950-0219-media-uapi-v4l2-core-Add-ISP-statistics-output-V4L2-.patch

From 6b4ccbece097b456c2fb910d7e74ac5e848dc699 Mon Sep 17 00:00:00 2001
From: Naushir Patuck <naush@raspberrypi.com>
Date: Thu, 23 Apr 2020 10:20:26 +0100
Subject: [PATCH] media: uapi: v4l2-core: Add ISP statistics output
 V4L2 fourcc type

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>
---
 .../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

--- 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:`met
 .. toctree::
     :maxdepth: 1
 
+    pixfmt-meta-bcm2835-isp-stats
     pixfmt-meta-d4xx
     pixfmt-meta-intel-ipu3
     pixfmt-meta-rkisp1
--- /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
+
+.. _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
+
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1390,6 +1390,7 @@ static void v4l_fill_fmtdesc(struct v4l2
 	case V4L2_META_FMT_RK_ISP1_PARAMS:	descr = "Rockchip ISP1 3A Parameters"; break;
 	case V4L2_META_FMT_RK_ISP1_STAT_3A:	descr = "Rockchip ISP1 3A Statistics"; 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 */
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -776,6 +776,7 @@ 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 */