lc-compliance: Add a libcamera compliance tool

Add a compliance tool to ease testing of cameras. In contrast to the
unit-tests under test/ that aims to test the internal components of
libcamera the compliance tool aims to test application use-cases and to
some extent the public API.

This change adds the boilerplate code of a simple framework for the
creation of tests. The tests aim both to demonstrate the tool and to
catch real problems. The tests added are:

 - Test that if one queues exactly N requests to a camera exactly N
   requests are eventually completed.

 - Test that a configured camera can be started and stopped multiple
   times in an attempt to exercise cleanup code paths otherwise not
   often tested with 'cam' for example.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>

src/lc-compliance/main.cpp

@@ -0,0 +1,148 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * main.cpp - lc-compliance - The libcamera compliance tool
+ */
+
+#include <iomanip>
+#include <iostream>
+#include <string.h>
+
+#include <libcamera/libcamera.h>
+
+#include "../cam/options.h"
+#include "tests.h"
+
+using namespace libcamera;
+
+enum {
+	OptCamera = 'c',
+	OptHelp = 'h',
+};
+
+class Harness
+{
+public:
+	Harness(const OptionsParser::Options &options);
+	~Harness();
+
+	int exec();
+
+private:
+	int init();
+	void listCameras();
+
+	OptionsParser::Options options_;
+	std::unique_ptr<CameraManager> cm_;
+	std::shared_ptr<Camera> camera_;
+};
+
+Harness::Harness(const OptionsParser::Options &options)
+	: options_(options)
+{
+	cm_ = std::make_unique<CameraManager>();
+}
+
+Harness::~Harness()
+{
+	if (camera_) {
+		camera_->release();
+		camera_.reset();
+	}
+
+	cm_->stop();
+}
+
+int Harness::exec()
+{
+	int ret = init();
+	if (ret)
+		return ret;
+
+	std::vector<Results> results;
+
+	results.push_back(testSingleStream(camera_));
+
+	for (const Results &result : results) {
+		ret = result.summary();
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+int Harness::init()
+{
+	int ret = cm_->start();
+	if (ret) {
+		std::cout << "Failed to start camera manager: "
+			  << strerror(-ret) << std::endl;
+		return ret;
+	}
+
+	if (!options_.isSet(OptCamera)) {
+		std::cout << "No camera specified, available cameras:" << std::endl;
+		listCameras();
+		return -ENODEV;
+	}
+
+	const std::string &cameraId = options_[OptCamera];
+	camera_ = cm_->get(cameraId);
+	if (!camera_) {
+		std::cout << "Camera " << cameraId << " not found, available cameras:" << std::endl;
+		listCameras();
+		return -ENODEV;
+	}
+
+	if (camera_->acquire()) {
+		std::cout << "Failed to acquire camera" << std::endl;
+		return -EINVAL;
+	}
+
+	std::cout << "Using camera " << cameraId << std::endl;
+
+	return 0;
+}
+
+void Harness::listCameras()
+{
+	for (const std::shared_ptr<Camera> &cam : cm_->cameras())
+		std::cout << "- " << cam.get()->id() << std::endl;
+}
+
+static int parseOptions(int argc, char **argv, OptionsParser::Options *options)
+{
+	OptionsParser parser;
+	parser.addOption(OptCamera, OptionString,
+			 "Specify which camera to operate on, by id", "camera",
+			 ArgumentRequired, "camera");
+	parser.addOption(OptHelp, OptionNone, "Display this help message",
+			 "help");
+
+	*options = parser.parse(argc, argv);
+	if (!options->valid())
+		return -EINVAL;
+
+	if (options->isSet(OptHelp)) {
+		parser.usage();
+		return -EINTR;
+	}
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	OptionsParser::Options options;
+	int ret = parseOptions(argc, argv, &options);
+	if (ret == -EINTR)
+		return EXIT_SUCCESS;
+	if (ret < 0)
+		return EXIT_FAILURE;
+
+	Harness harness(options);
+
+	return harness.exec() ? EXIT_FAILURE : EXIT_SUCCESS;
+}