[PATCH v2 7/7] of: Add KUnit test to confirm DTB is loaded

From: Stephen Boyd <sboyd@kernel.org>
To: Rob Herring <robh+dt@kernel.org>
Cc: linux-kernel@vger.kernel.org, patches@lists.linux.dev,
	linux-um@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org, kunit-dev@googlegroups.com,
	linux-kselftest@vger.kernel.org, devicetree@vger.kernel.org,
	Frank Rowand <frowand.list@gmail.com>,
	David Gow <davidgow@google.com>,
	Brendan Higgins <brendan.higgins@linux.dev>
Subject: [PATCH v2 7/7] of: Add KUnit test to confirm DTB is loaded
Date: Mon, 29 Jan 2024 16:45:06 -0800	[thread overview]
Message-ID: <20240130004508.1700335-8-sboyd@kernel.org> (raw)
In-Reply-To: <20240130004508.1700335-1-sboyd@kernel.org>

Add a KUnit test that confirms a DTB has been loaded, i.e. there is a
root node, and that the of_have_populated_dt() API works properly.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: David Gow <davidgow@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
---
 drivers/of/.kunitconfig |  3 +++
 drivers/of/Kconfig      |  9 ++++++++
 drivers/of/Makefile     |  2 ++
 drivers/of/of_test.c    | 48 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+)
 create mode 100644 drivers/of/.kunitconfig
 create mode 100644 drivers/of/of_test.c

diff --git a/drivers/of/.kunitconfig b/drivers/of/.kunitconfig
new file mode 100644
index 000000000000..5a8fee11978c
--- /dev/null
+++ b/drivers/of/.kunitconfig
@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_OF=y
+CONFIG_OF_KUNIT_TEST=y
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 17733285b415..53d1b5dd89e8 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -37,6 +37,15 @@ config OF_UNITTEST
 
 	  If unsure, say N here. This option is not safe to enable.
 
+config OF_KUNIT_TEST
+	tristate "Devicetree KUnit Test" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This option builds KUnit unit tests for device tree infrastructure.
+
+	  If unsure, say N here, but this option is safe to enable.
+
 config OF_ALL_DTBS
 	bool "Build all Device Tree Blobs"
 	depends on COMPILE_TEST
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index df305348d1cb..251d33532148 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -19,4 +19,6 @@ obj-y	+= kexec.o
 endif
 endif
 
+obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
+
 obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/of_test.c b/drivers/of/of_test.c
new file mode 100644
index 000000000000..71a767b42b43
--- /dev/null
+++ b/drivers/of/of_test.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for OF APIs
+ */
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <kunit/test.h>
+
+/*
+ * Test that the root node "/" can be found by path.
+ */
+static void dtb_root_node_found_by_path(struct kunit *test)
+{
+	struct device_node *np;
+
+	np = of_find_node_by_path("/");
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+	of_node_put(np);
+}
+
+/*
+ * Test that the 'of_root' global variable is always populated when DT code is
+ * enabled.
+ */
+static void dtb_root_node_populates_of_root(struct kunit *test)
+{
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, of_root);
+}
+
+static struct kunit_case dtb_test_cases[] = {
+	KUNIT_CASE(dtb_root_node_found_by_path),
+	KUNIT_CASE(dtb_root_node_populates_of_root),
+	{}
+};
+
+/*
+ * Test suite to confirm a DTB is loaded.
+ */
+static struct kunit_suite dtb_suite = {
+	.name = "dtb",
+	.test_cases = dtb_test_cases,
+};
+
+kunit_test_suites(
+	&dtb_suite,
+);
+MODULE_LICENSE("GPL");
-- 
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git

