ipa: rkisp1: Port to the new AEGC controls

The newly introduced controls to drive the AEGC algorithm allow
controlling the computation of the exposure time and analogue gain
separately.

Augument the RkISP1 AEGC implementation to handle the exposure and gain
controls separately using the new controls.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

3 files changed, 133 insertions, 30 deletions

diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp
index 40e5a8f4..78122a1f 100644
--- a/src/ipa/rkisp1/algorithms/agc.cpp
+++ b/src/ipa/rkisp1/algorithms/agc.cpp
@@ -148,7 +148,14 @@ int Agc::init(IPAContext &context, const YamlObject &tuningData)
 	if (ret)
 		return ret;
 
-	context.ctrlMap[&controls::AeEnable] = ControlInfo(false, true);
+	context.ctrlMap[&controls::ExposureTimeMode] =
+		ControlInfo(static_cast<int32_t>(controls::ExposureTimeModeAuto),
+			    static_cast<int32_t>(controls::ExposureTimeModeManual),
+			    static_cast<int32_t>(controls::ExposureTimeModeAuto));
+	context.ctrlMap[&controls::AnalogueGainMode] =
+		ControlInfo(static_cast<int32_t>(controls::AnalogueGainModeAuto),
+			    static_cast<int32_t>(controls::AnalogueGainModeManual),
+			    static_cast<int32_t>(controls::AnalogueGainModeAuto));
 	context.ctrlMap.merge(controls());
 
 	return 0;
@@ -169,7 +176,8 @@ int Agc::configure(IPAContext &context, const IPACameraSensorInfo &configInfo)
 		10ms / context.configuration.sensor.lineDuration;
 	context.activeState.agc.manual.gain = context.activeState.agc.automatic.gain;
 	context.activeState.agc.manual.exposure = context.activeState.agc.automatic.exposure;
-	context.activeState.agc.autoEnabled = !context.configuration.raw;
+	context.activeState.agc.autoExposureEnabled = !context.configuration.raw;
+	context.activeState.agc.autoGainEnabled = !context.configuration.raw;
 
 	context.activeState.agc.constraintMode =
 		static_cast<controls::AeConstraintModeEnum>(constraintModes().begin()->first);
@@ -215,18 +223,47 @@ void Agc::queueRequest(IPAContext &context,
 	auto &agc = context.activeState.agc;
 
 	if (!context.configuration.raw) {
-		const auto &agcEnable = controls.get(controls::AeEnable);
-		if (agcEnable && *agcEnable != agc.autoEnabled) {
-			agc.autoEnabled = *agcEnable;
+		const auto &aeEnable = controls.get(controls::ExposureTimeMode);
+		if (aeEnable &&
+		    (*aeEnable == controls::ExposureTimeModeAuto) != agc.autoExposureEnabled) {
+			agc.autoExposureEnabled = (*aeEnable == controls::ExposureTimeModeAuto);
 
 			LOG(RkISP1Agc, Debug)
-				<< (agc.autoEnabled ? "Enabling" : "Disabling")
-				<< " AGC";
+				<< (agc.autoExposureEnabled ? "Enabling" : "Disabling")
+				<< " AGC (exposure)";
+
+			/*
+			 * If we go from auto -> manual with no manual control
+			 * set, use the last computed value, which we don't
+			 * know until prepare() so save this information.
+			 *
+			 * \todo Check the previous frame at prepare() time
+			 * instead of saving a flag here
+			 */
+			if (!agc.autoExposureEnabled && !controls.get(controls::ExposureTime))
+				frameContext.agc.autoExposureModeChange = true;
+		}
+
+		const auto &agEnable = controls.get(controls::AnalogueGainMode);
+		if (agEnable &&
+		    (*agEnable == controls::AnalogueGainModeAuto) != agc.autoGainEnabled) {
+			agc.autoGainEnabled = (*agEnable == controls::AnalogueGainModeAuto);
+
+			LOG(RkISP1Agc, Debug)
+				<< (agc.autoGainEnabled ? "Enabling" : "Disabling")
+				<< " AGC (gain)";
+			/*
+			 * If we go from auto -> manual with no manual control
+			 * set, use the last computed value, which we don't
+			 * know until prepare() so save this information.
+			 */
+			if (!agc.autoGainEnabled && !controls.get(controls::AnalogueGain))
+				frameContext.agc.autoGainModeChange = true;
 		}
 	}
 
 	const auto &exposure = controls.get(controls::ExposureTime);
-	if (exposure && !agc.autoEnabled) {
+	if (exposure && !agc.autoExposureEnabled) {
 		agc.manual.exposure = *exposure * 1.0us
 				    / context.configuration.sensor.lineDuration;
 
