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.\" Copyright (c) 2020 Takanori Watanabe <takawata@freebsd.org>
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.Dd March 15, 2020
.Dt pchtherm 4
.Os
.Sh NAME
.Nm pchtherm
.Nd Intel PCH thermal subsystem
.Sh SYNOPSIS
.Cd "device pci"
.Cd "device pchtherm"
.Sh DESCRIPTION
The
.Nm
driver provides access to sensor data and configuration
installed in Intel PCH chipset.
.Nm
configuration register.
.Pp
The access to
.Nm
data is made via the
.Xr sysctl 8
interface:
.Bd -literal
dev.pchtherm.0.ctt: 115.0C
dev.pchtherm.0.temperature: 28.5C
dev.pchtherm.0.t2temp: 91.0C
dev.pchtherm.0.t1temp: 86.0C
dev.pchtherm.0.t0temp: 81.0C
dev.pchtherm.0.tahv: 83.0C
dev.pchtherm.0.talv: 30.0C
dev.pchtherm.0.pmtime: 32
dev.pchtherm.0.pmtemp: 50.0C
dev.pchtherm.0.%parent: pci0
dev.pchtherm.0.%pnpinfo: vendor=0x8086 device=0x9d31 subvendor=0x17aa subdevice=0x2256 class=0x118000
dev.pchtherm.0.%location: slot=20 function=2 dbsf=pci0:0:20:2
dev.pchtherm.0.%driver: pchtherm
dev.pchtherm.0.%desc: Skylake PCH Thermal Subsystem
dev.pchtherm.%parent:
.Ed
.Bl -tag -width ".Va dev.pchtherm.%d.pch_hot_level"
.It Va dev.pchtherm.%d.temperature
Is the read-only value of the current temperature read by the sensor.
.It Va dev.pchtherm.%d.ctt
When the system reaches this temperature, it will shut down.
This will not appear when this feature is disabled and locked down.
.It Va dev.pchtherm.%d.t0temp
When temperature is under this value, system will be in T0 state.
.It Va dev.pchtherm.%d.t1temp
When temperature is over
.Va t0temp
and under this value, system will be in T1 state.
.It Va dev.pchtherm.%d.t2temp
When temperature is over
.Va t1temp
and under this value, system will be in T2 state.
Over this value, system will be in T3 state.
.It Va dev.pchtherm.%d.talv
Lower alart value.
This will not appear when sensor enable bit is locked down and the value is zero(which will show -50.0C).
.It Va dev.pchtherm.%d.tahv
High alart value.
This will not appear when sensor enable bit is locked down and the value is zero(which will show -50.0C).
.It Va dev.pchtherm.%d.pmtemp
Sensor Power management temperature.
Under this temperature, sensor will idle during
.Va pmtime
second.
.It Va dev.pchtherm.%d.pmtime
Sensor idle duration when low temperature.
.It Va dev.pchtherm.%d.pch_hot_level
When temperature is higher than this value, PCHHOT# pin will assert.
This value is not appear when this feature is disabled and locked down.
.El
.Pp
Please check the PCH datasheets for more details.
.Pp
.Sh CAVEATS
All values are read-only.
And it do not support event interrupt for now.
.Sh SEE ALSO
.Xr sysctl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 13.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver and this manual page were written by
.An Takanori Watanabe Aq Mt takawata@FreeBSD.org .