This patch extends the CSC API in video devices to be supported
also on sub-devices. The flag V4L2_MBUS_FRAMEFMT_SET_CSC set by
the application when calling VIDIOC_SUBDEV_S_FMT ioctl.
The flags:
V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE, V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC,
V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC,
are set by the driver in the VIDIOC_SUBDEV_ENUM_MBUS_CODE ioctl.
New 'flags' fields were added to the structs
v4l2_subdev_mbus_code_enum, v4l2_mbus_framefmt which are borrowed
from the 'reserved' field
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
---
.../media/v4l/subdev-formats.rst | 78 +++++++++++++++++--
.../v4l/vidioc-subdev-enum-mbus-code.rst | 44 ++++++++++-
include/uapi/linux/v4l2-mediabus.h | 9 ++-
include/uapi/linux/v4l2-subdev.h | 8 +-
4 files changed, 129 insertions(+), 10 deletions(-)
diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst
index 9a4d61b0d76f..7362ee0b1e96 100644
--- a/Documentation/userspace-api/media/v4l/subdev-formats.rst
+++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst
@@ -41,32 +41,96 @@ Media Bus Formats
:ref:`field-order` for details.
* - __u32
- ``colorspace``
- - Image colorspace, from enum
- :c:type:`v4l2_colorspace`. See
- :ref:`colorspaces` for details.
+ - Image colorspace, from enum :c:type:`v4l2_colorspace`.
+ Must be set by the driver for capture streams and by the application
+ for output streams, see :ref:`colorspaces`. If the application sets the
+ flag ``V4L2_MBUS_FRAMEFMT_SET_CSC`` then the application can set
+ this field for a capture stream to request a specific colorspace
+ for the media bus data. If the driver cannot handle requested
+ conversion, it will return another supported colorspace.
+ The driver indicates that colorspace conversion is supported by setting
+ the flag V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE in the corresponding struct
+ :c:type:`v4l2_subdev_mbus_code_enum` during enumeration.
+ See :ref:`colorspaces`.
* - __u16
- ``ycbcr_enc``
- Y'CbCr encoding, from enum :c:type:`v4l2_ycbcr_encoding`.
This information supplements the ``colorspace`` and must be set by
the driver for capture streams and by the application for output
- streams, see :ref:`colorspaces`.
+ streams, see :ref:`colorspaces`. If the application sets the
+ flag ``V4L2_MBUS_FRAMEFMT_SET_CSC`` then the application can set
+ this field for a capture stream to request a specific Y'CbCr encoding
+ for the media bus data. If the driver cannot handle requested
+ conversion, it will return another supported encoding.
+ This field is ignored for HSV media bus formats. The driver indicates
+ that ycbcr_enc conversion is supported by setting the flag
+ V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC in the corresponding struct
+ :c:type:`v4l2_subdev_mbus_code_enum` during enumeration.
+ See :ref:`v4l2-subdev-mbus-code-flags`.
+
* - __u16
- ``quantization``
- Quantization range, from enum :c:type:`v4l2_quantization`.
This information supplements the ``colorspace`` and must be set by
the driver for capture streams and by the application for output
- streams, see :ref:`colorspaces`.
+ streams, see :ref:`colorspaces`. If the application sets the
+ flag ``V4L2_MBUS_FRAMEFMT_SET_CSC`` then the application can set
+ this field for a capture stream to request a specific quantization
+ encoding for the media bus data. If the driver cannot handle requested
+ conversion, it will return another supported encoding.
+ The driver indicates that quantization conversion is supported by
+ setting the flag V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION in the
+ corresponding struct :c:type:`v4l2_subdev_mbus_code_enum`
+ during enumeration. See :ref:`v4l2-subdev-mbus-code-flags`.
+
* - __u16
- ``xfer_func``
- Transfer function, from enum :c:type:`v4l2_xfer_func`.
This information supplements the ``colorspace`` and must be set by
the driver for capture streams and by the application for output
- streams, see :ref:`colorspaces`.
+ streams, see :ref:`colorspaces`. If the application sets the
+ flag ``V4L2_MBUS_FRAMEFMT_SET_CSC`` then the application can set
+ this field for a capture stream to request a specific transfer
+ function for the media bus data. If the driver cannot handle the requested
+ conversion, it will return another supported transfer function.
+ The driver indicates that the transfer function conversion is supported by
+ setting the flag V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC in the
+ corresponding struct :c:type:`v4l2_subdev_mbus_code_enum`
+ during enumeration. See :ref:`v4l2-subdev-mbus-code-flags`.
