ipa: raspberrypi: Add hardware configuration to the controller

Add a new Controller::HardwareConfig structure that captures the
hardware statistics grid/histogram sizes and pipeline widths. This
ensures there is a single centralised places for these parameters.

Add a getHardwareConfig() helper function to retrieve these values for a
given hardware target.

Update the statistics populating routine in the IPA to use the values
from this structure instead of the hardcoded numbers.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/ipa/raspberrypi/controller/algorithm.h

@@ -45,6 +45,10 @@ public:
 	{
 		return controller_->getTarget();
 	}
+	const Controller::HardwareConfig &getHardwareConfig() const
+	{
+		return controller_->getHardwareConfig();
+	}
 
 private:
 	Controller *controller_;

src/ipa/raspberrypi/controller/controller.cpp

@@ -20,6 +20,25 @@ using namespace libcamera;
 
 LOG_DEFINE_CATEGORY(RPiController)
 
+static const std::map<std::string, Controller::HardwareConfig> HardwareConfigMap = {
+	{
+		"bcm2835",
+		{
+			/*
+			 * There are only ever 15 AGC regions computed by the firmware
+			 * due to zoning, but the HW defines AGC_REGIONS == 16!
+			 */
+			.agcRegions = { 15 , 1 },
+			.agcZoneWeights = { 15 , 1 },
+			.awbRegions = { 16, 12 },
+			.focusRegions = { 4, 3 },
+			.numHistogramBins = 128,
+			.numGammaPoints = 33,
+			.pipelineWidth = 13
+		}
+	},
+};
+
 Controller::Controller()
 	: switchModeCalled_(false)
 {
@@ -148,3 +167,15 @@ const std::string &Controller::getTarget() const
 {
 	return target_;
 }
+
+const Controller::HardwareConfig &Controller::getHardwareConfig() const
+{
+	auto cfg = HardwareConfigMap.find(getTarget());
+
+	/*
+	 * This really should not happen, the IPA ought to validate the target
+	 * on initialisation.
+	 */
+	ASSERT(cfg != HardwareConfigMap.end());
+	return cfg->second;
+}

src/ipa/raspberrypi/controller/controller.h

@@ -37,6 +37,16 @@ typedef std::unique_ptr<Algorithm> AlgorithmPtr;
 class Controller
 {
 public:
+	struct HardwareConfig {
+		libcamera::Size agcRegions;
+		libcamera::Size agcZoneWeights;
+		libcamera::Size awbRegions;
+		libcamera::Size focusRegions;
+		unsigned int numHistogramBins;
+		unsigned int numGammaPoints;
+		unsigned int pipelineWidth;
+	};
+
 	Controller();
 	~Controller();
 	int read(char const *filename);
@@ -47,6 +57,7 @@ public:
 	Metadata &getGlobalMetadata();
 	Algorithm *getAlgorithm(std::string const &name) const;
 	const std::string &getTarget() const;
+	const HardwareConfig &getHardwareConfig() const;
 
 protected:
 	int createAlgorithm(const std::string &name, const libcamera::YamlObject &params);

src/ipa/raspberrypi/raspberrypi.cpp

@@ -1394,20 +1394,19 @@ RPiController::StatisticsPtr IPARPi::fillStatistics(bcm2835_isp_stats *stats) co
 {
 	using namespace RPiController;
 
+	const Controller::HardwareConfig &hw = controller_.getHardwareConfig();
 	unsigned int i;
 	StatisticsPtr statistics =
 		std::make_unique<Statistics>(Statistics::AgcStatsPos::PreWb, Statistics::ColourStatsPos::PostLsc);
 
 	/* RGB histograms are not used, so do not populate them. */
-	statistics->yHist = RPiController::Histogram(stats->hist[0].g_hist, NUM_HISTOGRAM_BINS);
+	statistics->yHist = RPiController::Histogram(stats->hist[0].g_hist,
+						     hw.numHistogramBins);
 
-	/*
+	/* All region sums are based on a 16-bit normalised pipeline bit-depth. */
-	 * All region sums are based on a 13-bit pipeline bit-depth. Normalise
+	unsigned int scale = Statistics::NormalisationFactorPow2 - hw.pipelineWidth;
-	 * this to 16-bits for the AGC/AWB/ALSC algorithms.
-	 */
-	constexpr unsigned int scale = Statistics::NormalisationFactorPow2 - 13;
 
-	statistics->awbRegions.init({ DEFAULT_AWB_REGIONS_X, DEFAULT_AWB_REGIONS_Y });
+	statistics->awbRegions.init(hw.awbRegions);
 	for (i = 0; i < statistics->awbRegions.numRegions(); i++)
 		statistics->awbRegions.set(i, { { stats->awb_stats[i].r_sum << scale,
 						  stats->awb_stats[i].g_sum << scale,
@@ -1415,11 +1414,7 @@ RPiController::StatisticsPtr IPARPi::fillStatistics(bcm2835_isp_stats *stats) co
 						stats->awb_stats[i].counted,
 						stats->awb_stats[i].notcounted });
 
-	/*
+	statistics->agcRegions.init(hw.agcRegions);
-	 * There are only ever 15 regions computed by the firmware due to zoning,
-	 * but the HW defines AGC_REGIONS == 16!
-	 */
-	statistics->agcRegions.init(15);
 	for (i = 0; i < statistics->agcRegions.numRegions(); i++)
 		statistics->agcRegions.set(i, { { stats->agc_stats[i].r_sum << scale,
 						  stats->agc_stats[i].g_sum << scale,
@@ -1427,7 +1422,7 @@ RPiController::StatisticsPtr IPARPi::fillStatistics(bcm2835_isp_stats *stats) co
 						stats->agc_stats[i].counted,
 						stats->awb_stats[i].notcounted });
 
-	statistics->focusRegions.init({ 4, 3 });
+	statistics->focusRegions.init(hw.focusRegions);
 	for (i = 0; i < statistics->focusRegions.numRegions(); i++)
 		statistics->focusRegions.set(i, { stats->focus_stats[i].contrast_val[1][1] / 1000,
 						  stats->focus_stats[i].contrast_val_num[1][1],