diff --git a/share/man/man4/dbcool.4 b/share/man/man4/dbcool.4 index 80997e3a54c2..516bd3c7b423 100644 --- a/share/man/man4/dbcool.4 +++ b/share/man/man4/dbcool.4 @@ -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.