media: uapi: Add generic serial metadata mbus formats

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>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Documentation/userspace-api/media/glossary.rst

@@ -25,6 +25,13 @@ Glossary
 
 	See :ref:`cec`.
 
+    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.

Documentation/userspace-api/media/v4l/subdev-formats.rst

@@ -8306,3 +8306,257 @@ 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 :term:`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

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 */