[PATCH 06/10] ipa: mali-c55: Add BLC Algorithm

[Daniel Scally]

From: Jacopo Mondi <jacopo.mondi at ideasonboard.com>

Add a Black Level Correction algorithm.

Acked-by: Nayden Kanchev  <nayden.kanchev at arm.com>
Jacopo Mondi <jacopo.mondi at ideasonboard.com>
---
 src/ipa/mali-c55/algorithms/blc.cpp     | 119 ++++++++++++++++++++++++
 src/ipa/mali-c55/algorithms/blc.h       |  40 ++++++++
 src/ipa/mali-c55/algorithms/meson.build |   1 +
 3 files changed, 160 insertions(+)
 create mode 100644 src/ipa/mali-c55/algorithms/blc.cpp
 create mode 100644 src/ipa/mali-c55/algorithms/blc.h

diff --git a/src/ipa/mali-c55/algorithms/blc.cpp b/src/ipa/mali-c55/algorithms/blc.cpp
new file mode 100644
index 00000000..c8590d8a
--- /dev/null
+++ b/src/ipa/mali-c55/algorithms/blc.cpp
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021-2022, Ideas On Board
+ *
+ * blc.cpp - Mali-C55 sensor offset (black level) correction
+ */
+
+#include "blc.h"
+
+#include <libcamera/base/log.h>
+#include <libcamera/control_ids.h>
+
+#include "libcamera/internal/yaml_parser.h"
+
+/**
+ * \file blc.h
+ */
+
+namespace libcamera {
+
+namespace ipa::mali_c55::algorithms {
+
+/**
+ * \class BlackLevelCorrection
+ * \brief MaliC55 Black Level Correction control
+ *
+ * todo
+ */
+
+LOG_DEFINE_CATEGORY(MaliC55Blc)
+
+BlackLevelCorrection::BlackLevelCorrection()
+	: tuningParameters_(false)
+{
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::init
+ */
+int BlackLevelCorrection::init([[maybe_unused]] IPAContext &context,
+			       const YamlObject &tuningData)
+{
+	offset00 = tuningData["offset00"].get<uint32_t>(256);
+	offset01 = tuningData["offset01"].get<uint32_t>(256);
+	offset10 = tuningData["offset10"].get<uint32_t>(256);
+	offset11 = tuningData["offset11"].get<uint32_t>(256);
+
+	if (offset00 > kMaxOffset || offset01 > kMaxOffset ||
+	    offset10 > kMaxOffset || offset11 > kMaxOffset) {
+		LOG(MaliC55Blc, Error) << "Invalid black level offsets";
+		return -EINVAL;
+	}
+
+	tuningParameters_ = true;
+
+	LOG(MaliC55Blc, Debug)
+		<< "Black levels: 00 " << offset00 << ", 01 " << offset01
+		<< ", 10 " << offset10 << ", 11 " << offset11;
+
+	return 0;
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::prepare
+ */
+void BlackLevelCorrection::prepare([[maybe_unused]] IPAContext &context,
+				   const uint32_t frame,
+				   [[maybe_unused]] IPAFrameContext &frameContext,
+				   mali_c55_params_block_header *block)
+{
+	if (frame > 0)
+		return;
+
+	if (!tuningParameters_)
+		return;
+
+	block->type = MALI_C55_PARAM_BLOCK_SENSOR_OFFS;
+	block->enabled = true;
+	block->size = sizeof(mali_c55_params_sensor_off_preshading);
+
+	struct mali_c55_params_sensor_off_preshading *sensor_offs =
+		reinterpret_cast<mali_c55_params_sensor_off_preshading *>(block);
+
+	sensor_offs->chan00 = offset00;
+	sensor_offs->chan01 = offset01;
+	sensor_offs->chan10 = offset10;
+	sensor_offs->chan11 = offset11;
+}
+
+void BlackLevelCorrection::process([[maybe_unused]] IPAContext &context,
+				   [[maybe_unused]] const uint32_t frame,
+				   [[maybe_unused]] IPAFrameContext &frameContext,
+				   [[maybe_unused]] const mali_c55_stats_buffer *stats,
+				   ControlList &metadata)
+{
+	/*
+	 * Black Level Offsets in tuning data need to be 20-bit, whereas the
+	 * metadata expects values from a 16-bit range. Right-shift to remove
+	 * the 4 least significant bits.
+	 *
+	 * The black levels should be reported in the order R, Gr, Gb, B. We
+	 * ignore that here given we're using matching values so far, but it
+	 * would be safer to check the sensor's bayer order.
+	 *
+	 * \todo Account for bayer order.
+	 */
+	metadata.set(controls::SensorBlackLevels, {
+		static_cast<int32_t>(offset00 >> 4),
+		static_cast<int32_t>(offset01 >> 4),
+		static_cast<int32_t>(offset10 >> 4),
+		static_cast<int32_t>(offset11 >> 4),
+	});
+}
+
+REGISTER_IPA_ALGORITHM(BlackLevelCorrection, "BlackLevelCorrection")
+
+} /* namespace ipa::mali_c55::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/mali-c55/algorithms/blc.h b/src/ipa/mali-c55/algorithms/blc.h
new file mode 100644
index 00000000..34d5a3ac
--- /dev/null
+++ b/src/ipa/mali-c55/algorithms/blc.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021-2022, Ideas On Board
+ *
+ * blc.h - Mali-C55 sensor offset (black level) correction
+ */
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::mali_c55::algorithms {
+
+class BlackLevelCorrection : public Algorithm
+{
+public:
+	BlackLevelCorrection();
+	~BlackLevelCorrection() = default;
+
+	int init(IPAContext &context, const YamlObject &tuningData) override;
+	void prepare(IPAContext &context, const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     mali_c55_params_block_header *block) override;
+	void process(IPAContext &context, const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const mali_c55_stats_buffer *stats,
+		     ControlList &metadata) override;
+
+private:
+	static constexpr uint32_t kMaxOffset = 0xfffff;
+
+	bool tuningParameters_;
+	uint32_t offset00;
+	uint32_t offset01;
+	uint32_t offset10;
+	uint32_t offset11;
+};
+
+} /* namespace ipa::mali_c55::algorithms */
+} /* namespace libcamera */
diff --git a/src/ipa/mali-c55/algorithms/meson.build b/src/ipa/mali-c55/algorithms/meson.build
index f2203b15..d84432b9 100644
--- a/src/ipa/mali-c55/algorithms/meson.build
+++ b/src/ipa/mali-c55/algorithms/meson.build
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: CC0-1.0
 
 mali_c55_ipa_algorithms = files([
+    'blc.cpp',
 ])
-- 
2.30.2