NAME
sensor_attach,
sensor_detach, sensor_find,
sensordev_install,
sensordev_deinstall,
sensordev_get,
sensor_task_register,
sensor_task_unregister —
sensors framework
SYNOPSIS
#include
<sys/sensors.h>
void
sensordev_install(struct
ksensordev *sensdev);
void
sensordev_deinstall(struct
ksensordev *sensdev);
struct ksensordev *
sensordev_get(int
devnum);
void
sensor_attach(struct
ksensordev *sensdev,
struct ksensor
*sens);
void
sensor_detach(struct
ksensordev *sensdev,
struct ksensor
*sens);
struct ksensor *
sensor_find(int
devnum, enum sensor_type
stype, int
numt);
struct sensor_task *
sensor_task_register(void
*arg, void (*func)(void
*), int
period);
void
sensor_task_unregister(struct
sensor_task *st);
DESCRIPTION
The sensors framework API provides a mechanism for manipulation of hardware sensors that are available under the hw.sensors sysctl(8) tree.
sensor_attach()
adds the sensor specified by the sens argument to the
sensor device specified by the sensdev argument.
sensor_detach()
can be used to remove sensors previously added by
sensor_attach().
sensordev_install()
registers the sensor device specified by the sensdev
argument so that all sensors that are attached to the device become
accessible via the sysctl interface.
sensordev_deinstall()
can be used to remove sensor devices previously registered by
sensordev_install().
sensordev_get()
takes ordinal number devnum specifying a sensor device
and returns a pointer to the corresponding struct
ksensordev, or NULL if no such sensor device
exists.
sensor_find()
takes ordinal number devnum specifying a sensor
device, sensor type stype and ordinal number of sensor
of such type numt, and returns a pointer to the
corresponding struct ksensor, or
NULL if no such sensor exists.
sensor_find() will always return
NULL if the corresponding sensor devices are not
registered by sensordev_install().
Drivers are responsible for retrieving, interpreting, and normalising sensor values and updating the sensor struct periodically. If the driver needs process context, for example to sleep, it can register a task with the sensor framework.
sensor_task_register()
is used to register a periodic task to update sensors. The
func argument is a pointer to the function to run with
an interval of period seconds. The
arg parameter is the argument given to the
func function.
sensor_task_unregister() ensures that the task
specified by the st argument is no longer running, and
then removes it from the queue.
All the functions in the sensor
framework must be called during
autoconf(9) or from a process context. Additionally,
sensor_task_unregister()
must not be called from the sensor task that it is about to remove.
SEE ALSO
HISTORY
The sensor framework was written by Alexander Yurchenko <grange@openbsd.org> and first appeared in OpenBSD 3.4. David Gwynne <dlg@openbsd.org> later extended it for OpenBSD 3.8. Constantine A. Murenin <cnst+openbsd@bugmail.mojo.ru> extended it even further by introducing the concept of sensor devices in OpenBSD 4.1.