diff mbox series

[v9,06/46] media: uapi: v4l: Add generic 8-bit metadata format definitions

Message ID 20240416193319.778192-7-sakari.ailus@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Generic line based metadata support, internal pads | expand

Commit Message

Sakari Ailus April 16, 2024, 7:32 p.m. UTC
Generic 8-bit metadata formats define the in-memory data layout but not
the format of the data itself. The reasoning for having such formats is to
allow CSI-2 receiver drivers to receive and DMA drivers to write the data
to memory without knowing a large number of device-specific formats.

These formats may be used only in conjunction with a Media controller
pipeline where the internal pad of the source sub-device defines the
specific format of the data (using an mbus code).

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 .../userspace-api/media/v4l/dev-subdev.rst    |   2 +
 .../userspace-api/media/v4l/meta-formats.rst  |   3 +-
 .../media/v4l/metafmt-generic.rst             | 328 ++++++++++++++++++
 drivers/media/v4l2-core/v4l2-ioctl.c          |   7 +
 include/uapi/linux/videodev2.h                |   8 +
 5 files changed, 347 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/userspace-api/media/v4l/metafmt-generic.rst

Comments

Laurent Pinchart April 19, 2024, 4:26 p.m. UTC | #1
Hi Sakari,

Thank you for the patch.

On Tue, Apr 16, 2024 at 10:32:39PM +0300, Sakari Ailus wrote:
> Generic 8-bit metadata formats define the in-memory data layout but not
> the format of the data itself. The reasoning for having such formats is to
> allow CSI-2 receiver drivers to receive and DMA drivers to write the data
> to memory without knowing a large number of device-specific formats.
> 
> These formats may be used only in conjunction with a Media controller

"Media Controller" or "media controller"

> pipeline where the internal pad of the source sub-device defines the
> specific format of the data (using an mbus code).
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>  .../userspace-api/media/v4l/dev-subdev.rst    |   2 +
>  .../userspace-api/media/v4l/meta-formats.rst  |   3 +-
>  .../media/v4l/metafmt-generic.rst             | 328 ++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-ioctl.c          |   7 +
>  include/uapi/linux/videodev2.h                |   8 +
>  5 files changed, 347 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/userspace-api/media/v4l/metafmt-generic.rst
> 
> diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst
> index 43988516acdd..f375b820ab68 100644
> --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst
> +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst
> @@ -506,6 +506,8 @@ source pads.
>  
>      subdev-formats
>  
> +.. _subdev-routing:
> +
>  Streams, multiplexed media pads and internal routing
>  ----------------------------------------------------
>  
> diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
> index 0bb61fc5bc00..c23aac823d2c 100644
> --- a/Documentation/userspace-api/media/v4l/meta-formats.rst
> +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
> @@ -13,9 +13,10 @@ These formats are used for the :ref:`metadata` interface only.
>      :maxdepth: 1
>  
>      metafmt-d4xx
> +    metafmt-generic
>      metafmt-intel-ipu3
>      metafmt-rkisp1
>      metafmt-uvc
> +    metafmt-vivid
>      metafmt-vsp1-hgo
>      metafmt-vsp1-hgt
> -    metafmt-vivid
> diff --git a/Documentation/userspace-api/media/v4l/metafmt-generic.rst b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> new file mode 100644
> index 000000000000..cba34be64dfe
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> @@ -0,0 +1,328 @@
> +.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
> +
> +********************************************************************************************************************************************************************************************************************************************************************************
> +V4L2_META_FMT_GENERIC_8 ('MET8'), V4L2_META_FMT_GENERIC_CSI2_10 ('MC1A'), V4L2_META_FMT_GENERIC_CSI2_12 ('MC1C'), V4L2_META_FMT_GENERIC_CSI2_14 ('MC1E'), V4L2_META_FMT_GENERIC_CSI2_16 ('MC1G'), V4L2_META_FMT_GENERIC_CSI2_20 ('MC1K'), V4L2_META_FMT_GENERIC_CSI2_24 ('MC1O')
> +********************************************************************************************************************************************************************************************************************************************************************************
> +
> +
> +Generic line-based metadata formats
> +
> +
> +Description
> +===========
> +
> +These generic line-based metadata formats define the memory layout of the data
> +without defining the format or meaning of the metadata itself. These formats may
> +only be used with a Media Controller pipeline where the more specific format is
> +reported by an :ref:`internal sink pad <MEDIA-PAD-FL-INTERNAL>` of the source
> +sub-device. See also :ref:`source routes <subdev-routing>`.
> +
> +.. _v4l2-meta-fmt-generic-8:
> +
> +V4L2_META_FMT_GENERIC_8
> +-----------------------
> +
> +The V4L2_META_FMT_GENERIC_8 format is a plain 8-bit metadata format.
> +
> +This format is also used on CSI-2 for both 8 bits per ``Data Unit
> +<media-glossary-data-unit>`` as well as for 16 bits per Data Unit when two bytes
> +of metadata are packed into one 16-bit Data Unit.
> +
> +**Byte Order Of V4L2_META_FMT_GENERIC_8.**
> +Each cell is one byte. "M" denotes a byte of metadata.
> +
> +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|
> +
> +.. flat-table:: Sample 4x2 Metadata Frame
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths: 12 8 8 8 8
> +
> +    * - start + 0:
> +      - M\ :sub:`00`
> +      - M\ :sub:`10`
> +      - M\ :sub:`20`
> +      - M\ :sub:`30`
> +    * - start + 4:
> +      - M\ :sub:`01`
> +      - M\ :sub:`11`
> +      - M\ :sub:`21`
> +      - M\ :sub:`31`
> +
> +.. _v4l2-meta-fmt-generic-csi2-10:
> +
> +V4L2_META_FMT_GENERIC_CSI2_10
> +-----------------------------
> +
> +V4L2_META_FMT_GENERIC_CSI2_10 contains 8-bit generic metadata packed in 10-bit
> +Data Units, with one padding byte after every four bytes of metadata. This
> +format is typically used by CSI-2 receivers with a source that transmits
> +MEDIA_BUS_FMT_META_10 and the CSI-2 receiver writes the received data to memory
> +as-is.
> +
> +The packing of the data follows the MIPI CSI-2 specification and the padding of
> +the data is defined in the MIPI CCS specification.
> +
> +This format is also used in conjunction with 20 bits per ``Data Unit

s/in conjunction with/for/

Same below.

> +<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
> +Data Unit.

How about adding a mention of MEDIA_BUS_FMT_META_20 here ? The CCS
specification calls this "RAW20 (with more optimal RAW10 packing)",
using the same vocabulary could help. Same for
V4L2_META_FMT_GENERIC_CSI2_12, and actually V4L2_META_FMT_GENERIC_8 too.

> +
> +This format is little endian.
> +
> +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_10.**
> +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> +
> +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
> +
> +.. flat-table:: Sample 4x2 Metadata Frame
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths: 12 8 8 8 8 8
> +
> +    * - start + 0:
> +      - M\ :sub:`00`
> +      - M\ :sub:`10`
> +      - M\ :sub:`20`
> +      - M\ :sub:`30`
> +      - x
> +    * - start + 5:
> +      - M\ :sub:`01`
> +      - M\ :sub:`11`
> +      - M\ :sub:`21`
> +      - M\ :sub:`31`
> +      - x
> +
> +.. _v4l2-meta-fmt-generic-csi2-12:
> +
> +V4L2_META_FMT_GENERIC_CSI2_12
> +-----------------------------
> +
> +V4L2_META_FMT_GENERIC_CSI2_12 contains 8-bit generic metadata packed in 12-bit
> +Data Units, with two padding bytes after every four bytes of metadata. This

Isn't it one padding byte every two bytes of metadata ?

> +format is typically used by CSI-2 receivers with a source that transmits
> +MEDIA_BUS_FMT_META_12 and the CSI-2 receiver writes the received data to memory
> +as-is.
> +
> +The packing of the data follows the MIPI CSI-2 specification and the padding of
> +the data is defined in the MIPI CCS specification.
> +
> +This format is also used in conjunction with 24 bits per ``Data Unit
> +<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
> +Data Unit.
> +
> +This format is little endian.
> +
> +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_12.**
> +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> +
> +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> +
> +.. flat-table:: Sample 4x2 Metadata Frame
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths: 12 8 8 8 8 8 8
> +
> +    * - start + 0:
> +      - M\ :sub:`00`
> +      - M\ :sub:`10`
> +      - x
> +      - M\ :sub:`20`
> +      - M\ :sub:`30`
> +      - x
> +    * - start + 6:
> +      - M\ :sub:`01`
> +      - M\ :sub:`11`
> +      - x
> +      - M\ :sub:`21`
> +      - M\ :sub:`31`
> +      - x
> +
> +.. _v4l2-meta-fmt-generic-csi2-14:
> +
> +V4L2_META_FMT_GENERIC_CSI2_14
> +-----------------------------
> +
> +V4L2_META_FMT_GENERIC_CSI2_14 contains 8-bit generic metadata packed in 14-bit
> +Data Units, with three padding bytes after every four bytes of metadata. This
> +format is typically used by CSI-2 receivers with a source that transmits
> +MEDIA_BUS_FMT_META_14 and the CSI-2 receiver writes the received data to memory
> +as-is.
> +
> +The packing of the data follows the MIPI CSI-2 specification and the padding of
> +the data is defined in the MIPI CCS specification.
> +
> +This format is little endian.
> +
> +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_14.**
> +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> +
> +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{.8cm}|
> +
> +.. flat-table:: Sample 4x2 Metadata Frame
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths: 12 8 8 8 8 8 8 8
> +
> +    * - start + 0:
> +      - M\ :sub:`00`
> +      - M\ :sub:`10`
> +      - M\ :sub:`20`
> +      - M\ :sub:`30`
> +      - x
> +      - x
> +      - x
> +    * - start + 7:
> +      - M\ :sub:`01`
> +      - M\ :sub:`11`
> +      - M\ :sub:`21`
> +      - M\ :sub:`31`
> +      - x
> +      - x
> +      - x
> +
> +.. _v4l2-meta-fmt-generic-csi2-16:
> +
> +V4L2_META_FMT_GENERIC_CSI2_16
> +-----------------------------
> +
> +V4L2_META_FMT_GENERIC_CSI2_16 contains 8-bit generic metadata packed in 16-bit
> +Data Units, with one padding byte after every byte of metadata. This format is
> +typically used by CSI-2 receivers with a source that transmits
> +MEDIA_BUS_FMT_META_16 and the CSI-2 receiver writes the received data to memory
> +as-is.
> +
> +The packing of the data follows the MIPI CSI-2 specification and the padding of
> +the data is defined in the MIPI CCS specification.

