libcamera: software_isp: Add brightness control

Signed-off-by: Vasiliy Doylov <nekocwd@mainlining.org>

src/ipa/simple/algorithms/agc.cpp

@@ -41,6 +41,33 @@ Agc::Agc()
 {
 }
 
+int Agc::init(IPAContext &context,
+	      [[maybe_unused]] const YamlObject &tuningData)
+{
+	context.ctrlMap[&controls::Brightness] = ControlInfo(0.0f, 2.0f, 1.0f);
+	return 0;
+}
+
+int Agc::configure(IPAContext &context,
+		   [[maybe_unused]] const IPAConfigInfo &configInfo)
+{
+	context.activeState.knobs.brightness = std::optional<double>();
+
+	return 0;
+}
+
+void Agc::queueRequest(typename Module::Context &context,
+		       [[maybe_unused]] const uint32_t frame,
+		       [[maybe_unused]] typename Module::FrameContext &frameContext,
+		       const ControlList &controls)
+{
+	const auto &brightness = controls.get(controls::Brightness);
+	if (brightness.has_value()) {
+		context.activeState.knobs.brightness = brightness;
+		LOG(IPASoftExposure, Debug) << "Setting brightness to " << brightness.value();
+	}
+}
+
 void Agc::updateExposure(IPAContext &context, IPAFrameContext &frameContext, double exposureMSV)
 {
 	/*
@@ -54,6 +81,8 @@ void Agc::updateExposure(IPAContext &context, IPAFrameContext &frameContext, dou
 	double next;
 	int32_t &exposure = frameContext.sensor.exposure;
 	double &again = frameContext.sensor.gain;
+	const auto brightness = context.activeState.knobs.brightness.value_or(1.0);
+	exposureMSV /= brightness;
 
 	if (exposureMSV < kExposureOptimal - kExposureSatisfactory) {
 		next = exposure * kExpNumeratorUp / kExpDenominator;

src/ipa/simple/algorithms/agc.h

@@ -19,6 +19,13 @@ public:
 	Agc();
 	~Agc() = default;
 
+	int init(IPAContext &context, const YamlObject &tuningData) override;
+	int configure(IPAContext &context, const IPAConfigInfo &configInfo) override;
+	void queueRequest(typename Module::Context &context,
+			  const uint32_t frame,
+			  typename Module::FrameContext &frameContext,
+			  const ControlList &controls)
+		override;
 	void process(IPAContext &context, const uint32_t frame,
 		     IPAFrameContext &frameContext,
 		     const SwIspStats *stats,

src/ipa/simple/ipa_context.h

@@ -64,6 +64,8 @@ struct IPAActiveState {
 		/* 0..2 range, 1.0 = normal */
 		std::optional<double> contrast;
 		std::optional<float> saturation;
+		/* 0..2 range, 1.0 = normal */
+		std::optional<double> brightness;
 	} knobs;
 };