pipeline: ipa: raspberrypi: Restructure the IPA mojom interface

Restructure the IPA mojom interface to be more consistent in the use
of the API. Function parameters are now grouped into *Params structures
and results are now returned in *Results structures.

The following pipeline -> IPA interfaces have been removed:

signalQueueRequest(libcamera.ControlList controls);
signalIspPrepare(ISPConfig data);
signalStatReady(uint32 bufferId, uint32 ipaContext);

and replaced with:

prepareIsp(PrepareParams params);
processStats(ProcessParams params);

signalQueueRequest() is now encompassed within prepareIsp().

The following IPA -> pipeline interfaces have been removed:

runIsp(uint32 bufferId);
embeddedComplete(uint32 bufferId);
statsMetadataComplete(uint32 bufferId, libcamera.ControlList controls);

and replaced with the following async calls:

prepareIspComplete(BufferIds buffers);
processStatsComplete(BufferIds buffers);
metadataReady(libcamera.ControlList metadata);

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

2 files changed, 121 insertions, 136 deletions

diff --git a/src/ipa/rpi/vc4/raspberrypi.cpp b/src/ipa/rpi/vc4/raspberrypi.cpp
index 5d3bf4ca..17ea5c04 100644
--- a/src/ipa/rpi/vc4/raspberrypi.cpp
+++ b/src/ipa/rpi/vc4/raspberrypi.cpp
@@ -136,30 +136,28 @@ public:
 			munmap(lsTable_, MaxLsGridSize);
 	}
 
-	int init(const IPASettings &settings, bool lensPresent, IPAInitResult *result) override;
-	void start(const ControlList &controls, StartConfig *startConfig) override;
+	int init(const IPASettings &settings, const InitParams &params, InitResult *result) override;
+	void start(const ControlList &controls, StartResult *result) override;
 	void stop() override {}
 
-	int configure(const IPACameraSensorInfo &sensorInfo, const IPAConfig &data,
-		      ControlList *controls, IPAConfigResult *result) override;
+	int configure(const IPACameraSensorInfo &sensorInfo, const ConfigParams &params,
+		      ConfigResult *result) override;
 	void mapBuffers(const std::vector<IPABuffer> &buffers) override;
 	void unmapBuffers(const std::vector<unsigned int> &ids) override;
-	void signalStatReady(const uint32_t bufferId, uint32_t ipaContext) override;
-	void signalQueueRequest(const ControlList &controls) override;
-	void signalIspPrepare(const ISPConfig &data) override;
+	void prepareIsp(const PrepareParams &params) override;
+	void processStats(const ProcessParams &params) override;
 
 private:
 	void setMode(const IPACameraSensorInfo &sensorInfo);
 	bool validateSensorControls();
 	bool validateIspControls();
 	bool validateLensControls();
-	void queueRequest(const ControlList &controls);
-	void returnEmbeddedBuffer(unsigned int bufferId);
-	void prepareISP(const ISPConfig &data);
+	void applyControls(const ControlList &controls);
+	void prepare(const PrepareParams &params);
 	void reportMetadata(unsigned int ipaContext);
 	void fillDeviceStatus(const ControlList &sensorControls, unsigned int ipaContext);
 	RPiController::StatisticsPtr fillStatistics(bcm2835_isp_stats *stats) const;
-	void processStats(unsigned int bufferId, unsigned int ipaContext);
+	void process(unsigned int bufferId, unsigned int ipaContext);
 	void setCameraTimeoutValue();
 	void applyFrameDurations(Duration minFrameDuration, Duration maxFrameDuration);
 	void applyAGC(const struct AgcStatus *agcStatus, ControlList &ctrls);
@@ -229,7 +227,7 @@ private:
 	Duration lastTimeout_;
 };
 