Here you could also mention that more optimal packing schemes for
MEDIA_BUS_FMT_META_16 use V4L2_META_FMT_GENERIC_8. Same below.

> +
> +This format is little endian.
> +
> +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_16.**
> +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> +
> +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|
> +
> +.. flat-table:: Sample 4x2 Metadata Frame
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths: 12 8 8 8 8 8 8 8 8
> +
> +    * - start + 0:
> +      - M\ :sub:`00`
> +      - x
> +      - M\ :sub:`10`
> +      - x
> +      - M\ :sub:`20`
> +      - x
> +      - M\ :sub:`30`
> +      - x
> +    * - start + 8:
> +      - M\ :sub:`01`
> +      - x
> +      - M\ :sub:`11`
> +      - x
> +      - M\ :sub:`21`
> +      - x
> +      - M\ :sub:`31`
> +      - x
> +
> +.. _v4l2-meta-fmt-generic-csi2-20:
> +
> +V4L2_META_FMT_GENERIC_CSI2_20
> +-----------------------------
> +
> +V4L2_META_FMT_GENERIC_CSI2_20 contains 8-bit generic metadata packed in 20-bit
> +Data Units, with alternating one or two padding bytes after every byte of
> +metadata. This format is typically used by CSI-2 receivers with a source that
> +transmits MEDIA_BUS_FMT_META_20 and the CSI-2 receiver writes the received data
> +to memory as-is.
> +
> +The packing of the data follows the MIPI CSI-2 specification and the padding of
> +the data is defined in the MIPI CCS specification.
> +
> +This format is little endian.
> +
> +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_20.**
> +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> +
> +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> +
> +.. flat-table:: Sample 4x2 Metadata Frame
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths: 12 8 8 8 8 8 8 8 8 8 8
> +
> +    * - start + 0:
> +      - M\ :sub:`00`
> +      - x
> +      - M\ :sub:`10`
> +      - x
> +      - x
> +      - M\ :sub:`20`
> +      - x
> +      - M\ :sub:`30`
> +      - x
> +      - x
> +    * - start + 10:
> +      - M\ :sub:`01`
> +      - x
> +      - M\ :sub:`11`
> +      - x
> +      - x
> +      - M\ :sub:`21`
> +      - x
> +      - M\ :sub:`31`
> +      - x
> +      - x
> +
> +.. _v4l2-meta-fmt-generic-csi2-24:
> +
> +V4L2_META_FMT_GENERIC_CSI2_24
> +-----------------------------
> +
> +V4L2_META_FMT_GENERIC_CSI2_24 contains 8-bit generic metadata packed in 24-bit
> +Data Units, with two padding bytes after every byte of metadata. This format is
> +typically used by CSI-2 receivers with a source that transmits
> +MEDIA_BUS_FMT_META_24 and the CSI-2 receiver writes the received data to memory
> +as-is.
> +
> +The packing of the data follows the MIPI CSI-2 specification and the padding of
> +the data is defined in the MIPI CCS specification.
> +
> +This format is little endian.
> +
> +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_24.**
> +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> +
> +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> +
> +.. flat-table:: Sample 4x2 Metadata Frame
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths: 12 8 8 8 8 8 8 8 8 8 8 8 8
> +
> +    * - start + 0:
> +      - M\ :sub:`00`
> +      - x
> +      - x
> +      - M\ :sub:`10`
> +      - x
> +      - x
> +      - M\ :sub:`20`
> +      - x
> +      - x
> +      - M\ :sub:`30`
> +      - x
> +      - x
> +    * - start + 12:
> +      - M\ :sub:`01`
> +      - x
> +      - x
> +      - M\ :sub:`11`
> +      - x
> +      - x
> +      - M\ :sub:`21`
> +      - x
> +      - x
> +      - M\ :sub:`31`
> +      - x
> +      - x
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 5aeff5519407..ae2dca7f2817 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1460,6 +1460,13 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>  	case V4L2_PIX_FMT_Y210:		descr = "10-bit YUYV Packed"; break;
>  	case V4L2_PIX_FMT_Y212:		descr = "12-bit YUYV Packed"; break;
>  	case V4L2_PIX_FMT_Y216:		descr = "16-bit YUYV Packed"; break;
> +	case V4L2_META_FMT_GENERIC_8:	descr = "8-bit Generic Metadata"; break;
> +	case V4L2_META_FMT_GENERIC_CSI2_10:	descr = "8-bit Generic Meta, 10b CSI-2"; break;
> +	case V4L2_META_FMT_GENERIC_CSI2_12:	descr = "8-bit Generic Meta, 12b CSI-2"; break;
> +	case V4L2_META_FMT_GENERIC_CSI2_14:	descr = "8-bit Generic Meta, 14b CSI-2"; break;
> +	case V4L2_META_FMT_GENERIC_CSI2_16:	descr = "8-bit Generic Meta, 16b CSI-2"; break;
> +	case V4L2_META_FMT_GENERIC_CSI2_20:	descr = "8-bit Generic Meta, 20b CSI-2"; break;
> +	case V4L2_META_FMT_GENERIC_CSI2_24:	descr = "8-bit Generic Meta, 24b CSI-2"; break;
>  
>  	default:
>  		/* Compressed formats */
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 2663213b76a4..c7cf20b5da67 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -839,6 +839,14 @@ struct v4l2_pix_format {
>  #define V4L2_META_FMT_RK_ISP1_PARAMS	v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
>  #define V4L2_META_FMT_RK_ISP1_STAT_3A	v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
>  
> +#define V4L2_META_FMT_GENERIC_8		v4l2_fourcc('M', 'E', 'T', '8') /* Generic 8-bit metadata */
> +#define V4L2_META_FMT_GENERIC_CSI2_10	v4l2_fourcc('M', 'C', '1', 'A') /* 10-bit CSI-2 packed 8-bit metadata */
> +#define V4L2_META_FMT_GENERIC_CSI2_12	v4l2_fourcc('M', 'C', '1', 'C') /* 12-bit CSI-2 packed 8-bit metadata */
> +#define V4L2_META_FMT_GENERIC_CSI2_14	v4l2_fourcc('M', 'C', '1', 'E') /* 14-bit CSI-2 packed 8-bit metadata */
> +#define V4L2_META_FMT_GENERIC_CSI2_16	v4l2_fourcc('M', 'C', '1', 'G') /* 16-bit CSI-2 packed 8-bit metadata */
> +#define V4L2_META_FMT_GENERIC_CSI2_20	v4l2_fourcc('M', 'C', '1', 'K') /* 20-bit CSI-2 packed 8-bit metadata */
> +#define V4L2_META_FMT_GENERIC_CSI2_24	v4l2_fourcc('M', 'C', '1', 'O') /* 24-bit CSI-2 packed 8-bit metadata */
> +
>  /* priv field value to indicates that subsequent fields are valid. */
>  #define V4L2_PIX_FMT_PRIV_MAGIC		0xfeedcafe
>
Sakari Ailus April 23, 2024, 7:04 a.m. UTC | #2
Hi Laurent,

On Fri, Apr 19, 2024 at 07:26:19PM +0300, Laurent Pinchart wrote:
> Hi Sakari,
> 
> Thank you for the patch.
> 
> On Tue, Apr 16, 2024 at 10:32:39PM +0300, Sakari Ailus wrote:
> > Generic 8-bit metadata formats define the in-memory data layout but not
> > the format of the data itself. The reasoning for having such formats is to
> > allow CSI-2 receiver drivers to receive and DMA drivers to write the data
> > to memory without knowing a large number of device-specific formats.
> > 
> > These formats may be used only in conjunction with a Media controller
> 
> "Media Controller" or "media controller"

Yes.

> 
> > pipeline where the internal pad of the source sub-device defines the
> > specific format of the data (using an mbus code).
> > 
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > ---
> >  .../userspace-api/media/v4l/dev-subdev.rst    |   2 +
> >  .../userspace-api/media/v4l/meta-formats.rst  |   3 +-
> >  .../media/v4l/metafmt-generic.rst             | 328 ++++++++++++++++++
> >  drivers/media/v4l2-core/v4l2-ioctl.c          |   7 +
> >  include/uapi/linux/videodev2.h                |   8 +
> >  5 files changed, 347 insertions(+), 1 deletion(-)
> >  create mode 100644 Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > 
> > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > index 43988516acdd..f375b820ab68 100644
> > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > @@ -506,6 +506,8 @@ source pads.
> >  
> >      subdev-formats
> >  
> > +.. _subdev-routing:
> > +
> >  Streams, multiplexed media pads and internal routing
> >  ----------------------------------------------------
> >  
> > diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
> > index 0bb61fc5bc00..c23aac823d2c 100644
> > --- a/Documentation/userspace-api/media/v4l/meta-formats.rst
> > +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
> > @@ -13,9 +13,10 @@ These formats are used for the :ref:`metadata` interface only.
> >      :maxdepth: 1
> >  
> >      metafmt-d4xx
> > +    metafmt-generic
> >      metafmt-intel-ipu3
> >      metafmt-rkisp1
> >      metafmt-uvc
> > +    metafmt-vivid
> >      metafmt-vsp1-hgo
> >      metafmt-vsp1-hgt
> > -    metafmt-vivid
> > diff --git a/Documentation/userspace-api/media/v4l/metafmt-generic.rst b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > new file mode 100644
> > index 000000000000..cba34be64dfe
> > --- /dev/null
> > +++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > @@ -0,0 +1,328 @@
> > +.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
> > +
> > +********************************************************************************************************************************************************************************************************************************************************************************
> > +V4L2_META_FMT_GENERIC_8 ('MET8'), V4L2_META_FMT_GENERIC_CSI2_10 ('MC1A'), V4L2_META_FMT_GENERIC_CSI2_12 ('MC1C'), V4L2_META_FMT_GENERIC_CSI2_14 ('MC1E'), V4L2_META_FMT_GENERIC_CSI2_16 ('MC1G'), V4L2_META_FMT_GENERIC_CSI2_20 ('MC1K'), V4L2_META_FMT_GENERIC_CSI2_24 ('MC1O')
> > +********************************************************************************************************************************************************************************************************************************************************************************
> > +
> > +
> > +Generic line-based metadata formats
> > +
> > +
> > +Description
> > +===========
> > +
> > +These generic line-based metadata formats define the memory layout of the data
> > +without defining the format or meaning of the metadata itself. These formats may
> > +only be used with a Media Controller pipeline where the more specific format is
> > +reported by an :ref:`internal sink pad <MEDIA-PAD-FL-INTERNAL>` of the source
> > +sub-device. See also :ref:`source routes <subdev-routing>`.
> > +
> > +.. _v4l2-meta-fmt-generic-8:
> > +
> > +V4L2_META_FMT_GENERIC_8
> > +-----------------------
> > +
> > +The V4L2_META_FMT_GENERIC_8 format is a plain 8-bit metadata format.
> > +
> > +This format is also used on CSI-2 for both 8 bits per ``Data Unit
> > +<media-glossary-data-unit>`` as well as for 16 bits per Data Unit when two bytes
> > +of metadata are packed into one 16-bit Data Unit.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_8.**
> > +Each cell is one byte. "M" denotes a byte of metadata.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|
> > +
> > +.. flat-table:: Sample 4x2 Metadata Frame
> > +    :header-rows:  0
> > +    :stub-columns: 0
> > +    :widths: 12 8 8 8 8
> > +
> > +    * - start + 0:
> > +      - M\ :sub:`00`
> > +      - M\ :sub:`10`
> > +      - M\ :sub:`20`
> > +      - M\ :sub:`30`
> > +    * - start + 4:
> > +      - M\ :sub:`01`
> > +      - M\ :sub:`11`
> > +      - M\ :sub:`21`
> > +      - M\ :sub:`31`
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-10:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_10
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_10 contains 8-bit generic metadata packed in 10-bit
> > +Data Units, with one padding byte after every four bytes of metadata. This
> > +format is typically used by CSI-2 receivers with a source that transmits
> > +MEDIA_BUS_FMT_META_10 and the CSI-2 receiver writes the received data to memory
> > +as-is.
> > +
> > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > +the data is defined in the MIPI CCS specification.
> > +
> > +This format is also used in conjunction with 20 bits per ``Data Unit
> 
> s/in conjunction with/for/
> 
> Same below.

