1 files changed, 83 insertions, 0 deletions
diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx296.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx296.cpp
new file mode 100644
index 00000000..ecb845e7
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx296.cpp
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2020, Raspberry Pi Ltd
+ *
+ * cam_helper_imx296.cpp - Camera helper for IMX296 sensor
+ */
+
+#include <algorithm>
+#include <cmath>
+#include <stddef.h>
+
+#include "cam_helper.h"
+
+using namespace RPiController;
+using libcamera::utils::Duration;
+using namespace std::literals::chrono_literals;
+
+class CamHelperImx296 : public CamHelper
+{
+public:
+	CamHelperImx296();
+	uint32_t gainCode(double gain) const override;
+	double gain(uint32_t gainCode) const override;
+	uint32_t exposureLines(const Duration exposure, const Duration lineLength) const override;
+	Duration exposure(uint32_t exposureLines, const Duration lineLength) const override;
+	void getDelays(int &exposureDelay, int &gainDelay,
+		       int &vblankDelay, int &hblankDelay) const override;
+
+private:
+	static constexpr uint32_t minExposureLines = 1;
+	static constexpr uint32_t maxGainCode = 239;
+	static constexpr Duration timePerLine = 550.0 / 37.125e6 * 1.0s;
+
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	static constexpr int frameIntegrationDiff = 4;
+};
+
+CamHelperImx296::CamHelperImx296()
+	: CamHelper(nullptr, frameIntegrationDiff)
+{
+}
+
+uint32_t CamHelperImx296::gainCode(double gain) const
+{
+	uint32_t code = 20 * std::log10(gain) * 10;
+	return std::min(code, maxGainCode);
+}
+
+double CamHelperImx296::gain(uint32_t gainCode) const
+{
+	return std::pow(10.0, gainCode / 200.0);
+}
+
+uint32_t CamHelperImx296::exposureLines(const Duration exposure,
+					[[maybe_unused]] const Duration lineLength) const
+{
+	return std::max<uint32_t>(minExposureLines, (exposure - 14.26us) / timePerLine);
+}
+
+Duration CamHelperImx296::exposure(uint32_t exposureLines,
+				   [[maybe_unused]] const Duration lineLength) const
+{
+	return std::max<uint32_t>(minExposureLines, exposureLines) * timePerLine + 14.26us;
+}
+
+void CamHelperImx296::getDelays(int &exposureDelay, int &gainDelay,
+				int &vblankDelay, int &hblankDelay) const
+{
+	exposureDelay = 2;
+	gainDelay = 2;
+	vblankDelay = 2;
+	hblankDelay = 2;
+}
+
+static CamHelper *create()
+{
+	return new CamHelperImx296();
+}
+
+static RegisterCamHelper reg("imx296", &create);