LM(4)                     OpenBSD Programmer's Manual                    LM(4)

NAME
     lm - National Semiconductor LM78/79/81 temperature, voltage, and fan sen-
     sor

SYNOPSIS
     lm0 at isa? port 0x290
     lm1 at isa? port 0x280
     lm2 at isa? port 0x310
     lm* at iic?
     lm* at wbsio?

DESCRIPTION
     The lm driver provides support for the National Semiconductor LM78/79/81
     hardware monitors and register compatible chips to be used with the
     sysctl(8) interface.

     The original LM78 hardware monitor supports 11 sensors:

           Sensor    Units    Typical Use
           IN0       uV DC    Core voltage
           IN1       uV DC    Unknown
           IN2       uV DC    +3.3V
           IN3       uV DC    +5V
           IN4       uV DC    +12V
           IN5       uV DC    -12V
           IN6       uV DC    -5V
           Temp      uK       Motherboard Temperature
           Fan0      RPM      Fan
           Fan1      RPM      Chassis Fan
           Fan2      RPM      Fan

     For other devices, sensors' names and numbers will be different.

HARDWARE
     Chips supported by the lm driver include:

           -   National Semiconductor LM78 and LM78-J
           -   National Semiconductor LM79
           -   National Semiconductor LM81
           -   Winbond W83627HF, W83627THF, W83637HF and W83697HF
           -   Winbond W83627DHG and W83627EHF
           -   Winbond W83781D, W83782D and W83783S
           -   Winbond W83791D, W83791SD and W83792D
           -   ASUS AS99127F

     Some devices can attach to both iic(4) and isa(4); others can only attach
     to either one or the other.  If the lm driver detects a device attaching
     to both iic(4) and isa(4), it will detach the device from iic(4).

SEE ALSO
     iic(4), isa(4), wbsio(4), sensorsd(8), sysctl(8)

HISTORY
     The lm driver first appeared in NetBSD 1.5; OpenBSD support was added in
     OpenBSD 3.4.

AUTHORS
     The lm driver was written by Bill Squier and ported to OpenBSD 3.4 by
     Alexander Yurchenko <grange@openbsd.org>.  The driver was largely rewrit-
     ten for OpenBSD 3.9 by Mark Kettenis <kettenis@openbsd.org>.

CAVEATS
     Some vendors connect these chips to non-standard thermal diodes and re-
     sistors.  This will result in bogus sensor values.

BUGS
     Interrupt support is unimplemented.

     There are currently no known pnpbios IDs assigned to LM chips.

     This driver attaches to the Winbond W83791SD chip even though that chip
     does not have any sensors.

OpenBSD 4.7                      June 26, 2008                               2
