xref: /OK3568_Linux_fs/kernel/Documentation/userspace-api/media/dvb/fe-get-info.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2*4882a593Smuzhiyun.. c:namespace:: DTV.fe
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun.. _FE_GET_INFO:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun*****************
7*4882a593Smuzhiyunioctl FE_GET_INFO
8*4882a593Smuzhiyun*****************
9*4882a593Smuzhiyun
10*4882a593SmuzhiyunName
11*4882a593Smuzhiyun====
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunFE_GET_INFO - Query Digital TV frontend capabilities and returns information
14*4882a593Smuzhiyunabout the - front-end. This call only requires read-only access to the device.
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunSynopsis
17*4882a593Smuzhiyun========
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun.. c:macro:: FE_GET_INFO
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun``int ioctl(int fd, FE_GET_INFO, struct dvb_frontend_info *argp)``
22*4882a593Smuzhiyun
23*4882a593SmuzhiyunArguments
24*4882a593Smuzhiyun=========
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun``fd``
27*4882a593Smuzhiyun    File descriptor returned by :c:func:`open()`.
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun``argp``
30*4882a593Smuzhiyun    pointer to struct :c:type:`dvb_frontend_info`
31*4882a593Smuzhiyun
32*4882a593SmuzhiyunDescription
33*4882a593Smuzhiyun===========
34*4882a593Smuzhiyun
35*4882a593SmuzhiyunAll Digital TV frontend devices support the :ref:`FE_GET_INFO` ioctl. It is
36*4882a593Smuzhiyunused to identify kernel devices compatible with this specification and to
37*4882a593Smuzhiyunobtain information about driver and hardware capabilities. The ioctl
38*4882a593Smuzhiyuntakes a pointer to dvb_frontend_info which is filled by the driver.
39*4882a593SmuzhiyunWhen the driver is not compatible with this specification the ioctl
40*4882a593Smuzhiyunreturns an error.
41*4882a593Smuzhiyun
42*4882a593Smuzhiyunfrontend capabilities
43*4882a593Smuzhiyun=====================
44*4882a593Smuzhiyun
45*4882a593SmuzhiyunCapabilities describe what a frontend can do. Some capabilities are
46*4882a593Smuzhiyunsupported only on some specific frontend types.
47*4882a593Smuzhiyun
48*4882a593SmuzhiyunThe frontend capabilities are described at :c:type:`fe_caps`.
49*4882a593Smuzhiyun
50*4882a593SmuzhiyunReturn Value
51*4882a593Smuzhiyun============
52*4882a593Smuzhiyun
53*4882a593SmuzhiyunOn success 0 is returned.
54*4882a593Smuzhiyun
55*4882a593SmuzhiyunOn error -1 is returned, and the ``errno`` variable is set
56*4882a593Smuzhiyunappropriately.
57*4882a593Smuzhiyun
58*4882a593SmuzhiyunGeneric error codes are described at the
59*4882a593Smuzhiyun:ref:`Generic Error Codes <gen-errors>` chapter.
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