+ * - __u16
+ - ``reserved2``
+ - Reserved for future extensions.
+ * - __u32
+ - ``flags``
+ - flags See: :ref:v4l2-mbus-framefmt-flags
* - __u16
- - ``reserved``\ [11]
+ - ``reserved``\ [8]
- Reserved for future extensions. Applications and drivers must set
the array to zero.
+.. _v4l2-mbus-framefmt-flags:
+
+.. flat-table:: v4l2_mbus_framefmt Flags
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 3 1 4
+
+ * .. _`mbus-framefmt-set-csc`:
+
+ - ``V4L2_MBUS_FRAMEFMT_SET_CSC``
+ - 0x00000001
+ - Set by the application. It is only used for capture and is
+ ignored for output streams. If set, then request the subdevice to do
+ colorspace conversion from the received colorspace to the requested
+ colorspace values. If colorimetry field (``colorspace``, ``ycbcr_enc``,
+ ``quantization`` or ``xfer_func``) is set to 0, then that colorimetry
+ setting will remain unchanged from what was received. So to change the
+ quantization, only the ``quantization`` field shall be set to non-zero values
+ (``V4L2_QUANTIZATION_FULL_RANGE`` or ``V4L2_QUANTIZATION_LIM_RANGE``)
+ and all other colorimetry fields shall be set to 0.
+
+ To check which conversions are supported by the hardware for the current
+ media bus frame format, see :ref:`v4l2-subdev-mbus-code-flags`.
.. _v4l2-mbus-pixelcode:
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
index 35b8607203a4..8ed355a285e9 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst
@@ -79,11 +79,53 @@ information about the try formats.
- Media bus format codes to be enumerated, from enum
:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
* - __u32
- - ``reserved``\ [8]
+ - ``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_YCBCR_ENC
+ - 0x00000002
+ - The driver allows the application to try to change the default Y'CbCr
+ encoding. The application can ask to configure the ycbcr_enc 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
+ - 0x00000004
+ - 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.
+ * - V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC
+ - 0x00000008
+ - 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.
+
Return Value
============
diff --git a/include/uapi/linux/v4l2-mediabus.h b/include/uapi/linux/v4l2-mediabus.h
index 123a231001a8..3b7d692b4015 100644
--- a/include/uapi/linux/v4l2-mediabus.h
+++ b/include/uapi/linux/v4l2-mediabus.h
@@ -16,6 +16,8 @@
#include <linux/types.h>
#include <linux/videodev2.h>
+#define V4L2_MBUS_FRAMEFMT_SET_CSC 0x00000001
+
/**
* struct v4l2_mbus_framefmt - frame format on the media bus
* @width: image width
@@ -26,6 +28,9 @@
* @ycbcr_enc: YCbCr encoding of the data (from enum v4l2_ycbcr_encoding)
* @quantization: quantization of the data (from enum v4l2_quantization)
* @xfer_func: transfer function of the data (from enum v4l2_xfer_func)
+ * @reserved2: two reserved bytes that can be later used
+ * @flags: flags (V4L2_MBUS_FRAMEFMT_*)
+ * @reserved: reserved bytes that can be later used
*/
struct v4l2_mbus_framefmt {
__u32 width;
@@ -36,7 +41,9 @@ struct v4l2_mbus_framefmt {
__u16 ycbcr_enc;
__u16 quantization;
__u16 xfer_func;
- __u16 reserved[11];
+ __u16 reserved2;
+ __u32 flags;
+ __u16 reserved[8];
};
#ifndef __KERNEL__
diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
index 5d2a1dab7911..c20aa9a89864 100644
--- a/include/uapi/linux/v4l2-subdev.h
+++ b/include/uapi/linux/v4l2-subdev.h
@@ -65,19 +65,25 @@ struct v4l2_subdev_crop {
__u32 reserved[8];
};
+#define V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE 0x00000001
+#define V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC 0x00000002
+#define V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION 0x00000004
+#define V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC 0x00000008
/**
* struct v4l2_subdev_mbus_code_enum - Media bus format enumeration
* @pad: pad number, as reported by the media API
* @index: format index during enumeration
* @code: format code (MEDIA_BUS_FMT_ definitions)
* @which: format type (from enum v4l2_subdev_format_whence)
+ * @flags: flags set by the driver, (V4L2_SUBDEV_MBUS_CODE_*)
*/
struct v4l2_subdev_mbus_code_enum {
__u32 pad;
__u32 index;
__u32 code;
__u32 which;
- __u32 reserved[8];
+ __u32 flags;
+ __u32 reserved[7];
};
/**
--
2.17.1