@@ -235,18 +272,19 @@ void Agc::queueRequest(IPAContext &context,
 	}
 
 	const auto &gain = controls.get(controls::AnalogueGain);
-	if (gain && !agc.autoEnabled) {
+	if (gain && !agc.autoGainEnabled) {
 		agc.manual.gain = *gain;
 
 		LOG(RkISP1Agc, Debug) << "Set gain to " << agc.manual.gain;
 	}
 
-	frameContext.agc.autoEnabled = agc.autoEnabled;
+	frameContext.agc.autoExposureEnabled = agc.autoExposureEnabled;
+	frameContext.agc.autoGainEnabled = agc.autoGainEnabled;
 
-	if (!frameContext.agc.autoEnabled) {
+	if (!frameContext.agc.autoExposureEnabled)
 		frameContext.agc.exposure = agc.manual.exposure;
+	if (!frameContext.agc.autoGainEnabled)
 		frameContext.agc.gain = agc.manual.gain;
-	}
 
 	const auto &meteringMode = controls.get(controls::AeMeteringMode);
 	if (meteringMode) {
@@ -283,9 +321,26 @@ void Agc::queueRequest(IPAContext &context,
 void Agc::prepare(IPAContext &context, const uint32_t frame,
 		  IPAFrameContext &frameContext, RkISP1Params *params)
 {
-	if (frameContext.agc.autoEnabled) {
-		frameContext.agc.exposure = context.activeState.agc.automatic.exposure;
-		frameContext.agc.gain = context.activeState.agc.automatic.gain;
+	uint32_t activeAutoExposure = context.activeState.agc.automatic.exposure;
+	double activeAutoGain = context.activeState.agc.automatic.gain;
+
+	/* Populate exposure and gain in auto mode */
+	if (frameContext.agc.autoExposureEnabled)
+		frameContext.agc.exposure = activeAutoExposure;
+	if (frameContext.agc.autoGainEnabled)
+		frameContext.agc.gain = activeAutoGain;
+
+	/*
+	 * Populate manual exposure and gain from the active auto values when
+	 * transitioning from auto to manual
+	 */
+	if (!frameContext.agc.autoExposureEnabled && frameContext.agc.autoExposureModeChange) {
+		context.activeState.agc.manual.exposure = activeAutoExposure;
+		frameContext.agc.exposure = activeAutoExposure;
+	}
+	if (!frameContext.agc.autoGainEnabled && frameContext.agc.autoGainModeChange) {
+		context.activeState.agc.manual.gain = activeAutoGain;
+		frameContext.agc.gain = activeAutoGain;
 	}
 
 	if (frame > 0 && !frameContext.agc.updateMetering)
@@ -333,7 +388,14 @@ void Agc::fillMetadata(IPAContext &context, IPAFrameContext &frameContext,
 				     * frameContext.sensor.exposure;
 	metadata.set(controls::AnalogueGain, frameContext.sensor.gain);
 	metadata.set(controls::ExposureTime, exposureTime.get<std::micro>());
-	metadata.set(controls::AeEnable, frameContext.agc.autoEnabled);
+	metadata.set(controls::ExposureTimeMode,
+		     frameContext.agc.autoExposureEnabled
+		     ? controls::ExposureTimeModeAuto
+		     : controls::ExposureTimeModeManual);
+	metadata.set(controls::AnalogueGainMode,
+		     frameContext.agc.autoGainEnabled
+		     ? controls::AnalogueGainModeAuto
+		     : controls::AnalogueGainModeManual);
 
 	/* \todo Use VBlank value calculated from each frame exposure. */
 	uint32_t vTotal = context.configuration.sensor.size.height
@@ -424,14 +486,35 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 		       [](uint32_t x) { return x >> 4; });
 	expMeans_ = { params->ae.exp_mean, context.hw->numAeCells };
 
-	utils::Duration maxExposureTime =
-		std::clamp(frameContext.agc.maxFrameDuration,
-			   context.configuration.sensor.minExposureTime,
-			   context.configuration.sensor.maxExposureTime);
-	setLimits(context.configuration.sensor.minExposureTime,
-		  maxExposureTime,
-		  context.configuration.sensor.minAnalogueGain,
-		  context.configuration.sensor.maxAnalogueGain);
+	/*
+	 * Set the AGC limits using the fixed exposure time and/or gain in
+	 * manual mode, or the sensor limits in auto mode.
+	 */
+	utils::Duration minExposureTime;
+	utils::Duration maxExposureTime;
+	double minAnalogueGain;
+	double maxAnalogueGain;
+
+	if (frameContext.agc.autoExposureEnabled) {
+		minExposureTime = context.configuration.sensor.minExposureTime;
+		maxExposureTime = std::clamp(frameContext.agc.maxFrameDuration,
+					     context.configuration.sensor.minExposureTime,
+					     context.configuration.sensor.maxExposureTime);
+	} else {
+		minExposureTime = context.configuration.sensor.lineDuration
+				* frameContext.agc.exposure;
+		maxExposureTime = minExposureTime;
+	}
+
+	if (frameContext.agc.autoGainEnabled) {
+		minAnalogueGain = context.configuration.sensor.minAnalogueGain;
+		maxAnalogueGain = context.configuration.sensor.maxAnalogueGain;
+	} else {
+		minAnalogueGain = frameContext.agc.gain;
+		maxAnalogueGain = frameContext.agc.gain;
+	}
+
+	setLimits(minExposureTime, maxExposureTime, minAnalogueGain, maxAnalogueGain);
 
