[PATCH 1/5] ipa: libipa: Add black levels to camera sensor helper

[Stefan Klug]

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.

Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
---
 src/ipa/libipa/camera_sensor_helper.cpp | 18 ++++++++++++++++++
 src/ipa/libipa/camera_sensor_helper.h   |  6 ++++++
 2 files changed, 24 insertions(+)

diff --git a/src/ipa/libipa/camera_sensor_helper.cpp b/src/ipa/libipa/camera_sensor_helper.cpp
index 782ff9904e81..6d8850eb25a5 100644
--- a/src/ipa/libipa/camera_sensor_helper.cpp
+++ b/src/ipa/libipa/camera_sensor_helper.cpp
@@ -47,6 +47,21 @@ namespace ipa {
  * function.
  */
 
+/**
+ * \brief Fetch the black levels of the sensor
+ *
+ * This function returns the black levels of the sensor with respect to a 16bit
+ * pixel width in R, Gr, Gb, B order. If these are unknown an empty optional is
+ * returned.
+ *
+ * \return The black levels of the sensor
+ */
+std::optional<CameraSensorHelper::BlackLevels>
+CameraSensorHelper::blackLevels() const
+{
+	return blackLevels_;
+}
+
 /**
  * \brief Compute gain code from the analogue gain absolute value
  * \param[in] gain The real gain to pass
@@ -396,6 +411,7 @@ class CameraSensorHelperImx219 : public CameraSensorHelper
 public:
 	CameraSensorHelperImx219()
 	{
+		blackLevels_ = { 4096, 4096, 4096, 4096 };
 		gainType_ = AnalogueGainLinear;
 		gainConstants_.linear = { 0, 256, -1, 256 };
 	}
@@ -407,6 +423,7 @@ class CameraSensorHelperImx258 : public CameraSensorHelper
 public:
 	CameraSensorHelperImx258()
 	{
+		blackLevels_ = { 4096, 4096, 4096, 4096 };
 		gainType_ = AnalogueGainLinear;
 		gainConstants_.linear = { 0, 512, -1, 512 };
 	}
@@ -456,6 +473,7 @@ class CameraSensorHelperImx335 : public CameraSensorHelper
 public:
 	CameraSensorHelperImx335()
 	{
+		blackLevels_ = { 3200, 3200, 3200, 3200 };
 		gainType_ = AnalogueGainExponential;
 		gainConstants_.exp = { 1.0, expGainDb(0.3) };
 	}
diff --git a/src/ipa/libipa/camera_sensor_helper.h b/src/ipa/libipa/camera_sensor_helper.h
index 0d99073bea82..f025727c06ee 100644
--- a/src/ipa/libipa/camera_sensor_helper.h
+++ b/src/ipa/libipa/camera_sensor_helper.h
@@ -9,7 +9,9 @@
 
 #include <stdint.h>
 
+#include <array>
 #include <memory>
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -22,9 +24,12 @@ namespace ipa {
 class CameraSensorHelper
 {
 public:
+	typedef std::array<int32_t, 4> BlackLevels;
+
 	CameraSensorHelper() = default;
 	virtual ~CameraSensorHelper() = default;
 
+	virtual std::optional<BlackLevels> blackLevels() const;
 	virtual uint32_t gainCode(double gain) const;
 	virtual double gain(uint32_t gainCode) const;
 
@@ -51,6 +56,7 @@ protected:
 		AnalogueGainExpConstants exp;
 	};
 
+	std::optional<BlackLevels> blackLevels_;
 	AnalogueGainType gainType_;
 	AnalogueGainConstants gainConstants_;
 
-- 
2.43.0