-int IPARPi::init(const IPASettings &settings, bool lensPresent, IPAInitResult *result)
+int IPARPi::init(const IPASettings &settings, const InitParams &params, InitResult *result)
 {
 	/*
 	 * Load the "helper" for this sensor. This tells us all the device specific stuff
@@ -274,7 +272,7 @@ int IPARPi::init(const IPASettings &settings, bool lensPresent, IPAInitResult *r
 		return -EINVAL;
 	}
 
-	lensPresent_ = lensPresent;
+	lensPresent_ = params.lensPresent;
 
 	controller_.initialise();
 
@@ -287,14 +285,13 @@ int IPARPi::init(const IPASettings &settings, bool lensPresent, IPAInitResult *r
 	return 0;
 }
 
-void IPARPi::start(const ControlList &controls, StartConfig *startConfig)
+void IPARPi::start(const ControlList &controls, StartResult *result)
 {
 	RPiController::Metadata metadata;
 
-	ASSERT(startConfig);
 	if (!controls.empty()) {
 		/* We have been given some controls to action before start. */
-		queueRequest(controls);
+		applyControls(controls);
 	}
 
 	controller_.switchMode(mode_, &metadata);
@@ -313,7 +310,7 @@ void IPARPi::start(const ControlList &controls, StartConfig *startConfig)
 	if (agcStatus.shutterTime && agcStatus.analogueGain) {
 		ControlList ctrls(sensorCtrls_);
 		applyAGC(&agcStatus, ctrls);
-		startConfig->controls = std::move(ctrls);
+		result->controls = std::move(ctrls);
 		setCameraTimeoutValue();
 	}
 
@@ -360,7 +357,7 @@ void IPARPi::start(const ControlList &controls, StartConfig *startConfig)
 		mistrustCount_ = helper_->mistrustFramesModeSwitch();
 	}
 
-	startConfig->dropFrameCount = dropFrameCount_;
+	result->dropFrameCount = dropFrameCount_;
 
 	firstStart_ = false;
 	lastRunTimestamp_ = 0;
@@ -435,11 +432,11 @@ void IPARPi::setMode(const IPACameraSensorInfo &sensorInfo)
 			     mode_.minFrameDuration, mode_.maxFrameDuration);
 }
 
-int IPARPi::configure(const IPACameraSensorInfo &sensorInfo, const IPAConfig &ipaConfig,
-		      ControlList *controls, IPAConfigResult *result)
+int IPARPi::configure(const IPACameraSensorInfo &sensorInfo, const ConfigParams &params,
+		      ConfigResult *result)
 {
-	sensorCtrls_ = ipaConfig.sensorControls;
-	ispCtrls_ = ipaConfig.ispControls;
+	sensorCtrls_ = params.sensorControls;
+	ispCtrls_ = params.ispControls;
 
 	if (!validateSensorControls()) {
 		LOG(IPARPI, Error) << "Sensor control validation failed.";
@@ -452,7 +449,7 @@ int IPARPi::configure(const IPACameraSensorInfo &sensorInfo, const IPAConfig &ip
 	}
 
 	if (lensPresent_) {
-		lensCtrls_ = ipaConfig.lensControls;
+		lensCtrls_ = params.lensControls;
 		if (!validateLensControls()) {
 			LOG(IPARPI, Warning) << "Lens validation failed, "
 					     << "no lens control will be available.";
@@ -466,10 +463,10 @@ int IPARPi::configure(const IPACameraSensorInfo &sensorInfo, const IPAConfig &ip
 	/* Re-assemble camera mode using the sensor info. */
 	setMode(sensorInfo);
 
-	mode_.transform = static_cast<libcamera::Transform>(ipaConfig.transform);
+	mode_.transform = static_cast<libcamera::Transform>(params.transform);
 
 	/* Store the lens shading table pointer and handle if available. */
-	if (ipaConfig.lsTableHandle.isValid()) {
+	if (params.lsTableHandle.isValid()) {
 		/* Remove any previous table, if there was one. */
 		if (lsTable_) {
 			munmap(lsTable_, MaxLsGridSize);
@@ -477,7 +474,7 @@ int IPARPi::configure(const IPACameraSensorInfo &sensorInfo, const IPAConfig &ip
 		}
 
