libcamera: ipa: rkisp1: Add basic control of auto exposure

Add an IPA which controls the exposure time and analog gain for a sensor
connected to the rkisp1 pipeline. The IPA supports turning AE on and off
and informing the camera of the status of the AE control loop.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

3 files changed, 263 insertions, 0 deletions

diff --git a/src/ipa/meson.build b/src/ipa/meson.build
index ac16e1da..4f2a4577 100644
--- a/src/ipa/meson.build
+++ b/src/ipa/meson.build
@@ -22,3 +22,5 @@ endforeach
 
 config_h.set('IPA_MODULE_DIR',
              '"' + join_paths(get_option('prefix'), ipa_install_dir) + '"')
+
+subdir('rkisp1')
diff --git a/src/ipa/rkisp1/meson.build b/src/ipa/rkisp1/meson.build
new file mode 100644
index 00000000..1cab319c
--- /dev/null
+++ b/src/ipa/rkisp1/meson.build
@@ -0,0 +1,7 @@
+rkisp1_ipa = shared_module('ipa_rkisp1',
+                           'rkisp1.cpp',
+                           name_prefix : '',
+                           include_directories : ipa_includes,
+                           dependencies : libcamera_dep,
+                           install : true,
+                           install_dir : ipa_install_dir)
diff --git a/src/ipa/rkisp1/rkisp1.cpp b/src/ipa/rkisp1/rkisp1.cpp
new file mode 100644
index 00000000..4f5fdb14
--- /dev/null
+++ b/src/ipa/rkisp1/rkisp1.cpp
@@ -0,0 +1,254 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * rkisp1.cpp - RkISP1 Image Processing Algorithms
+ */
+
+#include <algorithm>
+#include <cstdint>
+#include <math.h>
+#include <queue>
+#include <string.h>
+
+#include <linux/rkisp1-config.h>
+
+#include <ipa/ipa_interface.h>
+#include <ipa/ipa_module_info.h>
+#include <ipa/rkisp1.h>
+#include <libcamera/buffer.h>
+#include <libcamera/control_ids.h>
+#include <libcamera/request.h>
+
+#include "log.h"
+#include "utils.h"
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(IPARkISP1)
+
+class IPARkISP1 : public IPAInterface
+{
+public:
+	int init() override { return 0; }
+
+	void configure(const std::map<unsigned int, IPAStream> &streamConfig,
+		       const std::map<unsigned int, V4L2ControlInfoMap> &entityControls) override;
+	void mapBuffers(const std::vector<IPABuffer> &buffers) override;
+	void unmapBuffers(const std::vector<unsigned int> &ids) override;
+	void processEvent(const IPAOperationData &event) override;
+
+private:
+	void queueRequest(unsigned int frame, rkisp1_isp_params_cfg *params,
+			  const ControlList &controls);
+	void updateStatistics(unsigned int frame,
+			      const rkisp1_stat_buffer *stats);
+
+	void setControls(unsigned int frame);
+	void metadataReady(unsigned int frame, unsigned int aeState);
+
+	std::map<unsigned int, BufferMemory> bufferInfo_;
+
+	/* Camera sensor controls. */
+	bool autoExposure_;
+	uint32_t exposure_;
+	uint32_t minExposure_;
+	uint32_t maxExposure_;
+	uint32_t gain_;
+	uint32_t minGain_;
+	uint32_t maxGain_;
+};
+
+void IPARkISP1::configure(const std::map<unsigned int, IPAStream> &streamConfig,
+			  const std::map<unsigned int, V4L2ControlInfoMap> &entityControls)
+{
+	if (entityControls.empty())
+		return;
+
+	const V4L2ControlInfoMap &ctrls = entityControls.at(0);
+
+	const auto itExp = ctrls.find(V4L2_CID_EXPOSURE);
+	if (itExp == ctrls.end()) {
+		LOG(IPARkISP1, Error) << "Can't find exposure control";
+		return;
+	}
+
+	const auto itGain = ctrls.find(V4L2_CID_ANALOGUE_GAIN);
+	if (itGain == ctrls.end()) {
+		LOG(IPARkISP1, Error) << "Can't find gain control";
+		return;
+	}
+
+	autoExposure_ = true;
+
+	minExposure_ = std::max<uint32_t>(itExp->second.range().min().get<int32_t>(), 1);
+	maxExposure_ = itExp->second.range().max().get<int32_t>();
+	exposure_ = minExposure_;
+
+	minGain_ = std::max<uint32_t>(itGain->second.range().min().get<int32_t>(), 1);
+	maxGain_ = itGain->second.range().max().get<int32_t>();