That is shorter but is it better?

> 
> > +<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
> > +Data Unit.
> 
> How about adding a mention of MEDIA_BUS_FMT_META_20 here ? The CCS
> specification calls this "RAW20 (with more optimal RAW10 packing)",
> using the same vocabulary could help. Same for
> V4L2_META_FMT_GENERIC_CSI2_12, and actually V4L2_META_FMT_GENERIC_8 too.

Is it useful? It's the same as 10-bit packing after all.

RAW20 in CCS refers to image data.

> 
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_10.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
> > +
> > +.. flat-table:: Sample 4x2 Metadata Frame
> > +    :header-rows:  0
> > +    :stub-columns: 0
> > +    :widths: 12 8 8 8 8 8
> > +
> > +    * - start + 0:
> > +      - M\ :sub:`00`
> > +      - M\ :sub:`10`
> > +      - M\ :sub:`20`
> > +      - M\ :sub:`30`
> > +      - x
> > +    * - start + 5:
> > +      - M\ :sub:`01`
> > +      - M\ :sub:`11`
> > +      - M\ :sub:`21`
> > +      - M\ :sub:`31`
> > +      - x
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-12:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_12
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_12 contains 8-bit generic metadata packed in 12-bit
> > +Data Units, with two padding bytes after every four bytes of metadata. This
> 
> Isn't it one padding byte every two bytes of metadata ?

Uh, yes. This was mistakenly copied from text for a different bpp.

> 
> > +format is typically used by CSI-2 receivers with a source that transmits
> > +MEDIA_BUS_FMT_META_12 and the CSI-2 receiver writes the received data to memory
> > +as-is.
> > +
> > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > +the data is defined in the MIPI CCS specification.
> > +
> > +This format is also used in conjunction with 24 bits per ``Data Unit
> > +<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
> > +Data Unit.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_12.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > +
> > +.. flat-table:: Sample 4x2 Metadata Frame
> > +    :header-rows:  0
> > +    :stub-columns: 0
> > +    :widths: 12 8 8 8 8 8 8
> > +
> > +    * - start + 0:
> > +      - M\ :sub:`00`
> > +      - M\ :sub:`10`
> > +      - x
> > +      - M\ :sub:`20`
> > +      - M\ :sub:`30`
> > +      - x
> > +    * - start + 6:
> > +      - M\ :sub:`01`
> > +      - M\ :sub:`11`
> > +      - x
> > +      - M\ :sub:`21`
> > +      - M\ :sub:`31`
> > +      - x
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-14:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_14
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_14 contains 8-bit generic metadata packed in 14-bit
> > +Data Units, with three padding bytes after every four bytes of metadata. This
> > +format is typically used by CSI-2 receivers with a source that transmits
> > +MEDIA_BUS_FMT_META_14 and the CSI-2 receiver writes the received data to memory
> > +as-is.
> > +
> > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > +the data is defined in the MIPI CCS specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_14.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{.8cm}|
> > +
> > +.. flat-table:: Sample 4x2 Metadata Frame
> > +    :header-rows:  0
> > +    :stub-columns: 0
> > +    :widths: 12 8 8 8 8 8 8 8
> > +
> > +    * - start + 0:
> > +      - M\ :sub:`00`
> > +      - M\ :sub:`10`
> > +      - M\ :sub:`20`
> > +      - M\ :sub:`30`
> > +      - x
> > +      - x
> > +      - x
> > +    * - start + 7:
> > +      - M\ :sub:`01`
> > +      - M\ :sub:`11`
> > +      - M\ :sub:`21`
> > +      - M\ :sub:`31`
> > +      - x
> > +      - x
> > +      - x
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-16:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_16
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_16 contains 8-bit generic metadata packed in 16-bit
> > +Data Units, with one padding byte after every byte of metadata. This format is
> > +typically used by CSI-2 receivers with a source that transmits
> > +MEDIA_BUS_FMT_META_16 and the CSI-2 receiver writes the received data to memory
> > +as-is.
> > +
> > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > +the data is defined in the MIPI CCS specification.
> 
> Here you could also mention that more optimal packing schemes for
> MEDIA_BUS_FMT_META_16 use V4L2_META_FMT_GENERIC_8. Same below.

The "more optimal packing scheme" is really a different format. There's no
other relation between these, really. I wouldn't mention it here. A driver
would enumerate both for metadata when they're supported.

> 
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_16.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|
> > +
> > +.. flat-table:: Sample 4x2 Metadata Frame
> > +    :header-rows:  0
> > +    :stub-columns: 0
> > +    :widths: 12 8 8 8 8 8 8 8 8
> > +
> > +    * - start + 0:
> > +      - M\ :sub:`00`
> > +      - x
> > +      - M\ :sub:`10`
> > +      - x
> > +      - M\ :sub:`20`
> > +      - x
> > +      - M\ :sub:`30`
> > +      - x
> > +    * - start + 8:
> > +      - M\ :sub:`01`
> > +      - x
> > +      - M\ :sub:`11`
> > +      - x
> > +      - M\ :sub:`21`
> > +      - x
> > +      - M\ :sub:`31`
> > +      - x
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-20:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_20
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_20 contains 8-bit generic metadata packed in 20-bit
> > +Data Units, with alternating one or two padding bytes after every byte of
> > +metadata. This format is typically used by CSI-2 receivers with a source that
> > +transmits MEDIA_BUS_FMT_META_20 and the CSI-2 receiver writes the received data
> > +to memory as-is.
> > +
> > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > +the data is defined in the MIPI CCS specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_20.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > +
> > +.. flat-table:: Sample 4x2 Metadata Frame
> > +    :header-rows:  0
> > +    :stub-columns: 0
> > +    :widths: 12 8 8 8 8 8 8 8 8 8 8
> > +
> > +    * - start + 0:
> > +      - M\ :sub:`00`
> > +      - x
> > +      - M\ :sub:`10`
> > +      - x
> > +      - x
> > +      - M\ :sub:`20`
> > +      - x
> > +      - M\ :sub:`30`
> > +      - x
> > +      - x
> > +    * - start + 10:
> > +      - M\ :sub:`01`
> > +      - x
> > +      - M\ :sub:`11`
> > +      - x
> > +      - x
> > +      - M\ :sub:`21`
> > +      - x
> > +      - M\ :sub:`31`
> > +      - x
> > +      - x
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-24:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_24
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_24 contains 8-bit generic metadata packed in 24-bit
> > +Data Units, with two padding bytes after every byte of metadata. This format is
> > +typically used by CSI-2 receivers with a source that transmits
> > +MEDIA_BUS_FMT_META_24 and the CSI-2 receiver writes the received data to memory
> > +as-is.
> > +
> > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > +the data is defined in the MIPI CCS specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_24.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > +
> > +.. flat-table:: Sample 4x2 Metadata Frame
> > +    :header-rows:  0
> > +    :stub-columns: 0
> > +    :widths: 12 8 8 8 8 8 8 8 8 8 8 8 8
> > +
> > +    * - start + 0:
> > +      - M\ :sub:`00`
> > +      - x
> > +      - x
> > +      - M\ :sub:`10`
> > +      - x
> > +      - x
> > +      - M\ :sub:`20`
> > +      - x
> > +      - x
> > +      - M\ :sub:`30`
> > +      - x
> > +      - x
> > +    * - start + 12:
> > +      - M\ :sub:`01`
> > +      - x
> > +      - x
> > +      - M\ :sub:`11`
> > +      - x
> > +      - x
> > +      - M\ :sub:`21`
> > +      - x
> > +      - x
> > +      - M\ :sub:`31`
> > +      - x
> > +      - x
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > index 5aeff5519407..ae2dca7f2817 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -1460,6 +1460,13 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> >  	case V4L2_PIX_FMT_Y210:		descr = "10-bit YUYV Packed"; break;
> >  	case V4L2_PIX_FMT_Y212:		descr = "12-bit YUYV Packed"; break;
> >  	case V4L2_PIX_FMT_Y216:		descr = "16-bit YUYV Packed"; break;
> > +	case V4L2_META_FMT_GENERIC_8:	descr = "8-bit Generic Metadata"; break;
> > +	case V4L2_META_FMT_GENERIC_CSI2_10:	descr = "8-bit Generic Meta, 10b CSI-2"; break;
> > +	case V4L2_META_FMT_GENERIC_CSI2_12:	descr = "8-bit Generic Meta, 12b CSI-2"; break;
> > +	case V4L2_META_FMT_GENERIC_CSI2_14:	descr = "8-bit Generic Meta, 14b CSI-2"; break;
> > +	case V4L2_META_FMT_GENERIC_CSI2_16:	descr = "8-bit Generic Meta, 16b CSI-2"; break;
> > +	case V4L2_META_FMT_GENERIC_CSI2_20:	descr = "8-bit Generic Meta, 20b CSI-2"; break;
> > +	case V4L2_META_FMT_GENERIC_CSI2_24:	descr = "8-bit Generic Meta, 24b CSI-2"; break;
> >  
> >  	default:
> >  		/* Compressed formats */
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index 2663213b76a4..c7cf20b5da67 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -839,6 +839,14 @@ struct v4l2_pix_format {
> >  #define V4L2_META_FMT_RK_ISP1_PARAMS	v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
> >  #define V4L2_META_FMT_RK_ISP1_STAT_3A	v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
> >  
> > +#define V4L2_META_FMT_GENERIC_8		v4l2_fourcc('M', 'E', 'T', '8') /* Generic 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_10	v4l2_fourcc('M', 'C', '1', 'A') /* 10-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_12	v4l2_fourcc('M', 'C', '1', 'C') /* 12-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_14	v4l2_fourcc('M', 'C', '1', 'E') /* 14-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_16	v4l2_fourcc('M', 'C', '1', 'G') /* 16-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_20	v4l2_fourcc('M', 'C', '1', 'K') /* 20-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_24	v4l2_fourcc('M', 'C', '1', 'O') /* 24-bit CSI-2 packed 8-bit metadata */
> > +
> >  /* priv field value to indicates that subsequent fields are valid. */
> >  #define V4L2_PIX_FMT_PRIV_MAGIC		0xfeedcafe
> >  
>
Laurent Pinchart April 23, 2024, 7:32 a.m. UTC | #3
Hi Sakari,

