[PATCH 6/7] media: uapi: Add generic 8-bit metadata format definitions

Sakari Ailus
2023-06-30T20:44:00Z

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 of 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/meta-formats.rst | 1 +
.../media/v4l/metafmt-generic.rst | 331 ++++++++++++++++++
drivers/media/v4l2-core/v4l2-ioctl.c | 8 +
include/uapi/linux/videodev2.h | 9 +
4 files changed, 349 insertions(+)
create mode 100644 Documentation/userspace-api/media/v4l/metafmt-generic.rst

diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
index 0bb61fc5bc00..919f595576b9 100644
--- a/Documentation/userspace-api/media/v4l/meta-formats.rst
+++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
@@ -19,3 +19,4 @@ These formats are used for the :ref:`metadata` interface only.
metafmt-vsp1-hgo
metafmt-vsp1-hgt
metafmt-vivid
+ metafmt-generic
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..a27bfc721edf
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
@@ -0,0 +1,331 @@
+.. 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'), V4L2_META_FMT_GENERIC_CSI2_2_24 ('MC2O')
+**************************************************************************************************************************************************************************************************************************************************************************************************************************
+
+
+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
+defined in an :ref:`internal source pad <MEDIA-PAD-FL-INTERNAL>` of the source
+sub-device. See also :ref:`source routes <v4l2-subdev-source-routes>`.
+
+.. _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 on both 8 bits per sample as well as on
+16 bits per sample when two bytes of metadata are packed into one sample.
+
+**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::
+ :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 packed 8-bit generic metadata, 10 bits
+for each 8 bits of data. Every four bytes of metadata is followed by a single
+byte of padding. The way the data is stored follows the CSI-2 specification.
+
+This format is also used on CSI-2 on 20 bits per sample format that packs two
+bytes of metadata into one sample.
+
+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 "p" a byte of padding.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
+
+.. flat-table::
+ :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`
+ - p
+ * - start + 5:
+ - M\ :sub:`01`
+ - M\ :sub:`11`
+ - M\ :sub:`21`
+ - M\ :sub:`31`
+ - p
+
+.. _v4l2-meta-fmt-generic-csi2-12:
+
+V4L2_META_FMT_GENERIC_CSI2_12
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_12 contains packed 8-bit generic metadata, 12 bits
+for each 8 bits of data. Every four bytes of metadata is followed by two bytes
+of padding. The way the data is stored follows the CSI-2 specification.
+
+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 "p" 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::
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 12 8 8 8 8 8 8
+
+ * - start + 0:
+ - M\ :sub:`00`
+ - M\ :sub:`10`
+ - M\ :sub:`20`
+ - M\ :sub:`30`
+ - p
+ - p
+ * - start + 6:
+ - M\ :sub:`01`
+ - M\ :sub:`11`
+ - M\ :sub:`21`
+ - M\ :sub:`31`
+ - p
+ - p
+
+.. _v4l2-meta-fmt-generic-csi2-14:
+
+V4L2_META_FMT_GENERIC_CSI2_14
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_14 contains packed 8-bit generic metadata, 14 bits
+for each 8 bits of data. Every four bytes of metadata is followed by three
+bytes of padding. The way the data is stored follows the CSI-2 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 "p" 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::
+ :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`
+ - p
+ - p
+ - p
+ * - start + 7:
+ - M\ :sub:`01`
+ - M\ :sub:`11`
+ - M\ :sub:`21`
+ - M\ :sub:`31`
+ - p
+ - p
+ - p
+
+.. _v4l2-meta-fmt-generic-csi2-16:
+
+V4L2_META_FMT_GENERIC_CSI2_16
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_16 contains packed 8-bit generic metadata, 16 bits
+for each 8 bits of data. Every byte of metadata is followed by one byte of
