2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-23 12:43:55 +08:00
linux-next/Documentation/media/uapi/dvb/fe-read-snr.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

62 lines
997 B
ReStructuredText

.. -*- coding: utf-8; mode: rst -*-
.. _FE_READ_SNR:
***********
FE_READ_SNR
***********
Name
====
FE_READ_SNR
Synopsis
========
.. cpp:function:: int ioctl(int fd, int request = FE_READ_SNR, int16_t *snr)
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_SNR` for this command.
- .. row 3
- uint16_t \*snr
- The signal-to-noise ratio is stored into \*snr.
Description
===========
This ioctl call returns the signal-to-noise ratio 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.