ipa: ipu3: Move IPU3 agc into algorithms

Now that the interface is properly used by the AGC class, move it into
ipa::ipu3::algorithms and let the loops do the calls.
As we need to exchange the exposure_ and gain_ by passing them through the
FrameContext, use the calculated values in setControls() function to
ease the reading.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/ipa/ipu3/algorithms/agc.h

@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Ideas On Board
+ *
+ * agc.h - IPU3 AGC/AEC control algorithm
+ */
+#ifndef __LIBCAMERA_IPU3_ALGORITHMS_AGC_H__
+#define __LIBCAMERA_IPU3_ALGORITHMS_AGC_H__
+
+#include <linux/intel-ipu3.h>
+
+#include <libcamera/base/utils.h>
+
+#include <libcamera/geometry.h>
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+struct IPACameraSensorInfo;
+
+namespace ipa::ipu3::algorithms {
+
+using utils::Duration;
+
+class Agc : public Algorithm
+{
+public:
+	Agc();
+	~Agc() = default;
+
+	int configure(IPAContext &context, const IPAConfigInfo &configInfo) override;
+	void process(IPAContext &context, const ipu3_uapi_stats_3a *stats) override;
+
+private:
+	void processBrightness(const ipu3_uapi_stats_3a *stats);
+	void filterExposure();
+	void lockExposureGain(uint32_t &exposure, double &gain);
+
+	struct ipu3_uapi_grid_config aeGrid_;
+
+	uint64_t frameCount_;
+	uint64_t lastFrame_;
+
+	double iqMean_;
+
+	Duration lineDuration_;
+	Duration maxExposureTime_;
+
+	Duration prevExposure_;
+	Duration prevExposureNoDg_;
+	Duration currentExposure_;
+	Duration currentExposureNoDg_;
+};
+
+} /* namespace ipa::ipu3::algorithms */
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_IPU3_ALGORITHMS_AGC_H__ */