[PATCH v2 5/5] tests: of_overlay: add fragment application tests

[Stefan Kerkmann <s.kerkmann@pengutronix.de>]

These tests exercise the application of the overlay fragments by
of_overlay_apply_fragment() with the following test cases:

1. Fragment target is found by target-path and phandle
2. Fragment properties are merged into existing nodes
3. Fragment children without an __overlay__ node are skipped
4. Error path for a fragment whose target does not exist

Signed-off-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>
---
 test/self/Makefile                       |  1 +
 test/self/of_overlay.c                   | 68 ++++++++++++++++++++++++++++++++
 test/self/of_overlay.dtso                | 34 ++++++++++++++++
 test/self/of_overlay_missing_target.dtso | 24 +++++++++++
 4 files changed, 127 insertions(+)

diff --git a/test/self/Makefile b/test/self/Makefile
index f6cec81011..0fba7ac566 100644
--- a/test/self/Makefile
+++ b/test/self/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_SELFTEST_OF_OVERLAY) += of_overlay.o
 # Enforce generation of __symbols__ table for overlay tests
 DTC_FLAGS_of_overlay_with_symbols := -@
 obj-$(CONFIG_SELFTEST_OF_OVERLAY) += of_overlay_with_symbols.dtb.o of_overlay_with_symbols.dtbo.o
+obj-$(CONFIG_SELFTEST_OF_OVERLAY) += of_overlay.dtbo.o of_overlay_missing_target.dtbo.o
 obj-$(CONFIG_SELFTEST_ENVIRONMENT_VARIABLES) += envvar.o
 obj-$(CONFIG_SELFTEST_FS_RAMFS) += ramfs.o
 obj-$(CONFIG_SELFTEST_DIRFD) += dirfd.o
diff --git a/test/self/of_overlay.c b/test/self/of_overlay.c
index 2804c936c0..4c17cae16d 100644
--- a/test/self/of_overlay.c
+++ b/test/self/of_overlay.c
@@ -98,9 +98,77 @@ static void test_of_overlay_symbol_outside_overlay(void)
 	of_delete_node(root);
 }
 
+extern char __dtbo_of_overlay_start[], __dtbo_of_overlay_end[];
+
+static void test_of_overlay_fragments(void)
+{
+	struct device_node *root, *overlay, *node;
+	int ret;
+
+	if (!test_setup(&root, &overlay, __dtb_of_overlay_with_symbols_start,
+			__dtb_of_overlay_with_symbols_end,
+			__dtbo_of_overlay_start, __dtbo_of_overlay_end))
+		return;
+
+	ret = of_overlay_apply_tree(root, overlay);
+	assert_inteq(ret, 0);
+
+	node = of_find_node_by_path_from(root, "/target-node");
+	assert_cond(node != NULL);
+	assert_inteq(of_property_match_string(node, "new-prop", "target-path"),
+		     0);
+	assert_cond(of_get_child_by_name(node, "added-child") != NULL);
+
+	node = of_find_node_by_path_from(root, "/target-node/existing-child");
+	assert_cond(node != NULL);
+	assert_inteq(of_property_match_string(node, "old-prop", "old"), 0);
+	assert_inteq(of_property_match_string(node, "new-prop", "merged"), 0);
+
+	node = of_find_node_by_path_from(root, "/phandle-target-node");
+	assert_cond(node != NULL);
+	assert_inteq(of_property_match_string(node, "new-prop",
+					      "target-phandle"),
+		     0);
+
+	node = of_find_node_by_path_from(root, "/non-fragment-node");
+	assert_cond(node == NULL);
+
+	of_delete_node(overlay);
+	of_delete_node(root);
+}
+
+extern char __dtbo_of_overlay_missing_target_start[],
+	__dtbo_of_overlay_missing_target_end[];
+
+static void test_of_overlay_missing_target(void)
+{
+	struct device_node *root, *overlay, *node;
+	int ret;
+
+	if (!test_setup(&root, &overlay, __dtb_of_overlay_with_symbols_start,
+			__dtb_of_overlay_with_symbols_end,
+			__dtbo_of_overlay_missing_target_start,
+			__dtbo_of_overlay_missing_target_end))
+		return;
+
+	ret = of_overlay_apply_tree(root, overlay);
+	assert_inteq(ret, -ENOENT);
+
+	node = of_find_node_by_path_from(root, "/does-not-exist");
+	assert_cond(node == NULL);
+
+	node = of_find_node_by_path_from(root, "/target-node/applied-anyway");
+	assert_cond(node != NULL);
+
+	of_delete_node(overlay);
+	of_delete_node(root);
+}
+
 static void test_of_overlay(void)
 {
 	test_of_overlay_symbol_without_overlay();
 	test_of_overlay_symbol_outside_overlay();
+	test_of_overlay_fragments();
+	test_of_overlay_missing_target();
 }
 bselftest(core, test_of_overlay);
diff --git a/test/self/of_overlay.dtso b/test/self/of_overlay.dtso
new file mode 100644
index 0000000000..21dc85a8e4
--- /dev/null
+++ b/test/self/of_overlay.dtso
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/dts-v1/;
+/plugin/;
+
+/ {
+	/* not a fragment, must not be applied */
+	non-fragment-node {
+	};
+
+	fragment@0 {
+		target-path = "/target-node";
+
+		__overlay__ {
+			new-prop = "target-path";
+
+			added-child {
+				child-prop;
+			};
+
+			existing-child {
+				new-prop = "merged";
+			};
+		};
+	};
+
+	fragment@1 {
+		target = <&phandle_target>;
+
+		__overlay__ {
+			new-prop = "target-phandle";
+		};
+	};
+};
diff --git a/test/self/of_overlay_missing_target.dtso b/test/self/of_overlay_missing_target.dtso
new file mode 100644
index 0000000000..39362b0a0e
--- /dev/null
+++ b/test/self/of_overlay_missing_target.dtso
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/dts-v1/;
+/plugin/;
+
+/ {
+	fragment@0 {
+		target-path = "/does-not-exist";
+
+		__overlay__ {
+			never-applied {
+			};
+		};
+	};
+
+	fragment@1 {
+		target-path = "/target-node";
+
+		__overlay__ {
+			applied-anyway {
+			};
+		};
+	};
+};

-- 
2.47.3