1.. Permission is granted to copy, distribute and/or modify this
2.. document under the terms of the GNU Free Documentation License,
3.. Version 1.1 or any later version published by the Free Software
4.. Foundation, with no Invariant Sections, no Front-Cover Texts
5.. and no Back-Cover Texts. A copy of the license is included at
6.. Documentation/userspace-api/media/fdl-appendix.rst.
7..
8.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
9
10.. _FE_GET_PROPERTY:
11
12**************************************
13ioctl FE_SET_PROPERTY, FE_GET_PROPERTY
14**************************************
15
16Name
17====
18
19FE_SET_PROPERTY - FE_GET_PROPERTY - FE_SET_PROPERTY sets one or more frontend properties. - FE_GET_PROPERTY returns one or more frontend properties.
20
21
22Synopsis
23========
24
25.. c:function:: int ioctl( int fd, FE_GET_PROPERTY, struct dtv_properties *argp )
26    :name: FE_GET_PROPERTY
27
28.. c:function:: int ioctl( int fd, FE_SET_PROPERTY, struct dtv_properties *argp )
29    :name: FE_SET_PROPERTY
30
31
32Arguments
33=========
34
35``fd``
36    File descriptor returned by :ref:`open() <frontend_f_open>`.
37
38``argp``
39    Pointer to struct :c:type:`dtv_properties`.
40
41
42Description
43===========
44
45All Digital TV frontend devices support the ``FE_SET_PROPERTY`` and
46``FE_GET_PROPERTY`` ioctls. The supported properties and statistics
47depends on the delivery system and on the device:
48
49-  ``FE_SET_PROPERTY:``
50
51   -  This ioctl is used to set one or more frontend properties.
52
53   -  This is the basic command to request the frontend to tune into
54      some frequency and to start decoding the digital TV signal.
55
56   -  This call requires read/write access to the device.
57
58.. note::
59
60   At return, the values aren't updated to reflect the actual
61   parameters used. If the actual parameters are needed, an explicit
62   call to ``FE_GET_PROPERTY`` is needed.
63
64-  ``FE_GET_PROPERTY:``
65
66   -  This ioctl is used to get properties and statistics from the
67      frontend.
68
69   -  No properties are changed, and statistics aren't reset.
70
71   -  This call only requires read-only access to the device.
72
73
74Return Value
75============
76
77On success 0 is returned.
78
79On error -1 is returned, and the ``errno`` variable is set
80appropriately.
81
82Generic error codes are described at the
83:ref:`Generic Error Codes <gen-errors>` chapter.
84