diff options
Diffstat (limited to 'Documentation/media/uapi/dvb/fe-set-tone.rst')
-rw-r--r-- | Documentation/media/uapi/dvb/fe-set-tone.rst | 91 |
1 files changed, 91 insertions, 0 deletions
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 000000000000..545e2afba2c0 --- /dev/null +++ b/Documentation/media/uapi/dvb/fe-set-tone.rst @@ -0,0 +1,91 @@ +.. -*- 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 +======== + +.. cpp:function:: int ioctl( int fd, int request, enum fe_sec_tone_mode *tone ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <frontend_f_open>`. + +``request`` + FE_SET_TONE + +``tone`` + pointer to enum :ref:`fe_sec_tone_mode <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. + +.. _fe-sec-tone-mode-t: + +enum fe_sec_tone_mode +===================== + +.. _fe-sec-tone-mode: + +.. flat-table:: enum fe_sec_tone_mode + :header-rows: 1 + :stub-columns: 0 + + + - .. row 1 + + - ID + + - Description + + - .. row 2 + + - .. _SEC-TONE-ON: + + ``SEC_TONE_ON`` + + - Sends a 22kHz tone burst to the antenna + + - .. row 3 + + - .. _SEC-TONE-OFF: + + ``SEC_TONE_OFF`` + + - Don't send a 22kHz tone to the antenna (except if the + FE_DISEQC_* ioctls are called) + + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. |