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diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst new file mode 100644 index 0000000000..4ad7dec27e --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst @@ -0,0 +1,164 @@ +.. 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 +=========== + +This call is used by the application to access the enumeration +of media bus formats for the selected pad. + +The enumerations are defined by the driver, and indexed using the ``index`` field +of struct :c:type:`v4l2_subdev_mbus_code_enum`. +Each enumeration starts with the ``index`` of 0, and +the lowest invalid index marks the end of enumeration. + +Therefore, to enumerate media bus formats available at a given sub-device pad, +initialize the ``pad``, and ``which`` fields to desired values, +and set ``index`` to 0. +Then call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl +with a pointer to this structure. + +A successful call will return with the ``code`` field filled in +with a mbus code value. +Repeat with increasing ``index`` until ``EINVAL`` is received. +``EINVAL`` means that either ``pad`` is invalid, +or that there are no more codes available at this pad. + +The driver must not return the same value of ``code`` for different indices +at the same pad. + +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{8.5cm}| + +.. 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. Filled in by the + application. + * - __u32 + - ``index`` + - Index of the mbus code in the enumeration belonging to the given pad. + Filled in by the application. + * - __u32 + - ``code`` + - The media bus format code, as defined in + :ref:`v4l2-mbus-format`. Filled in by the driver. + * - __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 + - ``stream`` + - Stream identifier. + * - __u32 + - ``reserved``\ [6] + - Reserved for future extensions. Applications and drivers must set + the array to zero. + + + +.. raw:: latex + + \footnotesize + +.. tabularcolumns:: |p{8.8cm}|p{2.2cm}|p{6.3cm}| + +.. _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. + +.. raw:: latex + + \normalsize + +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. |