VIAPM(4) BSD Kernel Interfaces Manual VIAPM(4)
viapm -- VIA SMBus controller and VIA VT82C686A/VT8231 hardware monitor
viapm* at pci?
iic* at viapm?
The viapm driver provides support for the bus control and power manage-
ment component of the VIA VT82C596, VT82C596B, VT82C686A, VT8231, VT8233,
VT8233A, VT8235, VT8237, VT8237A, VT8237S, VT8251, CX700, VX800 and VX855
South Bridges. Only the SMBus host interface is supported and can be
used with the iic(4) framework.
The viapm driver provides support for the hardware monitor in the VIA
VT82C686A and VT8231 South Bridges. The hardware monitor is used with
the sysctl(8) interface.
The device has 10 sensors:
Sensor Units Typical Use
TSENS1 uK CPU temperature
TSENS2 uK System temperature
TSENS3 uK Unknown
FAN1 RPM CPU fan
FAN2 RPM System fan
VSENS1 uV DC CPU core voltage (2.0V)
VSENS2 uV DC North Bridge core voltage (2.5V)
Vcore uV DC Internal core voltage (3.3V)
VSENS3 uV DC +5V
VSENS4 uV DC +12V
Sensor data is updated every 1.5 seconds.
iic(4), intro(4), pci(4), sensorsd(8), sysctl(8)
The viapm driver first appeared in OpenBSD 3.9.
The viaenv driver first appeared in NetBSD 1.5. OpenBSD support was
added in OpenBSD 3.4.
The viapm driver was written by Mark Kettenis <firstname.lastname@example.org>.
The viaenv driver was written by Johan Danielsson and ported to
OpenBSD 3.4 by Alexander Yurchenko <email@example.com>. It was merged
with viapm in OpenBSD 5.0.
The driver doesn't support commands with a data buffer size of more than
Interrupt support is unimplemented, as is support for setting values.
BSD July 16, 2013 BSD