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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
.. -*- coding: utf-8; mode: rst -*-
.. _media-ioc-enum-links:
**************************
ioctl MEDIA_IOC_ENUM_LINKS
**************************
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
MEDIA_IOC_ENUM_LINKS - Enumerate all pads and links for a given entity
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
========
doc-rst: linux_tv: supress lots of warnings The c language parser checks if there are duplicated object definitions. That causes lots of warnings like: WARNING: duplicate C object description of ioctl Let's remove those by telling Sphinx that the language for those objects are c++. The look of the descriptions will be close, and the warnings will be gone. Please notice that we had to keep a few of them as C, as the c++ parser seems to be broken when it finds an enum. Yet, this reduced from 219 warnings to 143, with is a good thing. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-02 20:49:16 +08:00
.. cpp:function:: int ioctl( int fd, int request, struct media_links_enum *argp )
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() <media-func-open>`.
``request``
MEDIA_IOC_ENUM_LINKS
``argp``
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
===========
To enumerate pads and/or links for a given entity, applications set the
entity field of a struct :ref:`media_links_enum <media-links-enum>`
structure and initialize the struct
:ref:`media_pad_desc <media-pad-desc>` and struct
:ref:`media_link_desc <media-link-desc>` structure arrays pointed by
the ``pads`` and ``links`` fields. They then call the
MEDIA_IOC_ENUM_LINKS ioctl with a pointer to this structure.
If the ``pads`` field is not NULL, the driver fills the ``pads`` array
with information about the entity's pads. The array must have enough
room to store all the entity's pads. The number of pads can be retrieved
with the :ref:`MEDIA_IOC_ENUM_ENTITIES <media-ioc-enum-entities>`
ioctl.
If the ``links`` field is not NULL, the driver fills the ``links`` array
with information about the entity's outbound links. The array must have
enough room to store all the entity's outbound links. The number of
outbound links can be retrieved with the
:ref:`MEDIA_IOC_ENUM_ENTITIES <media-ioc-enum-entities>` ioctl.
Only forward links that originate at one of the entity's source pads are
returned during the enumeration process.
.. _media-links-enum:
.. flat-table:: struct media_links_enum
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- __u32
- ``entity``
- Entity id, set by the application.
- .. row 2
- struct :ref:`media_pad_desc <media-pad-desc>`
doc-rst: linux_tv: fix remaining lack of escapes Add escape before asterisk to fix those warnings: Documentation/linux_tv/media/dvb/FE_GET_EVENT:47: WARNING: Inline emphasis start-string without end-string. Documentation/linux_tv/media/v4l/media-ioc-enum-links:78: WARNING: Inline emphasis start-string without end-string. Documentation/linux_tv/media/v4l/media-ioc-enum-links:87: WARNING: Inline emphasis start-string without end-string. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-04 23:46:04 +08:00
- \*\ ``pads``
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
- Pointer to a pads array allocated by the application. Ignored if
doc-rst: linux_tv: remove whitespaces Let's remove bad whitespaces on the entire book. That helps to avoid mixing whitespace removal with other patches. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-05 03:25:48 +08:00
NULL.
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
- .. row 3
- struct :ref:`media_link_desc <media-link-desc>`
doc-rst: linux_tv: fix remaining lack of escapes Add escape before asterisk to fix those warnings: Documentation/linux_tv/media/dvb/FE_GET_EVENT:47: WARNING: Inline emphasis start-string without end-string. Documentation/linux_tv/media/v4l/media-ioc-enum-links:78: WARNING: Inline emphasis start-string without end-string. Documentation/linux_tv/media/v4l/media-ioc-enum-links:87: WARNING: Inline emphasis start-string without end-string. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-04 23:46:04 +08:00
- \*\ ``links``
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
- Pointer to a links array allocated by the application. Ignored if
doc-rst: linux_tv: remove whitespaces Let's remove bad whitespaces on the entire book. That helps to avoid mixing whitespace removal with other patches. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-05 03:25:48 +08:00
NULL.
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-pad-desc:
.. flat-table:: struct media_pad_desc
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- __u32
- ``entity``
- ID of the entity this pad belongs to.
- .. row 2
- __u16
- ``index``
- 0-based pad index.
- .. row 3
- __u32
- ``flags``
- Pad flags, see :ref:`media-pad-flag` for more details.
.. _media-link-desc:
.. flat-table:: struct media_link_desc
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- struct :ref:`media_pad_desc <media-pad-desc>`
- ``source``
- Pad at the origin of this link.
- .. row 2
- struct :ref:`media_pad_desc <media-pad-desc>`
- ``sink``
- Pad at the target of this link.
- .. row 3
- __u32
- ``flags``
- Link flags, see :ref:`media-link-flag` for more details.
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 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
============
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.
EINVAL
The struct :ref:`media_links_enum <media-links-enum>` ``id``
references a non-existing entity.