@@ -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 @@
 .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 @@
 .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 @@
 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 @@
 .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 @@
 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 @@
 .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 @@
 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 @@
 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 @@
    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 @@
 }
 .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 @@
 .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
+programmed quite differently.
-this chip are not currently implemented.
+The fan controllers and sensor limits on this chip are not currently
+implemented.