SWSENSOR(4)             NetBSD Kernel Interfaces Manual            SWSENSOR(4)

NAME
     swsensor -- software environmental sensor

SYNOPSIS
     pseudo-device swsensor

DESCRIPTION
     The swsensor driver provides a software environmental sensor that works
     with sysctl(8) and envstat(8).  The driver is intended to be loaded as a
     kernel module.  One can, however, include the swsensor driver directly in
     a kernel using the configuration from the synopsis.  By default, the sen-
     sor is of type ENVSYS_UNITS_INTEGER.

     The following values can be specified in the modload(8) command when
     loading the swsensor module to alter the driver's behavior.

     Variable Usage

     mode        Controls whether or not swsensor provides internally-main-
                 tained limits and limit checking

                 Value Meaning

                 0      sensor has no internally-maintained limits

                 1      sensor provides its own internal limit value

                 2      sensor maintains an internal adjustable limit and per-
                        forms its own comparison between the sensor's limit
                        and its current value

     limit       The initial alarm limit value, if limit emulation is selected
                 (i.e., if mode is set to 1 or 2)

     value_max

     value_min   The maximum and minimum values.  The corresponding
                 ENVSYS_FVALID_MAX and ENVSYS_FVALID_MIN flags are implicitly
                 set.

     percentage  This boolean value controls the setting of the
                 ENVSYS_FPERCENT flag.

     type        Define the sensor's unit/type.  By default, a Temperature
                 sensor is created.  Any of the string values from the follow-
                 ing table can be specified:

                 Temperature         Fan               Voltage AC
                 Voltage DC          Ohms              Watts
                 Ampere              Watt hour         Ampere hour
                 Indicator           Integer           Drive
                 Battery capacity    Battery charge
                 (Values are case-sensitive, and spaces must be included.)

     value       Provide an initial value for the sensor.  If this is omitted,
                 the sensor's initial value is set to zero.

     For example,
           modload -s type=Voltage\ DC swsensor
     will create a sensor of type ENVSYS_UNITS_SVOLTS_DC, while
           modload -i mode=1 -i limit=50 swsensor
     will create a sensor which has an initial, device-provided limit of 50.

     The sensor's raw value can be manually updated by modifying the sysctl(8)
     variable ``hw.swsensor.cur_value''.

SEE ALSO
     modctl(2), envstat(8), sysctl(8)

HISTORY
     The swsensor driver was written by Paul Goyette and first appeared in
     NetBSD 6.0.

BUGS
     The swsensor driver emulates a device with only a single sensor.

     The swsensor driver can only emulate one hardware-managed limit; this is
     assumed to be the critical-min limit.

NetBSD 5.0                       June 19, 2011                      NetBSD 5.0