.\" Copyright (c) 2011 Henrik Brix Andersen <brix@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd May 15, 2011
.Dt GLXIIC 4 i386
.Os
.Sh NAME
.Nm glxiic
.Nd Geode LX CS5536 I2C controller driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device pci"
.Cd "device isa"
.Cd "device glxiic"
.Cd "device iicbus"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
glxiic_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver supports the System Management Bus controller of the Geode LX
series CS5536 Companion Device.  The Geode LX is a member of the AMD
Geode family of integrated x86 system chips.
.Pp
Although AMD refers to this device as a System Management Bus (SMBus)
controller, it is really an I2C controller (it lacks SMBus ALERT# and
Alert Response support).
.Pp
The
.Nm
driver supports both I2C master and slave mode.
.Sh SYSCTL VARIABLE
The
.Nm
driver supports the following variable as both
.Xr sysctl 8
and
.Xr loader 8
tunable:
.Bl -tag -width indent
.It Va dev.glxiic.0.timeout
This variable controls the I2C bus timeout in milliseconds.  The
default timeout is 35 milliseconds.  A value of zero disables the
timeout.
.El
.Sh CAVEAT
The
.Nm
driver uses the interrupt line number configured by the board firmware
by default.  If no interrupt line number has been configured by the
board firmware (or to override the interrupt line number configured by
board firmware), place the following line in
.Xr device.hints 5 :
.Bd -ragged -offset indent
hint.glxiic.0.irq="10"
.Ed
.Pp
The interrupt line number must be between 1 and 15.
.Sh SEE ALSO
.Xr iicbus 4 ,
.Xr device.hints 5 ,
.Xr loader.conf 5 ,
.Xr loader 8 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
device driver and manual page first appeared in
.Fx 9.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
device driver and manual page were written by
.An Henrik Brix Andersen Aq Mt brix@FreeBSD.org .