xref: /linux/Documentation/userspace-api/media/dvb/fe-get-info.rst (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: DTV.fe
3
4.. _FE_GET_INFO:
5
6*****************
7ioctl FE_GET_INFO
8*****************
9
10Name
11====
12
13FE_GET_INFO - Query Digital TV frontend capabilities and returns information
14about the - front-end. This call only requires read-only access to the device.
15
16Synopsis
17========
18
19.. c:macro:: FE_GET_INFO
20
21``int ioctl(int fd, FE_GET_INFO, struct dvb_frontend_info *argp)``
22
23Arguments
24=========
25
26``fd``
27    File descriptor returned by :c:func:`open()`.
28
29``argp``
30    pointer to struct :c:type:`dvb_frontend_info`
31
32Description
33===========
34
35All Digital TV frontend devices support the :ref:`FE_GET_INFO` ioctl. It is
36used to identify kernel devices compatible with this specification and to
37obtain information about driver and hardware capabilities. The ioctl
38takes a pointer to dvb_frontend_info which is filled by the driver.
39When the driver is not compatible with this specification the ioctl
40returns an error.
41
42frontend capabilities
43=====================
44
45Capabilities describe what a frontend can do. Some capabilities are
46supported only on some specific frontend types.
47
48The frontend capabilities are described at :c:type:`fe_caps`.
49
50Return Value
51============
52
53On success 0 is returned.
54
55On error -1 is returned, and the ``errno`` variable is set
56appropriately.
57
58Generic error codes are described at the
59:ref:`Generic Error Codes <gen-errors>` chapter.
60