SWSENSOR(4) BSD Kernel Interfaces Manual SWSENSOR(4)NAMEswsensor — software environmental sensor
SYNOPSIS
pseudo-device swsensorDESCRIPTION
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 and state can be manually updated by modifying the
sysctl(8) variables “hw.swsensor.cur_value” and “hw.swsensor.state” vari‐
ables respectively.
SEE ALSOmodctl(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.
BSD August 27, 2012 BSD
