.\"	$NetBSD: lm.4,v 1.38 2022/12/16 00:02:28 msaitoh Exp $
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.Dd December 15, 2022
.Dt LM 4
.Os
.Sh NAME
.Nm lm
.Nd National Semiconductor LM78, LM79 and compatible hardware monitors
.Sh SYNOPSIS
.Cd "lm0 at isa? port 0x280 flags 0x00"
.Cd "lm1 at isa? port 0x290 flags 0x00"
.Cd "lm2 at isa? port 0x310 flags 0x00"
.Cd "lm3 at isa? port 0xa00 flags 0x00"
.Cd "lm0 at pnpbios0 index ? flags 0x00"
.Cd "lm0 at iic? addr 0x2e flags 0x00"
.Cd "lm* at wbsio?"
.Sh DESCRIPTION
The
.Nm
driver provides support for the National Semiconductor
LM series hardware monitors and register compatible chips to be used with
the
.Xr envsys 4
API.
.Pp
The original LM78 hardware monitor supports 11 sensors:
.Bl -column "Sensor" "Units" "Typical" -offset indent
.It Sy "Sensor" Ta Sy "Units" Ta Sy "Typical Use"
.It Li "IN0" Ta "uV DC" Ta "Core voltage"
.It Li "IN1" Ta "uV DC" Ta "unknown"
.It Li "IN2" Ta "uV DC" Ta "+3.3V"
.It Li "IN3" Ta "uV DC" Ta "+5V"
.It Li "IN4" Ta "uV DC" Ta "+12V"
.It Li "IN5" Ta "uV DC" Ta "-12V"
.It Li "IN6" Ta "uV DC" Ta "-5V"
.It Li "Temp" Ta "uK" Ta "Motherboard Temperature"
.It Li "Fan0" Ta "RPM" Ta "Fan"
.It Li "Fan1" Ta "RPM" Ta "Chassis Fan"
.It Li "Fan2" Ta "RPM" Ta "Fan"
.El
For other devices, sensors' names and numbers will be different.
.Pp
Due to hardware limitations, fresh sensor data is only available every
2 seconds.
.Sh HARDWARE
Chips supported by the
.Nm
driver include:
.Bl -item -offset indent
.It
National Semiconductor
.Em LM78 ,
.Em LM78-J ,
.Em LM79 ,
and
.Em LM81 .
.It
Nuvoton
.Em NCT5104D ,
.Em NCT6775F ,
.Em NCT6776F ,
.Em NCT6102D ,
.Em NCT6104D ,
.Em NCT6106D ,
.Em NCT6779D
and
.Em NCT679[12356789]D .
.It
Winbond
.Em W83627HF* ,
.Em W83627THF* ,
.Em W83627EHF* ,
.Em W83627DHG* ,
.Em W83637HF* ,
.Em W83697HF* ,
.Em W83781D ,
.Em W83782D* ,
.Em W83783S* ,
.Em W83791D* ,
.Em W83791SD ,
and
.Em W83792D .
.It
ASUS
.Em AS99127F .
.El
.Pp
For most of the Winbond chips (identified with a * above), the
.Em flags
configuration option can be specified to select the type of temperature
sensor:
.Bl -column "flags" "Sensor Type" -offset indent
.It Sy "flags" Ta Sy "Sensor Type"
.It Li "0" Ta "Thermistor diode (Power-On default)"
.It Li "1" Ta "Pentium-II diode"
.It Li "2" Ta "2N3904 Bipolar"
.It Li "4" Ta "Thermistor diode"
.El
.Sh SEE ALSO
.Xr envsys 4 ,
.Xr wbsio 4 ,
.Xr envstat 8
.Sh HISTORY
The
.Nm
device appeared in
.Nx 1.5 .
.Sh CAVEATS
Some vendors connect these chips to non-standard thermal diodes and
resistors.
This will result in bogus sensor values.
.Sh BUGS
Interrupt support is unimplemented.
.Pp
There are currently no known pnpbios IDs assigned to LM chips.