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Whitespace changes (including new sentence, new line). 

Uppercase Dt argument.
Use more macros.
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wiz 2008-10-02 07:55:26 +00:00
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share/man/man4/dbcool.4
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@ -1,4 +1,4 @@
.\" $NetBSD: dbcool.4,v 1.1 2008/10/02 00:47:51 pgoyette Exp $
.\" $NetBSD: dbcool.4,v 1.2 2008/10/02 07:55:26 wiz Exp $
.\"
.\" Copyright (c) 2008 The NetBSD Foundation, Inc.
.\" All rights reserved.
@ -28,7 +28,7 @@
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd September 28, 2008
.Dt dbCool 4
.Dt DBCOOL 4
.Os
.Sh NAME
.Nm dbcool ,
@ -53,8 +53,8 @@ dbCool environmental monitor chips to be used with the
.Xr envsys 4
API.
.Pp
These chips support up to twelve sensors. Not all of the following sensors
are supported on all chips.
These chips support up to twelve sensors.
Not all of the following sensors are supported on all chips.
.Bl -column "Sensor" "Units" "Typical" -offset indent
.It Sy "Sensor" Ta Sy "Units" Ta Sy "Typical Use"
.It Li "l_temp" Ta "uK" Ta "local chip temperature"
@ -74,8 +74,8 @@ are supported on all chips.
.El
.Pp
Except on the ADT7466, each temperature and voltage sensor has a
programmable high- and low-limit; fan sensors have only a low-limit. The
user can set the threshold values using
programmable high- and low-limit; fan sensors have only a low-limit.
The user can set the threshold values using
.Xr sysctl 8
.Bd -literal -offset indent
hw.dbcool0.l_temp.low_lim = 35 degrees C
@ -91,27 +91,30 @@ Temperature sensors also have
and
.Em Ttherm
.Xr sysctl 8
variables; these values are used by the fan speed controllers.
variables; these values are used by the fan speed controllers.
.Pp
All
.Xr sysctl 8
variables associated with temperature sensors are in units of degC, since
this is the unit which is programmed into the device registers. Limit
values for voltage sensors are in millivolts. The low limit value for
fan sensors is measured in RPM; due to the manner in which fan speed is
measured, the lowest possible value for a fan limit is 83 RPM.
this is the unit which is programmed into the device registers.
Limit values for voltage sensors are in millivolts.
The low limit value for fan sensors is measured in RPM; due to
the manner in which fan speed is measured, the lowest possible
value for a fan limit is 83 RPM.
.Pp
All members of the dbCool family support Pulse-Width Modulated (PWM)
fan speed control based on temperature thresholds - the fan will spin up
when one or more thermal sensors exceeds its configured
when one or more thermal sensors exceeds its configured
.Em Tmin
value. The fan will go faster as the temperature rises, and will slow
down as the temperature falls. If the temperature exceeds the sensor's
value.
The fan will go faster as the temperature rises, and will slow down
as the temperature falls.
If the temperature exceeds the sensor's
.Em Ttherm
value, the THERM signal will be asserted, and if enabled the fan will
run at full speed. The fan will be turned
off when the sensor(s) that triggered it reports a temperature which is
at least
run at full speed.
The fan will be turned off when the sensor(s) that triggered it
reports a temperature which is at least
.Em Thyst
degrees below its
.Em Tmin
@ -129,13 +132,14 @@ hw.dbcool0.fan_ctl_0.cur_duty
.Ed
(On the ADM1030, the
.Em range
variable is associated with each individual temperature sensor rather
variable is associated with each individual temperature sensor rather
than with the fan controller.)
.Pp
The
The
.Em behavior
variable controls the selection of temperature sensors associated with
the fan controller. When the associated temperature sensor reaches its
the fan controller.
When the associated temperature sensor reaches its
.Em Tmin
value, the fan controller starts the fan at its minimum duty cycle;
when the associated temperature sensor reaches its
@ -145,16 +149,18 @@ asserted), the fan controller sets the fan speed to a 100% duty cycle.
Between these two settings, each temperature sensor is used to calculate
a duty cycle linearly based on the slope defined by the temperature sensor's
.Em range
variable. When the associated temperature falls at least
variable.
When the associated temperature falls at least
.Em Thyst
degress below its
.Em Tmin
value, the fan controller will turn off the fan. (On the ADM1030, the
value, the fan controller will turn off the fan.
(On the ADM1030, the
value for
.Em Thyst
is fixed at 5 degrees C.)
.Pp
Valid values for the
Valid values for the
.Em behavior
variable are:
.Bd -literal -offset indent
@ -170,10 +176,13 @@ disabled
.Pp
When the
.Em behavior
variable is set to "manual", the
variable is set to
.Dq manual ,
the
.Em cur-duty
variable becomes user-writeable and can be set to any value between 0 and
100 inclusive to control the fan's duty cycle manually. In all other
100 inclusive to control the fan's duty cycle manually.
In all other
.Em behavior
modes, the
.Em cur-duty
@ -184,8 +193,9 @@ The
and
.Em max-duty
variables define the range over which the fan controller will manage the
fan's duty cycle. On the ADM1030, these values are not separately
controllable. The
fan's duty cycle.
On the ADM1030, these values are not separately controllable.
The
.Em max-duty
is fixed at 100%, and the
.Em cur-duty
@ -193,10 +203,12 @@ variable is used to specify the minimum duty cycle when the fan
controller is running in automatic mode.
.Pp
Note that the duty-cycle value does not directly correspond to the fan's
speed. That is, a 33% duty cycle does not mean that the fan runs at 33%
of its maximum speed; in actuality, a 33% duty cycle drives the fan at
a speed close to 50% of its maximum. Fan speed correlates approximately
to the square root of the duty cycle.
speed.
That is, a 33% duty cycle does not mean that the fan runs at 33%
of its maximum speed; in actuality, a 33% duty cycle drives the
fan at a speed close to 50% of its maximum.
Fan speed correlates approximately to the square root of the duty
cycle.
.Sh EXAMPLES
The
.Xr envstat 8
@ -214,9 +226,10 @@ r2_temp: N/A
fan4: N/A
.Ed
.Pp
Using this information, the following commands in /etc/envsys.conf will
set appropriate limits for CPU temperature and chip supply voltage, and
powerd will be notified if the limits are exceeded:
Using this information, the following commands in
.Pa /etc/envsys.conf
will set appropriate limits for CPU temperature and chip supply
voltage, and powerd will be notified if the limits are exceeded:
.Bd -literal -offset indent
dbcool0 {
sensor0 {
@ -231,8 +244,9 @@ dbcool0 {
}
.Ed
.Pp
Alternatively, set the following commands in /etc/sysctl.conf to perform
limit checking in the hardware:
Alternatively, set the following commands in
.Pa /etc/sysctl.conf
to perform limit checking in the hardware:
.Bd -literal -offset indent
hw.dbcool0.l_temp.hi_lim = 65
hw.dbcool0.Vcc.low_lim = 3200
@ -251,9 +265,11 @@ device appeared in
.Sh BUGS
Although the sensor limit registers can be programmed, there is currently
no use of the dbCool chips' ability to generate an SMBus interrupt when the
limits are exceeded. Limit checking is only performed when the sensor
values are polled and refreshed.
limits are exceeded.
Limit checking is only performed when the sensor values are polled
and refreshed.
.Pp
The ADT7466 chip, although officially a member of the dbCool family, is
programmed quite differently. The fan controllers and sensor limits on
this chip are not currently implemented.
programmed quite differently.
The fan controllers and sensor limits on this chip are not currently
implemented.