+padding. The way the data is stored follows the CSI-2 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 "p" 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::
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 12 8 8 8 8 8 8 8 8
+
+ * - start + 0:
+ - M\ :sub:`00`
+ - p
+ - M\ :sub:`10`
+ - p
+ - M\ :sub:`20`
+ - p
+ - M\ :sub:`30`
+ - p
+ * - start + 8:
+ - M\ :sub:`01`
+ - p
+ - M\ :sub:`11`
+ - p
+ - M\ :sub:`21`
+ - p
+ - M\ :sub:`31`
+ - p
+
+.. _v4l2-meta-fmt-generic-csi2-20:
+
+V4L2_META_FMT_GENERIC_CSI2_20
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_20 contains packed 8-bit generic metadata, 20 bits
+for each 8 bits of data. Every byte of metadata is followed by alternating one
+and two bytes of padding. The way the data is stored follows the CSI-2
+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 "p" 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::
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 12 8 8 8 8 8 8 8 8 8 8
+
+ * - start + 0:
+ - M\ :sub:`00`
+ - p
+ - M\ :sub:`10`
+ - p
+ - p
+ - M\ :sub:`20`
+ - p
+ - M\ :sub:`30`
+ - p
+ - p
+ * - start + 10:
+ - M\ :sub:`01`
+ - p
+ - M\ :sub:`11`
+ - p
+ - p
+ - M\ :sub:`21`
+ - p
+ - M\ :sub:`31`
+ - p
+ - p
+
+.. _v4l2-meta-fmt-generic-csi2-24:
+
+V4L2_META_FMT_GENERIC_CSI2_24
+-----------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_24 contains packed 8-bit generic metadata, 24 bits
+for each 8 bits of data. Every byte of metadata is followed by two bytes of
+padding. The way the data is stored follows the CSI-2 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 "p" 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::
+ :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`
+ - p
+ - p
+ - M\ :sub:`10`
+ - p
+ - p
+ - M\ :sub:`20`
+ - p
+ - p
+ - M\ :sub:`30`
+ - p
+ - p
+ * - start + 12:
+ - M\ :sub:`01`
+ - p
+ - p
+ - M\ :sub:`11`
+ - p
+ - p
+ - M\ :sub:`21`
+ - p
+ - p
+ - M\ :sub:`31`
+ - p
+ - p
+
+.. _v4l2-meta-fmt-generic-csi2-2-24:
+
+V4L2_META_FMT_GENERIC_CSI2_2_24
+-------------------------------
+
+V4L2_META_FMT_GENERIC_CSI2_2_24 contains packed 8-bit generic metadata, 24 bits
+for each two times 8 bits of data. Every two bytes of metadata are followed by
+one byte of padding. The way the data is stored follows the CSI-2
+specification.
+
+This format is little endian.
+
+**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_2_24.**
+Each cell is one byte. "M" denotes a byte of metadata and "p" a byte of padding.
+
+.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
+
+.. flat-table::
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 12 8 8 8 8 8 8
+
+ * - start + 0:
+ - M\ :sub:`00`
+ - M\ :sub:`10`
+ - p
+ - M\ :sub:`20`
+ - M\ :sub:`30`
+ - p
+ * - start + 6:
+ - M\ :sub:`01`
+ - M\ :sub:`11`
+ - p
+ - M\ :sub:`21`
+ - M\ :sub:`31`
+ - p
+
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index a858acea6547..7781b0bd3e7d 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1451,6 +1451,14 @@ 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 = "8b Generic Meta, 10b CSI-2"; break;
+ case V4L2_META_FMT_GENERIC_CSI2_12: descr = "8b Generic Meta, 12b CSI-2"; break;
+ case V4L2_META_FMT_GENERIC_CSI2_14: descr = "8b Generic Meta, 14b CSI-2"; break;
+ case V4L2_META_FMT_GENERIC_CSI2_16: descr = "8b Generic Meta, 16b CSI-2"; break;
+ case V4L2_META_FMT_GENERIC_CSI2_20: descr = "8b Generic Meta, 20b CSI-2"; break;
+ case V4L2_META_FMT_GENERIC_CSI2_24: descr = "8b Generic Meta, 24b CSI-2"; break;
+ case V4L2_META_FMT_GENERIC_CSI2_2_24: descr = "2x8b Generic Meta, 24b CSI-2"; break;

default:
/* Compressed formats */
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 5d8bd754c69f..13d404699842 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -834,6 +834,15 @@ 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 */
+#define V4L2_META_FMT_GENERIC_CSI2_2_24 v4l2_fourcc('M', 'C', '2', 'O') /* 2 bytes of 8-bit metadata, 24-bit CSI-2 packed */
+
/* priv field value to indicates that subsequent fields are valid. */
#define V4L2_PIX_FMT_PRIV_MAGIC 0xfeedcafe

--
2.39.2