On Tue, Apr 23, 2024 at 07:04:58AM +0000, Sakari Ailus wrote:
> On Fri, Apr 19, 2024 at 07:26:19PM +0300, Laurent Pinchart wrote:
> > On Tue, Apr 16, 2024 at 10:32:39PM +0300, Sakari Ailus wrote:
> > > Generic 8-bit metadata formats define the in-memory data layout but not
> > > the format of the data itself. The reasoning for having such formats is to
> > > allow CSI-2 receiver drivers to receive and DMA drivers to write the data
> > > to memory without knowing a large number of device-specific formats.
> > > 
> > > These formats may be used only in conjunction with a Media controller
> > 
> > "Media Controller" or "media controller"
> 
> Yes.
> 
> > > pipeline where the internal pad of the source sub-device defines the
> > > specific format of the data (using an mbus code).
> > > 
> > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > > ---
> > >  .../userspace-api/media/v4l/dev-subdev.rst    |   2 +
> > >  .../userspace-api/media/v4l/meta-formats.rst  |   3 +-
> > >  .../media/v4l/metafmt-generic.rst             | 328 ++++++++++++++++++
> > >  drivers/media/v4l2-core/v4l2-ioctl.c          |   7 +
> > >  include/uapi/linux/videodev2.h                |   8 +
> > >  5 files changed, 347 insertions(+), 1 deletion(-)
> > >  create mode 100644 Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > > 
> > > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > > index 43988516acdd..f375b820ab68 100644
> > > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > > @@ -506,6 +506,8 @@ source pads.
> > >  
> > >      subdev-formats
> > >  
> > > +.. _subdev-routing:
> > > +
> > >  Streams, multiplexed media pads and internal routing
> > >  ----------------------------------------------------
> > >  
> > > diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
> > > index 0bb61fc5bc00..c23aac823d2c 100644
> > > --- a/Documentation/userspace-api/media/v4l/meta-formats.rst
> > > +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
> > > @@ -13,9 +13,10 @@ These formats are used for the :ref:`metadata` interface only.
> > >      :maxdepth: 1
> > >  
> > >      metafmt-d4xx
> > > +    metafmt-generic
> > >      metafmt-intel-ipu3
> > >      metafmt-rkisp1
> > >      metafmt-uvc
> > > +    metafmt-vivid
> > >      metafmt-vsp1-hgo
> > >      metafmt-vsp1-hgt
> > > -    metafmt-vivid
> > > diff --git a/Documentation/userspace-api/media/v4l/metafmt-generic.rst b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > > new file mode 100644
> > > index 000000000000..cba34be64dfe
> > > --- /dev/null
> > > +++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > > @@ -0,0 +1,328 @@
> > > +.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
> > > +
> > > +********************************************************************************************************************************************************************************************************************************************************************************
> > > +V4L2_META_FMT_GENERIC_8 ('MET8'), V4L2_META_FMT_GENERIC_CSI2_10 ('MC1A'), V4L2_META_FMT_GENERIC_CSI2_12 ('MC1C'), V4L2_META_FMT_GENERIC_CSI2_14 ('MC1E'), V4L2_META_FMT_GENERIC_CSI2_16 ('MC1G'), V4L2_META_FMT_GENERIC_CSI2_20 ('MC1K'), V4L2_META_FMT_GENERIC_CSI2_24 ('MC1O')
> > > +********************************************************************************************************************************************************************************************************************************************************************************
> > > +
> > > +
> > > +Generic line-based metadata formats
> > > +
> > > +
> > > +Description
> > > +===========
> > > +
> > > +These generic line-based metadata formats define the memory layout of the data
> > > +without defining the format or meaning of the metadata itself. These formats may
> > > +only be used with a Media Controller pipeline where the more specific format is
> > > +reported by an :ref:`internal sink pad <MEDIA-PAD-FL-INTERNAL>` of the source
> > > +sub-device. See also :ref:`source routes <subdev-routing>`.
> > > +
> > > +.. _v4l2-meta-fmt-generic-8:
> > > +
> > > +V4L2_META_FMT_GENERIC_8
> > > +-----------------------
> > > +
> > > +The V4L2_META_FMT_GENERIC_8 format is a plain 8-bit metadata format.
> > > +
> > > +This format is also used on CSI-2 for both 8 bits per ``Data Unit
> > > +<media-glossary-data-unit>`` as well as for 16 bits per Data Unit when two bytes
> > > +of metadata are packed into one 16-bit Data Unit.
> > > +
> > > +**Byte Order Of V4L2_META_FMT_GENERIC_8.**
> > > +Each cell is one byte. "M" denotes a byte of metadata.
> > > +
> > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|
> > > +
> > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > +    :header-rows:  0
> > > +    :stub-columns: 0
> > > +    :widths: 12 8 8 8 8
> > > +
> > > +    * - start + 0:
> > > +      - M\ :sub:`00`
> > > +      - M\ :sub:`10`
> > > +      - M\ :sub:`20`
> > > +      - M\ :sub:`30`
> > > +    * - start + 4:
> > > +      - M\ :sub:`01`
> > > +      - M\ :sub:`11`
> > > +      - M\ :sub:`21`
> > > +      - M\ :sub:`31`
> > > +
> > > +.. _v4l2-meta-fmt-generic-csi2-10:
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_10
> > > +-----------------------------
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_10 contains 8-bit generic metadata packed in 10-bit
> > > +Data Units, with one padding byte after every four bytes of metadata. This
> > > +format is typically used by CSI-2 receivers with a source that transmits
> > > +MEDIA_BUS_FMT_META_10 and the CSI-2 receiver writes the received data to memory
> > > +as-is.
> > > +
> > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > +the data is defined in the MIPI CCS specification.
> > > +
> > > +This format is also used in conjunction with 20 bits per ``Data Unit
> > 
> > s/in conjunction with/for/
> > 
> > Same below.
> 
> That is shorter but is it better?

I think it's simpler and thus clearer. Up to you.

> > > +<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
> > > +Data Unit.
> > 
> > How about adding a mention of MEDIA_BUS_FMT_META_20 here ? The CCS
> > specification calls this "RAW20 (with more optimal RAW10 packing)",
> > using the same vocabulary could help. Same for
> > V4L2_META_FMT_GENERIC_CSI2_12, and actually V4L2_META_FMT_GENERIC_8 too.
> 
> Is it useful? It's the same as 10-bit packing after all.

I think cross-referencing the two entries that can be used to transmit
metadata for the same image format is useful. 

> RAW20 in CCS refers to image data.

The wording I quoted comes from the CCS specification :-) Using the same
terms as in the spec would help in my opinion.

