Re: [PATCH v2 07/15] media: uapi: v4l2-core: Add ISP statistics output V4L2 fourcc type

Stefan Wahren
2023-11-18T13:11:54Z

Hi Umang,

Am 09.11.23 um 22:02 schrieb Umang Jain:
> From: Naushir Patuck <naush@raspberrypi.com>
>
> Add V4L2_META_FMT_BCM2835_ISP_STATS V4L2 format type.
>
> This new format will be used by the bcm2835-isp device to return
> out ISP statistics for 3A.
>
> Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> ---
> .../userspace-api/media/v4l/meta-formats.rst | 1 +
> .../v4l/pixfmt-meta-bcm2835-isp-stats.rst | 32 +++++++++++++++++++
> drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
> include/uapi/linux/videodev2.h | 1 +
> 4 files changed, 35 insertions(+)
> create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-meta-bcm2835-isp-stats.rst
>
> diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
> index 919f595576b9..534542f235bc 100644
> --- a/Documentation/userspace-api/media/v4l/meta-formats.rst
> +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
> @@ -12,6 +12,7 @@ These formats are used for the :ref:`metadata` interface only.
> .. toctree::
> :maxdepth: 1
>
> + pixfmt-meta-bcm2835-isp-stats
> metafmt-d4xx
> metafmt-intel-ipu3
> metafmt-rkisp1
> diff --git a/Documentation/userspace-api/media/v4l/pixfmt-meta-bcm2835-isp-stats.rst b/Documentation/userspace-api/media/v4l/pixfmt-meta-bcm2835-isp-stats.rst
> new file mode 100644
> index 000000000000..2219235e0ecb
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/pixfmt-meta-bcm2835-isp-stats.rst
> @@ -0,0 +1,32 @@
> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> +.. _v4l2-meta-fmt-bcm2835-isp-stats:
> +
> ++*****************************************
> +V4L2_META_FMT_BCM2835_ISP_STATS ('BSTA')
> +*****************************************
> +
> +BCM2835 ISP Statistics
> +
> +Description
> +===========
> +
> +The BCM2835 ISP hardware calculate image statistics for an input Bayer frame.
> +These statistics are obtained from the "bcm2835-isp0-capture3" device node
> +using the :c:type:`v4l2_meta_format` interface. They are formatted as described
> +by the :c:type:`bcm2835_isp_stats` structure below.
> +
> +.. code-block:: c
> +
> + #define DEFAULT_AWB_REGIONS_X 16
> + #define DEFAULT_AWB_REGIONS_Y 12
> +
> + #define NUM_HISTOGRAMS 2
> + #define NUM_HISTOGRAM_BINS 128
> + #define AWB_REGIONS (DEFAULT_AWB_REGIONS_X * DEFAULT_AWB_REGIONS_Y)
> + #define FLOATING_REGIONS 16
> + #define AGC_REGIONS 16
> + #define FOCUS_REGIONS 12
> +
> +.. kernel-doc:: include/uapi/linux/bcm2835-isp.h
> + :functions: bcm2835_isp_stats_hist bcm2835_isp_stats_region
> + bcm2835_isp_stats_focus bcm2835_isp_stats
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 7f29886568b8..6f0f0f6526c9 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1463,6 +1463,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> 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;
> + case V4L2_META_FMT_BCM2835_ISP_STATS: descr = "BCM2835 ISP Image Statistics"; break;

tab instead of space?

>
> default:
> /* Compressed formats */
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 85b60199c618..eddaea8598db 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -836,6 +836,7 @@ struct v4l2_pix_format {
> #define V4L2_META_FMT_UVC v4l2_fourcc('U', 'V', 'C', 'H') /* UVC Payload Header metadata */
> #define V4L2_META_FMT_D4XX v4l2_fourcc('D', '4', 'X', 'X') /* D4XX Payload Header metadata */
> #define V4L2_META_FMT_VIVID v4l2_fourcc('V', 'I', 'V', 'D') /* Vivid Metadata */
> +#define V4L2_META_FMT_BCM2835_ISP_STATS v4l2_fourcc('B', 'S', 'T', 'A') /* BCM2835 ISP image statistics output */

Shouldn't this go to the vendor specific ones?

>
> /* Vendor specific - used for RK_ISP1 camera sub-system */
> #define V4L2_META_FMT_RK_ISP1_PARAMS v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */