event: Add a simple test

Add a test for event registration and activation.

Signed-off-by: Simon Glass <sjg@chromium.org>

test/common/Makefile

@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0+
 obj-y += cmd_ut_common.o
 obj-$(CONFIG_AUTOBOOT) += test_autoboot.o
+obj-$(CONFIG_EVENT) += event.o

test/common/event.c

@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Unit tests for event handling
+ *
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <event.h>
+#include <test/common.h>
+#include <test/test.h>
+#include <test/ut.h>
+
+struct test_state {
+	struct udevice *dev;
+	int val;
+};
+
+static int h_adder(void *ctx, struct event *event)
+{
+	struct event_data_test *data = &event->data.test;
+	struct test_state *test_state = ctx;
+
+	test_state->val += data->signal;
+
+	return 0;
+}
+
+static int test_event_base(struct unit_test_state *uts)
+{
+	struct test_state state;
+	int signal;
+
+	state.val = 12;
+	ut_assertok(event_register("wibble", EVT_TEST, h_adder, &state));
+
+	signal = 17;
+
+	/* Check that the handler is called */
+	ut_assertok(event_notify(EVT_TEST, &signal, sizeof(signal)));
+	ut_asserteq(12 + 17, state.val);
+
+	return 0;
+}
+COMMON_TEST(test_event_base, 0);