OpenCloudOS-Kernel/Documentation/userspace-api/media/dvb/fe-get-info.rst

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.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: DTV.fe
.. _FE_GET_INFO:
*****************
ioctl FE_GET_INFO
*****************
Name
====
FE_GET_INFO - Query Digital TV frontend capabilities and returns information
about the - front-end. This call only requires read-only access to the device.
Synopsis
========
.. c:macro:: FE_GET_INFO
``int ioctl(int fd, FE_GET_INFO, struct dvb_frontend_info *argp)``
Arguments
=========
``fd``
File descriptor returned by :c:func:`open()`.
``argp``
pointer to struct :c:type:`dvb_frontend_info`
Description
===========
All Digital TV frontend devices support the :ref:`FE_GET_INFO` ioctl. It is
used to identify kernel devices compatible with this specification and to
obtain information about driver and hardware capabilities. The ioctl
takes a pointer to dvb_frontend_info which is filled by the driver.
When the driver is not compatible with this specification the ioctl
returns an error.
frontend capabilities
=====================
Capabilities describe what a frontend can do. Some capabilities are
supported only on some specific frontend types.
The frontend capabilities are described at :c:type:`fe_caps`.
Return Value
============
On success 0 is returned.
On error -1 is returned, and the ``errno`` variable is set
appropriately.
Generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.