[libcamera-devel] [PATCH] ipa: rpi: cam_helper: PDAF support for IMX519

[Umang Jain]

From: sdfasdf <asdfasdfasdf at asdfasdf.com>

Adds the PDAF support for IMX519 camera module by Arducam.

Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
Patch originally not authored by me, but we are missing main author's 
full-name and email.
---
 src/ipa/rpi/cam_helper/cam_helper_imx519.cpp | 50 ++++++++++++++++++++
 src/ipa/rpi/vc4/data/imx519.json             | 40 ++++++++++++++++
 2 files changed, 90 insertions(+)

diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx519.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx519.cpp
index c7262aa0..6d032082 100644
--- a/src/ipa/rpi/cam_helper/cam_helper_imx519.cpp
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx519.cpp
@@ -15,9 +15,13 @@
 
 #include <libcamera/base/log.h>
 
+#include "controller/pdaf_data.h"
+
 #include "cam_helper.h"
 #include "md_parser.h"
 
+#define ALIGN_UP(x, a) (((x) + (a)-1) & ~(a - 1))
+
 using namespace RPiController;
 using namespace libcamera;
 using libcamera::utils::Duration;
@@ -66,8 +70,13 @@ private:
 	/* Largest long exposure scale factor given as a left shift on the frame length. */
 	static constexpr int longExposureShiftMax = 7;
 
+	static constexpr int pdafStatsRows = 12;
+	static constexpr int pdafStatsCols = 16;
+
 	void populateMetadata(const MdParser::RegisterMap &registers,
 			      Metadata &metadata) const override;
+	static bool parsePdafData(const uint8_t *ptr, size_t len, unsigned bpp,
+				  PdafRegions &pdaf);
 };
 
 CamHelperImx519::CamHelperImx519()
@@ -90,6 +99,11 @@ void CamHelperImx519::prepare(libcamera::Span<const uint8_t> buffer, Metadata &m
 	MdParser::RegisterMap registers;
 	DeviceStatus deviceStatus;
 
+	LOG(IPARPI, Debug) << "Embedded buffer size: " << buffer.size();
+
+	size_t bytesPerLine = (mode_.width * mode_.bitdepth) >> 3;
+	bytesPerLine = ALIGN_UP(bytesPerLine, 16);
+
 	if (metadata.get("device.status", deviceStatus)) {
 		LOG(IPARPI, Error) << "DeviceStatus not found from DelayedControls";
 		return;
@@ -97,6 +111,14 @@ void CamHelperImx519::prepare(libcamera::Span<const uint8_t> buffer, Metadata &m
 
 	parseEmbeddedData(buffer, metadata);
 
+	if (buffer.size() > 2 * bytesPerLine) {
+		PdafRegions pdaf;
+		parsePdafData(&buffer[2 * bytesPerLine],
+			      buffer.size() - 2 * bytesPerLine,
+			      mode_.bitdepth, pdaf);
+		metadata.set("pdaf.data", pdaf);
+	}
+
 	/*
 	 * The DeviceStatus struct is first populated with values obtained from
 	 * DelayedControls. If this reports frame length is > frameLengthMax,
@@ -188,6 +210,34 @@ void CamHelperImx519::populateMetadata(const MdParser::RegisterMap &registers,
 	metadata.set("device.status", deviceStatus);
 }
 
+bool CamHelperImx519::parsePdafData(const uint8_t *ptr, size_t len,
+				    unsigned bpp, PdafRegions &pdaf)
+{
+	size_t step = bpp >> 1; /* bytes per PDAF grid entry */
+
+	if (bpp < 10 || bpp > 12 || len < 194 * step || ptr[0] != 0 || ptr[1] >= 0x40) {
+		LOG(IPARPI, Error) << "PDAF data in unsupported format";
+		return false;
+	}
+
+	pdaf.init({ pdafStatsCols, pdafStatsRows });
+
+	ptr += 2 * step;
+	for (unsigned i = 0; i < pdafStatsRows; ++i) {
+		for (unsigned j = 0; j < pdafStatsCols; ++j) {
+			unsigned c = (ptr[0] << 3) | (ptr[1] >> 5);
+			int p = (((ptr[1] & 0x0F) - (ptr[1] & 0x10)) << 6) | (ptr[2] >> 2);
+			PdafData pdafData;
+			pdafData.conf = c;
+			pdafData.phase = c ? p : 0;
+			pdaf.set(libcamera::Point(j, i), { pdafData, 1, 0 });
+			ptr += step;
+		}
+	}
+
+	return true;
+}
+
 static CamHelper *create()
 {
 	return new CamHelperImx519();
diff --git a/src/ipa/rpi/vc4/data/imx519.json b/src/ipa/rpi/vc4/data/imx519.json
index 1b0a7747..0733d97e 100644
--- a/src/ipa/rpi/vc4/data/imx519.json
+++ b/src/ipa/rpi/vc4/data/imx519.json
@@ -350,6 +350,46 @@
                 ]
             }
         },
+        {
+            "rpi.af":
+            {
+                "ranges":
+                {
+                    "normal":
+                    {
+                        "min": 0.0,
+                        "max": 12.0,
+                        "default": 1.0
+                    },
+                    "macro":
+                    {
+                        "min": 3.0,
+                        "max": 15.0,
+                        "default": 4.0
+                    }
+                },
+                "speeds":
+                {
+                    "normal":
+                    {
+                        "step_coarse": 1.0,
+                        "step_fine": 0.25,
+                        "contrast_ratio": 0.75,
+                        "pdaf_gain": -0.02,
+                        "pdaf_squelch": 0.125,
+                        "max_slew": 2.0,
+                        "pdaf_frames": 20,
+                        "dropout_frames": 6,
+                        "step_frames": 4
+                    }
+                },
+                "conf_epsilon": 8,
+                "conf_thresh": 16,
+                "conf_clip": 512,
+                "skip_frames": 5,
+                "map": [ 0.0, 0.0, 15.0, 4095 ]
+            }
+        },
         {
             "rpi.ccm":
             {
-- 
2.39.1