+	gain_ = minGain_;
+
+	LOG(IPARkISP1, Info)
+		<< "Exposure: " << minExposure_ << "-" << maxExposure_
+		<< " Gain: " << minGain_ << "-" << maxGain_;
+
+	setControls(0);
+}
+
+void IPARkISP1::mapBuffers(const std::vector<IPABuffer> &buffers)
+{
+	for (IPABuffer buffer : buffers) {
+		bufferInfo_[buffer.id] = buffer.memory;
+		bufferInfo_[buffer.id].planes()[0].mem();
+	}
+}
+
+void IPARkISP1::unmapBuffers(const std::vector<unsigned int> &ids)
+{
+	for (unsigned int id : ids)
+		bufferInfo_.erase(id);
+}
+
+void IPARkISP1::processEvent(const IPAOperationData &event)
+{
+	switch (event.operation) {
+	case RKISP1_IPA_EVENT_SIGNAL_STAT_BUFFER: {
+		unsigned int frame = event.data[0];
+		unsigned int bufferId = event.data[1];
+
+		const rkisp1_stat_buffer *stats =
+			static_cast<rkisp1_stat_buffer *>(bufferInfo_[bufferId].planes()[0].mem());
+
+		updateStatistics(frame, stats);
+		break;
+	}
+	case RKISP1_IPA_EVENT_QUEUE_REQUEST: {
+		unsigned int frame = event.data[0];
+		unsigned int bufferId = event.data[1];
+
+		rkisp1_isp_params_cfg *params =
+			static_cast<rkisp1_isp_params_cfg *>(bufferInfo_[bufferId].planes()[0].mem());
+
+		queueRequest(frame, params, event.controls[0]);
+		break;
+	}
+	default:
+		LOG(IPARkISP1, Error) << "Unkown event " << event.operation;
+		break;
+	}
+}
+
+void IPARkISP1::queueRequest(unsigned int frame, rkisp1_isp_params_cfg *params,
+			     const ControlList &controls)
+{
+	/* Prepare parameters buffer. */
+	memset(params, 0, sizeof(*params));
+
+	/* Auto Exposure on/off. */
+	if (controls.contains(controls::AeEnable)) {
+		autoExposure_ = controls.get(controls::AeEnable);
+		if (autoExposure_)
+			params->module_ens = CIFISP_MODULE_AEC;
+
+		params->module_en_update = CIFISP_MODULE_AEC;
+	}
+
+	IPAOperationData op;
+	op.operation = RKISP1_IPA_ACTION_PARAM_FILLED;
+
+	queueFrameAction.emit(frame, op);
+}
+
+void IPARkISP1::updateStatistics(unsigned int frame,
+				 const rkisp1_stat_buffer *stats)
+{
+	const cifisp_stat *params = &stats->params;
+	unsigned int aeState = 0;
+
+	if (stats->meas_type & CIFISP_STAT_AUTOEXP) {
+		const cifisp_ae_stat *ae = &params->ae;
+
+		const unsigned int target = 60;
+
+		unsigned int value = 0;
+		unsigned int num = 0;
+		for (int i = 0; i < CIFISP_AE_MEAN_MAX; i++) {
+			if (ae->exp_mean[i] <= 15)
+				continue;
+
+			value += ae->exp_mean[i];
+			num++;
+		}
+		value /= num;
+
+		double factor = (double)target / value;
+
+		if (frame % 3 == 0) {
+			double exposure;
+
+			exposure = factor * exposure_ * gain_ / minGain_;
+			exposure_ = utils::clamp<uint64_t>((uint64_t)exposure,
+							   minExposure_,
+							   maxExposure_);
+
+			exposure = exposure / exposure_ * minGain_;
+			gain_ = utils::clamp<uint64_t>((uint64_t)exposure,
+						       minGain_, maxGain_);
+
+			setControls(frame + 1);
+		}
+
+		aeState = fabs(factor - 1.0f) < 0.05f ? 2 : 1;
+	}
+
+	metadataReady(frame, aeState);
+}
+
+void IPARkISP1::setControls(unsigned int frame)
+{
+	IPAOperationData op;
+	op.operation = RKISP1_IPA_ACTION_V4L2_SET;
+
+	V4L2ControlList ctrls;
+	ctrls.add(V4L2_CID_EXPOSURE, exposure_);
+	ctrls.add(V4L2_CID_ANALOGUE_GAIN, gain_);
+	op.v4l2controls.push_back(ctrls);
+
+	queueFrameAction.emit(frame, op);
+}
+
+void IPARkISP1::metadataReady(unsigned int frame, unsigned int aeState)
+{
+	ControlList ctrls(nullptr);
+
+	if (aeState)
+		ctrls.set(controls::AeLocked, aeState == 2);
+
+	IPAOperationData op;
+	op.operation = RKISP1_IPA_ACTION_METADATA;
+	op.controls.push_back(ctrls);
+
+	queueFrameAction.emit(frame, op);
+}
+
+/*
+ * External IPA module interface
+ */
+
+extern "C" {
+const struct IPAModuleInfo ipaModuleInfo = {
+	IPA_MODULE_API_VERSION,
+	1,
+	"PipelineHandlerRkISP1",
+	"RkISP1 IPA",
+	"LGPL-2.1-or-later",
+};
+
+IPAInterface *ipaCreate()
+{
+	return new IPARkISP1();
+}
+};
+
+}; /* namespace libcamera */