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diff --git a/Documentation/media/uapi/dvb/fe-set-tone.rst b/Documentation/media/uapi/dvb/fe-set-tone.rst new file mode 100644 index 000000000..758efa110 --- /dev/null +++ b/Documentation/media/uapi/dvb/fe-set-tone.rst @@ -0,0 +1,58 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _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. |