SENSOR_ATTACH(9) FreeBSD Kernel Developer's Manual SENSOR_ATTACH(9)
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
sysctl(8), autoconf(9)
HISTORY
The sensor framework was written by Alexander Yurchenko
<
[email protected]> and first appeared in OpenBSD 3.4. David Gwynne
<
[email protected]> later extended it for OpenBSD 3.8. Constantine A.
Murenin <
[email protected]> extended it even further by
introducing the concept of sensor devices in OpenBSD 4.1.
FreeBSD 14.1-RELEASE-p8 September 14, 2015 FreeBSD 14.1-RELEASE-p8