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linux-next/Documentation/media/uapi/dvb/fe-get-property.rst

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media: add SPDX header to media uAPI files All those files are under GFDL 1.1 or later, with no invariant sections. Tag them as such. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-08-30 22:15:26 +08:00
.. Permission is granted to copy, distribute and/or modify this
.. document under the terms of the GNU Free Documentation License,
.. Version 1.1 or any later version published by the Free Software
.. Foundation, with no Invariant Sections, no Front-Cover Texts
.. and no Back-Cover Texts. A copy of the license is included at
.. Documentation/media/uapi/fdl-appendix.rst.
..
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
.. _FE_GET_PROPERTY:
**************************************
ioctl FE_SET_PROPERTY, FE_GET_PROPERTY
**************************************
doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-06 02:14:35 +08:00
Name
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-05 18:58:48 +08:00
====
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-05 18:58:48 +08:00
FE_SET_PROPERTY - FE_GET_PROPERTY - FE_SET_PROPERTY sets one or more frontend properties. - FE_GET_PROPERTY returns one or more frontend properties.
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-06 02:14:35 +08:00
Synopsis
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
========
[media] docs-rst: Convert DVB uAPI to use C function references Name all ioctl references and make them match the ioctls that are documented. That will improve the cross-reference index, as it will have all ioctls and syscalls there. While here, improve the documentation, marking the deprecated ioctls, and making the non-deprecated ones more like the rest of the media book. Also, add a notice for ioctls that still require documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-08-20 03:56:15 +08:00
.. c:function:: int ioctl( int fd, FE_GET_PROPERTY, struct dtv_properties *argp )
:name: FE_GET_PROPERTY
.. c:function:: int ioctl( int fd, FE_SET_PROPERTY, struct dtv_properties *argp )
:name: FE_SET_PROPERTY
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-05 18:58:48 +08:00
doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-06 02:14:35 +08:00
Arguments
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
=========
``fd``
File descriptor returned by :ref:`open() <frontend_f_open>`.
``argp``
media: dvb frontend docs: use kernel-doc documentation Now that frontend.h contains most documentation for the frontend, remove the duplicated information from Documentation/ and use the kernel-doc auto-generated one instead. That should simplify maintainership of DVB frontend uAPI, as most of the documentation will stick with the header file. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-31 01:45:20 +08:00
Pointer to struct :c:type:`dtv_properties`.
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-06 02:14:35 +08:00
Description
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
===========
media: dvb uAPI docs: Prefer use "Digital TV instead of "DVB" The usage of the term "DVB" at the dvb API docs is confusing, as, right now, it can refer to either the European digital TV standard or to the subsystem. So, prefer calling it as "Digital TV" on most places, to avoid ambiguity. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-02 00:28:16 +08:00
All Digital TV frontend devices support the ``FE_SET_PROPERTY`` and
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
``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.
media: dvb_frontend: fix return values for FE_SET_PROPERTY There are several problems with regards to the return of FE_SET_PROPERTY. The original idea were to return per-property return codes via tvp->result field, and to return an updated set of values. However, that never worked. What's actually implemented is: - the FE_SET_PROPERTY implementation doesn't call .get_frontend callback in order to get the actual parameters after return; - the tvp->result field is only filled if there's no error. So, it is always filled with zero; - FE_SET_PROPERTY doesn't call memdup_user() nor any other copy_to_user() function. So, any changes to the properties will be lost; - FE_SET_PROPERTY is declared as a write-only ioctl (IOW). While we could fix the above, it could cause regressions. So, let's just assume what the code really does, updating the documentation accordingly and removing the logic that would update the discarded tvp->result. Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-18 20:21:37 +08:00
.. 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.
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
- ``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.
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-05 18:58:48 +08:00
doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-06 02:14:35 +08:00
Return Value
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-05 18:58:48 +08:00
============
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
media: dvb uAPI docs: adjust return value ioctl descriptions There are several issues on the return value for ioctls: - Text is confusing; - Some error codes don't exist; - The non-generic error codes should come before the text that points to the generic error codes; - Tables don't contain column size hints; - Some references are not marked as such. Correct them. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-02 00:15:43 +08:00
On success 0 is returned.
On error -1 is returned, and the ``errno`` variable is set
appropriately.
Generic error codes are described at the
doc-rst: linux_tv DocBook to reST migration (docs-next) This is the restructuredText (reST) migration of the ``media`` DocBook-XML set from the linux_tv project. Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-30 21:18:56 +08:00
:ref:`Generic Error Codes <gen-errors>` chapter.
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