513136363fSRuslan Ermilov.Pp 52eb8752d5SNicolas SouchuWith the SMBus, a device can provide manufacturer information, tell the 53eb8752d5SNicolas Souchusystem what its model/part number is, save its state for a suspend event, 54eb8752d5SNicolas Souchureport different types of errors, accept control parameters, and return its 55eb8752d5SNicolas Souchustatus. 563136363fSRuslan Ermilov.Pp 5756b1692aSJean-Marc ZucconiThe SMBus may share the same host device and physical bus as ACCESS bus 5856b1692aSJean-Marc Zucconicomponents provided that an appropriate electrical bridge is provided 5956b1692aSJean-Marc Zucconibetween the internal SMB devices and external ACCESS bus devices. 60eb8752d5SNicolas Souchu.Sh SEE ALSO 61eb8752d5SNicolas Souchu.Xr iicbus 4 , 62eb8752d5SNicolas Souchu.Xr iicsmb 4 , 63eb8752d5SNicolas Souchu.Xr smb 4 648d975d4fSJoerg Wunsch.Rs 658d975d4fSJoerg Wunsch.%T The SMBus specification 66aa4a335bSRuslan Ermilov.%U http://www.smbus.org/specs/ 678d975d4fSJoerg Wunsch.Re 68eb8752d5SNicolas Souchu.Sh HISTORY 69eb8752d5SNicolas SouchuThe 70eb8752d5SNicolas Souchu.Nm 71eb8752d5SNicolas Souchumanual page first appeared in 72eb8752d5SNicolas Souchu.Fx 3.0 . 73def37e7cSMike Pritchard.Sh AUTHORS 74eb8752d5SNicolas SouchuThis 75eb8752d5SNicolas Souchumanual page was written by 76eb8752d5SNicolas Souchu.An Nicolas Souchu . 77