> > > +
> > > +This format is little endian.
> > > +
> > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_10.**
> > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > +
> > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
> > > +
> > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > +    :header-rows:  0
> > > +    :stub-columns: 0
> > > +    :widths: 12 8 8 8 8 8
> > > +
> > > +    * - start + 0:
> > > +      - M\ :sub:`00`
> > > +      - M\ :sub:`10`
> > > +      - M\ :sub:`20`
> > > +      - M\ :sub:`30`
> > > +      - x
> > > +    * - start + 5:
> > > +      - M\ :sub:`01`
> > > +      - M\ :sub:`11`
> > > +      - M\ :sub:`21`
> > > +      - M\ :sub:`31`
> > > +      - x
> > > +
> > > +.. _v4l2-meta-fmt-generic-csi2-12:
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_12
> > > +-----------------------------
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_12 contains 8-bit generic metadata packed in 12-bit
> > > +Data Units, with two padding bytes after every four bytes of metadata. This
> > 
> > Isn't it one padding byte every two bytes of metadata ?
> 
> Uh, yes. This was mistakenly copied from text for a different bpp.
> 
> > > +format is typically used by CSI-2 receivers with a source that transmits
> > > +MEDIA_BUS_FMT_META_12 and the CSI-2 receiver writes the received data to memory
> > > +as-is.
> > > +
> > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > +the data is defined in the MIPI CCS specification.
> > > +
> > > +This format is also used in conjunction with 24 bits per ``Data Unit
> > > +<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
> > > +Data Unit.
> > > +
> > > +This format is little endian.
> > > +
> > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_12.**
> > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > +
> > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > > +
> > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > +    :header-rows:  0
> > > +    :stub-columns: 0
> > > +    :widths: 12 8 8 8 8 8 8
> > > +
> > > +    * - start + 0:
> > > +      - M\ :sub:`00`
> > > +      - M\ :sub:`10`
> > > +      - x
> > > +      - M\ :sub:`20`
> > > +      - M\ :sub:`30`
> > > +      - x
> > > +    * - start + 6:
> > > +      - M\ :sub:`01`
> > > +      - M\ :sub:`11`
> > > +      - x
> > > +      - M\ :sub:`21`
> > > +      - M\ :sub:`31`
> > > +      - x
> > > +
> > > +.. _v4l2-meta-fmt-generic-csi2-14:
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_14
> > > +-----------------------------
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_14 contains 8-bit generic metadata packed in 14-bit
> > > +Data Units, with three padding bytes after every four bytes of metadata. This
> > > +format is typically used by CSI-2 receivers with a source that transmits
> > > +MEDIA_BUS_FMT_META_14 and the CSI-2 receiver writes the received data to memory
> > > +as-is.
> > > +
> > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > +the data is defined in the MIPI CCS specification.
> > > +
> > > +This format is little endian.
> > > +
> > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_14.**
> > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > +
> > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{.8cm}|
> > > +
> > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > +    :header-rows:  0
> > > +    :stub-columns: 0
> > > +    :widths: 12 8 8 8 8 8 8 8
> > > +
> > > +    * - start + 0:
> > > +      - M\ :sub:`00`
> > > +      - M\ :sub:`10`
> > > +      - M\ :sub:`20`
> > > +      - M\ :sub:`30`
> > > +      - x
> > > +      - x
> > > +      - x
> > > +    * - start + 7:
> > > +      - M\ :sub:`01`
> > > +      - M\ :sub:`11`
> > > +      - M\ :sub:`21`
> > > +      - M\ :sub:`31`
> > > +      - x
> > > +      - x
> > > +      - x
> > > +
> > > +.. _v4l2-meta-fmt-generic-csi2-16:
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_16
> > > +-----------------------------
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_16 contains 8-bit generic metadata packed in 16-bit
> > > +Data Units, with one padding byte after every byte of metadata. This format is
> > > +typically used by CSI-2 receivers with a source that transmits
> > > +MEDIA_BUS_FMT_META_16 and the CSI-2 receiver writes the received data to memory
> > > +as-is.
> > > +
> > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > +the data is defined in the MIPI CCS specification.
> > 
> > Here you could also mention that more optimal packing schemes for
> > MEDIA_BUS_FMT_META_16 use V4L2_META_FMT_GENERIC_8. Same below.
> 
> The "more optimal packing scheme" is really a different format. There's no
> other relation between these, really. I wouldn't mention it here. A driver
> would enumerate both for metadata when they're supported.

It's a different format, but the two are linked to the same image
format. That's why I think it's useful to cross-reference them.

> > > +
> > > +This format is little endian.
> > > +
> > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_16.**
> > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > +
> > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|
> > > +
> > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > +    :header-rows:  0
> > > +    :stub-columns: 0
> > > +    :widths: 12 8 8 8 8 8 8 8 8
> > > +
> > > +    * - start + 0:
> > > +      - M\ :sub:`00`
> > > +      - x
> > > +      - M\ :sub:`10`
> > > +      - x
> > > +      - M\ :sub:`20`
> > > +      - x
> > > +      - M\ :sub:`30`
> > > +      - x
> > > +    * - start + 8:
> > > +      - M\ :sub:`01`
> > > +      - x
> > > +      - M\ :sub:`11`
> > > +      - x
> > > +      - M\ :sub:`21`
> > > +      - x
> > > +      - M\ :sub:`31`
> > > +      - x
> > > +
> > > +.. _v4l2-meta-fmt-generic-csi2-20:
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_20
> > > +-----------------------------
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_20 contains 8-bit generic metadata packed in 20-bit
> > > +Data Units, with alternating one or two padding bytes after every byte of
> > > +metadata. This format is typically used by CSI-2 receivers with a source that
> > > +transmits MEDIA_BUS_FMT_META_20 and the CSI-2 receiver writes the received data
> > > +to memory as-is.
> > > +
> > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > +the data is defined in the MIPI CCS specification.
> > > +
> > > +This format is little endian.
> > > +
> > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_20.**
> > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > +
> > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > > +
> > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > +    :header-rows:  0
> > > +    :stub-columns: 0
> > > +    :widths: 12 8 8 8 8 8 8 8 8 8 8
> > > +
> > > +    * - start + 0:
> > > +      - M\ :sub:`00`
> > > +      - x
> > > +      - M\ :sub:`10`
> > > +      - x
> > > +      - x
> > > +      - M\ :sub:`20`
> > > +      - x
> > > +      - M\ :sub:`30`
> > > +      - x
> > > +      - x
> > > +    * - start + 10:
> > > +      - M\ :sub:`01`
> > > +      - x
> > > +      - M\ :sub:`11`
> > > +      - x
> > > +      - x
> > > +      - M\ :sub:`21`
> > > +      - x
> > > +      - M\ :sub:`31`
> > > +      - x
> > > +      - x
> > > +
> > > +.. _v4l2-meta-fmt-generic-csi2-24:
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_24
> > > +-----------------------------
> > > +
> > > +V4L2_META_FMT_GENERIC_CSI2_24 contains 8-bit generic metadata packed in 24-bit
> > > +Data Units, with two padding bytes after every byte of metadata. This format is
> > > +typically used by CSI-2 receivers with a source that transmits
> > > +MEDIA_BUS_FMT_META_24 and the CSI-2 receiver writes the received data to memory
> > > +as-is.
> > > +
> > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > +the data is defined in the MIPI CCS specification.
> > > +
> > > +This format is little endian.
> > > +
> > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_24.**
> > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > +
> > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > > +
> > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > +    :header-rows:  0
> > > +    :stub-columns: 0
> > > +    :widths: 12 8 8 8 8 8 8 8 8 8 8 8 8
> > > +
> > > +    * - start + 0:
> > > +      - M\ :sub:`00`
> > > +      - x
> > > +      - x
> > > +      - M\ :sub:`10`
> > > +      - x
> > > +      - x
> > > +      - M\ :sub:`20`
> > > +      - x
> > > +      - x
> > > +      - M\ :sub:`30`
> > > +      - x
> > > +      - x
> > > +    * - start + 12:
> > > +      - M\ :sub:`01`
> > > +      - x
> > > +      - x
> > > +      - M\ :sub:`11`
> > > +      - x
> > > +      - x
> > > +      - M\ :sub:`21`
> > > +      - x
> > > +      - x
> > > +      - M\ :sub:`31`
> > > +      - x
> > > +      - x
> > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > index 5aeff5519407..ae2dca7f2817 100644
> > > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > @@ -1460,6 +1460,13 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> > >  	case V4L2_PIX_FMT_Y210:		descr = "10-bit YUYV Packed"; break;
> > >  	case V4L2_PIX_FMT_Y212:		descr = "12-bit YUYV Packed"; break;
> > >  	case V4L2_PIX_FMT_Y216:		descr = "16-bit YUYV Packed"; break;
> > > +	case V4L2_META_FMT_GENERIC_8:	descr = "8-bit Generic Metadata"; break;
> > > +	case V4L2_META_FMT_GENERIC_CSI2_10:	descr = "8-bit Generic Meta, 10b CSI-2"; break;
> > > +	case V4L2_META_FMT_GENERIC_CSI2_12:	descr = "8-bit Generic Meta, 12b CSI-2"; break;
> > > +	case V4L2_META_FMT_GENERIC_CSI2_14:	descr = "8-bit Generic Meta, 14b CSI-2"; break;
> > > +	case V4L2_META_FMT_GENERIC_CSI2_16:	descr = "8-bit Generic Meta, 16b CSI-2"; break;
> > > +	case V4L2_META_FMT_GENERIC_CSI2_20:	descr = "8-bit Generic Meta, 20b CSI-2"; break;
> > > +	case V4L2_META_FMT_GENERIC_CSI2_24:	descr = "8-bit Generic Meta, 24b CSI-2"; break;
> > >  
> > >  	default:
> > >  		/* Compressed formats */
> > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > > index 2663213b76a4..c7cf20b5da67 100644
> > > --- a/include/uapi/linux/videodev2.h
> > > +++ b/include/uapi/linux/videodev2.h
> > > @@ -839,6 +839,14 @@ struct v4l2_pix_format {
> > >  #define V4L2_META_FMT_RK_ISP1_PARAMS	v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
> > >  #define V4L2_META_FMT_RK_ISP1_STAT_3A	v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
> > >  
> > > +#define V4L2_META_FMT_GENERIC_8		v4l2_fourcc('M', 'E', 'T', '8') /* Generic 8-bit metadata */
> > > +#define V4L2_META_FMT_GENERIC_CSI2_10	v4l2_fourcc('M', 'C', '1', 'A') /* 10-bit CSI-2 packed 8-bit metadata */
> > > +#define V4L2_META_FMT_GENERIC_CSI2_12	v4l2_fourcc('M', 'C', '1', 'C') /* 12-bit CSI-2 packed 8-bit metadata */
> > > +#define V4L2_META_FMT_GENERIC_CSI2_14	v4l2_fourcc('M', 'C', '1', 'E') /* 14-bit CSI-2 packed 8-bit metadata */
> > > +#define V4L2_META_FMT_GENERIC_CSI2_16	v4l2_fourcc('M', 'C', '1', 'G') /* 16-bit CSI-2 packed 8-bit metadata */
> > > +#define V4L2_META_FMT_GENERIC_CSI2_20	v4l2_fourcc('M', 'C', '1', 'K') /* 20-bit CSI-2 packed 8-bit metadata */
> > > +#define V4L2_META_FMT_GENERIC_CSI2_24	v4l2_fourcc('M', 'C', '1', 'O') /* 24-bit CSI-2 packed 8-bit metadata */
> > > +
> > >  /* priv field value to indicates that subsequent fields are valid. */
> > >  #define V4L2_PIX_FMT_PRIV_MAGIC		0xfeedcafe
> > >
Sakari Ailus April 23, 2024, 9:54 a.m. UTC | #4
Hi Laurent,

