new file mode 100644
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021-2022, Ideas On Board
+ *
+ * gsl.cpp - RkISP1 Gamma Sensor Linearization control
+ */
+
+#include "gsl.h"
+
+#include <libcamera/base/log.h>
+
+#include "libcamera/internal/yaml_parser.h"
+
+#include "linux/rkisp1-config.h"
+
+/**
+ * \file gsl.h
+ */
+
+namespace libcamera {
+
+namespace ipa::rkisp1::algorithms {
+
+/**
+ * \class GammaSensorLinearization
+ * \brief RkISP1 Gamma Sensor Linearization control
+ *
+ * This algorithm linearizes the sensor output to compensate the sensor
+ * non-linearities by applying piecewise linear functions to the red, green and
+ * blue channels.
+ *
+ * The curves are specified in the tuning data and defined using 17 points.
+ *
+ * - The X coordinates are expressed using 16 intervals, with the first point
+ * at X coordinate 0. Each interval is expressed as a 2-bit value DX (from
+ * GAMMA_DX_1 to GAMMA_DX_16), stored in the RKISP1_CIF_ISP_GAMMA_DX_LO and
+ * RKISP1_CIF_ISP_GAMMA_DX_HI registers. The real interval is equal to
+ * \f$2^{dx+4}\f$. X coordinates are shared between the red, green and blue
+ * curves.
+ *
+ * - The Y coordinates are specified as 17 values separately for the
+ * red, green and blue channels, with a 12-bit resolution. Each value must be
+ * in the [-2048, 2047] range compared to the previous value.
+ */
+
+LOG_DEFINE_CATEGORY(RkISP1Gsl)
+
+static constexpr unsigned int kDegammaXIntervals = 16;
+
+GammaSensorLinearization::GammaSensorLinearization()
+ : initialized_(false)
+{
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::init
+ */
+int GammaSensorLinearization::init([[maybe_unused]] IPAContext &context,
+ const YamlObject &tuningData)
+{
+ std::vector<uint16_t> xIntervals = tuningData["x-intervals"].getList<uint16_t>();
+ if (xIntervals.size() != kDegammaXIntervals) {
+ LOG(RkISP1Gsl, Error)
+ << "Invalid 'x' coordinates: expected "
+ << kDegammaXIntervals << " elements, got "
+ << xIntervals.size();
+
+ return -EINVAL;
+ }
+
+ /* Compute gammaDx_ intervals from xIntervals values */
+ gammaDx_[0] = 0;
+ gammaDx_[1] = 0;
+ for (unsigned int i = 0; i < kDegammaXIntervals; ++i)
+ gammaDx_[i / 8] |= (xIntervals[i] & 0x07) << ((i % 8) * 4);
+
+ const YamlObject &yObject = tuningData["y"];
+ if (!yObject.isDictionary()) {
+ LOG(RkISP1Gsl, Error)
+ << "Issue while parsing 'y' in tuning file: "
+ << "entry must be a dictionary";
+ return -EINVAL;
+ }
+
+ curveYr_ = yObject["red"].getList<uint16_t>();
+ if (curveYr_.size() != RKISP1_CIF_ISP_DEGAMMA_CURVE_SIZE) {
+ LOG(RkISP1Gsl, Error)
+ << "Invalid 'y:red' coordinates: expected "
+ << RKISP1_CIF_ISP_DEGAMMA_CURVE_SIZE
+ << " elements, got " << curveYr_.size();
+ return -EINVAL;
+ }
+
+ curveYg_ = yObject["green"].getList<uint16_t>();
+ if (curveYg_.size() != RKISP1_CIF_ISP_DEGAMMA_CURVE_SIZE) {
+ LOG(RkISP1Gsl, Error)
+ << "Invalid 'y:green' coordinates: expected "
+ << RKISP1_CIF_ISP_DEGAMMA_CURVE_SIZE
+ << " elements, got " << curveYg_.size();
+ return -EINVAL;
+ }
+
+ curveYb_ = yObject["blue"].getList<uint16_t>();
+ if (curveYb_.size() != RKISP1_CIF_ISP_DEGAMMA_CURVE_SIZE) {
+ LOG(RkISP1Gsl, Error)
+ << "Invalid 'y:blue' coordinates: expected "
+ << RKISP1_CIF_ISP_DEGAMMA_CURVE_SIZE
+ << " elements, got " << curveYb_.size();
+ return -EINVAL;
+ }
+
+ initialized_ = true;
+ return 0;
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::prepare
+ */
+void GammaSensorLinearization::prepare(IPAContext &context,
+ rkisp1_params_cfg *params)
+{
+ if (context.frameContext.frameCount > 0)
+ return;
+
+ if (!initialized_)
+ return;
+
+ params->others.sdg_config.xa_pnts.gamma_dx0 = gammaDx_[0];
+ params->others.sdg_config.xa_pnts.gamma_dx1 = gammaDx_[1];
+
+ std::copy(curveYr_.begin(), curveYr_.end(),
+ params->others.sdg_config.curve_r.gamma_y);
+ std::copy(curveYg_.begin(), curveYg_.end(),
+ params->others.sdg_config.curve_g.gamma_y);
+ std::copy(curveYb_.begin(), curveYb_.end(),
+ params->others.sdg_config.curve_b.gamma_y);
+
+ params->module_en_update |= RKISP1_CIF_ISP_MODULE_SDG;
+ params->module_ens |= RKISP1_CIF_ISP_MODULE_SDG;
+ params->module_cfg_update |= RKISP1_CIF_ISP_MODULE_SDG;
+}
+
+REGISTER_IPA_ALGORITHM(GammaSensorLinearization, "GammaSensorLinearization")
+
+} /* namespace ipa::rkisp1::algorithms */
+
+} /* namespace libcamera */
new file mode 100644
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021-2022, Ideas On Board
+ *
+ * gsl.h - RkISP1 Gamma Sensor Linearization control
+ */
+
+#pragma once
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::rkisp1::algorithms {
+
+class GammaSensorLinearization : public Algorithm
+{
+public:
+ GammaSensorLinearization();
+ ~GammaSensorLinearization() = default;
+
+ int init(IPAContext &context, const YamlObject &tuningData) override;
+ void prepare(IPAContext &context, rkisp1_params_cfg *params) override;
+
+private:
+ bool initialized_;
+ uint32_t gammaDx_[2];
+ std::vector<uint16_t> curveYr_;
+ std::vector<uint16_t> curveYg_;
+ std::vector<uint16_t> curveYb_;
+};
+
+} /* namespace ipa::rkisp1::algorithms */
+} /* namespace libcamera */
@@ -4,4 +4,5 @@ rkisp1_ipa_algorithms = files([
'agc.cpp',
'awb.cpp',
'blc.cpp',
+ 'gsl.cpp',
])
@@ -10,4 +10,10 @@ algorithms:
Gr: 256
Gb: 256
B: 256
+ - GammaSensorLinearization:
+ x-intervals: [ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 ]
+ y:
+ red: [ 0, 256, 512, 768, 1024, 1280, 1536, 1792, 2048, 2304, 2560, 2816, 3072, 3328, 3584, 3840, 4095 ]
+ green: [ 0, 256, 512, 768, 1024, 1280, 1536, 1792, 2048, 2304, 2560, 2816, 3072, 3328, 3584, 3840, 4095 ]
+ blue: [ 0, 256, 512, 768, 1024, 1280, 1536, 1792, 2048, 2304, 2560, 2816, 3072, 3328, 3584, 3840, 4095 ]
...