[PATCH v2 00/14] Generic line based metadata, without sensor API changes

[PATCH v2 00/14] Generic line based metadata, without sensor API changes

[Sakari Ailus]

Hello everyone,

I've split these patches off the metadata set [1], it'll still take more
time to merge the internal pad support as it is evident we need to
properly define the recommended sensor APIs to merge the drivers that are
using them.

In the meantime, these patches are seen as what can be merged for 6.10.

The patches include changes to the routing API before the internal pads.

[1] <URL:https://lore.kernel.org/linux-media/20240420100518.GA5618@pendragon.ideasonboard.com/T/#t>

changes since v1:

- Improve len_routes field documentation in struct v4l2_subdev_routing.

changes since v9 metadata set:

- Fix metadata format documentation.

- Improve language of struct v4l2_subdev_format field documentation when
  it comes to metadata.

- Improved documentation for routing API.

- Set (and unset) the V4L2_FMT_FLAG_META_LINE_BASED flag in the framework
  based on the format, don't rely on the driver to do it. Added a comment
  to the format list to remind developers to update v4l_fill_fmtdesc when
  adding new metadata formats.

- Drop the patch that moved G_ROUTING below S_ROUTING handling in
  v4l2-subdev.c. It's no longer needed.

Laurent Pinchart (1):
  media: v4l2-subdev: Clearly document that the crop API won't be
    extended

Sakari Ailus (13):
  media: Documentation: Add "stream" into glossary
  media: uapi: Add generic serial metadata mbus formats
  media: uapi: Document which mbus format fields are valid for metadata
  media: uapi: v4l: Add generic 8-bit metadata format definitions
  media: v4l: Support line-based metadata capture
  media: v4l: Set line based metadata flag in V4L2 core
  media: Documentation: Additional streams generally don't harm capture
  media: Documentation: Document S_ROUTING behaviour
  media: v4l: subdev: Add a function to lock two sub-device states, use
    it
  media: v4l: subdev: Copy argument back to user also for S_ROUTING
  media: v4l: subdev: Add len_routes field to struct v4l2_subdev_routing
  media: v4l: subdev: Return routes set using S_ROUTING
  media: v4l: subdev: Add trivial set_routing support

 .../userspace-api/media/glossary.rst          |  15 +
 .../userspace-api/media/v4l/dev-meta.rst      |  21 ++
 .../userspace-api/media/v4l/dev-subdev.rst    |  31 +-
 .../userspace-api/media/v4l/meta-formats.rst  |   3 +-
 .../media/v4l/metafmt-generic.rst             | 343 ++++++++++++++++++
 .../media/v4l/subdev-formats.rst              | 270 +++++++++++++-
 .../media/v4l/vidioc-enum-fmt.rst             |   7 +
 .../media/v4l/vidioc-subdev-g-crop.rst        |   6 +-
 .../media/v4l/vidioc-subdev-g-routing.rst     |  51 ++-
 .../media/videodev2.h.rst.exceptions          |   1 +
 drivers/media/v4l2-core/v4l2-ioctl.c          |  41 ++-
 drivers/media/v4l2-core/v4l2-subdev.c         |  50 ++-
 include/media/v4l2-subdev.h                   |  42 +++
 include/uapi/linux/media-bus-format.h         |   9 +
 include/uapi/linux/v4l2-mediabus.h            |  18 +-
 include/uapi/linux/v4l2-subdev.h              |  14 +-
 include/uapi/linux/videodev2.h                |  22 ++
 17 files changed, 881 insertions(+), 63 deletions(-)
 create mode 100644 Documentation/userspace-api/media/v4l/metafmt-generic.rst


base-commit: e42a204f0519a2540f1507ac2798be2aeaa76bee
-- 
2.39.2

[PATCH v2 01/14] media: v4l2-subdev: Clearly document that the crop API won't be extended

[Sakari Ailus]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The V4L2 subdev crop API has been marked as obsolete, deprecated by the
selection API. Despite this, it has recently been extended with streams
support. In hindsight this was a mistake. Make sure it doesn't happen
again by clearly documenting that no new extensions will be accepted.

Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 .../userspace-api/media/v4l/vidioc-subdev-g-crop.rst        | 6 +++---
 include/uapi/linux/v4l2-subdev.h                            | 4 ++++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst
index 92d933631fda..88a748103a71 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst
@@ -37,9 +37,9 @@ Description
 
 .. note::
 
-    This is an :ref:`obsolete` interface and may be removed
-    in the future. It is superseded by
-    :ref:`the selection API <VIDIOC_SUBDEV_G_SELECTION>`.
+    This is an :ref:`obsolete` interface and may be removed in the future. It is
+    superseded by :ref:`the selection API <VIDIOC_SUBDEV_G_SELECTION>`. No new
+    extensions to the :c:type:`v4l2_subdev_crop` structure will be accepted.
 
 To retrieve the current crop rectangle applications set the ``pad``
 field of a struct :c:type:`v4l2_subdev_crop` to the
diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
index 7048c51581c6..81a24bd38003 100644
--- a/include/uapi/linux/v4l2-subdev.h
+++ b/include/uapi/linux/v4l2-subdev.h
@@ -50,6 +50,10 @@ struct v4l2_subdev_format {
  * @rect: pad crop rectangle boundaries
  * @stream: stream number, defined in subdev routing
  * @reserved: drivers and applications must zero this array
+ *
+ * The subdev crop API is an obsolete interface and may be removed in the
+ * future. It is superseded by the selection API. No new extensions to this
+ * structure will be accepted.
  */
 struct v4l2_subdev_crop {
 	__u32 which;
-- 
2.39.2

[PATCH v2 02/14] media: Documentation: Add "stream" into glossary

[Sakari Ailus]

Add term "stream" to the glossary of the Media subsystem documentation.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 Documentation/userspace-api/media/glossary.rst | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/userspace-api/media/glossary.rst b/Documentation/userspace-api/media/glossary.rst
index 96a360edbf3b..ef0ab601b5bf 100644
--- a/Documentation/userspace-api/media/glossary.rst
+++ b/Documentation/userspace-api/media/glossary.rst
@@ -173,6 +173,12 @@ Glossary
 	An integrated circuit that integrates all components of a computer
 	or other electronic systems.
 
