[PATCH 07/10] media: uapi: v4l2-core: Add ISP statistics output V4L2 fourcc type

[Jai Luthra]

From: Naushir Patuck <naush at 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 at raspberrypi.com>
Signed-off-by: Jai Luthra <jai.luthra at ideasonboard.com>
---
 .../userspace-api/media/v4l/meta-formats.rst       |  1 +
 .../media/v4l/pixfmt-meta-bcm2835-isp-stats.rst    | 35 ++++++++++++++++++++++
 drivers/media/v4l2-core/v4l2-ioctl.c               |  1 +
 include/uapi/linux/videodev2.h                     |  1 +
 4 files changed, 38 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
index 3e0cab153f0ac5e6d76696c5b78eebb0db43b354..be3f20f0e68fd225274428b4a712275654bf539c 100644
--- a/Documentation/userspace-api/media/v4l/meta-formats.rst
+++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
@@ -14,6 +14,7 @@ These formats are used for the :ref:`metadata` interface only.
     :maxdepth: 1
 
     metafmt-arm-mali-c55
+    metafmt-bcm2835-isp-stats
     metafmt-c3-isp
     metafmt-d4xx
     metafmt-generic
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 0000000000000000000000000000000000000000..d5d71f3ae752a41b86f755c24b487c7cfadfac4b
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/pixfmt-meta-bcm2835-isp-stats.rst
@@ -0,0 +1,35 @@
+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: V4L
+
+.. _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 98512ea4cc5b9d725e1851af2ed38df85bb4fa8c..30bfa35ae9f5119dd89251716e4da45e88d30aa9 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1488,6 +1488,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 	case V4L2_META_FMT_GENERIC_CSI2_16:	descr = "8-bit Generic Meta, 16b CSI-2"; break;
 	case V4L2_META_FMT_GENERIC_CSI2_20:	descr = "8-bit Generic Meta, 20b CSI-2"; break;
 	case V4L2_META_FMT_GENERIC_CSI2_24:	descr = "8-bit Generic Meta, 24b CSI-2"; 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 add08188f06890182a5c399a223c1ab0a546cae1..b0dff5e124d7eaab933e57909b8421c475de1da3 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -869,6 +869,7 @@ struct v4l2_pix_format {
 #define V4L2_META_FMT_D4XX        v4l2_fourcc('D', '4', 'X', 'X') /* D4XX Payload Header metadata */
 #define V4L2_META_FMT_UVC_MSXU_1_5  v4l2_fourcc('U', 'V', 'C', 'M') /* UVC MSXU 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 */
 
 /* 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 */

-- 
2.52.0