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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>
136 lines
2.4 KiB
ReStructuredText
136 lines
2.4 KiB
ReStructuredText
.. -*- coding: utf-8; mode: rst -*-
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.. _FE_READ_STATUS:
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********************
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ioctl FE_READ_STATUS
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********************
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Name
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====
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FE_READ_STATUS - Returns status information about the front-end. This call only requires - read-only access to the device
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Synopsis
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========
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.. cpp:function:: int ioctl( int fd, int request, unsigned int *status )
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Arguments
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=========
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``fd``
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File descriptor returned by :ref:`open() <frontend_f_open>`.
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``request``
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FE_READ_STATUS
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``status``
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pointer to a bitmask integer filled with the values defined by enum
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:ref:`fe_status <fe-status>`.
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Description
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===========
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All DVB frontend devices support the ``FE_READ_STATUS`` ioctl. It is
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used to check about the locking status of the frontend after being
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tuned. The ioctl takes a pointer to an integer where the status will be
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written.
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NOTE: the size of status is actually sizeof(enum fe_status), with
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varies according with the architecture. This needs to be fixed in the
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future.
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.. _fe-status-t:
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int fe_status
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=============
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The fe_status parameter is used to indicate the current state and/or
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state changes of the frontend hardware. It is produced using the enum
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:ref:`fe_status <fe-status>` values on a bitmask
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.. _fe-status:
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.. flat-table:: enum fe_status
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:header-rows: 1
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:stub-columns: 0
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- .. row 1
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- ID
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- Description
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- .. row 2
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- .. _FE-HAS-SIGNAL:
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``FE_HAS_SIGNAL``
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- The frontend has found something above the noise level
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- .. row 3
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- .. _FE-HAS-CARRIER:
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``FE_HAS_CARRIER``
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- The frontend has found a DVB signal
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- .. row 4
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- .. _FE-HAS-VITERBI:
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``FE_HAS_VITERBI``
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- The frontend FEC inner coding (Viterbi, LDPC or other inner code)
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is stable
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- .. row 5
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- .. _FE-HAS-SYNC:
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``FE_HAS_SYNC``
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- Synchronization bytes was found
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- .. row 6
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- .. _FE-HAS-LOCK:
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``FE_HAS_LOCK``
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- The DVB were locked and everything is working
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- .. row 7
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- .. _FE-TIMEDOUT:
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``FE_TIMEDOUT``
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- no lock within the last about 2 seconds
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- .. row 8
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- .. _FE-REINIT:
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``FE_REINIT``
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- The frontend was reinitialized, application is recommended to
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reset DiSEqC, tone and parameters
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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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