+_media-glossary-stream:
+    Stream
+	A distinct flow of data (image data or metadata) from an initial source
+	to a final sink. The initial source may be e.g. an image sensor and the
+	final sink e.g. a memory buffer.
+
     V4L2 API
 	**V4L2 userspace API**
 
-- 
2.39.2

[PATCH v2 03/14] media: uapi: Add generic serial metadata mbus formats

[Sakari Ailus]

Add generic serial metadata mbus formats. These formats describe data
width and packing but not the content itself. The reason for specifying
such formats is that the formats as such are fairly device specific but
they are still handled by CSI-2 receiver drivers that should not be aware
of device specific formats. What makes generic metadata formats possible
is that these formats are parsed by software only, after capturing the
data to system memory.

Also add a definition for "Data Unit" to cover what is essentially a pixel
but is not image data.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../userspace-api/media/glossary.rst          |   9 +
 .../media/v4l/subdev-formats.rst              | 255 ++++++++++++++++++
 include/uapi/linux/media-bus-format.h         |   9 +
 3 files changed, 273 insertions(+)

diff --git a/Documentation/userspace-api/media/glossary.rst b/Documentation/userspace-api/media/glossary.rst
index ef0ab601b5bf..84dbded08b47 100644
--- a/Documentation/userspace-api/media/glossary.rst
+++ b/Documentation/userspace-api/media/glossary.rst
@@ -25,6 +25,15 @@ Glossary
 
 	See :ref:`cec`.
 
+.. _media-glossary-data-unit:
+
+    Data Unit
+
+	Unit of data transported by a bus. On parallel buses, the data unit
+	consists of one or more related samples while on serial buses the data
+	unit is logical. If the data unit is image data, it may also be called a
+	pixel.
+
     Device Driver
 	Part of the Linux Kernel that implements support for a hardware
 	component.
diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst
index eb3cd20b0cf2..d9a5ee954cdd 100644
--- a/Documentation/userspace-api/media/v4l/subdev-formats.rst
+++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst
@@ -8306,3 +8306,258 @@ The following table lists the existing metadata formats.
 	both sides of the link and the bus format is a fixed
 	metadata format that is not configurable from userspace.
 	Width and height will be set to 0 for this format.
+
+Generic Serial Metadata Formats
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Generic serial metadata formats are used on serial buses where the actual data
+content is more or less device specific but the data is transmitted and received
+by multiple devices that do not process the data in any way, simply writing
+it to system memory for processing in software at the end of the pipeline.
+
+"b" in an array cell signifies a byte of data, followed by the number of the bit
+and finally the bit number in subscript. "x" indicates a padding bit.
+
+.. _media-bus-format-generic-meta:
+
+.. cssclass: longtable
+
+.. flat-table:: Generic Serial Metadata Formats
+    :header-rows:  2
+    :stub-columns: 0
+
+    * - Identifier
+      - Code
+      -
+      - :cspan:`23` Data organization within bus ``Data Unit
+	<media-glossary-data-unit>``
+    * -
+      -
+      - Bit
+      - 23
+      - 22
+      - 21
+      - 20
+      - 19
+      - 18
+      - 17
+      - 16
+      - 15
+      - 14
+      - 13
+      - 12
+      - 11
+      - 10
+      - 9
+      - 8
+      - 7
+      - 6
+      - 5
+      - 4
+      - 3
+      - 2
+      - 1
+      - 0
+    * .. _MEDIA-BUS-FMT-META-8:
+
+      - MEDIA_BUS_FMT_META_8
+      - 0x8001
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      - b0\ :sub:`7`
+      - b0\ :sub:`6`
+      - b0\ :sub:`5`
+      - b0\ :sub:`4`
+      - b0\ :sub:`3`
+      - b0\ :sub:`2`
+      - b0\ :sub:`1`
+      - b0\ :sub:`0`
+    * .. _MEDIA-BUS-FMT-META-10:
+
+      - MEDIA_BUS_FMT_META_10
+      - 0x8002
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      - b0\ :sub:`7`
+      - b0\ :sub:`6`
+      - b0\ :sub:`5`
+      - b0\ :sub:`4`
+      - b0\ :sub:`3`
+      - b0\ :sub:`2`
+      - b0\ :sub:`1`
+      - b0\ :sub:`0`
+      - x
+      - x
+    * .. _MEDIA-BUS-FMT-META-12:
+
+      - MEDIA_BUS_FMT_META_12
+      - 0x8003
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      - b0\ :sub:`7`
+      - b0\ :sub:`6`
+      - b0\ :sub:`5`
+      - b0\ :sub:`4`
+      - b0\ :sub:`3`
+      - b0\ :sub:`2`
+      - b0\ :sub:`1`
+      - b0\ :sub:`0`
+      - x
+      - x
+      - x
+      - x
+    * .. _MEDIA-BUS-FMT-META-14:
+
+      - MEDIA_BUS_FMT_META_14
+      - 0x8004
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      - b0\ :sub:`7`
+      - b0\ :sub:`6`
+      - b0\ :sub:`5`
+      - b0\ :sub:`4`
+      - b0\ :sub:`3`
+      - b0\ :sub:`2`
+      - b0\ :sub:`1`
+      - b0\ :sub:`0`
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+    * .. _MEDIA-BUS-FMT-META-16:
+
+      - MEDIA_BUS_FMT_META_16
+      - 0x8005
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      - b0\ :sub:`7`
+      - b0\ :sub:`6`
+      - b0\ :sub:`5`
+      - b0\ :sub:`4`
+      - b0\ :sub:`3`
+      - b0\ :sub:`2`
+      - b0\ :sub:`1`
+      - b0\ :sub:`0`
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+    * .. _MEDIA-BUS-FMT-META-20:
+
+      - MEDIA_BUS_FMT_META_20
+      - 0x8006
+      -
+      -
+      -
+      -
+      -
+      - b0\ :sub:`7`
+      - b0\ :sub:`6`
+      - b0\ :sub:`5`
+      - b0\ :sub:`4`
+      - b0\ :sub:`3`
+      - b0\ :sub:`2`
+      - b0\ :sub:`1`
+      - b0\ :sub:`0`
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+    * .. _MEDIA-BUS-FMT-META-24:
+
+      - MEDIA_BUS_FMT_META_24
+      - 0x8007
+      -
+      - b0\ :sub:`7`
+      - b0\ :sub:`6`
+      - b0\ :sub:`5`
+      - b0\ :sub:`4`
+      - b0\ :sub:`3`
+      - b0\ :sub:`2`
+      - b0\ :sub:`1`
+      - b0\ :sub:`0`
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
+      - x
diff --git a/include/uapi/linux/media-bus-format.h b/include/uapi/linux/media-bus-format.h
index f05f747e444d..d4c1d991014b 100644
--- a/include/uapi/linux/media-bus-format.h
+++ b/include/uapi/linux/media-bus-format.h
@@ -174,4 +174,13 @@
  */
 #define MEDIA_BUS_FMT_METADATA_FIXED		0x7001
 
