fe-get-property.rst (1877B)
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2.. c:namespace:: DTV.fe 3 4.. _FE_GET_PROPERTY: 5 6************************************** 7ioctl FE_SET_PROPERTY, FE_GET_PROPERTY 8************************************** 9 10Name 11==== 12 13FE_SET_PROPERTY - FE_GET_PROPERTY - FE_SET_PROPERTY sets one or more frontend properties. - FE_GET_PROPERTY returns one or more frontend properties. 14 15Synopsis 16======== 17 18.. c:macro:: FE_GET_PROPERTY 19 20``int ioctl(int fd, FE_GET_PROPERTY, struct dtv_properties *argp)`` 21 22.. c:macro:: FE_SET_PROPERTY 23 24``int ioctl(int fd, FE_SET_PROPERTY, struct dtv_properties *argp)`` 25 26Arguments 27========= 28 29``fd`` 30 File descriptor returned by :c:func:`open()`. 31 32``argp`` 33 Pointer to struct :c:type:`dtv_properties`. 34 35Description 36=========== 37 38All Digital TV frontend devices support the ``FE_SET_PROPERTY`` and 39``FE_GET_PROPERTY`` ioctls. The supported properties and statistics 40depends on the delivery system and on the device: 41 42- ``FE_SET_PROPERTY:`` 43 44 - This ioctl is used to set one or more frontend properties. 45 46 - This is the basic command to request the frontend to tune into 47 some frequency and to start decoding the digital TV signal. 48 49 - This call requires read/write access to the device. 50 51.. note:: 52 53 At return, the values aren't updated to reflect the actual 54 parameters used. If the actual parameters are needed, an explicit 55 call to ``FE_GET_PROPERTY`` is needed. 56 57- ``FE_GET_PROPERTY:`` 58 59 - This ioctl is used to get properties and statistics from the 60 frontend. 61 62 - No properties are changed, and statistics aren't reset. 63 64 - This call only requires read-only access to the device. 65 66Return Value 67============ 68 69On success 0 is returned. 70 71On error -1 is returned, and the ``errno`` variable is set 72appropriately. 73 74Generic error codes are described at the 75:ref:`Generic Error Codes <gen-errors>` chapter.