 		/* Map the LS table buffer into user space. */
-		lsTableHandle_ = std::move(ipaConfig.lsTableHandle);
+		lsTableHandle_ = std::move(params.lsTableHandle);
 		if (lsTableHandle_.isValid()) {
 			lsTable_ = mmap(nullptr, MaxLsGridSize, PROT_READ | PROT_WRITE,
 					MAP_SHARED, lsTableHandle_.get(), 0);
@@ -512,8 +509,7 @@ int IPARPi::configure(const IPACameraSensorInfo &sensorInfo, const IPAConfig &ip
 		applyAGC(&agcStatus, ctrls);
 	}
 
-	ASSERT(controls);
-	*controls = std::move(ctrls);
+	result->controls = std::move(ctrls);
 
 	/*
 	 * Apply the correct limits to the exposure, gain and frame duration controls
@@ -560,37 +556,34 @@ void IPARPi::unmapBuffers(const std::vector<unsigned int> &ids)
 	}
 }
 
-void IPARPi::signalStatReady(uint32_t bufferId, uint32_t ipaContext)
+void IPARPi::processStats(const ProcessParams &params)
 {
-	unsigned int context = ipaContext % rpiMetadata_.size();
+	unsigned int context = params.ipaContext % rpiMetadata_.size();
 
 	if (++checkCount_ != frameCount_) /* assert here? */
 		LOG(IPARPI, Error) << "WARNING: Prepare/Process mismatch!!!";
 	if (processPending_ && frameCount_ > mistrustCount_)
-		processStats(bufferId, context);
+		process(params.buffers.stats, context);
 
 	reportMetadata(context);
-
-	statsMetadataComplete.emit(bufferId, libcameraMetadata_);
+	processStatsComplete.emit(params.buffers);
 }
 
-void IPARPi::signalQueueRequest(const ControlList &controls)
-{
-	queueRequest(controls);
-}
 
-void IPARPi::signalIspPrepare(const ISPConfig &data)
+void IPARPi::prepareIsp(const PrepareParams &params)
 {
+	applyControls(params.requestControls);
+
 	/*
 	 * At start-up, or after a mode-switch, we may want to
 	 * avoid running the control algos for a few frames in case
 	 * they are "unreliable".
 	 */
-	prepareISP(data);
+	prepare(params);
 	frameCount_++;
 
 	/* Ready to push the input buffer into the ISP. */
-	runIsp.emit(data.bayerBufferId);
+	prepareIspComplete.emit(params.buffers);
 }
 
 void IPARPi::reportMetadata(unsigned int ipaContext)
@@ -703,6 +696,8 @@ void IPARPi::reportMetadata(unsigned int ipaContext)
 		libcameraMetadata_.set(controls::AfState, s);
 		libcameraMetadata_.set(controls::AfPauseState, p);
 	}
+
+	metadataReady.emit(libcameraMetadata_);
 }
 
 bool IPARPi::validateSensorControls()
@@ -826,7 +821,7 @@ static const std::map<int32_t, RPiController::AfAlgorithm::AfPause> AfPauseTable
 	{ controls::AfPauseResume, RPiController::AfAlgorithm::AfPauseResume },
 };
 
-void IPARPi::queueRequest(const ControlList &controls)
+void IPARPi::applyControls(const ControlList &controls)
 {
 	using RPiController::AfAlgorithm;
 
@@ -1256,27 +1251,22 @@ void IPARPi::queueRequest(const ControlList &controls)
 	}
 }
 
