OpenCloudOS-Kernel/Documentation/userspace-api/media/dvb/fe-read-status.rst

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.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: DTV.fe
.. _FE_READ_STATUS:
********************
ioctl FE_READ_STATUS
********************
Name
====
FE_READ_STATUS - Returns status information about the front-end. This call only requires - read-only access to the device
Synopsis
========
.. c:macro:: FE_READ_STATUS
``int ioctl(int fd, FE_READ_STATUS, unsigned int *status)``
Arguments
=========
``fd``
File descriptor returned by :c:func:`open()`.
``status``
pointer to a bitmask integer filled with the values defined by enum
:c:type:`fe_status`.
Description
===========
All Digital TV frontend devices support the ``FE_READ_STATUS`` ioctl. It is
used to check about the locking status of the frontend after being
tuned. The ioctl takes a pointer to an integer where the status will be
written.
.. note::
The size of status is actually sizeof(enum fe_status), with
varies according with the architecture. This needs to be fixed in the
future.
int fe_status
=============
The fe_status parameter is used to indicate the current state and/or
state changes of the frontend hardware. It is produced using the enum
:c:type:`fe_status` values on a bitmask
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.