Hi Sakari, Thank you for the patch. On Wed, Mar 13, 2024 at 09:25:01AM +0200, Sakari Ailus wrote: > Add new MIPI CCS embedded data media bus code > (MEDIA_BUS_FMT_CCS_EMBEDDED). > > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> > --- > .../media/v4l/subdev-formats.rst | 28 +++++++++++++++++++ > include/uapi/linux/media-bus-format.h | 3 ++ > 2 files changed, 31 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst > index cbd475f7cae9..c8f982411e70 100644 > --- a/Documentation/userspace-api/media/v4l/subdev-formats.rst > +++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst > @@ -8564,3 +8564,31 @@ and finally the bit number in subscript. "X" indicates a padding bit. > - X > - X > - X > + > +.. _MEDIA-BUS-FMT-CCS-EMBEDDED: > + > +MIPI CCS Embedded Data Formats > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > + > +`MIPI CCS <https://www.mipi.org/specifications/camera-command-set>`_ defines a > +metadata format for sensor embedded data, which is used to store the register > +configuration used for capturing a given frame. The format is defined in the CCS > +specification. The media bus code for this format is > +``MEDIA_BUS_FMT_CCS_EMBEDDED``. > + > +The CCS embedded data format definition includes three levels: > + > +1. Padding within CSI-2 bus :ref:`Data unit <media-glossary-data-unit>` as s/Data unit/Data Unit/ > + documented in the MIPI CCS specification. > + > +2. The tagged data format as documented in the MIPI CCS specification. > + > +3. Register addresses and register documentation as documented in the MIPI CCS > + specification. > + > +The format definition shall be used only by devices that fulfill all three > +levels above. Hmmmm... Do we need to mandate level 3 ? There are lots of sensors that comply with the first two levels but have their own register set. Would you like a sensor-specific embedded data format for each of them ? If so, how would we document it without essentially copying the datasheet ? > + > +This mbus code are only used for "2-byte simplified tagged data format" (code > +0xa) but their use may be extended further in the future, to cover other CCS > +embedded data format codes. > diff --git a/include/uapi/linux/media-bus-format.h b/include/uapi/linux/media-bus-format.h > index d4c1d991014b..03f7e9ab517b 100644 > --- a/include/uapi/linux/media-bus-format.h > +++ b/include/uapi/linux/media-bus-format.h > @@ -183,4 +183,7 @@ > #define MEDIA_BUS_FMT_META_20 0x8006 > #define MEDIA_BUS_FMT_META_24 0x8007 > > +/* Specific metadata formats. Next is 0x9002. */ > +#define MEDIA_BUS_FMT_CCS_EMBEDDED 0x9001 > + > #endif /* __LINUX_MEDIA_BUS_FORMAT_H */ -- Regards, Laurent Pinchart