+/* Generic line based metadata formats for serial buses. Next is 0x8008. */
+#define MEDIA_BUS_FMT_META_8			0x8001
+#define MEDIA_BUS_FMT_META_10			0x8002
+#define MEDIA_BUS_FMT_META_12			0x8003
+#define MEDIA_BUS_FMT_META_14			0x8004
+#define MEDIA_BUS_FMT_META_16			0x8005
+#define MEDIA_BUS_FMT_META_20			0x8006
+#define MEDIA_BUS_FMT_META_24			0x8007
+
 #endif /* __LINUX_MEDIA_BUS_FORMAT_H */
-- 
2.39.2

[PATCH v2 04/14] media: uapi: Document which mbus format fields are valid for metadata

[Sakari Ailus]

Now that metadata mbus formats have been added, it is necessary to define
which fields in struct v4l2_mbus_format are applicable to them (not many).

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../userspace-api/media/v4l/subdev-formats.rst | 15 ++++++++-------
 include/uapi/linux/v4l2-mediabus.h             | 18 ++++++++++++------
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst
index d9a5ee954cdd..25ba4c788ca0 100644
--- a/Documentation/userspace-api/media/v4l/subdev-formats.rst
+++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst
@@ -33,7 +33,7 @@ Media Bus Formats
     * - __u32
       - ``field``
       - Field order, from enum :c:type:`v4l2_field`. See
-	:ref:`field-order` for details.
+	:ref:`field-order` for details. Zero for metadata mbus codes.
     * - __u32
       - ``colorspace``
       - Image colorspace, from enum :c:type:`v4l2_colorspace`.
@@ -45,7 +45,7 @@ Media Bus Formats
 	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:`v4l2-subdev-mbus-code-flags`.
+	See :ref:`v4l2-subdev-mbus-code-flags`. Zero for metadata mbus codes.
     * - union {
       - (anonymous)
     * - __u16
@@ -61,7 +61,7 @@ Media Bus Formats
 	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`.
+	See :ref:`v4l2-subdev-mbus-code-flags`. Zero for metadata mbus codes.
     * - __u16
       - ``hsv_enc``
       - HSV encoding, from enum :c:type:`v4l2_hsv_encoding`.
@@ -75,7 +75,7 @@ Media Bus Formats
 	that hsv_enc conversion is supported by setting the flag
 	V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC in the corresponding struct
 	:c:type:`v4l2_subdev_mbus_code_enum` during enumeration.
-	See :ref:`v4l2-subdev-mbus-code-flags`
+	See :ref:`v4l2-subdev-mbus-code-flags`. Zero for metadata mbus codes.
     * - }
       -
     * - __u16
@@ -90,8 +90,8 @@ Media Bus Formats
 	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`.
-
+	during enumeration. See :ref:`v4l2-subdev-mbus-code-flags`. Zero for
+	metadata mbus codes.
     * - __u16
       - ``xfer_func``
       - Transfer function, from enum :c:type:`v4l2_xfer_func`.
@@ -104,7 +104,8 @@ Media Bus Formats
 	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`.
+	during enumeration. See :ref:`v4l2-subdev-mbus-code-flags`. Zero for
+	metadata mbus codes.
     * - __u16
       - ``flags``
       - flags See:  :ref:v4l2-mbus-framefmt-flags
diff --git a/include/uapi/linux/v4l2-mediabus.h b/include/uapi/linux/v4l2-mediabus.h
index 6b07b73473b5..946520bc49f1 100644
--- a/include/uapi/linux/v4l2-mediabus.h
+++ b/include/uapi/linux/v4l2-mediabus.h
@@ -19,12 +19,18 @@
  * @width:	image width
  * @height:	image height
  * @code:	data format code (from enum v4l2_mbus_pixelcode)
- * @field:	used interlacing type (from enum v4l2_field)
- * @colorspace:	colorspace of the data (from enum v4l2_colorspace)
- * @ycbcr_enc:	YCbCr encoding of the data (from enum v4l2_ycbcr_encoding)
- * @hsv_enc:	HSV encoding of the data (from enum v4l2_hsv_encoding)
- * @quantization: quantization of the data (from enum v4l2_quantization)
- * @xfer_func:  transfer function of the data (from enum v4l2_xfer_func)
+ * @field:	used interlacing type (from enum v4l2_field), zero for metadata
+ *		mbus codes
+ * @colorspace:	colorspace of the data (from enum v4l2_colorspace), zero on
+ *		metadata mbus codes
+ * @ycbcr_enc:	YCbCr encoding of the data (from enum v4l2_ycbcr_encoding), zero
+ *		for metadata mbus codes
+ * @hsv_enc:	HSV encoding of the data (from enum v4l2_hsv_encoding), zero for
+ *		metadata mbus codes
+ * @quantization: quantization of the data (from enum v4l2_quantization), zero
+ *		for metadata mbus codes
+ * @xfer_func:  transfer function of the data (from enum v4l2_xfer_func), zero
+ *		for metadata mbus codes
  * @flags:	flags (V4L2_MBUS_FRAMEFMT_*)
  * @reserved:  reserved bytes that can be later used
  */
-- 
2.39.2

[PATCH v2 05/14] media: uapi: v4l: Add generic 8-bit metadata format definitions

[Sakari Ailus]

