xref: /linux/Documentation/userspace-api/media/dvb/fe-read-status.rst (revision cbecf716ca618fd44feda6bd9a64a8179d031fc5)
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: DTV.fe
3
4.. _FE_READ_STATUS:
5
6********************
7ioctl FE_READ_STATUS
8********************
9
10Name
11====
12
13FE_READ_STATUS - Returns status information about the front-end. This call only requires - read-only access to the device
14
15Synopsis
16========
17
18.. c:macro:: FE_READ_STATUS
19
20``int ioctl(int fd, FE_READ_STATUS, unsigned int *status)``
21
22Arguments
23=========
24
25``fd``
26    File descriptor returned by :c:func:`open()`.
27
28``status``
29    pointer to a bitmask integer filled with the values defined by enum
30    :c:type:`fe_status`.
31
32Description
33===========
34
35All Digital TV frontend devices support the ``FE_READ_STATUS`` ioctl. It is
36used to check about the locking status of the frontend after being
37tuned. The ioctl takes a pointer to an integer where the status will be
38written.
39
40.. note::
41
42   The size of status is actually sizeof(enum fe_status), with
43   varies according with the architecture. This needs to be fixed in the
44   future.
45
46int fe_status
47=============
48
49The fe_status parameter is used to indicate the current state and/or
50state changes of the frontend hardware. It is produced using the enum
51:c:type:`fe_status` values on a bitmask
52
53Return Value
54============
55
56On success 0 is returned.
57
58On error -1 is returned, and the ``errno`` variable is set
59appropriately.
60
61Generic error codes are described at the
62:ref:`Generic Error Codes <gen-errors>` chapter.
63