mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
1473c75e9a
Several ioctls are missing descriptions for the third argument of the ioctl() command. They should have a description, as otherwise the output won't be ok, and will sound like something is missing. So, add them. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
119 lines
3.4 KiB
ReStructuredText
119 lines
3.4 KiB
ReStructuredText
.. -*- coding: utf-8; mode: rst -*-
|
|
|
|
.. _VIDIOC_SUBDEV_G_SELECTION:
|
|
|
|
**********************************************************
|
|
ioctl VIDIOC_SUBDEV_G_SELECTION, VIDIOC_SUBDEV_S_SELECTION
|
|
**********************************************************
|
|
|
|
Name
|
|
====
|
|
|
|
VIDIOC_SUBDEV_G_SELECTION - VIDIOC_SUBDEV_S_SELECTION - Get or set selection rectangles on a subdev pad
|
|
|
|
|
|
Synopsis
|
|
========
|
|
|
|
.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_SELECTION, struct v4l2_subdev_selection *argp )
|
|
:name: VIDIOC_SUBDEV_G_SELECTION
|
|
|
|
.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_SELECTION, struct v4l2_subdev_selection *argp )
|
|
:name: VIDIOC_SUBDEV_S_SELECTION
|
|
|
|
|
|
Arguments
|
|
=========
|
|
|
|
``fd``
|
|
File descriptor returned by :ref:`open() <func-open>`.
|
|
|
|
``argp``
|
|
Pointer to struct :c:type:`v4l2_subdev_selection`.
|
|
|
|
|
|
Description
|
|
===========
|
|
|
|
The selections are used to configure various image processing
|
|
functionality performed by the subdevs which affect the image size. This
|
|
currently includes cropping, scaling and composition.
|
|
|
|
The selection API replaces
|
|
:ref:`the old subdev crop API <VIDIOC_SUBDEV_G_CROP>`. All the
|
|
function of the crop API, and more, are supported by the selections API.
|
|
|
|
See :ref:`subdev` for more information on how each selection target
|
|
affects the image processing pipeline inside the subdevice.
|
|
|
|
|
|
Types of selection targets
|
|
--------------------------
|
|
|
|
There are two types of selection targets: actual and bounds. The actual
|
|
targets are the targets which configure the hardware. The BOUNDS target
|
|
will return a rectangle that contain all possible actual rectangles.
|
|
|
|
|
|
Discovering supported features
|
|
------------------------------
|
|
|
|
To discover which targets are supported, the user can perform
|
|
``VIDIOC_SUBDEV_G_SELECTION`` on them. Any unsupported target will
|
|
return ``EINVAL``.
|
|
|
|
Selection targets and flags are documented in
|
|
:ref:`v4l2-selections-common`.
|
|
|
|
|
|
.. c:type:: v4l2_subdev_selection
|
|
|
|
.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
|
|
|
|
.. flat-table:: struct v4l2_subdev_selection
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 1 1 2
|
|
|
|
* - __u32
|
|
- ``which``
|
|
- Active or try selection, from enum
|
|
:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
|
|
* - __u32
|
|
- ``pad``
|
|
- Pad number as reported by the media framework.
|
|
* - __u32
|
|
- ``target``
|
|
- Target selection rectangle. See :ref:`v4l2-selections-common`.
|
|
* - __u32
|
|
- ``flags``
|
|
- Flags. See :ref:`v4l2-selection-flags`.
|
|
* - struct :c:type:`v4l2_rect`
|
|
- ``r``
|
|
- Selection rectangle, in pixels.
|
|
* - __u32
|
|
- ``reserved``\ [8]
|
|
- Reserved for future extensions. Applications and drivers 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.
|
|
|
|
EBUSY
|
|
The selection rectangle can't be changed because the pad is
|
|
currently busy. This can be caused, for instance, by an active video
|
|
stream on the pad. The ioctl must not be retried without performing
|
|
another action to fix the problem first. Only returned by
|
|
``VIDIOC_SUBDEV_S_SELECTION``
|
|
|
|
EINVAL
|
|
The struct :c:type:`v4l2_subdev_selection`
|
|
``pad`` references a non-existing pad, the ``which`` field
|
|
references a non-existing format, or the selection target is not
|
|
supported on the given subdev pad.
|