 	/*
 	 * The Agc algorithm needs to know the effective exposure value that was
diff --git a/src/ipa/rkisp1/ipa_context.cpp b/src/ipa/rkisp1/ipa_context.cpp
index 80b99df8..261c0472 100644
--- a/src/ipa/rkisp1/ipa_context.cpp
+++ b/src/ipa/rkisp1/ipa_context.cpp
@@ -165,8 +165,11 @@ namespace libcamera::ipa::rkisp1 {
  * \var IPAActiveState::agc.automatic.gain
  * \brief Automatic analogue gain multiplier
  *
- * \var IPAActiveState::agc.autoEnabled
- * \brief Manual/automatic AGC state as set by the AeEnable control
+ * \var IPAActiveState::agc.autoExposureEnabled
+ * \brief Manual/automatic AGC state (exposure) as set by the ExposureTimeMode control
+ *
+ * \var IPAActiveState::agc.autoGainEnabled
+ * \brief Manual/automatic AGC state (gain) as set by the AnalogueGainMode control
  *
  * \var IPAActiveState::agc.constraintMode
  * \brief Constraint mode as set by the AeConstraintMode control
@@ -289,8 +292,11 @@ namespace libcamera::ipa::rkisp1 {
  *
  * The gain should be adapted to the sensor specific gain code before applying.
  *
- * \var IPAFrameContext::agc.autoEnabled
- * \brief Manual/automatic AGC state as set by the AeEnable control
+ * \var IPAFrameContext::agc.autoExposureEnabled
+ * \brief Manual/automatic AGC state (exposure) as set by the ExposureTimeMode control
+ *
+ * \var IPAFrameContext::agc.autoGainEnabled
+ * \brief Manual/automatic AGC state (gain) as set by the AnalogueGainMode control
  *
  * \var IPAFrameContext::agc.constraintMode
  * \brief Constraint mode as set by the AeConstraintMode control
@@ -306,6 +312,16 @@ namespace libcamera::ipa::rkisp1 {
  *
  * \var IPAFrameContext::agc.updateMetering
  * \brief Indicate if new ISP AGC metering parameters need to be applied
+ *
+ * \var IPAFrameContext::agc.autoExposureModeChange
+ * \brief Indicate if autoExposureEnabled has changed from true in the previous
+ * frame to false in the current frame, and no manual exposure value has been
+ * supplied in the current frame.
+ *
+ * \var IPAFrameContext::agc.autoGainModeChange
+ * \brief Indicate if autoGainEnabled has changed from true in the previous
+ * frame to false in the current frame, and no manual gain value has been
+ * supplied in the current frame.
  */
 
 /**
diff --git a/src/ipa/rkisp1/ipa_context.h b/src/ipa/rkisp1/ipa_context.h
index b83c1822..5d5b79fa 100644
--- a/src/ipa/rkisp1/ipa_context.h
+++ b/src/ipa/rkisp1/ipa_context.h
@@ -79,7 +79,8 @@ struct IPAActiveState {
 			double gain;
 		} automatic;
 
-		bool autoEnabled;
+		bool autoExposureEnabled;
+		bool autoGainEnabled;
 		controls::AeConstraintModeEnum constraintMode;
 		controls::AeExposureModeEnum exposureMode;
 		controls::AeMeteringModeEnum meteringMode;
@@ -124,12 +125,15 @@ struct IPAFrameContext : public FrameContext {
 	struct {
 		uint32_t exposure;
 		double gain;
-		bool autoEnabled;
+		bool autoExposureEnabled;
+		bool autoGainEnabled;
 		controls::AeConstraintModeEnum constraintMode;
 		controls::AeExposureModeEnum exposureMode;
 		controls::AeMeteringModeEnum meteringMode;
 		utils::Duration maxFrameDuration;
 		bool updateMetering;
+		bool autoExposureModeChange;
+		bool autoGainModeChange;
 	} agc;
 
 	struct {