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>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../userspace-api/media/v4l/dev-subdev.rst    |   2 +
 .../userspace-api/media/v4l/meta-formats.rst  |   3 +-
 .../media/v4l/metafmt-generic.rst             | 343 ++++++++++++++++++
 drivers/media/v4l2-core/v4l2-ioctl.c          |   7 +
 include/uapi/linux/videodev2.h                |   8 +
 5 files changed, 362 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..399de3d52a76
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
@@ -0,0 +1,343 @@
+.. 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 used on CSI-2 for 8 bits per :ref:`Data Unit <media-glossary-data-unit>`.
+
+Additionally it is used for 16 bits per Data Unit when two bytes of metadata are
+packed into one 16-bit Data Unit. Otherwise the 16 bits per pixel dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_16 <v4l2-meta-fmt-generic-csi2-16>`.
+
+**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 :ref:`Data Unit
+<media-glossary-data-unit>` formats that pack two bytes of metadata into one
+Data Unit. Otherwise the 20 bits per pixel dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_20 <v4l2-meta-fmt-generic-csi2-20>`.
+
+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 one padding byte after every two 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 :ref:`Data Unit
+<media-glossary-data-unit>` formats that pack two bytes of metadata into one
+Data Unit. Otherwise the 24 bits per pixel dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_24 <v4l2-meta-fmt-generic-csi2-24>`.
+
+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.
+
+Some devices support more efficient packing of metadata in conjunction with
+16-bit image data. In that case the dataformat is
+:ref:`V4L2_META_FMT_GENERIC_8 <v4l2-meta-fmt-generic-8>`.
+
+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.
+
+Some devices support more efficient packing of metadata in conjunction with
+16-bit image data. In that case the dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_10 <v4l2-meta-fmt-generic-csi2-10>`.
+
+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.
+
+Some devices support more efficient packing of metadata in conjunction with
+16-bit image data. In that case the dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_12 <v4l2-meta-fmt-generic-csi2-12>`.
+
+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 bf12860d570a..0f44b8486ea8 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
 
-- 
2.39.2

[PATCH v2.1 05/14] media: uapi: v4l: Add generic 8-bit metadata format definitions

[Sakari Ailus]

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>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
since v2:

- Remove the sentence on internal pads, including the cross reference. It
  will be reintroduced later on separately.

 .../userspace-api/media/v4l/dev-subdev.rst    |   2 +
 .../userspace-api/media/v4l/meta-formats.rst  |   3 +-
 .../media/v4l/metafmt-generic.rst             | 340 ++++++++++++++++++
 drivers/media/v4l2-core/v4l2-ioctl.c          |   7 +
 include/uapi/linux/videodev2.h                |   8 +
 5 files changed, 359 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..72b1d0b3fee6
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
@@ -0,0 +1,340 @@
+.. 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.
+
+.. _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 used on CSI-2 for 8 bits per :ref:`Data Unit <media-glossary-data-unit>`.
+
+Additionally it is used for 16 bits per Data Unit when two bytes of metadata are
+packed into one 16-bit Data Unit. Otherwise the 16 bits per pixel dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_16 <v4l2-meta-fmt-generic-csi2-16>`.
+
+**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 :ref:`Data Unit
+<media-glossary-data-unit>` formats that pack two bytes of metadata into one
+Data Unit. Otherwise the 20 bits per pixel dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_20 <v4l2-meta-fmt-generic-csi2-20>`.
+
+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 one padding byte after every two 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 :ref:`Data Unit
+<media-glossary-data-unit>` formats that pack two bytes of metadata into one
+Data Unit. Otherwise the 24 bits per pixel dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_24 <v4l2-meta-fmt-generic-csi2-24>`.
+
+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.
+
+Some devices support more efficient packing of metadata in conjunction with
+16-bit image data. In that case the dataformat is
+:ref:`V4L2_META_FMT_GENERIC_8 <v4l2-meta-fmt-generic-8>`.
+
+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.
+
+Some devices support more efficient packing of metadata in conjunction with
+16-bit image data. In that case the dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_10 <v4l2-meta-fmt-generic-csi2-10>`.
+
+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.
+
+Some devices support more efficient packing of metadata in conjunction with
+16-bit image data. In that case the dataformat is
+:ref:`V4L2_META_FMT_GENERIC_CSI2_12 <v4l2-meta-fmt-generic-csi2-12>`.
+
+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 bf12860d570a..0f44b8486ea8 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
 

base-commit: 36ce7124a1502bf8321668c73182372985859590
-- 
2.39.2

[PATCH v2 06/14] media: v4l: Support line-based metadata capture

[Sakari Ailus]

Many camera sensors, among other devices, transmit embedded data and image
data for each CSI-2 frame. This embedded data typically contains register
configuration of the sensor that has been used to capture the image data
of the same frame.

The embedded data is received by the CSI-2 receiver and has the same
properties as the image data, including that it is line based: it has
width, height and bytesperline (stride).

Add these fields to struct v4l2_meta_format and document them.

Also add V4L2_FMT_FLAG_META_LINE_BASED to tell a given format is
line-based i.e. these fields of struct v4l2_meta_format are valid for it.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../userspace-api/media/v4l/dev-meta.rst      | 21 +++++++++++++++++++
 .../media/v4l/vidioc-enum-fmt.rst             |  7 +++++++
 .../media/videodev2.h.rst.exceptions          |  1 +
 drivers/media/v4l2-core/v4l2-ioctl.c          |  5 +++--
 include/uapi/linux/videodev2.h                | 10 +++++++++
 5 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/dev-meta.rst b/Documentation/userspace-api/media/v4l/dev-meta.rst
index 0e7e1ee1471a..5eee9ab60395 100644
--- a/Documentation/userspace-api/media/v4l/dev-meta.rst
+++ b/Documentation/userspace-api/media/v4l/dev-meta.rst
@@ -47,6 +47,12 @@ member of the ``fmt`` union as needed per the desired operation. Both drivers
 and applications must set the remainder of the :c:type:`v4l2_format` structure
 to 0.
 
