LM(4) | Device Drivers Manual | LM(4) |
lm
— National
Semiconductor LM78/79/81 temperature, voltage, and fan sensor
lm0 at isa? port 0x290
lm1 at isa? port 0x280
lm2 at isa? port 0x310
lm* at iic?
lm* at wbsio?
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.
Chips supported by the lm
driver
include:
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).
The lm
driver first appeared in
NetBSD 1.5; OpenBSD support
was added in OpenBSD 3.4.
The lm
driver was written by
Bill Squier and ported to OpenBSD
3.4 by Alexander Yurchenko
<grange@openbsd.org>.
The driver was largely rewritten for OpenBSD 3.9 by
Mark Kettenis
<kettenis@openbsd.org>.
Some vendors connect these chips to non-standard thermal diodes and resistors. This will result in bogus sensor values.
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.
December 17, 2019 | OpenBSD-current |