Documentation/userspace-api/media/dvb/fe-get-property.rst

Source file repositories/reference/linux-study-clean/Documentation/userspace-api/media/dvb/fe-get-property.rst

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System: Linux kernel
Corpus path: Documentation/userspace-api/media/dvb/fe-get-property.rst
Extension: .rst
Size: 1877 bytes
Lines: 76
Domain: Support Tooling And Documentation
Bucket: Documentation
Inferred role: Support Tooling And Documentation: documentation
Status: atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

No C-style include directives detected by the generator.

Detected Declarations

No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: DTV.fe

.. _FE_GET_PROPERTY:

**************************************
ioctl FE_SET_PROPERTY, FE_GET_PROPERTY
**************************************

Name
====

FE_SET_PROPERTY - FE_GET_PROPERTY - FE_SET_PROPERTY sets one or more frontend properties. - FE_GET_PROPERTY returns one or more frontend properties.

Synopsis
========

.. c:macro:: FE_GET_PROPERTY

``int ioctl(int fd, FE_GET_PROPERTY, struct dtv_properties *argp)``

.. c:macro:: FE_SET_PROPERTY

``int ioctl(int fd, FE_SET_PROPERTY, struct dtv_properties *argp)``

Arguments
=========

``fd``
    File descriptor returned by :c:func:`open()`.

``argp``
    Pointer to struct :c:type:`dtv_properties`.

Description
===========

All Digital TV frontend devices support the ``FE_SET_PROPERTY`` and
``FE_GET_PROPERTY`` ioctls. The supported properties and statistics
depends on the delivery system and on the device:

-  ``FE_SET_PROPERTY:``

   -  This ioctl is used to set one or more frontend properties.

   -  This is the basic command to request the frontend to tune into
      some frequency and to start decoding the digital TV signal.

   -  This call requires read/write access to the device.

.. note::

   At return, the values aren't updated to reflect the actual
   parameters used. If the actual parameters are needed, an explicit
   call to ``FE_GET_PROPERTY`` is needed.

-  ``FE_GET_PROPERTY:``

   -  This ioctl is used to get properties and statistics from the
      frontend.

   -  No properties are changed, and statistics aren't reset.

   -  This call only requires read-only access to the device.

Return Value
============

On success 0 is returned.

Annotation

Atlas domain: Support Tooling And Documentation / Documentation.
Implementation status: atlas-only.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.