diff options
Diffstat (limited to 'Documentation/media/uapi/mediactl/media-ioc-enum-links.rst')
| -rw-r--r-- | Documentation/media/uapi/mediactl/media-ioc-enum-links.rst | 157 |
1 files changed, 0 insertions, 157 deletions
diff --git a/Documentation/media/uapi/mediactl/media-ioc-enum-links.rst b/Documentation/media/uapi/mediactl/media-ioc-enum-links.rst deleted file mode 100644 index b827ebc398f8..000000000000 --- a/Documentation/media/uapi/mediactl/media-ioc-enum-links.rst +++ /dev/null @@ -1,157 +0,0 @@ -.. 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 - -.. _media_ioc_enum_links: - -************************** -ioctl MEDIA_IOC_ENUM_LINKS -************************** - -Name -==== - -MEDIA_IOC_ENUM_LINKS - Enumerate all pads and links for a given entity - - -Synopsis -======== - -.. c:function:: int ioctl( int fd, MEDIA_IOC_ENUM_LINKS, struct media_links_enum *argp ) - :name: MEDIA_IOC_ENUM_LINKS - - -Arguments -========= - -``fd`` - File descriptor returned by :ref:`open() <media-func-open>`. - -``argp`` - Pointer to struct :c:type:`media_links_enum`. - - -Description -=========== - -To enumerate pads and/or links for a given entity, applications set the -entity field of a struct :c:type:`media_links_enum` -structure and initialize the struct -:c:type:`media_pad_desc` and struct -:c:type:`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 :ref:`MEDIA_IOC_ENUM_ENTITIES`. - -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 :ref:`MEDIA_IOC_ENUM_ENTITIES`. - -Only forward links that originate at one of the entity's source pads are -returned during the enumeration process. - - -.. c:type:: media_links_enum - -.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| - -.. flat-table:: struct media_links_enum - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - __u32 - - ``entity`` - - Entity id, set by the application. - - * - struct :c:type:`media_pad_desc` - - \*\ ``pads`` - - Pointer to a pads array allocated by the application. Ignored if - NULL. - - * - struct :c:type:`media_link_desc` - - \*\ ``links`` - - Pointer to a links array allocated by the application. Ignored if - NULL. - - * - __u32 - - ``reserved[4]`` - - Reserved for future extensions. Drivers and applications must set - the array to zero. - - -.. c:type:: media_pad_desc - -.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| - -.. flat-table:: struct media_pad_desc - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - __u32 - - ``entity`` - - ID of the entity this pad belongs to. - - * - __u16 - - ``index`` - - Pad index, starts at 0. - - * - __u32 - - ``flags`` - - Pad flags, see :ref:`media-pad-flag` for more details. - - * - __u32 - - ``reserved[2]`` - - Reserved for future extensions. Drivers and applications must set - the array to zero. - - - -.. c:type:: media_link_desc - -.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| - -.. flat-table:: struct media_link_desc - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - struct :c:type:`media_pad_desc` - - ``source`` - - Pad at the origin of this link. - - * - struct :c:type:`media_pad_desc` - - ``sink`` - - Pad at the target of this link. - - * - __u32 - - ``flags`` - - Link flags, see :ref:`media-link-flag` for more details. - - * - __u32 - - ``reserved[2]`` - - Reserved for future extensions. Drivers and applications must set - the array to zero. - - -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. - -EINVAL - The struct :c:type:`media_links_enum` ``id`` - references a non-existing entity. |