18c2ecf20Sopenharmony_ci.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 28c2ecf20Sopenharmony_ci.. c:namespace:: DTV.fe 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_ci.. _FE_SET_TONE: 58c2ecf20Sopenharmony_ci 68c2ecf20Sopenharmony_ci***************** 78c2ecf20Sopenharmony_ciioctl FE_SET_TONE 88c2ecf20Sopenharmony_ci***************** 98c2ecf20Sopenharmony_ci 108c2ecf20Sopenharmony_ciName 118c2ecf20Sopenharmony_ci==== 128c2ecf20Sopenharmony_ci 138c2ecf20Sopenharmony_ciFE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone. 148c2ecf20Sopenharmony_ci 158c2ecf20Sopenharmony_ciSynopsis 168c2ecf20Sopenharmony_ci======== 178c2ecf20Sopenharmony_ci 188c2ecf20Sopenharmony_ci.. c:macro:: FE_SET_TONE 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci``int ioctl(int fd, FE_SET_TONE, enum fe_sec_tone_mode tone)`` 218c2ecf20Sopenharmony_ci 228c2ecf20Sopenharmony_ciArguments 238c2ecf20Sopenharmony_ci========= 248c2ecf20Sopenharmony_ci 258c2ecf20Sopenharmony_ci``fd`` 268c2ecf20Sopenharmony_ci File descriptor returned by :c:func:`open()`. 278c2ecf20Sopenharmony_ci 288c2ecf20Sopenharmony_ci``tone`` 298c2ecf20Sopenharmony_ci an integer enumered value described at :c:type:`fe_sec_tone_mode` 308c2ecf20Sopenharmony_ci 318c2ecf20Sopenharmony_ciDescription 328c2ecf20Sopenharmony_ci=========== 338c2ecf20Sopenharmony_ci 348c2ecf20Sopenharmony_ciThis ioctl is used to set the generation of the continuous 22kHz tone. 358c2ecf20Sopenharmony_ciThis call requires read/write permissions. 368c2ecf20Sopenharmony_ci 378c2ecf20Sopenharmony_ciUsually, satellite antenna subsystems require that the digital TV device 388c2ecf20Sopenharmony_cito send a 22kHz tone in order to select between high/low band on some 398c2ecf20Sopenharmony_cidual-band LNBf. It is also used to send signals to DiSEqC equipment, but 408c2ecf20Sopenharmony_cithis is done using the DiSEqC ioctls. 418c2ecf20Sopenharmony_ci 428c2ecf20Sopenharmony_ci.. attention:: If more than one device is connected to the same antenna, 438c2ecf20Sopenharmony_ci setting a tone may interfere on other devices, as they may lose the 448c2ecf20Sopenharmony_ci capability of selecting the band. So, it is recommended that applications 458c2ecf20Sopenharmony_ci would change to SEC_TONE_OFF when the device is not used. 468c2ecf20Sopenharmony_ci 478c2ecf20Sopenharmony_ciReturn Value 488c2ecf20Sopenharmony_ci============ 498c2ecf20Sopenharmony_ci 508c2ecf20Sopenharmony_ciOn success 0 is returned. 518c2ecf20Sopenharmony_ci 528c2ecf20Sopenharmony_ciOn error -1 is returned, and the ``errno`` variable is set 538c2ecf20Sopenharmony_ciappropriately. 548c2ecf20Sopenharmony_ci 558c2ecf20Sopenharmony_ciGeneric error codes are described at the 568c2ecf20Sopenharmony_ci:ref:`Generic Error Codes <gen-errors>` chapter. 57