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

[Umang Jain]

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: Umang Jain <umang.jain at 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;
 
 	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 */
 
 /* 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 */
-- 
2.41.0