66 lines
1.8 KiB
ReStructuredText
66 lines
1.8 KiB
ReStructuredText
.. Permission is granted to copy, distribute and/or modify this
|
|
.. document under the terms of the GNU Free Documentation License,
|
|
.. Version 1.1 or any later version published by the Free Software
|
|
.. Foundation, with no Invariant Sections, no Front-Cover Texts
|
|
.. and no Back-Cover Texts. A copy of the license is included at
|
|
.. Documentation/media/uapi/fdl-appendix.rst.
|
|
..
|
|
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
|
|
|
|
.. _FE_SET_TONE:
|
|
|
|
*****************
|
|
ioctl FE_SET_TONE
|
|
*****************
|
|
|
|
Name
|
|
====
|
|
|
|
FE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone.
|
|
|
|
|
|
Synopsis
|
|
========
|
|
|
|
.. c:function:: int ioctl( int fd, FE_SET_TONE, enum fe_sec_tone_mode tone )
|
|
:name: FE_SET_TONE
|
|
|
|
|
|
Arguments
|
|
=========
|
|
|
|
``fd``
|
|
File descriptor returned by :ref:`open() <frontend_f_open>`.
|
|
|
|
``tone``
|
|
an integer enumered value described at :c:type:`fe_sec_tone_mode`
|
|
|
|
|
|
Description
|
|
===========
|
|
|
|
This ioctl is used to set the generation of the continuous 22kHz tone.
|
|
This call requires read/write permissions.
|
|
|
|
Usually, satellite antenna subsystems require that the digital TV device
|
|
to send a 22kHz tone in order to select between high/low band on some
|
|
dual-band LNBf. It is also used to send signals to DiSEqC equipment, but
|
|
this is done using the DiSEqC ioctls.
|
|
|
|
.. attention:: If more than one device is connected to the same antenna,
|
|
setting a tone may interfere on other devices, as they may lose the
|
|
capability of selecting the band. So, it is recommended that applications
|
|
would change to SEC_TONE_OFF when the device is not used.
|
|
|
|
|
|
Return Value
|
|
============
|
|
|
|
On success 0 is returned.
|
|
|
|
On error -1 is returned, and the ``errno`` variable is set
|
|
appropriately.
|
|
|
|
Generic error codes are described at the
|
|
:ref:`Generic Error Codes <gen-errors>` chapter.
|