+Devices that capture metadata by line have the struct v4l2_fmtdesc
+``V4L2_FMT_FLAG_META_LINE_BASED`` flag set for :c:func:`VIDIOC_ENUM_FMT`. Such
+devices can typically also :ref:`capture image data <capture>`. This primarily
+involves devices that receive the data from a different devices such as a camera
+sensor.
+
 .. c:type:: v4l2_meta_format
 
 .. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}|
@@ -65,3 +71,18 @@ to 0.
       - ``buffersize``
       - Maximum buffer size in bytes required for data. The value is set by the
         driver.
+    * - __u32
+      - ``width``
+      - Width of a line of metadata in Data Units. Valid when
+	:c:type`v4l2_fmtdesc` flag ``V4L2_FMT_FLAG_META_LINE_BASED`` is set,
+	otherwise zero. See :c:func:`VIDIOC_ENUM_FMT`.
+    * - __u32
+      - ``height``
+      - Number of rows of metadata. Valid when :c:type`v4l2_fmtdesc` flag
+	``V4L2_FMT_FLAG_META_LINE_BASED`` is set, otherwise zero. See
+	:c:func:`VIDIOC_ENUM_FMT`.
+    * - __u32
+      - ``bytesperline``
+      - Offset in bytes between the beginning of two consecutive lines. Valid
+	when :c:type`v4l2_fmtdesc` flag ``V4L2_FMT_FLAG_META_LINE_BASED`` is
+	set, otherwise zero. See :c:func:`VIDIOC_ENUM_FMT`.
diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
index 000c154b0f98..3adb3d205531 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
@@ -227,6 +227,13 @@ the ``mbus_code`` field is handled differently:
 	The application can ask to configure the quantization of the capture
 	device when calling the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl with
 	:ref:`V4L2_PIX_FMT_FLAG_SET_CSC <v4l2-pix-fmt-flag-set-csc>` set.
+    * - ``V4L2_FMT_FLAG_META_LINE_BASED``
+      - 0x0200
+      - The metadata format is line-based. In this case the ``width``,
+	``height`` and ``bytesperline`` fields of :c:type:`v4l2_meta_format` are
+	valid. The buffer consists of ``height`` lines, each having ``width``
+	Data Units of data and the offset (in bytes) between the beginning of
+	each two consecutive lines is ``bytesperline``.
 
 Return Value
 ============
diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
index 3e58aac4ef0b..bdc628e8c1d6 100644
--- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
+++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
@@ -215,6 +215,7 @@ replace define V4L2_FMT_FLAG_CSC_XFER_FUNC fmtdesc-flags
 replace define V4L2_FMT_FLAG_CSC_YCBCR_ENC fmtdesc-flags
 replace define V4L2_FMT_FLAG_CSC_HSV_ENC fmtdesc-flags
 replace define V4L2_FMT_FLAG_CSC_QUANTIZATION fmtdesc-flags
+replace define V4L2_FMT_FLAG_META_LINE_BASED fmtdesc-flags
 
 # V4L2 timecode types
 replace define V4L2_TC_TYPE_24FPS timecode-type
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index ae2dca7f2817..2cfc9106857a 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -343,8 +343,9 @@ static void v4l_print_format(const void *arg, bool write_only)
 	case V4L2_BUF_TYPE_META_OUTPUT:
 		meta = &p->fmt.meta;
 		pixelformat = meta->dataformat;
-		pr_cont(", dataformat=%p4cc, buffersize=%u\n",
-			&pixelformat, meta->buffersize);
+		pr_cont(", dataformat=%p4cc, buffersize=%u, width=%u, height=%u, bytesperline=%u\n",
+			&pixelformat, meta->buffersize, meta->width,
+			meta->height, meta->bytesperline);
 		break;
 	}
 }
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 0f44b8486ea8..647ce3419bd8 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -877,6 +877,7 @@ struct v4l2_fmtdesc {
 #define V4L2_FMT_FLAG_CSC_YCBCR_ENC		0x0080
 #define V4L2_FMT_FLAG_CSC_HSV_ENC		V4L2_FMT_FLAG_CSC_YCBCR_ENC
 #define V4L2_FMT_FLAG_CSC_QUANTIZATION		0x0100
+#define V4L2_FMT_FLAG_META_LINE_BASED		0x0200
 
 	/* Frame Size and frame rate enumeration */
 /*
@@ -2424,10 +2425,19 @@ struct v4l2_sdr_format {
  * struct v4l2_meta_format - metadata format definition
  * @dataformat:		little endian four character code (fourcc)
  * @buffersize:		maximum size in bytes required for data
+ * @width:		number of data units of data per line (valid for line
+ *			based formats only, see format documentation)
+ * @height:		number of lines of data per buffer (valid for line based
+ *			formats only)
+ * @bytesperline:	offset between the beginnings of two adjacent lines in
+ *			bytes (valid for line based formats only)
  */
 struct v4l2_meta_format {
 	__u32				dataformat;
 	__u32				buffersize;
+	__u32				width;
+	__u32				height;
+	__u32				bytesperline;
 } __attribute__ ((packed));
 
 /**
-- 
2.39.2

[PATCH v2 07/14] media: v4l: Set line based metadata flag in V4L2 core

[Sakari Ailus]

Set (and unset) the V4L2_FMT_FLAG_META_LINE_BASED flag in struct
v4l2_fmtdesc based on the format after returning the driver callback for
enumerating formats. This way the drivers don't need to care about the
flag.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-ioctl.c | 16 ++++++++++++++++
 include/uapi/linux/videodev2.h       |  4 ++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 2cfc9106857a..5e928e2a2beb 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1538,6 +1538,22 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 		}
 	}
 
+	if (fmt->type == V4L2_BUF_TYPE_META_CAPTURE) {
+		switch (fmt->pixelformat) {
+		case V4L2_META_FMT_GENERIC_8:
+		case V4L2_META_FMT_GENERIC_CSI2_10:
+		case V4L2_META_FMT_GENERIC_CSI2_12:
+		case V4L2_META_FMT_GENERIC_CSI2_14:
+		case V4L2_META_FMT_GENERIC_CSI2_16:
+		case V4L2_META_FMT_GENERIC_CSI2_20:
+		case V4L2_META_FMT_GENERIC_CSI2_24:
+			fmt->flags |= V4L2_FMT_FLAG_META_LINE_BASED;
+			break;
+		default:
+			fmt->flags &= ~V4L2_FMT_FLAG_META_LINE_BASED;
+		}
+	}
+
 	if (descr)
 		WARN_ON(strscpy(fmt->description, descr, sz) < 0);
 	fmt->flags |= flags;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 647ce3419bd8..d944db7ae1ed 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -839,6 +839,10 @@ 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 */
 
+/*
+ * Line-based metadata formats. Remember to update v4l_fill_fmtdesc() when
+ * adding new ones!
+ */
 #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 */
-- 
2.39.2

[PATCH v2 08/14] media: Documentation: Additional streams generally don't harm capture

[Sakari Ailus]

Having extra streams on the source end of the link that cannot be captured
by the sink sub-device generally are not an issue, at least not on CSI-2
bus. Still document that there may be hardware-specific limitations. For
example on parallel bus this might not work on all cases.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 Documentation/userspace-api/media/v4l/dev-subdev.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst
index f375b820ab68..b76e02e54512 100644
--- a/Documentation/userspace-api/media/v4l/dev-subdev.rst
+++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst
@@ -529,9 +529,9 @@ the its sink pad and allows to route them individually to one of its source
 pads.
 
