mirror of https://gitee.com/openkylin/linux.git
139 lines
4.8 KiB
ReStructuredText
139 lines
4.8 KiB
ReStructuredText
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
|
|
.. c:namespace:: V4L
|
|
|
|
.. _VIDIOC_SUBDEV_ENUM_MBUS_CODE:
|
|
|
|
**********************************
|
|
ioctl VIDIOC_SUBDEV_ENUM_MBUS_CODE
|
|
**********************************
|
|
|
|
Name
|
|
====
|
|
|
|
VIDIOC_SUBDEV_ENUM_MBUS_CODE - Enumerate media bus formats
|
|
|
|
Synopsis
|
|
========
|
|
|
|
.. c:macro:: VIDIOC_SUBDEV_ENUM_MBUS_CODE
|
|
|
|
``int ioctl(int fd, VIDIOC_SUBDEV_ENUM_MBUS_CODE, struct v4l2_subdev_mbus_code_enum * argp)``
|
|
|
|
Arguments
|
|
=========
|
|
|
|
``fd``
|
|
File descriptor returned by :c:func:`open()`.
|
|
|
|
``argp``
|
|
Pointer to struct :c:type:`v4l2_subdev_mbus_code_enum`.
|
|
|
|
Description
|
|
===========
|
|
|
|
To enumerate media bus formats available at a given sub-device pad
|
|
applications initialize the ``pad``, ``which`` and ``index`` fields of
|
|
struct
|
|
:c:type:`v4l2_subdev_mbus_code_enum` and
|
|
call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl with a pointer to this
|
|
structure. Drivers fill the rest of the structure or return an ``EINVAL``
|
|
error code if either the ``pad`` or ``index`` are invalid. All media bus
|
|
formats are enumerable by beginning at index zero and incrementing by
|
|
one until ``EINVAL`` is returned.
|
|
|
|
Available media bus formats may depend on the current 'try' formats at
|
|
other pads of the sub-device, as well as on the current active links.
|
|
See :ref:`VIDIOC_SUBDEV_G_FMT` for more
|
|
information about the try formats.
|
|
|
|
.. c:type:: v4l2_subdev_mbus_code_enum
|
|
|
|
.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
|
|
|
|
.. flat-table:: struct v4l2_subdev_mbus_code_enum
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 1 1 2
|
|
|
|
* - __u32
|
|
- ``pad``
|
|
- Pad number as reported by the media controller API.
|
|
* - __u32
|
|
- ``index``
|
|
- Number of the format in the enumeration, set by the application.
|
|
* - __u32
|
|
- ``code``
|
|
- The media bus format code, as defined in
|
|
:ref:`v4l2-mbus-format`.
|
|
* - __u32
|
|
- ``which``
|
|
- Media bus format codes to be enumerated, from enum
|
|
:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
|
|
* - __u32
|
|
- ``flags``
|
|
- See :ref:`v4l2-subdev-mbus-code-flags`
|
|
* - __u32
|
|
- ``reserved``\ [7]
|
|
- Reserved for future extensions. Applications and drivers must set
|
|
the array to zero.
|
|
|
|
|
|
|
|
.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{7.7cm}|
|
|
|
|
.. _v4l2-subdev-mbus-code-flags:
|
|
|
|
.. flat-table:: Subdev Media Bus Code Enumerate Flags
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 1 1 2
|
|
|
|
* - V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE
|
|
- 0x00000001
|
|
- The driver allows the application to try to change the default colorspace
|
|
encoding. The application can ask to configure the colorspace of the
|
|
subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
|
|
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
|
|
See :ref:`v4l2-mbus-format` on how to do this.
|
|
* - V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC
|
|
- 0x00000002
|
|
- The driver allows the application to try to change the default transform function.
|
|
The application can ask to configure the transform function of
|
|
the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
|
|
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
|
|
See :ref:`v4l2-mbus-format` on how to do this.
|
|
* - V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC
|
|
- 0x00000004
|
|
- The driver allows the application to try to change the default Y'CbCr
|
|
encoding. The application can ask to configure the Y'CbCr encoding of the
|
|
subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
|
|
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
|
|
See :ref:`v4l2-mbus-format` on how to do this.
|
|
* - V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC
|
|
- 0x00000004
|
|
- The driver allows the application to try to change the default HSV
|
|
encoding. The application can ask to configure the HSV encoding of the
|
|
subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
|
|
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
|
|
See :ref:`v4l2-mbus-format` on how to do this.
|
|
* - V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION
|
|
- 0x00000008
|
|
- The driver allows the application to try to change the default
|
|
quantization. The application can ask to configure the quantization of
|
|
the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
|
|
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
|
|
See :ref:`v4l2-mbus-format` on how to do this.
|
|
|
|
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:`v4l2_subdev_mbus_code_enum`
|
|
``pad`` references a non-existing pad, or the ``index`` field is out
|
|
of bounds.
|