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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 23:58:31 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 23:58:31 +0200 |
commit | ff9a082fda424257976f08fce942609f358015e0 (patch) | |
tree | 478e6b449b19baaf842369a13923499ce83ef895 /Documentation/media/uapi/dvb/fe-read-status.rst | |
parent | Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi (diff) | |
parent | Merge branch 'topic/docs-next' into v4l_for_linus (diff) | |
download | linux-ff9a082fda424257976f08fce942609f358015e0.tar.xz linux-ff9a082fda424257976f08fce942609f358015e0.zip |
Merge tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media documentation updates from Mauro Carvalho Chehab:
"This patch series does the conversion of all media documentation stuff
to Restrutured Text markup format and add them to the
Documentation/index.rst file.
The media documentation was grouped into 4 books:
- media uAPI
- media kAPI
- V4L driver-specific documentation
- DVB driver-specific documentation
It also contains several documentation improvements and one fixup
patch for a core issue with cropcap.
PS. After this patch series, the media DocBook is deprecated and
should be removed. I'll add such patch on a future pull request"
* tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (322 commits)
[media] cx23885-cardlist.rst: add a new card
[media] doc-rst: add some needed escape codes
[media] doc-rst: kapi: use :c:func: instead of :cpp:func
doc-rst: kernel-doc: fix a change introduced by mistake
[media] v4l2-ioctl.h add debug info for struct v4l2_ioctl_ops
[media] dvb_ringbuffer.h: some documentation improvements
[media] v4l2-ctrls.h: fully document the header file
[media] doc-rst: Fix some typedef ugly warnings
[media] doc-rst: reorganize the kAPI v4l2 chapters
[media] rename v4l2-framework.rst to v4l2-intro.rst
[media] move V4L2 clocks to a separate .rst file
[media] v4l2-fh.rst: add cross references and markups
[media] v4l2-fh.rst: add fh contents from v4l2-framework.rst
[media] v4l2-fh.h: add documentation for it
[media] v4l2-event.rst: add cross-references and markups
[media] v4l2-event.h: document all functions
[media] v4l2-event.rst: add text from v4l2-framework.rst
[media] v4l2-framework.rst: remove videobuf quick chapter
[media] v4l2-dev: add cross-references and improve markup
[media] doc-rst: move v4l2-dev doc to a separate file
...
Diffstat (limited to 'Documentation/media/uapi/dvb/fe-read-status.rst')
-rw-r--r-- | Documentation/media/uapi/dvb/fe-read-status.rst | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/Documentation/media/uapi/dvb/fe-read-status.rst b/Documentation/media/uapi/dvb/fe-read-status.rst new file mode 100644 index 000000000000..624ed9d06488 --- /dev/null +++ b/Documentation/media/uapi/dvb/fe-read-status.rst @@ -0,0 +1,135 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _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 +======== + +.. cpp:function:: int ioctl( int fd, int request, unsigned int *status ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <frontend_f_open>`. + +``request`` + FE_READ_STATUS + +``status`` + pointer to a bitmask integer filled with the values defined by enum + :ref:`fe_status <fe-status>`. + + +Description +=========== + +All DVB 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. + + +.. _fe-status-t: + +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 +:ref:`fe_status <fe-status>` values on a bitmask + + +.. _fe-status: + +.. flat-table:: enum fe_status + :header-rows: 1 + :stub-columns: 0 + + + - .. row 1 + + - ID + + - Description + + - .. row 2 + + - .. _FE-HAS-SIGNAL: + + ``FE_HAS_SIGNAL`` + + - The frontend has found something above the noise level + + - .. row 3 + + - .. _FE-HAS-CARRIER: + + ``FE_HAS_CARRIER`` + + - The frontend has found a DVB signal + + - .. row 4 + + - .. _FE-HAS-VITERBI: + + ``FE_HAS_VITERBI`` + + - The frontend FEC inner coding (Viterbi, LDPC or other inner code) + is stable + + - .. row 5 + + - .. _FE-HAS-SYNC: + + ``FE_HAS_SYNC`` + + - Synchronization bytes was found + + - .. row 6 + + - .. _FE-HAS-LOCK: + + ``FE_HAS_LOCK`` + + - The DVB were locked and everything is working + + - .. row 7 + + - .. _FE-TIMEDOUT: + + ``FE_TIMEDOUT`` + + - no lock within the last about 2 seconds + + - .. row 8 + + - .. _FE-REINIT: + + ``FE_REINIT`` + + - The frontend was reinitialized, application is recommended to + reset DiSEqC, tone and parameters + + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. |