 Subdevice drivers that support multiplexed streams are compatible with
-non-multiplexed subdev drivers, but, of course, require a routing configuration
-where the link between those two types of drivers contains only a single
-stream.
+non-multiplexed subdev drivers. However, if the driver at the sink end of a link
+does not support streams, then only stream 0 of source end may be captured.
+There may be additional limitations specific to the sink device.
 
 Understanding streams
 ^^^^^^^^^^^^^^^^^^^^^
-- 
2.39.2

[PATCH v2 09/14] media: Documentation: Document S_ROUTING behaviour

[Sakari Ailus]

Document S_ROUTING behaviour for different devices.

Generally in devices that produce streams the streams are static and some
can be enabled and disabled, whereas in devices that just transport them
or write them to memory, more configurability is allowed. Document this.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Julien Massot <julien.massot@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../userspace-api/media/v4l/dev-subdev.rst    | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst
index b76e02e54512..0f9eda3187f3 100644
--- a/Documentation/userspace-api/media/v4l/dev-subdev.rst
+++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst
@@ -572,6 +572,29 @@ Any configurations of a stream within a pad, such as format or selections,
 are independent of similar configurations on other streams. This is
 subject to change in the future.
 
+Device types and routing setup
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Different kinds of sub-devices have differing behaviour for route activation,
+depending on the hardware. In all cases, however, only routes that have the
+``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag set are active.
+
+Devices generating the streams may allow enabling and disabling some of the
+routes or have a fixed routing configuration. If the routes can be disabled, not
+declaring the routes (or declaring them without
+``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in ``VIDIOC_SUBDEV_S_ROUTING`` will
+disable the routes. ``VIDIOC_SUBDEV_S_ROUTING`` will still return such routes
+back to the user in the routes array, with the ``V4L2_SUBDEV_STREAM_FL_ACTIVE``
+flag unset.
+
+Devices transporting the streams almost always have more configurability with
+respect to routing. Typically any route between the sub-device's sink and source
+pads is possible, and multiple routes (usually up to certain limited number) may
+be active simultaneously. For such devices, no routes are created by the driver
+and user-created routes are fully replaced when ``VIDIOC_SUBDEV_S_ROUTING`` is
+called on the sub-device. Such newly created routes have the device's default
+configuration for format and selection rectangles.
+
 Configuring streams
 ^^^^^^^^^^^^^^^^^^^
 
-- 
2.39.2

[PATCH v2 10/14] media: v4l: subdev: Add a function to lock two sub-device states, use it

[Sakari Ailus]

Add two new functions, v4l2_subdev_lock_states() and
v4l2_subdev_unclock_states(), to acquire and release the state of two
sub-devices. They differ from calling v4l2_subdev_{un,}lock_state() so
that if the two states share the same lock, the lock is acquired only
once.

Also use the new functions in v4l2_subdev_link_validate().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Julien Massot <julien.massot@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-subdev.c | 12 +++-----
 include/media/v4l2-subdev.h           | 40 +++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 2d67ec54569a..779583447eac 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1437,17 +1437,13 @@ int v4l2_subdev_link_validate(struct media_link *link)
 
 	states_locked = sink_state && source_state;
 
-	if (states_locked) {
-		v4l2_subdev_lock_state(sink_state);
-		v4l2_subdev_lock_state(source_state);
-	}
+	if (states_locked)
+		v4l2_subdev_lock_states(sink_state, source_state);
 
 	ret = v4l2_subdev_link_validate_locked(link, states_locked);
 
-	if (states_locked) {
-		v4l2_subdev_unlock_state(sink_state);
-		v4l2_subdev_unlock_state(source_state);
-	}
+	if (states_locked)
+		v4l2_subdev_unlock_states(sink_state, source_state);
 
 	return ret;
 }
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 1af16b16f0bf..e22c50ce7e05 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1724,6 +1724,46 @@ static inline void v4l2_subdev_unlock_state(struct v4l2_subdev_state *state)
 	mutex_unlock(state->lock);
 }
 
+/**
+ * v4l2_subdev_lock_states - Lock two sub-device states
+ * @state1: One subdevice state
+ * @state2: The other subdevice state
+ *
+ * Locks the state of two sub-devices.
+ *
+ * The states must be unlocked with v4l2_subdev_unlock_states() after use.
+ *
+ * This differs from calling v4l2_subdev_lock_state() on both states so that if
+ * the states share the same lock, the lock is acquired only once (so no
+ * deadlock occurs). The caller is responsible for ensuring the locks will
+ * always be acquired in the same order.
+ */
+static inline void v4l2_subdev_lock_states(struct v4l2_subdev_state *state1,
+					   struct v4l2_subdev_state *state2)
+{
+	mutex_lock(state1->lock);
+	if (state1->lock != state2->lock)
+		mutex_lock(state2->lock);
+}
+
+/**
+ * v4l2_subdev_unlock_states() - Unlock two sub-device states
+ * @state1: One subdevice state
+ * @state2: The other subdevice state
+ *
+ * Unlocks the state of two sub-devices.
+ *
+ * This differs from calling v4l2_subdev_unlock_state() on both states so that
+ * if the states share the same lock, the lock is released only once.
+ */
+static inline void v4l2_subdev_unlock_states(struct v4l2_subdev_state *state1,
+					     struct v4l2_subdev_state *state2)
+{
+	mutex_unlock(state1->lock);
+	if (state1->lock != state2->lock)
+		mutex_unlock(state2->lock);
+}
+
 /**
  * v4l2_subdev_get_unlocked_active_state() - Checks that the active subdev state
  *					     is unlocked and returns it
-- 
2.39.2

[PATCH v2 11/14] media: v4l: subdev: Copy argument back to user also for S_ROUTING

[Sakari Ailus]

