linux/Documentation/media/uapi/dvb/fe-read-signal-strength.rst
Mauro Carvalho Chehab 60c2820d0f doc_rst: rename the media Sphinx suff to Documentation/media
The name of the subsystem is "media", and not "linux_tv". Also,
as we plan to add other stuff there in the future, let's
rename also the media uAPI book to media_uapi, to make it
clearer.

No functional changes.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 11:59:40 -03:00

64 lines
1.1 KiB
ReStructuredText

.. -*- coding: utf-8; mode: rst -*-
.. _FE_READ_SIGNAL_STRENGTH:
***********************
FE_READ_SIGNAL_STRENGTH
***********************
Name
====
FE_READ_SIGNAL_STRENGTH
Synopsis
========
.. cpp:function:: int ioctl( int fd, int request = FE_READ_SIGNAL_STRENGTH, uint16_t *strength)
Arguments
=========
.. flat-table::
:header-rows: 0
:stub-columns: 0
- .. row 1
- int fd
- File descriptor returned by a previous call to open().
- .. row 2
- int request
- Equals
:ref:`FE_READ_SIGNAL_STRENGTH`
for this command.
- .. row 3
- uint16_t \*strength
- The signal strength value is stored into \*strength.
Description
===========
This ioctl call returns the signal strength value for the signal
currently received by the front-end. For this command, read-only access
to the device is sufficient.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.