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+.. 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/userspace-api/media/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.