sandbox: Add a test for IRQ

Add a simple sandbox test for this uclass.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/test/dm/irq.c b/test/dm/irq.c
new file mode 100644
index 0000000..726189c
--- /dev/null
+++ b/test/dm/irq.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test for irq uclass
+ *
+ * Copyright 2019 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <irq.h>
+#include <dm/test.h>
+#include <test/ut.h>
+
+/* Base test of the irq uclass */
+static int dm_test_irq_base(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_first_device_err(UCLASS_IRQ, &dev));
+
+	ut_asserteq(5, irq_route_pmc_gpio_gpe(dev, 4));
+	ut_asserteq(-ENOENT, irq_route_pmc_gpio_gpe(dev, 14));
+
+	ut_assertok(irq_set_polarity(dev, 4, true));
+	ut_asserteq(-EINVAL, irq_set_polarity(dev, 14, true));
+
+	ut_assertok(irq_snapshot_polarities(dev));
+	ut_assertok(irq_restore_polarities(dev));
+
+	return 0;
+}
+DM_TEST(dm_test_irq_base, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);