Re: [PATCH 07/14] media: uapi: v4l2-core: Add ISP statistics output V4L2 fourcc type

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Umang and Naush,

Thank you for the patch.

On Tue, Nov 22, 2022 at 03:17:15AM +0530, Umang Jain wrote:
> 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     | 41 +++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-ioctl.c          |  1 +
>  include/uapi/linux/videodev2.h                |  1 +
>  4 files changed, 44 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 d1ac3f3a2d8f..0c52f3df1576 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
>      pixfmt-meta-d4xx
>      pixfmt-meta-intel-ipu3
>      pixfmt-meta-sensor-data
> 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..f974774c8252
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/pixfmt-meta-bcm2835-isp-stats.rst
> @@ -0,0 +1,41 @@
> +.. Permission is granted to copy, distribute and/or modify this
> +.. document under the terms of the GNU Free Documentation License,
> +.. Version 1.1 or any later version published by the Free Software
> +.. Foundation, with no Invariant Sections, no Front-Cover Texts
> +.. and no Back-Cover Texts. A copy of the license is included at
> +.. Documentation/media/uapi/fdl-appendix.rst.
> +..
> +.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections

You can do so now.

> +
> +.. _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

This patch should go after 08/14 or it will break bisection.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 2680bc33f911..361e47ad6480 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1449,6 +1449,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>  	case V4L2_PIX_FMT_NV12M_8L128:	descr = "NV12M (8x128 Linear)"; break;
>  	case V4L2_PIX_FMT_NV12M_10BE_8L128:	descr = "10-bit NV12M (8x128 Linear, BE)"; break;
>  	case V4L2_META_FMT_SENSOR_DATA:	descr = "Sensor Ancillary Metadata"; break;
> +	case V4L2_META_FMT_BCM2835_ISP_STATS: descr = "BCM2835 ISP Image Statistics"; break;
>  
>  	default:
>  		/* Compressed formats */
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 026fbc7af034..9269b45b3b64 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -807,6 +807,7 @@ struct v4l2_pix_format {
>  #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_SENSOR_DATA v4l2_fourcc('S', 'E', 'N', 'S') /* Sensor Ancillary metadata */
> +#define V4L2_META_FMT_BCM2835_ISP_STATS v4l2_fourcc('B', 'S', 'T', 'A') /* BCM2835 ISP image statistics output */
>  
>  /* 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 */

-- 
Regards,

Laurent Pinchart