-void IPARPi::returnEmbeddedBuffer(unsigned int bufferId)
+void IPARPi::prepare(const PrepareParams &params)
 {
-	embeddedComplete.emit(bufferId);
-}
-
-void IPARPi::prepareISP(const ISPConfig &data)
-{
-	int64_t frameTimestamp = data.controls.get(controls::SensorTimestamp).value_or(0);
-	unsigned int ipaContext = data.ipaContext % rpiMetadata_.size();
+	int64_t frameTimestamp = params.sensorControls.get(controls::SensorTimestamp).value_or(0);
+	unsigned int ipaContext = params.ipaContext % rpiMetadata_.size();
 	RPiController::Metadata &rpiMetadata = rpiMetadata_[ipaContext];
 	Span<uint8_t> embeddedBuffer;
 
 	rpiMetadata.clear();
-	fillDeviceStatus(data.controls, ipaContext);
+	fillDeviceStatus(params.sensorControls, ipaContext);
 
-	if (data.embeddedBufferPresent) {
+	if (params.buffers.embedded) {
 		/*
 		 * Pipeline handler has supplied us with an embedded data buffer,
 		 * we must pass it to the CamHelper for parsing.
 		 */
-		auto it = buffers_.find(data.embeddedBufferId);
+		auto it = buffers_.find(params.buffers.embedded);
 		ASSERT(it != buffers_.end());
 		embeddedBuffer = it->second.planes()[0];
 	}
@@ -1288,7 +1278,7 @@ void IPARPi::prepareISP(const ISPConfig &data)
 	 * metadata.
 	 */
 	AgcStatus agcStatus;
-	RPiController::Metadata &delayedMetadata = rpiMetadata_[data.delayContext];
+	RPiController::Metadata &delayedMetadata = rpiMetadata_[params.delayContext];
 	if (!delayedMetadata.get<AgcStatus>("agc.status", agcStatus))
 		rpiMetadata.set("agc.delayed_status", agcStatus);
 
@@ -1298,10 +1288,6 @@ void IPARPi::prepareISP(const ISPConfig &data)
 	 */
 	helper_->prepare(embeddedBuffer, rpiMetadata);
 
-	/* Done with embedded data now, return to pipeline handler asap. */
-	if (data.embeddedBufferPresent)
-		returnEmbeddedBuffer(data.embeddedBufferId);
-
 	/* Allow a 10% margin on the comparison below. */
 	Duration delta = (frameTimestamp - lastRunTimestamp_) * 1.0ns;
 	if (lastRunTimestamp_ && frameCount_ > dropFrameCount_ &&
@@ -1445,7 +1431,7 @@ RPiController::StatisticsPtr IPARPi::fillStatistics(bcm2835_isp_stats *stats) co
 	return statistics;
 }
 
-void IPARPi::processStats(unsigned int bufferId, unsigned int ipaContext)
+void IPARPi::process(unsigned int bufferId, unsigned int ipaContext)
 {
 	RPiController::Metadata &rpiMetadata = rpiMetadata_[ipaContext];
 
diff --git a/src/libcamera/pipeline/rpi/vc4/raspberrypi.cpp b/src/libcamera/pipeline/rpi/vc4/raspberrypi.cpp
index 96749c0d..27b3bde4 100644
--- a/src/libcamera/pipeline/rpi/vc4/raspberrypi.cpp
+++ b/src/libcamera/pipeline/rpi/vc4/raspberrypi.cpp
@@ -200,15 +200,15 @@ public:
 	void freeBuffers();
 	void frameStarted(uint32_t sequence);
 
-	int loadIPA(ipa::RPi::IPAInitResult *result);
-	int configureIPA(const CameraConfiguration *config, ipa::RPi::IPAConfigResult *result);
+	int loadIPA(ipa::RPi::InitResult *result);
+	int configureIPA(const CameraConfiguration *config, ipa::RPi::ConfigResult *result);
 	int loadPipelineConfiguration();
 
 	void enumerateVideoDevices(MediaLink *link);
 