On Tue, Apr 23, 2024 at 10:32:37AM +0300, Laurent Pinchart wrote:
> Hi Sakari,
> 
> On Tue, Apr 23, 2024 at 07:04:58AM +0000, Sakari Ailus wrote:
> > On Fri, Apr 19, 2024 at 07:26:19PM +0300, Laurent Pinchart wrote:
> > > On Tue, Apr 16, 2024 at 10:32:39PM +0300, Sakari Ailus wrote:
> > > > Generic 8-bit metadata formats define the in-memory data layout but not
> > > > the format of the data itself. The reasoning for having such formats is to
> > > > allow CSI-2 receiver drivers to receive and DMA drivers to write the data
> > > > to memory without knowing a large number of device-specific formats.
> > > > 
> > > > These formats may be used only in conjunction with a Media controller
> > > 
> > > "Media Controller" or "media controller"
> > 
> > Yes.
> > 
> > > > pipeline where the internal pad of the source sub-device defines the
> > > > specific format of the data (using an mbus code).
> > > > 
> > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > > > ---
> > > >  .../userspace-api/media/v4l/dev-subdev.rst    |   2 +
> > > >  .../userspace-api/media/v4l/meta-formats.rst  |   3 +-
> > > >  .../media/v4l/metafmt-generic.rst             | 328 ++++++++++++++++++
> > > >  drivers/media/v4l2-core/v4l2-ioctl.c          |   7 +
> > > >  include/uapi/linux/videodev2.h                |   8 +
> > > >  5 files changed, 347 insertions(+), 1 deletion(-)
> > > >  create mode 100644 Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > > > 
> > > > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > > > index 43988516acdd..f375b820ab68 100644
> > > > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > > > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst
> > > > @@ -506,6 +506,8 @@ source pads.
> > > >  
> > > >      subdev-formats
> > > >  
> > > > +.. _subdev-routing:
> > > > +
> > > >  Streams, multiplexed media pads and internal routing
> > > >  ----------------------------------------------------
> > > >  
> > > > diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
> > > > index 0bb61fc5bc00..c23aac823d2c 100644
> > > > --- a/Documentation/userspace-api/media/v4l/meta-formats.rst
> > > > +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
> > > > @@ -13,9 +13,10 @@ These formats are used for the :ref:`metadata` interface only.
> > > >      :maxdepth: 1
> > > >  
> > > >      metafmt-d4xx
> > > > +    metafmt-generic
> > > >      metafmt-intel-ipu3
> > > >      metafmt-rkisp1
> > > >      metafmt-uvc
> > > > +    metafmt-vivid
> > > >      metafmt-vsp1-hgo
> > > >      metafmt-vsp1-hgt
> > > > -    metafmt-vivid
> > > > diff --git a/Documentation/userspace-api/media/v4l/metafmt-generic.rst b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > > > new file mode 100644
> > > > index 000000000000..cba34be64dfe
> > > > --- /dev/null
> > > > +++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > > > @@ -0,0 +1,328 @@
> > > > +.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
> > > > +
> > > > +********************************************************************************************************************************************************************************************************************************************************************************
> > > > +V4L2_META_FMT_GENERIC_8 ('MET8'), V4L2_META_FMT_GENERIC_CSI2_10 ('MC1A'), V4L2_META_FMT_GENERIC_CSI2_12 ('MC1C'), V4L2_META_FMT_GENERIC_CSI2_14 ('MC1E'), V4L2_META_FMT_GENERIC_CSI2_16 ('MC1G'), V4L2_META_FMT_GENERIC_CSI2_20 ('MC1K'), V4L2_META_FMT_GENERIC_CSI2_24 ('MC1O')
> > > > +********************************************************************************************************************************************************************************************************************************************************************************
> > > > +
> > > > +
> > > > +Generic line-based metadata formats
> > > > +
> > > > +
> > > > +Description
> > > > +===========
> > > > +
> > > > +These generic line-based metadata formats define the memory layout of the data
> > > > +without defining the format or meaning of the metadata itself. These formats may
> > > > +only be used with a Media Controller pipeline where the more specific format is
> > > > +reported by an :ref:`internal sink pad <MEDIA-PAD-FL-INTERNAL>` of the source
> > > > +sub-device. See also :ref:`source routes <subdev-routing>`.
> > > > +
> > > > +.. _v4l2-meta-fmt-generic-8:
> > > > +
> > > > +V4L2_META_FMT_GENERIC_8
> > > > +-----------------------
> > > > +
> > > > +The V4L2_META_FMT_GENERIC_8 format is a plain 8-bit metadata format.
> > > > +
> > > > +This format is also used on CSI-2 for both 8 bits per ``Data Unit
> > > > +<media-glossary-data-unit>`` as well as for 16 bits per Data Unit when two bytes
> > > > +of metadata are packed into one 16-bit Data Unit.
> > > > +
> > > > +**Byte Order Of V4L2_META_FMT_GENERIC_8.**
> > > > +Each cell is one byte. "M" denotes a byte of metadata.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - M\ :sub:`00`
> > > > +      - M\ :sub:`10`
> > > > +      - M\ :sub:`20`
> > > > +      - M\ :sub:`30`
> > > > +    * - start + 4:
> > > > +      - M\ :sub:`01`
> > > > +      - M\ :sub:`11`
> > > > +      - M\ :sub:`21`
> > > > +      - M\ :sub:`31`
> > > > +
> > > > +.. _v4l2-meta-fmt-generic-csi2-10:
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_10
> > > > +-----------------------------
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_10 contains 8-bit generic metadata packed in 10-bit
> > > > +Data Units, with one padding byte after every four bytes of metadata. This
> > > > +format is typically used by CSI-2 receivers with a source that transmits
> > > > +MEDIA_BUS_FMT_META_10 and the CSI-2 receiver writes the received data to memory
> > > > +as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > > +the data is defined in the MIPI CCS specification.
> > > > +
> > > > +This format is also used in conjunction with 20 bits per ``Data Unit
> > > 
> > > s/in conjunction with/for/
> > > 
> > > Same below.
> > 
> > That is shorter but is it better?
> 
> I think it's simpler and thus clearer. Up to you.

The relation is indirect so I prefer the original text.

> 
> > > > +<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
> > > > +Data Unit.
> > > 
> > > How about adding a mention of MEDIA_BUS_FMT_META_20 here ? The CCS
> > > specification calls this "RAW20 (with more optimal RAW10 packing)",
> > > using the same vocabulary could help. Same for
> > > V4L2_META_FMT_GENERIC_CSI2_12, and actually V4L2_META_FMT_GENERIC_8 too.
> > 
> > Is it useful? It's the same as 10-bit packing after all.
> 
> I think cross-referencing the two entries that can be used to transmit
> metadata for the same image format is useful. 
> 
> > RAW20 in CCS refers to image data.
> 
> The wording I quoted comes from the CCS specification :-) Using the same
> terms as in the spec would help in my opinion.

RAW20 still refers to image data and we don't use that term in V4L2
documentation elsewhere. In the CCS spec the connection between the two is
stronger than in V4L2 as we support a number of different formats.

But I can mention the other format.

> 
> > > > +
> > > > +This format is little endian.
> > > > +
> > > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_10.**
> > > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - M\ :sub:`00`
> > > > +      - M\ :sub:`10`
> > > > +      - M\ :sub:`20`
> > > > +      - M\ :sub:`30`
> > > > +      - x
> > > > +    * - start + 5:
> > > > +      - M\ :sub:`01`
> > > > +      - M\ :sub:`11`
> > > > +      - M\ :sub:`21`
> > > > +      - M\ :sub:`31`
> > > > +      - x
> > > > +
> > > > +.. _v4l2-meta-fmt-generic-csi2-12:
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_12
> > > > +-----------------------------
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_12 contains 8-bit generic metadata packed in 12-bit
> > > > +Data Units, with two padding bytes after every four bytes of metadata. This
> > > 
> > > Isn't it one padding byte every two bytes of metadata ?
> > 
> > Uh, yes. This was mistakenly copied from text for a different bpp.
> > 
> > > > +format is typically used by CSI-2 receivers with a source that transmits
> > > > +MEDIA_BUS_FMT_META_12 and the CSI-2 receiver writes the received data to memory
> > > > +as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > > +the data is defined in the MIPI CCS specification.
> > > > +
> > > > +This format is also used in conjunction with 24 bits per ``Data Unit
> > > > +<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
> > > > +Data Unit.
> > > > +
> > > > +This format is little endian.
> > > > +
> > > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_12.**
> > > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - M\ :sub:`00`
> > > > +      - M\ :sub:`10`
> > > > +      - x
> > > > +      - M\ :sub:`20`
> > > > +      - M\ :sub:`30`
> > > > +      - x
> > > > +    * - start + 6:
> > > > +      - M\ :sub:`01`
> > > > +      - M\ :sub:`11`
> > > > +      - x
> > > > +      - M\ :sub:`21`
> > > > +      - M\ :sub:`31`
> > > > +      - x
> > > > +
> > > > +.. _v4l2-meta-fmt-generic-csi2-14:
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_14
> > > > +-----------------------------
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_14 contains 8-bit generic metadata packed in 14-bit
> > > > +Data Units, with three padding bytes after every four bytes of metadata. This
> > > > +format is typically used by CSI-2 receivers with a source that transmits
> > > > +MEDIA_BUS_FMT_META_14 and the CSI-2 receiver writes the received data to memory
> > > > +as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > > +the data is defined in the MIPI CCS specification.
> > > > +
> > > > +This format is little endian.
> > > > +
> > > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_14.**
> > > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - M\ :sub:`00`
> > > > +      - M\ :sub:`10`
> > > > +      - M\ :sub:`20`
> > > > +      - M\ :sub:`30`
> > > > +      - x
> > > > +      - x
> > > > +      - x
> > > > +    * - start + 7:
> > > > +      - M\ :sub:`01`
> > > > +      - M\ :sub:`11`
> > > > +      - M\ :sub:`21`
> > > > +      - M\ :sub:`31`
> > > > +      - x
> > > > +      - x
> > > > +      - x
> > > > +
> > > > +.. _v4l2-meta-fmt-generic-csi2-16:
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_16
> > > > +-----------------------------
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_16 contains 8-bit generic metadata packed in 16-bit
> > > > +Data Units, with one padding byte after every byte of metadata. This format is
> > > > +typically used by CSI-2 receivers with a source that transmits
> > > > +MEDIA_BUS_FMT_META_16 and the CSI-2 receiver writes the received data to memory
> > > > +as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > > +the data is defined in the MIPI CCS specification.
> > > 
> > > Here you could also mention that more optimal packing schemes for
> > > MEDIA_BUS_FMT_META_16 use V4L2_META_FMT_GENERIC_8. Same below.
> > 
> > The "more optimal packing scheme" is really a different format. There's no
> > other relation between these, really. I wouldn't mention it here. A driver
> > would enumerate both for metadata when they're supported.
> 
> It's a different format, but the two are linked to the same image
> format. That's why I think it's useful to cross-reference them.

I can add that.

> 
> > > > +
> > > > +This format is little endian.
> > > > +
> > > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_16.**
> > > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - M\ :sub:`00`
> > > > +      - x
> > > > +      - M\ :sub:`10`
> > > > +      - x
> > > > +      - M\ :sub:`20`
> > > > +      - x
> > > > +      - M\ :sub:`30`
> > > > +      - x
> > > > +    * - start + 8:
> > > > +      - M\ :sub:`01`
> > > > +      - x
> > > > +      - M\ :sub:`11`
> > > > +      - x
> > > > +      - M\ :sub:`21`
> > > > +      - x
> > > > +      - M\ :sub:`31`
> > > > +      - x
> > > > +
> > > > +.. _v4l2-meta-fmt-generic-csi2-20:
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_20
> > > > +-----------------------------
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_20 contains 8-bit generic metadata packed in 20-bit
> > > > +Data Units, with alternating one or two padding bytes after every byte of
> > > > +metadata. This format is typically used by CSI-2 receivers with a source that
> > > > +transmits MEDIA_BUS_FMT_META_20 and the CSI-2 receiver writes the received data
> > > > +to memory as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > > +the data is defined in the MIPI CCS specification.
> > > > +
> > > > +This format is little endian.
> > > > +
> > > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_20.**
> > > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - M\ :sub:`00`
> > > > +      - x
> > > > +      - M\ :sub:`10`
> > > > +      - x
> > > > +      - x
> > > > +      - M\ :sub:`20`
> > > > +      - x
> > > > +      - M\ :sub:`30`
> > > > +      - x
> > > > +      - x
> > > > +    * - start + 10:
> > > > +      - M\ :sub:`01`
> > > > +      - x
> > > > +      - M\ :sub:`11`
> > > > +      - x
> > > > +      - x
> > > > +      - M\ :sub:`21`
> > > > +      - x
> > > > +      - M\ :sub:`31`
> > > > +      - x
> > > > +      - x
> > > > +
> > > > +.. _v4l2-meta-fmt-generic-csi2-24:
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_24
> > > > +-----------------------------
> > > > +
> > > > +V4L2_META_FMT_GENERIC_CSI2_24 contains 8-bit generic metadata packed in 24-bit
> > > > +Data Units, with two padding bytes after every byte of metadata. This format is
> > > > +typically used by CSI-2 receivers with a source that transmits
> > > > +MEDIA_BUS_FMT_META_24 and the CSI-2 receiver writes the received data to memory
> > > > +as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification and the padding of
> > > > +the data is defined in the MIPI CCS specification.
> > > > +
> > > > +This format is little endian.
> > > > +
> > > > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_24.**
> > > > +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Metadata Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8 8 8 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - M\ :sub:`00`
> > > > +      - x
> > > > +      - x
> > > > +      - M\ :sub:`10`
> > > > +      - x
> > > > +      - x
> > > > +      - M\ :sub:`20`
> > > > +      - x
> > > > +      - x
> > > > +      - M\ :sub:`30`
> > > > +      - x
> > > > +      - x
> > > > +    * - start + 12:
> > > > +      - M\ :sub:`01`
> > > > +      - x
> > > > +      - x
> > > > +      - M\ :sub:`11`
> > > > +      - x
> > > > +      - x
> > > > +      - M\ :sub:`21`
> > > > +      - x
> > > > +      - x
> > > > +      - M\ :sub:`31`
> > > > +      - x
> > > > +      - x
> > > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > > index 5aeff5519407..ae2dca7f2817 100644
> > > > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > > > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > > @@ -1460,6 +1460,13 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> > > >  	case V4L2_PIX_FMT_Y210:		descr = "10-bit YUYV Packed"; break;
> > > >  	case V4L2_PIX_FMT_Y212:		descr = "12-bit YUYV Packed"; break;
> > > >  	case V4L2_PIX_FMT_Y216:		descr = "16-bit YUYV Packed"; break;
> > > > +	case V4L2_META_FMT_GENERIC_8:	descr = "8-bit Generic Metadata"; break;
> > > > +	case V4L2_META_FMT_GENERIC_CSI2_10:	descr = "8-bit Generic Meta, 10b CSI-2"; break;
> > > > +	case V4L2_META_FMT_GENERIC_CSI2_12:	descr = "8-bit Generic Meta, 12b CSI-2"; break;
> > > > +	case V4L2_META_FMT_GENERIC_CSI2_14:	descr = "8-bit Generic Meta, 14b CSI-2"; break;
> > > > +	case V4L2_META_FMT_GENERIC_CSI2_16:	descr = "8-bit Generic Meta, 16b CSI-2"; break;
> > > > +	case V4L2_META_FMT_GENERIC_CSI2_20:	descr = "8-bit Generic Meta, 20b CSI-2"; break;
> > > > +	case V4L2_META_FMT_GENERIC_CSI2_24:	descr = "8-bit Generic Meta, 24b CSI-2"; break;
> > > >  
> > > >  	default:
> > > >  		/* Compressed formats */
> > > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > > > index 2663213b76a4..c7cf20b5da67 100644
> > > > --- a/include/uapi/linux/videodev2.h
> > > > +++ b/include/uapi/linux/videodev2.h
> > > > @@ -839,6 +839,14 @@ struct v4l2_pix_format {
> > > >  #define V4L2_META_FMT_RK_ISP1_PARAMS	v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
> > > >  #define V4L2_META_FMT_RK_ISP1_STAT_3A	v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
> > > >  
> > > > +#define V4L2_META_FMT_GENERIC_8		v4l2_fourcc('M', 'E', 'T', '8') /* Generic 8-bit metadata */
> > > > +#define V4L2_META_FMT_GENERIC_CSI2_10	v4l2_fourcc('M', 'C', '1', 'A') /* 10-bit CSI-2 packed 8-bit metadata */
> > > > +#define V4L2_META_FMT_GENERIC_CSI2_12	v4l2_fourcc('M', 'C', '1', 'C') /* 12-bit CSI-2 packed 8-bit metadata */
> > > > +#define V4L2_META_FMT_GENERIC_CSI2_14	v4l2_fourcc('M', 'C', '1', 'E') /* 14-bit CSI-2 packed 8-bit metadata */
> > > > +#define V4L2_META_FMT_GENERIC_CSI2_16	v4l2_fourcc('M', 'C', '1', 'G') /* 16-bit CSI-2 packed 8-bit metadata */
> > > > +#define V4L2_META_FMT_GENERIC_CSI2_20	v4l2_fourcc('M', 'C', '1', 'K') /* 20-bit CSI-2 packed 8-bit metadata */
> > > > +#define V4L2_META_FMT_GENERIC_CSI2_24	v4l2_fourcc('M', 'C', '1', 'O') /* 24-bit CSI-2 packed 8-bit metadata */
> > > > +
> > > >  /* priv field value to indicates that subsequent fields are valid. */
> > > >  #define V4L2_PIX_FMT_PRIV_MAGIC		0xfeedcafe
> > > >
diff mbox series

Patch

diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst
index 43988516acdd..f375b820ab68 100644
--- a/Documentation/userspace-api/media/v4l/dev-subdev.rst
+++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst
@@ -506,6 +506,8 @@  source pads.
 
     subdev-formats
 
+.. _subdev-routing:
+
 Streams, multiplexed media pads and internal routing
 ----------------------------------------------------
 
diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
index 0bb61fc5bc00..c23aac823d2c 100644
--- a/Documentation/userspace-api/media/v4l/meta-formats.rst
+++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
@@ -13,9 +13,10 @@  These formats are used for the :ref:`metadata` interface only.
     :maxdepth: 1
 