As the user needs to know what went wrong for S_ROUTING, copy array
arguments back to the user.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Julien Massot <julien.massot@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-ioctl.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 5e928e2a2beb..0260acef97d2 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -3461,11 +3461,14 @@ video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg,
 	 * FIXME: subdev IOCTLS are partially handled here and partially in
 	 * v4l2-subdev.c and the 'always_copy' flag can only be set for IOCTLS
 	 * defined here as part of the 'v4l2_ioctls' array. As
-	 * VIDIOC_SUBDEV_G_ROUTING needs to return results to applications even
-	 * in case of failure, but it is not defined here as part of the
+	 * VIDIOC_SUBDEV_[GS]_ROUTING needs to return results to applications
+	 * even in case of failure, but it is not defined here as part of the
 	 * 'v4l2_ioctls' array, insert an ad-hoc check to address that.
 	 */
-	if (err < 0 && !always_copy && cmd != VIDIOC_SUBDEV_G_ROUTING)
+	if (cmd == VIDIOC_SUBDEV_G_ROUTING || cmd == VIDIOC_SUBDEV_S_ROUTING)
+		always_copy = true;
+
+	if (err < 0 && !always_copy)
 		goto out;
 
 	if (has_array_args) {
-- 
2.39.2

[PATCH v2 12/14] media: v4l: subdev: Add len_routes field to struct v4l2_subdev_routing

[Sakari Ailus]

The len_routes field is used to tell the size of the routes array in
struct v4l2_subdev_routing. This way the number of routes returned from
S_ROUTING IOCTL may be larger than the number of routes provided, in case
there are more routes returned by the driver.

Note that this uAPI is still disabled in the code, so this change can
safely be done. Anyone who manually patched the code to enable this uAPI
must update their code.

The patch also increases the number of reserved fields in struct
v4l2_subdev_routing.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../media/v4l/vidioc-subdev-g-routing.rst     | 46 +++++++++++++------
 drivers/media/v4l2-core/v4l2-ioctl.c          |  4 +-
 drivers/media/v4l2-core/v4l2-subdev.c         | 12 ++---
 include/media/v4l2-subdev.h                   |  2 +
 include/uapi/linux/v4l2-subdev.h              | 10 ++--
 5 files changed, 49 insertions(+), 25 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
index 26b5004bfe6d..cbd9370006b6 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
@@ -43,23 +43,38 @@ The routing configuration determines the flows of data inside an entity.
 Drivers report their current routing tables using the
 ``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes
 with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and
-setting or clearing flags of the  ``flags`` field of a
-struct :c:type:`v4l2_subdev_route`.
+setting or clearing flags of the ``flags`` field of a struct
+:c:type:`v4l2_subdev_route`.
 
-All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called. This
-means that the userspace must reconfigure all streams after calling the ioctl
-with e.g. ``VIDIOC_SUBDEV_S_FMT``.
+All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called.
+This means that the userspace must reconfigure all stream formats and selections
+after calling the ioctl with e.g. ``VIDIOC_SUBDEV_S_FMT``.
 
 Only subdevices which have both sink and source pads can support routing.
 
-When inspecting routes through ``VIDIOC_SUBDEV_G_ROUTING`` and the application
-provided ``num_routes`` is not big enough to contain all the available routes
-the subdevice exposes, drivers return the ENOSPC error code and adjust the
-value of the ``num_routes`` field. Application should then reserve enough memory
-for all the route entries and call ``VIDIOC_SUBDEV_G_ROUTING`` again.
-
-On a successful ``VIDIOC_SUBDEV_G_ROUTING`` call the driver updates the
-``num_routes`` field to reflect the actual number of routes returned.
+The ``len_routes`` field indicates the number of routes that can fit in the
+``routes`` array allocated by userspace. It is set by applications for both
+ioctls to indicate how many routes the kernel can return, and is never modified
+by the kernel.
+
+The ``num_routes`` field indicates the number of routes in the routing
+table. For ``VIDIOC_SUBDEV_S_ROUTING``, it is set by userspace to the number of
+routes that the application stored in the ``routes`` array. For both ioctls, it
+is returned by the kernel and indicates how many routes are stored in the
+subdevice routing table. This may be smaller or larger than the value of
+``num_routes`` set by the application for ``VIDIOC_SUBDEV_S_ROUTING``, as
+drivers may adjust the requested routing table.
+
+The kernel can return a ``num_routes`` value larger than ``len_routes`` from
+both ioctls. This indicates thare are more routes in the routing table than fits
+the ``routes`` array. In this case, the ``routes`` array is filled by the kernel
+with the first ``len_routes`` entries of the subdevice routing table. This is
+not considered to be an error, and the ioctl call succeeds. If the applications
+wants to retrieve the missing routes, it can issue a new
+``VIDIOC_SUBDEV_G_ROUTING`` call with a large enough ``routes`` array.
+
+``VIDIOC_SUBDEV_S_ROUTING`` may return more routes than the user provided in
+``num_routes`` field due to e.g. hardware properties.
 
 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
 
@@ -74,6 +89,9 @@ On a successful ``VIDIOC_SUBDEV_G_ROUTING`` call the driver updates the
       - ``which``
       - Routing table to be accessed, from enum
         :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
+    * - __u32
+      - ``len_routes``
+      - The length of the array (as in memory reserved for the array)
     * - struct :c:type:`v4l2_subdev_route`
       - ``routes[]``
       - Array of struct :c:type:`v4l2_subdev_route` entries
@@ -81,7 +99,7 @@ On a successful ``VIDIOC_SUBDEV_G_ROUTING`` call the driver updates the
       - ``num_routes``
       - Number of entries of the routes array
     * - __u32
-      - ``reserved``\ [5]
+      - ``reserved``\ [11]
       - Reserved for future extensions. Applications and drivers must set
 	the array to zero.
 