-	void statsMetadataComplete(uint32_t bufferId, const ControlList &controls);
-	void runIsp(uint32_t bufferId);
-	void embeddedComplete(uint32_t bufferId);
+	void processStatsComplete(const ipa::RPi::BufferIds &buffers);
+	void metadataReady(const ControlList &metadata);
+	void prepareIspComplete(const ipa::RPi::BufferIds &buffers);
 	void setIspControls(const ControlList &controls);
 	void setDelayedControls(const ControlList &controls, uint32_t delayContext);
 	void setLensControls(const ControlList &controls);
@@ -238,7 +238,7 @@ public:
 	/* The vector below is just for convenience when iterating over all streams. */
 	std::vector<RPi::Stream *> streams_;
 	/* Stores the ids of the buffers mapped in the IPA. */
-	std::unordered_set<unsigned int> ipaBuffers_;
+	std::unordered_set<unsigned int> bufferIds_;
 	/*
 	 * Stores a cascade of Video Mux or Bridge devices between the sensor and
 	 * Unicam together with media link across the entities.
@@ -1000,7 +1000,7 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
 
 	data->isp_[Isp::Input].dev()->setSelection(V4L2_SEL_TGT_CROP, &crop);
 
-	ipa::RPi::IPAConfigResult result;
+	ipa::RPi::ConfigResult result;
 	ret = data->configureIPA(config, &result);
 	if (ret)
 		LOG(RPI, Error) << "Failed to configure the IPA: " << ret;
@@ -1117,17 +1117,17 @@ int PipelineHandlerRPi::start(Camera *camera, const ControlList *controls)
 		data->applyScalerCrop(*controls);
 
 	/* Start the IPA. */
-	ipa::RPi::StartConfig startConfig;
+	ipa::RPi::StartResult result;
 	data->ipa_->start(controls ? *controls : ControlList{ controls::controls },
-			  &startConfig);
+			  &result);
 
 	/* Apply any gain/exposure settings that the IPA may have passed back. */
-	if (!startConfig.controls.empty())
-		data->setSensorControls(startConfig.controls);
+	if (!result.controls.empty())
+		data->setSensorControls(result.controls);
 
 	/* Configure the number of dropped frames required on startup. */
 	data->dropFrameCount_ = data->config_.disableStartupFrameDrops
-			      ? 0 : startConfig.dropFrameCount;
+				? 0 : result.dropFrameCount;
 
 	for (auto const stream : data->streams_)
 		stream->resetBuffers();
@@ -1358,7 +1358,7 @@ int PipelineHandlerRPi::registerCamera(MediaDevice *unicam, MediaDevice *isp, Me
 
 	data->sensorFormats_ = populateSensorFormats(data->sensor_);
 
-	ipa::RPi::IPAInitResult result;
+	ipa::RPi::InitResult result;
 	if (data->loadIPA(&result)) {
 		LOG(RPI, Error) << "Failed to load a suitable IPA library";
 		return -EINVAL;
@@ -1599,7 +1599,7 @@ int PipelineHandlerRPi::prepareBuffers(Camera *camera)
 void PipelineHandlerRPi::mapBuffers(Camera *camera, const RPi::BufferMap &buffers, unsigned int mask)
 {
 	RPiCameraData *data = cameraData(camera);
-	std::vector<IPABuffer> ipaBuffers;
+	std::vector<IPABuffer> bufferIds;
 	/*
 	 * Link the FrameBuffers with the id (key value) in the map stored in
 	 * the RPi stream object - along with an identifier mask.
@@ -1608,12 +1608,12 @@ void PipelineHandlerRPi::mapBuffers(Camera *camera, const RPi::BufferMap &buffer
 	 * handler and the IPA.
 	 */
 	for (auto const &it : buffers) {
-		ipaBuffers.push_back(IPABuffer(mask | it.first,
+		bufferIds.push_back(IPABuffer(mask | it.first,
 					       it.second->planes()));
-		data->ipaBuffers_.insert(mask | it.first);
+		data->bufferIds_.insert(mask | it.first);
 	}
 
