1*86d7f5d3SJohn Marino.\" Copyright (c) 1998, Nicolas Souchu 2*86d7f5d3SJohn Marino.\" All rights reserved. 3*86d7f5d3SJohn Marino.\" 4*86d7f5d3SJohn Marino.\" Redistribution and use in source and binary forms, with or without 5*86d7f5d3SJohn Marino.\" modification, are permitted provided that the following conditions 6*86d7f5d3SJohn Marino.\" are met: 7*86d7f5d3SJohn Marino.\" 1. Redistributions of source code must retain the above copyright 8*86d7f5d3SJohn Marino.\" notice, this list of conditions and the following disclaimer. 9*86d7f5d3SJohn Marino.\" 2. Redistributions in binary form must reproduce the above copyright 10*86d7f5d3SJohn Marino.\" notice, this list of conditions and the following disclaimer in the 11*86d7f5d3SJohn Marino.\" documentation and/or other materials provided with the distribution. 12*86d7f5d3SJohn Marino.\" 13*86d7f5d3SJohn Marino.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14*86d7f5d3SJohn Marino.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15*86d7f5d3SJohn Marino.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16*86d7f5d3SJohn Marino.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17*86d7f5d3SJohn Marino.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18*86d7f5d3SJohn Marino.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19*86d7f5d3SJohn Marino.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20*86d7f5d3SJohn Marino.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21*86d7f5d3SJohn Marino.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22*86d7f5d3SJohn Marino.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23*86d7f5d3SJohn Marino.\" SUCH DAMAGE. 24*86d7f5d3SJohn Marino.\" 25*86d7f5d3SJohn Marino.\" $FreeBSD: src/share/man/man4/smbus.4,v 1.9.2.3 2001/08/17 13:08:39 ru Exp $ 26*86d7f5d3SJohn Marino.\" $DragonFly: src/share/man/man4/smbus.4,v 1.2 2003/06/17 04:36:59 dillon Exp $ 27*86d7f5d3SJohn Marino.\" 28*86d7f5d3SJohn Marino.Dd August 10, 1998 29*86d7f5d3SJohn Marino.Dt SMBUS 4 30*86d7f5d3SJohn Marino.Os 31*86d7f5d3SJohn Marino.Sh NAME 32*86d7f5d3SJohn Marino.Nm smbus 33*86d7f5d3SJohn Marino.Nd System Management Bus 34*86d7f5d3SJohn Marino.Sh SYNOPSIS 35*86d7f5d3SJohn Marino.Cd "device smbus" 36*86d7f5d3SJohn Marino.Pp 37*86d7f5d3SJohn Marino.Cd "device iicsmb" 38*86d7f5d3SJohn Marino.Cd "device bktr" 39*86d7f5d3SJohn Marino.Sh DESCRIPTION 40*86d7f5d3SJohn MarinoThe 41*86d7f5d3SJohn Marino.Em smbus 42*86d7f5d3SJohn Marinosystem provides a uniform, modular and architecture-independent 43*86d7f5d3SJohn Marinosystem for the implementation of drivers to control various SMB devices 44*86d7f5d3SJohn Marinoand to utilize different SMB controllers (I2C, PIIX4, Brooktree848, vm86...). 45*86d7f5d3SJohn Marino.Sh System Management Bus 46*86d7f5d3SJohn MarinoThe 47*86d7f5d3SJohn Marino.Em System Management Bus 48*86d7f5d3SJohn Marinois a two-wire interface through which simple power-related chips can communicate 49*86d7f5d3SJohn Marinowith rest of the system. 50*86d7f5d3SJohn MarinoIt uses I2C as its backbone (see 51*86d7f5d3SJohn Marino.Xr iicbus 4 ) . 52*86d7f5d3SJohn Marino.Pp 53*86d7f5d3SJohn MarinoA system using SMB passes messages to and from devices instead of tripping 54*86d7f5d3SJohn Marinoindividual control lines. 55*86d7f5d3SJohn Marino.Pp 56*86d7f5d3SJohn MarinoWith the SMBus, a device can provide manufacturer information, tell the 57*86d7f5d3SJohn Marinosystem what its model/part number is, save its state for a suspend event, 58*86d7f5d3SJohn Marinoreport different types of errors, accept control parameters, and return its 59*86d7f5d3SJohn Marinostatus. 60*86d7f5d3SJohn Marino.Pp 61*86d7f5d3SJohn MarinoThe SMBus may share the same host device and physical bus as ACCESS bus 62*86d7f5d3SJohn Marinocomponents provided that an appropriate electrical bridge is provided 63*86d7f5d3SJohn Marinobetween the internal SMB devices and external ACCESS bus devices. 64*86d7f5d3SJohn Marino.Sh SEE ALSO 65*86d7f5d3SJohn Marino.Xr bktr 4 , 66*86d7f5d3SJohn Marino.Xr iicbus 4 , 67*86d7f5d3SJohn Marino.Xr iicsmb 4 , 68*86d7f5d3SJohn Marino.Xr smb 4 69*86d7f5d3SJohn Marino.Sh HISTORY 70*86d7f5d3SJohn MarinoThe 71*86d7f5d3SJohn Marino.Nm 72*86d7f5d3SJohn Marinomanual page first appeared in 73*86d7f5d3SJohn Marino.Fx 3.0 . 74*86d7f5d3SJohn Marino.Sh AUTHORS 75*86d7f5d3SJohn MarinoThis 76*86d7f5d3SJohn Marinomanual page was written by 77*86d7f5d3SJohn Marino.An Nicolas Souchu . 78