xref: /linux/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst (revision b5bee6ced21ca98389000b7017dd41b0cc37fa50)
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: V4L
3
4.. _VIDIOC_SUBDEV_ENUM_MBUS_CODE:
5
6**********************************
7ioctl VIDIOC_SUBDEV_ENUM_MBUS_CODE
8**********************************
9
10Name
11====
12
13VIDIOC_SUBDEV_ENUM_MBUS_CODE - Enumerate media bus formats
14
15Synopsis
16========
17
18.. c:macro:: VIDIOC_SUBDEV_ENUM_MBUS_CODE
19
20``int ioctl(int fd, VIDIOC_SUBDEV_ENUM_MBUS_CODE, struct v4l2_subdev_mbus_code_enum * argp)``
21
22Arguments
23=========
24
25``fd``
26    File descriptor returned by :c:func:`open()`.
27
28``argp``
29    Pointer to struct :c:type:`v4l2_subdev_mbus_code_enum`.
30
31Description
32===========
33
34To enumerate media bus formats available at a given sub-device pad
35applications initialize the ``pad``, ``which`` and ``index`` fields of
36struct
37:c:type:`v4l2_subdev_mbus_code_enum` and
38call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl with a pointer to this
39structure. Drivers fill the rest of the structure or return an ``EINVAL``
40error code if either the ``pad`` or ``index`` are invalid. All media bus
41formats are enumerable by beginning at index zero and incrementing by
42one until ``EINVAL`` is returned.
43
44Available media bus formats may depend on the current 'try' formats at
45other pads of the sub-device, as well as on the current active links.
46See :ref:`VIDIOC_SUBDEV_G_FMT` for more
47information about the try formats.
48
49.. c:type:: v4l2_subdev_mbus_code_enum
50
51.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
52
53.. flat-table:: struct v4l2_subdev_mbus_code_enum
54    :header-rows:  0
55    :stub-columns: 0
56    :widths:       1 1 2
57
58    * - __u32
59      - ``pad``
60      - Pad number as reported by the media controller API.
61    * - __u32
62      - ``index``
63      - Number of the format in the enumeration, set by the application.
64    * - __u32
65      - ``code``
66      - The media bus format code, as defined in
67	:ref:`v4l2-mbus-format`.
68    * - __u32
69      - ``which``
70      - Media bus format codes to be enumerated, from enum
71	:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
72    * - __u32
73      - ``flags``
74      - See :ref:`v4l2-subdev-mbus-code-flags`
75    * - __u32
76      - ``reserved``\ [7]
77      - Reserved for future extensions. Applications and drivers must set
78	the array to zero.
79
80
81
82.. raw:: latex
83
84   \footnotesize
85
86.. tabularcolumns:: |p{8.8cm}|p{2.2cm}|p{6.3cm}|
87
88.. _v4l2-subdev-mbus-code-flags:
89
90.. flat-table:: Subdev Media Bus Code Enumerate Flags
91    :header-rows:  0
92    :stub-columns: 0
93    :widths:       1 1 2
94
95    * - V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE
96      - 0x00000001
97      - The driver allows the application to try to change the default colorspace
98	encoding. The application can ask to configure the colorspace of the
99	subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
100	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
101	See :ref:`v4l2-mbus-format` on how to do this.
102    * - V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC
103      - 0x00000002
104      - The driver allows the application to try to change the default transform function.
105	The application can ask to configure the transform function of
106	the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
107	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
108	See :ref:`v4l2-mbus-format` on how to do this.
109    * - V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC
110      - 0x00000004
111      - The driver allows the application to try to change the default Y'CbCr
112	encoding. The application can ask to configure the Y'CbCr encoding of the
113	subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
114	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
115	See :ref:`v4l2-mbus-format` on how to do this.
116    * - V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC
117      - 0x00000004
118      - The driver allows the application to try to change the default HSV
119	encoding. The application can ask to configure the HSV encoding of the
120	subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
121	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
122	See :ref:`v4l2-mbus-format` on how to do this.
123    * - V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION
124      - 0x00000008
125      - The driver allows the application to try to change the default
126	quantization. The application can ask to configure the quantization of
127	the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
128	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
129	See :ref:`v4l2-mbus-format` on how to do this.
130
131.. raw:: latex
132
133   \normalsize
134
135Return Value
136============
137
138On success 0 is returned, on error -1 and the ``errno`` variable is set
139appropriately. The generic error codes are described at the
140:ref:`Generic Error Codes <gen-errors>` chapter.
141
142EINVAL
143    The struct
144    :c:type:`v4l2_subdev_mbus_code_enum`
145    ``pad`` references a non-existing pad, or the ``index`` field is out
146    of bounds.
147