76 lines
1.8 KiB
ReStructuredText
76 lines
1.8 KiB
ReStructuredText
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
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.. c:namespace:: DTV.fe
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.. _FE_GET_PROPERTY:
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**************************************
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ioctl FE_SET_PROPERTY, FE_GET_PROPERTY
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**************************************
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Name
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====
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FE_SET_PROPERTY - FE_GET_PROPERTY - FE_SET_PROPERTY sets one or more frontend properties. - FE_GET_PROPERTY returns one or more frontend properties.
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Synopsis
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========
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.. c:macro:: FE_GET_PROPERTY
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``int ioctl(int fd, FE_GET_PROPERTY, struct dtv_properties *argp)``
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.. c:macro:: FE_SET_PROPERTY
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``int ioctl(int fd, FE_SET_PROPERTY, struct dtv_properties *argp)``
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Arguments
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=========
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``fd``
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File descriptor returned by :c:func:`open()`.
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``argp``
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Pointer to struct :c:type:`dtv_properties`.
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Description
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===========
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All Digital TV frontend devices support the ``FE_SET_PROPERTY`` and
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``FE_GET_PROPERTY`` ioctls. The supported properties and statistics
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depends on the delivery system and on the device:
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- ``FE_SET_PROPERTY:``
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- This ioctl is used to set one or more frontend properties.
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- This is the basic command to request the frontend to tune into
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some frequency and to start decoding the digital TV signal.
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- This call requires read/write access to the device.
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.. note::
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At return, the values aren't updated to reflect the actual
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parameters used. If the actual parameters are needed, an explicit
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call to ``FE_GET_PROPERTY`` is needed.
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- ``FE_GET_PROPERTY:``
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- This ioctl is used to get properties and statistics from the
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frontend.
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- No properties are changed, and statistics aren't reset.
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- This call only requires read-only access to the device.
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Return Value
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============
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On success 0 is returned.
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On error -1 is returned, and the ``errno`` variable is set
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appropriately.
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Generic error codes are described at the
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:ref:`Generic Error Codes <gen-errors>` chapter.
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