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 sensor 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-maintained 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 performs 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 following 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 and state can be manually updated by modifying the sysctl(8) variables “hw.swsensor.cur_value” and “hw.swsensor.state” variables respectively.

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.