ipa: libipa: Add black levels to camera sensor helper

For a proper tuning process we need to know the sensor black levels. In
most cases these are fixed and not reported by the kernel driver. Store
them inside the sensor helpers for later retrieval by the algorithms.

Add black level value corresponding to the data pedestal for three
initial sensors as documented in the datasheets. More should be added,
eventually filling the gaps for all supported sensors.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/src/ipa/libipa/camera_sensor_helper.h b/src/ipa/libipa/camera_sensor_helper.h
index 0d99073b..ac276e27 100644
--- a/src/ipa/libipa/camera_sensor_helper.h
+++ b/src/ipa/libipa/camera_sensor_helper.h
@@ -10,6 +10,7 @@
 #include <stdint.h>
 
 #include <memory>
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -25,6 +26,7 @@ public:
 	CameraSensorHelper() = default;
 	virtual ~CameraSensorHelper() = default;
 
+	std::optional<int16_t> blackLevel() const { return blackLevel_; }
 	virtual uint32_t gainCode(double gain) const;
 	virtual double gain(uint32_t gainCode) const;
 
@@ -51,6 +53,7 @@ protected:
 		AnalogueGainExpConstants exp;
 	};
 
+	std::optional<int16_t> blackLevel_;
 	AnalogueGainType gainType_;
 	AnalogueGainConstants gainConstants_;