test: Add media device test

Add media device test infrastructure and an intial test that
print out the media devices available in the system.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

test/media_device/media_device_test.cpp

@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2018, Google Inc.
+ *
+ * media_device_test.cpp - Tests for the media device class.
+ *
+ * Test library for the media device class.
+ */
+#include <iostream>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "media_device.h"
+
+#include "test.h"
+
+using namespace libcamera;
+using namespace std;
+
+/*
+ * MediaDeviceTest object: runs a sequence of tests on all media
+ * devices found in the system.
+ *
+ * If no accessible media device is found, the test is skipped.
+ */
+class MediaDeviceTest : public Test
+{
+public:
+	MediaDeviceTest() { }
+	~MediaDeviceTest() { }
+
+protected:
+	int init() { return 0; }
+	int run();
+	void cleanup() { }
+
+private:
+	int testMediaDevice(string devnode);
+
+	void printMediaGraph(const MediaDevice &media, ostream &os);
+	void printLinkFlags(const MediaLink *link, ostream &os);
+	void printNode(const MediaPad *pad, ostream &os);
+};
+
+void MediaDeviceTest::printNode(const MediaPad *pad, ostream &os)
+{
+	const MediaEntity *entity = pad->entity();
+
+	os << "\"" << entity->name() << "\"["
+	   << pad->index() << "]";
+}
+
+void MediaDeviceTest::printLinkFlags(const MediaLink *link, ostream &os)
+{
+	unsigned int flags = link->flags();
+
+	os << " [";
+	if (flags) {
+		os << (flags & MEDIA_LNK_FL_ENABLED ? "ENABLED," : "")
+		   << (flags & MEDIA_LNK_FL_IMMUTABLE ? "IMMUTABLE" : "");
+	}
+	os  << "]\n";
+}
+
+/*
+ * For each entity in the media graph, printout links directed to its sinks
+ * and source pads.
+ */
+void MediaDeviceTest::printMediaGraph(const MediaDevice &media, ostream &os)
+{
+	os << "\n" << media.driver() << " - " << media.devnode() << "\n\n";
+
+	for (auto const &entity : media.entities()) {
+		os << "\"" << entity->name() << "\"\n";
+
+		for (auto const &sink : entity->pads()) {
+			if (!(sink->flags() & MEDIA_PAD_FL_SINK))
+				continue;
+
+			os << "  [" << sink->index() << "]" << ": Sink\n";
+			for (auto const &link : sink->links()) {
+				os << "\t";
+				printNode(sink, os);
+				os << " <- ";
+				printNode(link->source(), os);
+				printLinkFlags(link, os);
+			}
+			os << "\n";
+		}
+
+		for (auto const &source : entity->pads()) {
+			if (!(source->flags() & MEDIA_PAD_FL_SOURCE))
+				continue;
+
+			os << "  [" << source->index() << "]" << ": Source\n";
+			for (auto const &link : source->links()) {
+				os << "\t";
+				printNode(source, os);
+				os << " -> ";
+				printNode(link->sink(), os);
+				printLinkFlags(link, os);
+			}
+			os << "\n";
+		}
+	}
+
+	os.flush();
+}
+
+/* Test a single media device. */
+int MediaDeviceTest::testMediaDevice(const string devnode)
+{
+	MediaDevice dev(devnode);
+	int ret;
+
+	/* Fuzzy open/close sequence. */
+	ret = dev.open();
+	if (ret)
+		return ret;
+
+	ret = dev.open();
+	if (!ret)
+		return ret;
+
+	dev.close();
+
+	ret = dev.open();
+	if (ret)
+		return ret;
+
+	ret = dev.populate();
+	if (ret)
+		return ret;
+
+	/* Run tests in sequence. */
+	printMediaGraph(dev, cerr);
+	/* TODO: add more tests here. */
+
+	dev.close();
+
+	return 0;
+}
+
+/* Run tests on all media devices. */
+#define MAX_MEDIA_DEV 256
+int MediaDeviceTest::run()
+{
+	const string devnode("/dev/media");
+	unsigned int i;
+	int ret = 77; /* skip test exit code */
+
+	/*
+	 * Run the test sequence on all media device found in the
+	 * system, if any.
+	 */
+	for (i = 0; i < MAX_MEDIA_DEV; i++) {
+		string mediadev = devnode + to_string(i);
+		struct stat pstat = { };
+
+		if (stat(mediadev.c_str(), &pstat))
+			continue;
+
+		ret = testMediaDevice(mediadev);
+		if (ret)
+			return ret;
+
+	}
+
+	return ret;
+}
+
+TEST_REGISTER(MediaDeviceTest);

test/media_device/meson.build

@@ -0,0 +1,5 @@
+
+media_device_test = executable('media_device_test', 'media_device_test.cpp',
+                       link_with : [libcamera, libtest],
+                       include_directories : [libcamera_internal_includes,
+					      libtest_includes],)

test/meson.build

@@ -3,6 +3,7 @@ libtest_sources = files([
 ])
 
 libtest = static_library('libtest', libtest_sources)
+libtest_includes = include_directories('./')
 
 test_init = executable('test_init', 'init.cpp',
                        link_with : libcamera,
@@ -12,5 +13,8 @@ list = executable('list', 'list.cpp',
                     link_with : [libcamera, libtest],
                     include_directories : libcamera_includes)
 
+subdir('media_device')
+
 test('Initialisation test', test_init)
 test('List Camera API tests', list)
+test('Media Device Test', media_device_test)