Hi Sakari, Thank you for the patch. On Tue, Apr 16, 2024 at 10:33:00PM +0300, 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> > Reviewed-by: Julien Massot <julien.massot@xxxxxxxxxxxxx> There's still an open question on how to document embedded data formats for sensors compatible with level 2 only. The discussion is ongoing and may affect this patch, but the changes can be implemented later, so Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > --- > .../media/v4l/subdev-formats.rst | 32 +++++++++++++++++++ > include/uapi/linux/media-bus-format.h | 3 ++ > 2 files changed, 35 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst > index 0547f2733ee3..fa181ce8f48c 100644 > --- a/Documentation/userspace-api/media/v4l/subdev-formats.rst > +++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst > @@ -8316,6 +8316,10 @@ 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. > > +The exact format of the data generated by the device is reported on the internal > +source pad of the originating sub-device, using one of the more specific > +metadata formats such as MEDIA_BUS_FMT_CCS_EMBEDDED. > + > "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. > > @@ -8562,3 +8566,31 @@ 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 > + 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. > + > +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
