pipeline: rkisp1: Enable the dewarper based on the tuning file

To do actual lens dewarping, the dewarper will be configured based on
the tuning file.

As a first step implement the basic loading of the
tuning file and enable/disable the dewarper for the given camera based
on the existence of the "Dewarp" entry under a new top level element
'modules' in the tuning file.

Note: This is an backwards incompatible change in that the dewarper is
currently included in the chain unconditionally. Some users may want to
not use the dewarper, so it is sensible to make that configurable.

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>

src/libcamera/pipeline/rkisp1/rkisp1.cpp

@@ -16,6 +16,7 @@
 #include <linux/media-bus-format.h>
 #include <linux/rkisp1-config.h>
 
+#include <libcamera/base/file.h>
 #include <libcamera/base/log.h>
 #include <libcamera/base/utils.h>
 
@@ -46,6 +47,7 @@
 #include "libcamera/internal/pipeline_handler.h"
 #include "libcamera/internal/v4l2_subdevice.h"
 #include "libcamera/internal/v4l2_videodevice.h"
+#include "libcamera/internal/yaml_parser.h"
 
 #include "rkisp1_path.h"
 
@@ -94,7 +96,8 @@ public:
 	RkISP1CameraData(PipelineHandler *pipe, RkISP1MainPath *mainPath,
 			 RkISP1SelfPath *selfPath)
 		: Camera::Private(pipe), frame_(0), frameInfo_(pipe),
-		  mainPath_(mainPath), selfPath_(selfPath)
+		  mainPath_(mainPath), selfPath_(selfPath),
+		  canUseDewarper_(false), usesDewarper_(false)
 	{
 	}
 
@@ -122,6 +125,7 @@ public:
 	 */
 	MediaPipeline pipe_;
 
+	bool canUseDewarper_;
 	bool usesDewarper_;
 
 private:
@@ -130,6 +134,7 @@ private:
 			       const ControlList &sensorControls);
 
 	void metadataReady(unsigned int frame, const ControlList &metadata);
+	int loadTuningFile(const std::string &file);
 };
 
 class RkISP1CameraConfiguration : public CameraConfiguration
@@ -411,6 +416,49 @@ int RkISP1CameraData::loadIPA(unsigned int hwRevision, uint32_t supportedBlocks)
 		return ret;
 	}
 
+	ret = loadTuningFile(ipaTuningFile);
+	if (ret < 0) {
+		LOG(RkISP1, Error) << "Failed to load tuning file";
+		return ret;
+	}
+
+	return 0;
+}
+
+int RkISP1CameraData::loadTuningFile(const std::string &path)
+{
+	int ret;
+
+	if (!pipe()->dewarper_)
+		/* Nothing to do without dewarper */
+		return 0;
+
+	LOG(RkISP1, Debug) << "Load tuning file " << path;
+
+	File file(path);
+	if (!file.open(File::OpenModeFlag::ReadOnly)) {
+		ret = file.error();
+		LOG(RkISP1, Error)
+			<< "Failed to open tuning file "
+			<< path << ": " << strerror(-ret);
+		return ret;
+	}
+
+	std::unique_ptr<libcamera::YamlObject> data = YamlParser::parse(file);
+	if (!data)
+		return -EINVAL;
+
+	if (!data->contains("modules"))
+		return 0;
+
+	const auto &modules = (*data)["modules"].asList();
+	for (const auto &module : modules) {
+		if (module.contains("Dewarp")) {
+			canUseDewarper_ = true;
+			break;
+		}
+	}
+
 	return 0;
 }
 
@@ -574,7 +622,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
 		}
 	}
 
-	bool useDewarper = (pipe->dewarper_ && !isRaw);
+	bool useDewarper = (data_->canUseDewarper_ && !isRaw);
 
 	/*
 	 * If there are more than one stream in the configuration figure out the