Hi Jacopo, On Thu, May 02, 2024 at 01:04:58PM +0200, Jacopo Mondi wrote: > Add format description for the PiSP Back End configuration parameter > buffer. > > Signed-off-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx> > Reviewed-by: Naushir Patuck <naush@xxxxxxxxxxxxxxx> > --- > .../userspace-api/media/v4l/meta-formats.rst | 1 + > .../media/v4l/metafmt-pisp-be.rst | 46 +++++++++++++++++++ > drivers/media/v4l2-core/v4l2-ioctl.c | 1 + > include/uapi/linux/videodev2.h | 3 ++ > 4 files changed, 51 insertions(+) > create mode 100644 Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst > > diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst > index c23aac823d2c..c6e56b5888bc 100644 > --- a/Documentation/userspace-api/media/v4l/meta-formats.rst > +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst > @@ -15,6 +15,7 @@ These formats are used for the :ref:`metadata` interface only. > metafmt-d4xx > metafmt-generic > metafmt-intel-ipu3 > + metafmt-pisp-be > metafmt-rkisp1 > metafmt-uvc > metafmt-vivid > diff --git a/Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst b/Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst > new file mode 100644 > index 000000000000..f3d30ba989b3 > --- /dev/null > +++ b/Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst > @@ -0,0 +1,46 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +.. _v4l2-meta-fmt-rpi-be-cfg: > + > +************************ > +V4L2_META_FMT_RPI_BE_CFG > +************************ > + > +Raspberry Pi PiSP Back End configuration format > +=============================================== > + > +The Raspberry Pi PiSP Back End memory-to-memory image signal processor is > +configured by userspace by providing a buffer of configuration parameters > +to the `pispbe-config` output video device node using the > +:c:type:`v4l2_meta_format` interface. > + > +The PiSP Back End processes images in tiles, and its configuration requires > +specifying two different sets of parameters by populating the members of > +:c:type:`pisp_be_tiles_config` defined in the ``pisp_be_config.h`` header file. Could you add kernel-doc documentation for pisp_be_config.h and refer to that instead? Also the header would need to be moved to an earlier patch. > + > +The `Raspberry Pi PiSP technical specification > +<https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf>_` > +provide detailed description of the ISP back end configuration and programming > +model. > + > +Global configuration data > +------------------------- > + > +The global configuration data describe how the pixels in a particular image are > +to be processed and is therefore shared across all the tiles of the image. So > +for example, LSC (Lens Shading Correction) or Denoise parameters would be common > +across all tiles from the same frame. > + > +Global configuration data are passed to the ISP by populating the member of > +:c:type:`pisp_be_config`. > + > +Tile parameters > +--------------- > + > +As the ISP processes images in tiles, each set of tiles parameters describe how > +a single tile in an image is going to be processed. A single set of tile > +parameters consist of 160 bytes of data and to process a batch of tiles several > +sets of tiles parameters are required. > + > +Tiles parameters are passed to the ISP by populating the member of > +:c:type:`pisp_tile` and the :c:type:`num_tiles` field. > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index ee97643ff3a7..7c684788997c 100644 > --- a/drivers/media/v4l2-core/v4l2-ioctl.c > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c > @@ -1465,6 +1465,7 @@ 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_RPI_BE_CFG: descr = "RPi PiSP BE Config format"; 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; > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index dd6876380fe3..530898b5b342 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -843,6 +843,9 @@ 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 */ > > +/* Vendor specific - used for RaspberryPi PiSP */ > +#define V4L2_META_FMT_RPI_BE_CFG v4l2_fourcc('R', 'P', 'B', 'C') /* PiSP BE configuration */ > + > #ifdef __KERNEL__ > /* > * Line-based metadata formats. Remember to update v4l_fill_fmtdesc() when -- Kind regards, Sakari Ailus