     metafmt-d4xx
+    metafmt-generic
     metafmt-intel-ipu3
     metafmt-rkisp1
     metafmt-uvc
+    metafmt-vivid
     metafmt-vsp1-hgo
     metafmt-vsp1-hgt
-    metafmt-vivid
diff --git a/Documentation/userspace-api/media/v4l/metafmt-generic.rst b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
new file mode 100644
index 000000000000..cba34be64dfe
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
@@ -0,0 +1,328 @@ 
+.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
+
+********************************************************************************************************************************************************************************************************************************************************************************
+V4L2_META_FMT_GENERIC_8 ('MET8'), V4L2_META_FMT_GENERIC_CSI2_10 ('MC1A'), V4L2_META_FMT_GENERIC_CSI2_12 ('MC1C'), V4L2_META_FMT_GENERIC_CSI2_14 ('MC1E'), V4L2_META_FMT_GENERIC_CSI2_16 ('MC1G'), V4L2_META_FMT_GENERIC_CSI2_20 ('MC1K'), V4L2_META_FMT_GENERIC_CSI2_24 ('MC1O')
+********************************************************************************************************************************************************************************************************************************************************************************
+
+
+Generic line-based metadata formats
+
+
+Description
+===========
+
+These generic line-based metadata formats define the memory layout of the data
+without defining the format or meaning of the metadata itself. These formats may
+only be used with a Media Controller pipeline where the more specific format is
+reported by an :ref:`internal sink pad <MEDIA-PAD-FL-INTERNAL>` of the source
+sub-device. See also :ref:`source routes <subdev-routing>`.
+
+.. _v4l2-meta-fmt-generic-8:
+
+V4L2_META_FMT_GENERIC_8
+-----------------------
+
+The V4L2_META_FMT_GENERIC_8 format is a plain 8-bit metadata format.
+
+This format is also used on CSI-2 for both 8 bits per ``Data Unit
+<media-glossary-data-unit>`` as well as for 16 bits per Data Unit when two bytes
+of metadata are packed into one 16-bit Data Unit.
+
+**Byte Order Of V4L2_META_FMT_GENERIC_8.**
+Each cell is one byte. "M" denotes a byte of metadata.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|
+
+.. flat-table:: Sample 4x2 Metadata Frame
+    :header-rows:  0
+    :stub-columns: 0
+    :widths: 12 8 8 8 8
+
+    * - start + 0:
+      - M\ :sub:`00`
+      - M\ :sub:`10`
+      - M\ :sub:`20`
+      - M\ :sub:`30`
+    * - start + 4:
+      - M\ :sub:`01`
+      - M\ :sub:`11`
+      - M\ :sub:`21`
+      - M\ :sub:`31`
+
+.. _v4l2-meta-fmt-generic-csi2-10:
+
+V4L2_META_FMT_GENERIC_CSI2_10
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_10 contains 8-bit generic metadata packed in 10-bit
+Data Units, with one padding byte after every four bytes of metadata. This
+format is typically used by CSI-2 receivers with a source that transmits
+MEDIA_BUS_FMT_META_10 and the CSI-2 receiver writes the received data to memory
+as-is.
+
+The packing of the data follows the MIPI CSI-2 specification and the padding of
+the data is defined in the MIPI CCS specification.
+
+This format is also used in conjunction with 20 bits per ``Data Unit
+<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
+Data Unit.
+
+This format is little endian.
+
+**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_10.**
+Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
+
+.. flat-table:: Sample 4x2 Metadata Frame
+    :header-rows:  0
+    :stub-columns: 0
+    :widths: 12 8 8 8 8 8
+
+    * - start + 0:
+      - M\ :sub:`00`
+      - M\ :sub:`10`
+      - M\ :sub:`20`
+      - M\ :sub:`30`
+      - x
+    * - start + 5:
+      - M\ :sub:`01`
+      - M\ :sub:`11`
+      - M\ :sub:`21`
+      - M\ :sub:`31`
+      - x
+
+.. _v4l2-meta-fmt-generic-csi2-12:
+
+V4L2_META_FMT_GENERIC_CSI2_12
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_12 contains 8-bit generic metadata packed in 12-bit
+Data Units, with two padding bytes after every four bytes of metadata. This
+format is typically used by CSI-2 receivers with a source that transmits
+MEDIA_BUS_FMT_META_12 and the CSI-2 receiver writes the received data to memory
+as-is.
+
+The packing of the data follows the MIPI CSI-2 specification and the padding of
+the data is defined in the MIPI CCS specification.
+
+This format is also used in conjunction with 24 bits per ``Data Unit
+<media-glossary-data-unit>`` formats that pack two bytes of metadata into one
+Data Unit.
+
+This format is little endian.
+
+**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_12.**
+Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
+
+.. flat-table:: Sample 4x2 Metadata Frame
+    :header-rows:  0
+    :stub-columns: 0
+    :widths: 12 8 8 8 8 8 8
+
+    * - start + 0:
+      - M\ :sub:`00`
+      - M\ :sub:`10`
+      - x
+      - M\ :sub:`20`
+      - M\ :sub:`30`
+      - x
+    * - start + 6:
+      - M\ :sub:`01`
+      - M\ :sub:`11`
+      - x
+      - M\ :sub:`21`
+      - M\ :sub:`31`
+      - x
+
+.. _v4l2-meta-fmt-generic-csi2-14:
+
+V4L2_META_FMT_GENERIC_CSI2_14
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_14 contains 8-bit generic metadata packed in 14-bit
+Data Units, with three padding bytes after every four bytes of metadata. This
+format is typically used by CSI-2 receivers with a source that transmits
+MEDIA_BUS_FMT_META_14 and the CSI-2 receiver writes the received data to memory
+as-is.
+
+The packing of the data follows the MIPI CSI-2 specification and the padding of
+the data is defined in the MIPI CCS specification.
+
+This format is little endian.
+
+**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_14.**
+Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{.8cm}|
+
+.. flat-table:: Sample 4x2 Metadata Frame
+    :header-rows:  0
+    :stub-columns: 0
+    :widths: 12 8 8 8 8 8 8 8
+
+    * - start + 0:
+      - M\ :sub:`00`
+      - M\ :sub:`10`
+      - M\ :sub:`20`
+      - M\ :sub:`30`
+      - x
+      - x
+      - x
+    * - start + 7:
+      - M\ :sub:`01`
+      - M\ :sub:`11`
+      - M\ :sub:`21`
+      - M\ :sub:`31`
+      - x
+      - x
+      - x
+
+.. _v4l2-meta-fmt-generic-csi2-16:
+
+V4L2_META_FMT_GENERIC_CSI2_16
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_16 contains 8-bit generic metadata packed in 16-bit
+Data Units, with one padding byte after every byte of metadata. This format is
+typically used by CSI-2 receivers with a source that transmits
+MEDIA_BUS_FMT_META_16 and the CSI-2 receiver writes the received data to memory
+as-is.
+
+The packing of the data follows the MIPI CSI-2 specification and the padding of
+the data is defined in the MIPI CCS specification.
+
+This format is little endian.
+
+**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_16.**
+Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|
+
+.. flat-table:: Sample 4x2 Metadata Frame
+    :header-rows:  0
+    :stub-columns: 0
+    :widths: 12 8 8 8 8 8 8 8 8
+
+    * - start + 0:
+      - M\ :sub:`00`
+      - x
+      - M\ :sub:`10`
+      - x
+      - M\ :sub:`20`
+      - x
+      - M\ :sub:`30`
+      - x
+    * - start + 8:
+      - M\ :sub:`01`
+      - x
+      - M\ :sub:`11`
+      - x
+      - M\ :sub:`21`
+      - x
+      - M\ :sub:`31`
+      - x
+
+.. _v4l2-meta-fmt-generic-csi2-20:
+
+V4L2_META_FMT_GENERIC_CSI2_20
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_20 contains 8-bit generic metadata packed in 20-bit
+Data Units, with alternating one or two padding bytes after every byte of
+metadata. This format is typically used by CSI-2 receivers with a source that
+transmits MEDIA_BUS_FMT_META_20 and the CSI-2 receiver writes the received data
+to memory as-is.
+
+The packing of the data follows the MIPI CSI-2 specification and the padding of
+the data is defined in the MIPI CCS specification.
+
+This format is little endian.
+
+**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_20.**
+Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
+
+.. flat-table:: Sample 4x2 Metadata Frame
+    :header-rows:  0
+    :stub-columns: 0
+    :widths: 12 8 8 8 8 8 8 8 8 8 8
+
+    * - start + 0:
+      - M\ :sub:`00`
+      - x
+      - M\ :sub:`10`
+      - x
+      - x
+      - M\ :sub:`20`
+      - x
+      - M\ :sub:`30`
+      - x
+      - x
+    * - start + 10:
+      - M\ :sub:`01`
+      - x
+      - M\ :sub:`11`
+      - x
+      - x
+      - M\ :sub:`21`
+      - x
+      - M\ :sub:`31`
+      - x
+      - x
+
+.. _v4l2-meta-fmt-generic-csi2-24:
+
+V4L2_META_FMT_GENERIC_CSI2_24
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_24 contains 8-bit generic metadata packed in 24-bit
+Data Units, with two padding bytes after every byte of metadata. This format is
+typically used by CSI-2 receivers with a source that transmits
+MEDIA_BUS_FMT_META_24 and the CSI-2 receiver writes the received data to memory
+as-is.
+
+The packing of the data follows the MIPI CSI-2 specification and the padding of
+the data is defined in the MIPI CCS specification.
+
+This format is little endian.
+
+**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_24.**
+Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
+
+.. flat-table:: Sample 4x2 Metadata Frame
+    :header-rows:  0
+    :stub-columns: 0
+    :widths: 12 8 8 8 8 8 8 8 8 8 8 8 8
+
+    * - start + 0:
+      - M\ :sub:`00`
+      - x
+      - x
+      - M\ :sub:`10`
+      - x
+      - x
+      - M\ :sub:`20`
+      - x
+      - x
+      - M\ :sub:`30`
+      - x
+      - x
+    * - start + 12:
+      - M\ :sub:`01`
+      - x
+      - x
+      - M\ :sub:`11`
+      - x
+      - x
+      - M\ :sub:`21`
+      - x
+      - x
+      - M\ :sub:`31`
+      - x
+      - x
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 5aeff5519407..ae2dca7f2817 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1460,6 +1460,13 @@  static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 	case V4L2_PIX_FMT_Y210:		descr = "10-bit YUYV Packed"; break;
 	case V4L2_PIX_FMT_Y212:		descr = "12-bit YUYV Packed"; break;
 	case V4L2_PIX_FMT_Y216:		descr = "16-bit YUYV Packed"; break;
+	case V4L2_META_FMT_GENERIC_8:	descr = "8-bit Generic Metadata"; break;
+	case V4L2_META_FMT_GENERIC_CSI2_10:	descr = "8-bit Generic Meta, 10b CSI-2"; break;
+	case V4L2_META_FMT_GENERIC_CSI2_12:	descr = "8-bit Generic Meta, 12b CSI-2"; break;
+	case V4L2_META_FMT_GENERIC_CSI2_14:	descr = "8-bit Generic Meta, 14b CSI-2"; break;
+	case V4L2_META_FMT_GENERIC_CSI2_16:	descr = "8-bit Generic Meta, 16b CSI-2"; break;
+	case V4L2_META_FMT_GENERIC_CSI2_20:	descr = "8-bit Generic Meta, 20b CSI-2"; break;
+	case V4L2_META_FMT_GENERIC_CSI2_24:	descr = "8-bit Generic Meta, 24b CSI-2"; break;
 
 	default:
 		/* Compressed formats */
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 2663213b76a4..c7cf20b5da67 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -839,6 +839,14 @@  struct v4l2_pix_format {
 #define V4L2_META_FMT_RK_ISP1_PARAMS	v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
 #define V4L2_META_FMT_RK_ISP1_STAT_3A	v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
 
+#define V4L2_META_FMT_GENERIC_8		v4l2_fourcc('M', 'E', 'T', '8') /* Generic 8-bit metadata */
+#define V4L2_META_FMT_GENERIC_CSI2_10	v4l2_fourcc('M', 'C', '1', 'A') /* 10-bit CSI-2 packed 8-bit metadata */
+#define V4L2_META_FMT_GENERIC_CSI2_12	v4l2_fourcc('M', 'C', '1', 'C') /* 12-bit CSI-2 packed 8-bit metadata */
+#define V4L2_META_FMT_GENERIC_CSI2_14	v4l2_fourcc('M', 'C', '1', 'E') /* 14-bit CSI-2 packed 8-bit metadata */
+#define V4L2_META_FMT_GENERIC_CSI2_16	v4l2_fourcc('M', 'C', '1', 'G') /* 16-bit CSI-2 packed 8-bit metadata */
+#define V4L2_META_FMT_GENERIC_CSI2_20	v4l2_fourcc('M', 'C', '1', 'K') /* 20-bit CSI-2 packed 8-bit metadata */
+#define V4L2_META_FMT_GENERIC_CSI2_24	v4l2_fourcc('M', 'C', '1', 'O') /* 24-bit CSI-2 packed 8-bit metadata */
+
 /* priv field value to indicates that subsequent fields are valid. */
 #define V4L2_PIX_FMT_PRIV_MAGIC		0xfeedcafe