-	data->ipa_->mapBuffers(ipaBuffers);
+	data->ipa_->mapBuffers(bufferIds);
 }
 
 void RPiCameraData::freeBuffers()
@@ -1623,10 +1623,10 @@ void RPiCameraData::freeBuffers()
 		 * Copy the buffer ids from the unordered_set to a vector to
 		 * pass to the IPA.
 		 */
-		std::vector<unsigned int> ipaBuffers(ipaBuffers_.begin(),
-						     ipaBuffers_.end());
-		ipa_->unmapBuffers(ipaBuffers);
-		ipaBuffers_.clear();
+		std::vector<unsigned int> bufferIds(bufferIds_.begin(),
+						    bufferIds_.end());
+		ipa_->unmapBuffers(bufferIds);
+		bufferIds_.clear();
 	}
 
 	for (auto const stream : streams_)
@@ -1643,16 +1643,16 @@ void RPiCameraData::frameStarted(uint32_t sequence)
 	delayedCtrls_->applyControls(sequence);
 }
 
-int RPiCameraData::loadIPA(ipa::RPi::IPAInitResult *result)
+int RPiCameraData::loadIPA(ipa::RPi::InitResult *result)
 {
 	ipa_ = IPAManager::createIPA<ipa::RPi::IPAProxyRPi>(pipe(), 1, 1);
 
 	if (!ipa_)
 		return -ENOENT;
 
-	ipa_->statsMetadataComplete.connect(this, &RPiCameraData::statsMetadataComplete);
-	ipa_->runIsp.connect(this, &RPiCameraData::runIsp);
-	ipa_->embeddedComplete.connect(this, &RPiCameraData::embeddedComplete);
+	ipa_->processStatsComplete.connect(this, &RPiCameraData::processStatsComplete);
+	ipa_->prepareIspComplete.connect(this, &RPiCameraData::prepareIspComplete);
+	ipa_->metadataReady.connect(this, &RPiCameraData::metadataReady);
 	ipa_->setIspControls.connect(this, &RPiCameraData::setIspControls);
 	ipa_->setDelayedControls.connect(this, &RPiCameraData::setDelayedControls);
 	ipa_->setLensControls.connect(this, &RPiCameraData::setLensControls);
@@ -1674,23 +1674,25 @@ int RPiCameraData::loadIPA(ipa::RPi::IPAInitResult *result)
 	}
 
 	IPASettings settings(configurationFile, sensor_->model());
+	ipa::RPi::InitParams params;
 
-	return ipa_->init(settings, !!sensor_->focusLens(), result);
+	params.lensPresent = !!sensor_->focusLens();
+	return ipa_->init(settings, params, result);
 }
 
-int RPiCameraData::configureIPA(const CameraConfiguration *config, ipa::RPi::IPAConfigResult *result)
+int RPiCameraData::configureIPA(const CameraConfiguration *config, ipa::RPi::ConfigResult *result)
 {
 	std::map<unsigned int, ControlInfoMap> entityControls;
-	ipa::RPi::IPAConfig ipaConfig;
+	ipa::RPi::ConfigParams params;
 
 	/* \todo Move passing of ispControls and lensControls to ipa::init() */
-	ipaConfig.sensorControls = sensor_->controls();
-	ipaConfig.ispControls = isp_[Isp::Input].dev()->controls();
+	params.sensorControls = sensor_->controls();
+	params.ispControls = isp_[Isp::Input].dev()->controls();
 	if (sensor_->focusLens())
-		ipaConfig.lensControls = sensor_->focusLens()->controls();
+		params.lensControls = sensor_->focusLens()->controls();
 
 	/* Always send the user transform to the IPA. */
-	ipaConfig.transform = static_cast<unsigned int>(config->transform);
+	params.transform = static_cast<unsigned int>(config->transform);
 
 	/* Allocate the lens shading table via dmaHeap and pass to the IPA. */
 	if (!lsTable_.isValid()) {
@@ -1703,7 +1705,7 @@ int RPiCameraData::configureIPA(const CameraConfiguration *config, ipa::RPi::IPA
 		 * \todo Investigate if mapping the lens shading table buffer
 		 * could be handled with mapBuffers().
 		 */
-		ipaConfig.lsTableHandle = lsTable_;
+		params.lsTableHandle = lsTable_;
 	}
 
