xref: /linux/Documentation/userspace-api/media/dvb/fe-set-tone.rst (revision cbecf716ca618fd44feda6bd9a64a8179d031fc5)
1059b1c5bSMauro Carvalho Chehab.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2*f9b2e8aaSMauro Carvalho Chehab.. c:namespace:: DTV.fe
354f38fcaSMauro Carvalho Chehab
454f38fcaSMauro Carvalho Chehab.. _FE_SET_TONE:
554f38fcaSMauro Carvalho Chehab
654f38fcaSMauro Carvalho Chehab*****************
754f38fcaSMauro Carvalho Chehabioctl FE_SET_TONE
854f38fcaSMauro Carvalho Chehab*****************
954f38fcaSMauro Carvalho Chehab
1054f38fcaSMauro Carvalho ChehabName
1154f38fcaSMauro Carvalho Chehab====
1254f38fcaSMauro Carvalho Chehab
1354f38fcaSMauro Carvalho ChehabFE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone.
1454f38fcaSMauro Carvalho Chehab
1554f38fcaSMauro Carvalho ChehabSynopsis
1654f38fcaSMauro Carvalho Chehab========
1754f38fcaSMauro Carvalho Chehab
18*f9b2e8aaSMauro Carvalho Chehab.. c:macro:: FE_SET_TONE
1954f38fcaSMauro Carvalho Chehab
20*f9b2e8aaSMauro Carvalho Chehab``int ioctl(int fd, FE_SET_TONE, enum fe_sec_tone_mode tone)``
2154f38fcaSMauro Carvalho Chehab
2254f38fcaSMauro Carvalho ChehabArguments
2354f38fcaSMauro Carvalho Chehab=========
2454f38fcaSMauro Carvalho Chehab
2554f38fcaSMauro Carvalho Chehab``fd``
26*f9b2e8aaSMauro Carvalho Chehab    File descriptor returned by :c:func:`open()`.
2754f38fcaSMauro Carvalho Chehab
2854f38fcaSMauro Carvalho Chehab``tone``
2954f38fcaSMauro Carvalho Chehab    an integer enumered value described at :c:type:`fe_sec_tone_mode`
3054f38fcaSMauro Carvalho Chehab
3154f38fcaSMauro Carvalho ChehabDescription
3254f38fcaSMauro Carvalho Chehab===========
3354f38fcaSMauro Carvalho Chehab
3454f38fcaSMauro Carvalho ChehabThis ioctl is used to set the generation of the continuous 22kHz tone.
3554f38fcaSMauro Carvalho ChehabThis call requires read/write permissions.
3654f38fcaSMauro Carvalho Chehab
3754f38fcaSMauro Carvalho ChehabUsually, satellite antenna subsystems require that the digital TV device
3854f38fcaSMauro Carvalho Chehabto send a 22kHz tone in order to select between high/low band on some
3954f38fcaSMauro Carvalho Chehabdual-band LNBf. It is also used to send signals to DiSEqC equipment, but
4054f38fcaSMauro Carvalho Chehabthis is done using the DiSEqC ioctls.
4154f38fcaSMauro Carvalho Chehab
4254f38fcaSMauro Carvalho Chehab.. attention:: If more than one device is connected to the same antenna,
4354f38fcaSMauro Carvalho Chehab   setting a tone may interfere on other devices, as they may lose the
4454f38fcaSMauro Carvalho Chehab   capability of selecting the band. So, it is recommended that applications
4554f38fcaSMauro Carvalho Chehab   would change to SEC_TONE_OFF when the device is not used.
4654f38fcaSMauro Carvalho Chehab
4754f38fcaSMauro Carvalho ChehabReturn Value
4854f38fcaSMauro Carvalho Chehab============
4954f38fcaSMauro Carvalho Chehab
5054f38fcaSMauro Carvalho ChehabOn success 0 is returned.
5154f38fcaSMauro Carvalho Chehab
5254f38fcaSMauro Carvalho ChehabOn error -1 is returned, and the ``errno`` variable is set
5354f38fcaSMauro Carvalho Chehabappropriately.
5454f38fcaSMauro Carvalho Chehab
5554f38fcaSMauro Carvalho ChehabGeneric error codes are described at the
5654f38fcaSMauro Carvalho Chehab:ref:`Generic Error Codes <gen-errors>` chapter.
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