0001 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
0002 .. c:namespace:: DTV.fe
0003
0004 .. _FE_GET_PROPERTY:
0005
0006 **************************************
0007 ioctl FE_SET_PROPERTY, FE_GET_PROPERTY
0008 **************************************
0009
0010 Name
0011 ====
0012
0013 FE_SET_PROPERTY - FE_GET_PROPERTY - FE_SET_PROPERTY sets one or more frontend properties. - FE_GET_PROPERTY returns one or more frontend properties.
0014
0015 Synopsis
0016 ========
0017
0018 .. c:macro:: FE_GET_PROPERTY
0019
0020 ``int ioctl(int fd, FE_GET_PROPERTY, struct dtv_properties *argp)``
0021
0022 .. c:macro:: FE_SET_PROPERTY
0023
0024 ``int ioctl(int fd, FE_SET_PROPERTY, struct dtv_properties *argp)``
0025
0026 Arguments
0027 =========
0028
0029 ``fd``
0030 File descriptor returned by :c:func:`open()`.
0031
0032 ``argp``
0033 Pointer to struct :c:type:`dtv_properties`.
0034
0035 Description
0036 ===========
0037
0038 All Digital TV frontend devices support the ``FE_SET_PROPERTY`` and
0039 ``FE_GET_PROPERTY`` ioctls. The supported properties and statistics
0040 depends on the delivery system and on the device:
0041
0042 - ``FE_SET_PROPERTY:``
0043
0044 - This ioctl is used to set one or more frontend properties.
0045
0046 - This is the basic command to request the frontend to tune into
0047 some frequency and to start decoding the digital TV signal.
0048
0049 - This call requires read/write access to the device.
0050
0051 .. note::
0052
0053 At return, the values aren't updated to reflect the actual
0054 parameters used. If the actual parameters are needed, an explicit
0055 call to ``FE_GET_PROPERTY`` is needed.
0056
0057 - ``FE_GET_PROPERTY:``
0058
0059 - This ioctl is used to get properties and statistics from the
0060 frontend.
0061
0062 - No properties are changed, and statistics aren't reset.
0063
0064 - This call only requires read-only access to the device.
0065
0066 Return Value
0067 ============
0068
0069 On success 0 is returned.
0070
0071 On error -1 is returned, and the ``errno`` variable is set
0072 appropriately.
0073
0074 Generic error codes are described at the
0075 :ref:`Generic Error Codes <gen-errors>` chapter.
