.\"	$OpenBSD: viapm.4,v 1.12 2018/07/05 10:09:11 fcambus Exp $
.\"
.\" Copyright (c) 2006 Mark Kettenis <kettenis@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: July 5 2018 $
.Dt VIAPM 4
.Os
.Sh NAME
.Nm viapm
.Nd VIA SMBus controller and VIA VT82C686A/VT8231 hardware monitor
.Sh SYNOPSIS
.Cd "viapm* at pci?"
.Cd "iic* at viapm?"
.Sh DESCRIPTION
The
.Nm
driver provides support for the bus control and power management
component of the VIA VT82C596, VT82C596B, VT82C686A, VT8231, VT8233,
VT8233A, VT8235, VT8237, VT8237A, VT8237S, VT8251, CX700, VX800,
VX855 and VX900 South Bridges.
Only the SMBus host interface is supported and can be used with the
.Xr iic 4
framework.
.Pp
The
.Nm
driver provides support for the hardware monitor in the VIA VT82C686A
and VT8231 South Bridges.
The hardware monitor is used with the
.Xr sysctl 8
interface.
.Pp
The device has 10 sensors:
.Bl -column "Sensor" "Units" "Typical" -offset indent
.It Sy "Sensor" Ta Sy "Units" Ta Sy "Typical Use"
.It Li "TSENS1" Ta "uK" Ta "CPU temperature"
.It Li "TSENS2" Ta "uK" Ta "System temperature"
.It Li "TSENS3" Ta "uK" Ta "Unknown"
.It Li "FAN1" Ta "RPM" Ta "CPU fan"
.It Li "FAN2" Ta "RPM" Ta "System fan"
.It Li "VSENS1" Ta "uV DC" Ta "CPU core voltage (2.0V)"
.It Li "VSENS2" Ta "uV DC" Ta "North Bridge core voltage (2.5V)"
.It Li "Vcore" Ta "uV DC" Ta "Internal core voltage (3.3V)"
.It Li "VSENS3" Ta "uV DC" Ta "+5V"
.It Li "VSENS4" Ta "uV DC" Ta "+12V"
.El
.Pp
Sensor data is updated every 1.5 seconds.
.Sh SEE ALSO
.Xr iic 4 ,
.Xr intro 4 ,
.Xr pci 4 ,
.Xr sensorsd 8 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 3.9 .
.Pp
The
.Nm viaenv
driver first appeared in
.Nx 1.5 .
.Ox
support was added in
.Ox 3.4 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Mark Kettenis Aq Mt kettenis@openbsd.org .
.Pp
The
.Nm viaenv
driver was written by
.An Johan Danielsson
and ported to
.Ox 3.4
by
.An Alexander Yurchenko Aq Mt grange@openbsd.org .
It was merged with
.Nm
in
.Ox 5.0 .
.Sh BUGS
The driver doesn't support commands with a data buffer size of more
than 2 bytes.
.Pp
Interrupt support is unimplemented, as is support for setting values.