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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
34This call is used by the application to access the enumeration
35of media bus formats for the selected pad.
36
37The enumerations are defined by the driver, and indexed using the ``index`` field
38of struct :c:type:`v4l2_subdev_mbus_code_enum`.
39Each enumeration starts with the ``index`` of 0, and
40the lowest invalid index marks the end of enumeration.
41
42Therefore, to enumerate media bus formats available at a given sub-device pad,
43initialize the ``pad``, and ``which`` fields to desired values,
44and set ``index`` to 0.
45Then call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl
46with a pointer to this structure.
47
48A successful call will return with the ``code`` field filled in
49with a mbus code value.
50Repeat with increasing ``index`` until ``EINVAL`` is received.
51``EINVAL`` means that either ``pad`` is invalid,
52or that there are no more codes available at this pad.
53
54The driver must not return the same value of ``code`` for different indices
55at the same pad.
56
57Available media bus formats may depend on the current 'try' formats at
58other pads of the sub-device, as well as on the current active links.
59See :ref:`VIDIOC_SUBDEV_G_FMT` for more
60information about the try formats.
61
62.. c:type:: v4l2_subdev_mbus_code_enum
63
64.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
65
66.. flat-table:: struct v4l2_subdev_mbus_code_enum
67 :header-rows: 0
68 :stub-columns: 0
69 :widths: 1 1 2
70
71 * - __u32
72 - ``pad``
73 - Pad number as reported by the media controller API. Filled in by the
74 application.
75 * - __u32
76 - ``index``
77 - Index of the mbus code in the enumeration belonging to the given pad.
78 Filled in by the application.
79 * - __u32
80 - ``code``
81 - The media bus format code, as defined in
82 :ref:`v4l2-mbus-format`. Filled in by the driver.
83 * - __u32
84 - ``which``
85 - Media bus format codes to be enumerated, from enum
86 :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
87 * - __u32
88 - ``flags``
89 - See :ref:`v4l2-subdev-mbus-code-flags`
90 * - __u32
91 - ``stream``
92 - Stream identifier.
93 * - __u32
94 - ``reserved``\ [6]
95 - Reserved for future extensions. Applications and drivers must set
96 the array to zero.
97
98
99
100.. raw:: latex
101
102 \footnotesize
103
104.. tabularcolumns:: |p{8.8cm}|p{2.2cm}|p{6.3cm}|
105
106.. _v4l2-subdev-mbus-code-flags:
107
108.. flat-table:: Subdev Media Bus Code Enumerate Flags
109 :header-rows: 0
110 :stub-columns: 0
111 :widths: 1 1 2
112
113 * - V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE
114 - 0x00000001
115 - The driver allows the application to try to change the default colorspace
116 encoding. The application can ask to configure the colorspace of the
117 subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
118 ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
119 See :ref:`v4l2-mbus-format` on how to do this.
120 * - V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC
121 - 0x00000002
122 - The driver allows the application to try to change the default transform function.
123 The application can ask to configure the transform function of
124 the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
125 ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
126 See :ref:`v4l2-mbus-format` on how to do this.
127 * - V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC
128 - 0x00000004
129 - The driver allows the application to try to change the default Y'CbCr
130 encoding. The application can ask to configure the Y'CbCr encoding of the
131 subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
132 ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
133 See :ref:`v4l2-mbus-format` on how to do this.
134 * - V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC
135 - 0x00000004
136 - The driver allows the application to try to change the default HSV
137 encoding. The application can ask to configure the HSV encoding of the
138 subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
139 ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
140 See :ref:`v4l2-mbus-format` on how to do this.
141 * - V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION
142 - 0x00000008
143 - The driver allows the application to try to change the default
144 quantization. The application can ask to configure the quantization of
145 the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
146 ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
147 See :ref:`v4l2-mbus-format` on how to do this.
148
149.. raw:: latex
150
151 \normalsize
152
153Return Value
154============
155
156On success 0 is returned, on error -1 and the ``errno`` variable is set
157appropriately. The generic error codes are described at the
158:ref:`Generic Error Codes <gen-errors>` chapter.
159
160EINVAL
161 The struct :c:type:`v4l2_subdev_mbus_code_enum` ``pad`` references a
162 non-existing pad, the ``which`` field has an unsupported value, or the
163 ``index`` field is out of bounds.