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Linux kernel mirror (for testing)
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linux
1.. -*- coding: utf-8; mode: rst -*-
2
3.. _FE_SET_TONE:
4
5*****************
6ioctl FE_SET_TONE
7*****************
8
9Name
10====
11
12FE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone.
13
14
15Synopsis
16========
17
18.. c:function:: int ioctl( int fd, FE_SET_TONE, enum fe_sec_tone_mode tone )
19 :name: FE_SET_TONE
20
21
22Arguments
23=========
24
25``fd``
26 File descriptor returned by :ref:`open() <frontend_f_open>`.
27
28``tone``
29 an integer enumered value described at :c:type:`fe_sec_tone_mode`
30
31
32Description
33===========
34
35This ioctl is used to set the generation of the continuous 22kHz tone.
36This call requires read/write permissions.
37
38Usually, satellite antenna subsystems require that the digital TV device
39to send a 22kHz tone in order to select between high/low band on some
40dual-band LNBf. It is also used to send signals to DiSEqC equipment, but
41this is done using the DiSEqC ioctls.
42
43.. attention:: If more than one device is connected to the same antenna,
44 setting a tone may interfere on other devices, as they may lose the
45 capability of selecting the band. So, it is recommended that applications
46 would change to SEC_TONE_OFF when the device is not used.
47
48.. c:type:: fe_sec_tone_mode
49
50.. flat-table:: enum fe_sec_tone_mode
51 :header-rows: 1
52 :stub-columns: 0
53
54
55 - .. row 1
56
57 - ID
58
59 - Description
60
61 - .. row 2
62
63 - .. _SEC-TONE-ON:
64
65 ``SEC_TONE_ON``
66
67 - Sends a 22kHz tone burst to the antenna
68
69 - .. row 3
70
71 - .. _SEC-TONE-OFF:
72
73 ``SEC_TONE_OFF``
74
75 - Don't send a 22kHz tone to the antenna (except if the
76 FE_DISEQC_* ioctls are called)
77
78
79Return Value
80============
81
82On success 0 is returned, on error -1 and the ``errno`` variable is set
83appropriately. The generic error codes are described at the
84:ref:`Generic Error Codes <gen-errors>` chapter.