 	/* We store the IPACameraSensorInfo for digital zoom calculations. */
@@ -1714,15 +1716,14 @@ int RPiCameraData::configureIPA(const CameraConfiguration *config, ipa::RPi::IPA
 	}
 
 	/* Ready the IPA - it must know about the sensor resolution. */
-	ControlList controls;
-	ret = ipa_->configure(sensorInfo_, ipaConfig, &controls, result);
+	ret = ipa_->configure(sensorInfo_, params, result);
 	if (ret < 0) {
 		LOG(RPI, Error) << "IPA configuration failed!";
 		return -EPIPE;
 	}
 
-	if (!controls.empty())
-		setSensorControls(controls);
+	if (!result->controls.empty())
+		setSensorControls(result->controls);
 
 	return 0;
 }
@@ -1883,24 +1884,32 @@ void RPiCameraData::enumerateVideoDevices(MediaLink *link)
 	}
 }
 
-void RPiCameraData::statsMetadataComplete(uint32_t bufferId, const ControlList &controls)
+void RPiCameraData::processStatsComplete(const ipa::RPi::BufferIds &buffers)
 {
 	if (!isRunning())
 		return;
 
-	FrameBuffer *buffer = isp_[Isp::Stats].getBuffers().at(bufferId & RPi::MaskID);
+	FrameBuffer *buffer = isp_[Isp::Stats].getBuffers().at(buffers.stats & RPi::MaskID);
 
 	handleStreamBuffer(buffer, &isp_[Isp::Stats]);
+	state_ = State::IpaComplete;
+	handleState();
+}
+
+void RPiCameraData::metadataReady(const ControlList &metadata)
+{
+	if (!isRunning())
+		return;
 
 	/* Add to the Request metadata buffer what the IPA has provided. */
 	Request *request = requestQueue_.front();
-	request->metadata().merge(controls);
+	request->metadata().merge(metadata);
 
 	/*
 	 * Inform the sensor of the latest colour gains if it has the
 	 * V4L2_CID_NOTIFY_GAINS control (which means notifyGainsUnity_ is set).
 	 */
-	const auto &colourGains = controls.get(libcamera::controls::ColourGains);
+	const auto &colourGains = metadata.get(libcamera::controls::ColourGains);
 	if (notifyGainsUnity_ && colourGains) {
 		/* The control wants linear gains in the order B, Gb, Gr, R. */
 		ControlList ctrls(sensor_->controls());
@@ -1914,33 +1923,29 @@ void RPiCameraData::statsMetadataComplete(uint32_t bufferId, const ControlList &
 
 		sensor_->setControls(&ctrls);
 	}
-
-	state_ = State::IpaComplete;
-	handleState();
 }
 
-void RPiCameraData::runIsp(uint32_t bufferId)
+void RPiCameraData::prepareIspComplete(const ipa::RPi::BufferIds &buffers)
 {
+	unsigned int embeddedId = buffers.embedded & RPi::MaskID;
+	unsigned int bayer = buffers.bayer & RPi::MaskID;
+	FrameBuffer *buffer;
+
 	if (!isRunning())
 		return;
 
-	FrameBuffer *buffer = unicam_[Unicam::Image].getBuffers().at(bufferId & RPi::MaskID);
-
-	LOG(RPI, Debug) << "Input re-queue to ISP, buffer id " << (bufferId & RPi::MaskID)
+	buffer = unicam_[Unicam::Image].getBuffers().at(bayer & RPi::MaskID);
+	LOG(RPI, Debug) << "Input re-queue to ISP, buffer id " << (bayer & RPi::MaskID)
 			<< ", timestamp: " << buffer->metadata().timestamp;
 
 	isp_[Isp::Input].queueBuffer(buffer);
 	ispOutputCount_ = 0;
-	handleState();
-}
 
-void RPiCameraData::embeddedComplete(uint32_t bufferId)
-{
-	if (!isRunning())
-		return;
+	if (sensorMetadata_ && embeddedId) {
+		buffer = unicam_[Unicam::Embedded].getBuffers().at(embeddedId & RPi::MaskID);
+		handleStreamBuffer(buffer, &unicam_[Unicam::Embedded]);
+	}
 
