VIAPM(4) - Device Drivers Manual #

VIAPM(4) - Device Drivers Manual

NAME #

viapm - VIA SMBus controller and VIA VT82C686A/VT8231 hardware monitor

SYNOPSIS #

viapm* at pci? iic* at viapm?

DESCRIPTION #

The viapm 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 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.

SEE ALSO #

iic(4), intro(4), pci(4), sensorsd(8), sysctl(8)

HISTORY #

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.

AUTHORS #

The viapm driver was written by Mark Kettenis <kettenis@openbsd.org>.

The viaenv driver was written by Johan Danielsson and ported to OpenBSD 3.4 by Alexander Yurchenko <grange@openbsd.org>. It was merged with viapm in OpenBSD 5.0.

BUGS #

The driver doesn’t support commands with a data buffer size of more than 2 bytes.

Interrupt support is unimplemented, as is support for setting values.

OpenBSD 7.5 - July 5, 2018