pipeline: ipa: raspberrypi: Refactor and move the Raspberry Pi code

Split the Raspberry Pi pipeline handler and IPA source code into common
and VC4/BCM2835 specific file structures.

For the pipeline handler, the common code files now live in
src/libcamera/pipeline/rpi/common/
and the VC4-specific files in src/libcamera/pipeline/rpi/vc4/.

For the IPA, the common code files now live in
src/ipa/rpi/{cam_helper,controller}/
and the vc4 specific files in src/ipa/rpi/vc4/. With this change, the
camera tuning files are now installed under share/libcamera/ipa/rpi/vc4/.

To build the pipeline and IPA, the meson configuration options have now
changed from "raspberrypi" to "rpi/vc4":

meson setup build -Dipas=rpi/vc4 -Dpipelines=rpi/vc4

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/ipa/rpi/controller/algorithm.cpp

@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * algorithm.cpp - ISP control algorithms
+ */
+
+#include "algorithm.h"
+
+using namespace RPiController;
+
+int Algorithm::read([[maybe_unused]] const libcamera::YamlObject &params)
+{
+	return 0;
+}
+
+void Algorithm::initialise()
+{
+}
+
+void Algorithm::switchMode([[maybe_unused]] CameraMode const &cameraMode,
+			   [[maybe_unused]] Metadata *metadata)
+{
+}
+
+void Algorithm::prepare([[maybe_unused]] Metadata *imageMetadata)
+{
+}
+
+void Algorithm::process([[maybe_unused]] StatisticsPtr &stats,
+			[[maybe_unused]] Metadata *imageMetadata)
+{
+}
+
+/* For registering algorithms with the system: */
+
+namespace {
+
+std::map<std::string, AlgoCreateFunc> &algorithms()
+{
+	static std::map<std::string, AlgoCreateFunc> algorithms;
+	return algorithms;
+}
+
+} /* namespace */
+
+std::map<std::string, AlgoCreateFunc> const &RPiController::getAlgorithms()
+{
+	return algorithms();
+}
+
+RegisterAlgorithm::RegisterAlgorithm(char const *name,
+				     AlgoCreateFunc createFunc)
+{
+	algorithms()[std::string(name)] = createFunc;
+}