-	FrameBuffer *buffer = unicam_[Unicam::Embedded].getBuffers().at(bufferId & RPi::MaskID);
-	handleStreamBuffer(buffer, &unicam_[Unicam::Embedded]);
 	handleState();
 }
 
@@ -2116,8 +2121,10 @@ void RPiCameraData::ispOutputDequeue(FrameBuffer *buffer)
 	 * application until after the IPA signals so.
 	 */
 	if (stream == &isp_[Isp::Stats]) {
-		ipa_->signalStatReady(RPi::MaskStats | static_cast<unsigned int>(index),
-				      requestQueue_.front()->sequence());
+		ipa::RPi::ProcessParams params;
+		params.buffers.stats = index | RPi::MaskStats;
+		params.ipaContext = requestQueue_.front()->sequence();
+		ipa_->processStats(params);
 	} else {
 		/* Any other ISP output can be handed back to the application now. */
 		handleStreamBuffer(buffer, stream);
@@ -2344,38 +2351,30 @@ void RPiCameraData::tryRunPipeline()
 	request->metadata().clear();
 	fillRequestMetadata(bayerFrame.controls, request);
 
-	/*
-	 * Process all the user controls by the IPA. Once this is complete, we
-	 * queue the ISP output buffer listed in the request to start the HW
-	 * pipeline.
-	 */
-	ipa_->signalQueueRequest(request->controls());
-
 	/* Set our state to say the pipeline is active. */
 	state_ = State::Busy;
 
-	unsigned int bayerId = unicam_[Unicam::Image].getBufferId(bayerFrame.buffer);
+	unsigned int bayer = unicam_[Unicam::Image].getBufferId(bayerFrame.buffer);
 
-	LOG(RPI, Debug) << "Signalling signalIspPrepare:"
-			<< " Bayer buffer id: " << bayerId;
+	LOG(RPI, Debug) << "Signalling prepareIsp:"
+			<< " Bayer buffer id: " << bayer;
 
-	ipa::RPi::ISPConfig ispPrepare;
-	ispPrepare.bayerBufferId = RPi::MaskBayerData | bayerId;
-	ispPrepare.controls = std::move(bayerFrame.controls);
-	ispPrepare.ipaContext = request->sequence();
-	ispPrepare.delayContext = bayerFrame.delayContext;
+	ipa::RPi::PrepareParams params;
+	params.buffers.bayer = RPi::MaskBayerData | bayer;
+	params.sensorControls = std::move(bayerFrame.controls);
+	params.requestControls = request->controls();
+	params.ipaContext = request->sequence();
+	params.delayContext = bayerFrame.delayContext;
 
 	if (embeddedBuffer) {
 		unsigned int embeddedId = unicam_[Unicam::Embedded].getBufferId(embeddedBuffer);
 
-		ispPrepare.embeddedBufferId = RPi::MaskEmbeddedData | embeddedId;
-		ispPrepare.embeddedBufferPresent = true;
-
-		LOG(RPI, Debug) << "Signalling signalIspPrepare:"
+		params.buffers.embedded = RPi::MaskEmbeddedData | embeddedId;
+		LOG(RPI, Debug) << "Signalling prepareIsp:"
 				<< " Embedded buffer id: " << embeddedId;
 	}
 
-	ipa_->signalIspPrepare(ispPrepare);
+	ipa_->prepareIsp(params);
 }
 
 bool RPiCameraData::findMatchingBuffers(BayerFrame &bayerFrame, FrameBuffer *&embeddedBuffer)