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 0260acef97d2..aab671fae45b 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -3201,13 +3201,13 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size,
 	case VIDIOC_SUBDEV_S_ROUTING: {
 		struct v4l2_subdev_routing *routing = parg;
 
-		if (routing->num_routes > 256)
+		if (routing->len_routes > 256)
 			return -E2BIG;
 
 		*user_ptr = u64_to_user_ptr(routing->routes);
 		*kernel_ptr = (void **)&routing->routes;
 		*array_size = sizeof(struct v4l2_subdev_route)
-			    * routing->num_routes;
+			    * routing->len_routes;
 		ret = 1;
 		break;
 	}
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 779583447eac..b565f202df67 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -960,14 +960,10 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 
 		krouting = &state->routing;
 
-		if (routing->num_routes < krouting->num_routes) {
-			routing->num_routes = krouting->num_routes;
-			return -ENOSPC;
-		}
-
 		memcpy((struct v4l2_subdev_route *)(uintptr_t)routing->routes,
 		       krouting->routes,
-		       krouting->num_routes * sizeof(*krouting->routes));
+		       min(krouting->num_routes, routing->len_routes) *
+		       sizeof(*krouting->routes));
 		routing->num_routes = krouting->num_routes;
 
 		return 0;
@@ -989,6 +985,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 		if (routing->which != V4L2_SUBDEV_FORMAT_TRY && ro_subdev)
 			return -EPERM;
 
+		if (routing->num_routes > routing->len_routes)
+			return -EINVAL;
+
 		memset(routing->reserved, 0, sizeof(routing->reserved));
 
 		for (i = 0; i < routing->num_routes; ++i) {
@@ -1015,6 +1014,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 		}
 
 		krouting.num_routes = routing->num_routes;
+		krouting.len_routes = routing->len_routes;
 		krouting.routes = routes;
 
 		return v4l2_subdev_call(sd, pad, set_routing, state,
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index e22c50ce7e05..e30c463d90e5 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -714,12 +714,14 @@ struct v4l2_subdev_stream_configs {
 /**
  * struct v4l2_subdev_krouting - subdev routing table
  *
+ * @len_routes: length of routes array, in routes
  * @num_routes: number of routes
  * @routes: &struct v4l2_subdev_route
  *
  * This structure contains the routing table for a subdev.
  */
 struct v4l2_subdev_krouting {
+	unsigned int len_routes;
 	unsigned int num_routes;
 	struct v4l2_subdev_route *routes;
 };
diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
index 81a24bd38003..2347e266cf75 100644
--- a/include/uapi/linux/v4l2-subdev.h
+++ b/include/uapi/linux/v4l2-subdev.h
@@ -228,15 +228,19 @@ struct v4l2_subdev_route {
  * struct v4l2_subdev_routing - Subdev routing information
  *
  * @which: configuration type (from enum v4l2_subdev_format_whence)
- * @num_routes: the total number of routes in the routes array
+ * @len_routes: the length of the routes array, in routes; set by the user, not
+ *		modified by the kernel
  * @routes: pointer to the routes array
+ * @num_routes: the total number of routes, possibly more than fits in the
+ *		routes array
  * @reserved: drivers and applications must zero this array
  */
 struct v4l2_subdev_routing {
 	__u32 which;
-	__u32 num_routes;
+	__u32 len_routes;
 	__u64 routes;
-	__u32 reserved[6];
+	__u32 num_routes;
+	__u32 reserved[11];
 };
 
 /*
-- 
2.39.2

[PATCH v2 13/14] media: v4l: subdev: Return routes set using S_ROUTING

[Sakari Ailus]

Return the routes set using S_ROUTING back to the user. Also reflect this
in documentation.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../media/v4l/vidioc-subdev-g-routing.rst            |  7 ++-----
 drivers/media/v4l2-core/v4l2-subdev.c                | 12 +++++++++++-
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
index cbd9370006b6..1cf795480602 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
@@ -44,7 +44,8 @@ Drivers report their current routing tables using the
 ``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes
 with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and
 setting or clearing flags of the ``flags`` field of a struct
-:c:type:`v4l2_subdev_route`.
+:c:type:`v4l2_subdev_route`. Similarly to ``VIDIOC_SUBDEV_G_ROUTING``, also
+``VIDIOC_SUBDEV_S_ROUTING`` returns the routes back to the user.
 
 All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called.
 This means that the userspace must reconfigure all stream formats and selections
@@ -153,10 +154,6 @@ On success 0 is returned, on error -1 and the ``errno`` variable is set
 appropriately. The generic error codes are described at the
 :ref:`Generic Error Codes <gen-errors>` chapter.
 
-ENOSPC
-   The application provided ``num_routes`` is not big enough to contain
-   all the available routes the subdevice exposes.
-
 EINVAL
    The sink or source pad identifiers reference a non-existing pad or reference
    pads of different types (ie. the sink_pad identifiers refers to a source
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index b565f202df67..3d1ed8ab5229 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1017,8 +1017,18 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 		krouting.len_routes = routing->len_routes;
 		krouting.routes = routes;
 
-		return v4l2_subdev_call(sd, pad, set_routing, state,
+		rval = v4l2_subdev_call(sd, pad, set_routing, state,
 					routing->which, &krouting);
+		if (rval < 0)
+			return rval;
+
+		memcpy((struct v4l2_subdev_route *)(uintptr_t)routing->routes,
+		       state->routing.routes,
+		       min(state->routing.num_routes, routing->len_routes) *
+		       sizeof(*state->routing.routes));
+		routing->num_routes = state->routing.num_routes;
+
+		return 0;
 	}
 
 	case VIDIOC_SUBDEV_G_CLIENT_CAP: {
-- 
2.39.2

[PATCH v2 14/14] media: v4l: subdev: Add trivial set_routing support

[Sakari Ailus]

Add trivial S_ROUTING IOCTL support for drivers where routing is static.
Essentially this means returning the same information G_ROUTING call would
have done.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Co-developed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Julien Massot <julien.massot@collabora.com>
---
 drivers/media/v4l2-core/v4l2-subdev.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 3d1ed8ab5229..8470d6eda9a3 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1013,6 +1013,20 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 				return -EINVAL;
 		}
 
+		/*
+		 * If the driver doesn't support setting routing, just return
+		 * the routing table.
+		 */
+		if (!v4l2_subdev_has_op(sd, pad, set_routing)) {
+			memcpy((struct v4l2_subdev_route *)(uintptr_t)routing->routes,
+			       state->routing.routes,
+			       min(state->routing.num_routes, routing->len_routes) *
+			       sizeof(*state->routing.routes));
+			routing->num_routes = state->routing.num_routes;
+
+			return 0;
+		}
+
 		krouting.num_routes = routing->num_routes;
 		krouting.len_routes = routing->len_routes;
 		krouting.routes = routes;
-- 
2.39.2