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60c2820d0f
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>
62 lines
997 B
ReStructuredText
62 lines
997 B
ReStructuredText
.. -*- coding: utf-8; mode: rst -*-
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.. _FE_READ_SNR:
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***********
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FE_READ_SNR
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***********
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Name
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====
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FE_READ_SNR
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Synopsis
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========
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.. cpp:function:: int ioctl(int fd, int request = FE_READ_SNR, int16_t *snr)
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Arguments
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=========
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.. flat-table::
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:header-rows: 0
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:stub-columns: 0
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- .. row 1
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- int fd
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- File descriptor returned by a previous call to open().
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- .. row 2
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- int request
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- Equals :ref:`FE_READ_SNR` for this command.
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- .. row 3
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- uint16_t \*snr
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- The signal-to-noise ratio is stored into \*snr.
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Description
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===========
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This ioctl call returns the signal-to-noise ratio for the signal
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currently received by the front-end. For this command, read-only access
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to the device is sufficient.
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Return Value
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============
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On success 0 is returned, on error -1 and the ``errno`` variable is set
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appropriately. The generic error codes are described at the
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:ref:`Generic Error Codes <gen-errors>` chapter.
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