[v5,4/7] v4l2: extend the CSC API to subdevice.
diff mbox series

Message ID 20200703171019.19270-5-dafna.hirschfeld@collabora.com
State New
Headers show
Series
  • v4l2: add support for colorspace conversion API (CSC) for video capture and subdevices
Related show

Commit Message

Dafna Hirschfeld July 3, 2020, 5:10 p.m. UTC
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@collabora.com>
---
 .../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(-)

Comments

Hans Verkuil July 21, 2020, 1:52 p.m. UTC | #1
On 03/07/2020 19:10, Dafna Hirschfeld wrote:
> 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,

Reorder.

> 
> 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@collabora.com>
> ---
>  .../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``,

If -> If the

> +	``quantization`` or ``xfer_func``) is set to 0, then that colorimetry

Reorder.

> +	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.

Reorder and renumber the V4L2_SUBDEV_MBUS_CODE_CSC_ values.

> +
>  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

Reorder and renumber.

Regards,

	Hans

>  /**
>   * 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];
>  };
>  
>  /**
>
Tomasz Figa July 22, 2020, 12:53 p.m. UTC | #2
Hi Dafna,

On Fri, Jul 03, 2020 at 07:10:16PM +0200, Dafna Hirschfeld wrote:
> 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@collabora.com>
> ---
>  .../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(-)
> 

Thank you for the patch. Please see my comments inline.

> 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

What is a "capture stream" in terms of the subdev API? Should this
perhaps refer to "source pads" instead?

[snip]
> +.. _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

Ditto.

> +	colorspace conversion from the received colorspace to the requested
> +	colorspace values. If colorimetry field (``colorspace``, ``ycbcr_enc``,

nit: a colorimetry field

> +	``quantization`` or ``xfer_func``) is set to 0, then that colorimetry

Is it okay to explicitly mention 0 here, rather than the defined
"_DEFAULT" values?

Best regards,
Tomasz

Patch
diff mbox series

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];
 };
 
 /**