of/unittest: Overlays with sub-devices tests

Introduce selftests for overlays using sub-devices present
in children nodes.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
diff --git a/drivers/of/unittest-data/tests-overlay.dtsi b/drivers/of/unittest-data/tests-overlay.dtsi
index 75976da..a2b687d 100644
--- a/drivers/of/unittest-data/tests-overlay.dtsi
+++ b/drivers/of/unittest-data/tests-overlay.dtsi
@@ -176,5 +176,60 @@
 			};
 		};
 
+		overlay10 {
+			fragment@0 {
+				target-path = "/testcase-data/overlay-node/test-bus";
+				__overlay__ {
+
+					/* suppress DTC warning */
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					test-selftest10 {
+						compatible = "selftest";
+						status = "okay";
+						reg = <10>;
+
+						#address-cells = <1>;
+						#size-cells = <0>;
+
+						test-selftest101 {
+							compatible = "selftest";
+							status = "okay";
+							reg = <1>;
+						};
+
+					};
+				};
+			};
+		};
+
+		overlay11 {
+			fragment@0 {
+				target-path = "/testcase-data/overlay-node/test-bus";
+				__overlay__ {
+
+					/* suppress DTC warning */
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					test-selftest11 {
+						compatible = "selftest";
+						status = "okay";
+						reg = <11>;
+
+						#address-cells = <1>;
+						#size-cells = <0>;
+
+						test-selftest111 {
+							compatible = "selftest";
+							status = "okay";
+							reg = <1>;
+						};
+
+					};
+				};
+			};
+		};
 	};
 };
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 844838e..41a4a13 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -978,6 +978,9 @@
 	}
 
 	dev_dbg(dev, "%s for node @%s\n", __func__, np->full_name);
+
+	of_platform_populate(np, NULL, NULL, &pdev->dev);
+
 	return 0;
 }
 
@@ -1385,6 +1388,39 @@
 	selftest(1, "overlay test %d passed\n", 8);
 }
 
+/* test insertion of a bus with parent devices */
+static void of_selftest_overlay_10(void)
+{
+	int ret;
+	char *child_path;
+
+	/* device should disable */
+	ret = of_selftest_apply_overlay_check(10, 10, 0, 1);
+	if (selftest(ret == 0, "overlay test %d failed; overlay application\n", 10))
+		return;
+
+	child_path = kasprintf(GFP_KERNEL, "%s/test-selftest101",
+			selftest_path(10));
+	if (selftest(child_path, "overlay test %d failed; kasprintf\n", 10))
+		return;
+
+	ret = of_path_platform_device_exists(child_path);
+	kfree(child_path);
+	if (selftest(ret, "overlay test %d failed; no child device\n", 10))
+		return;
+}
+
+/* test insertion of a bus with parent devices (and revert) */
+static void of_selftest_overlay_11(void)
+{
+	int ret;
+
+	/* device should disable */
+	ret = of_selftest_apply_revert_overlay_check(11, 11, 0, 1);
+	if (selftest(ret == 0, "overlay test %d failed; overlay application\n", 11))
+		return;
+}
+
 static void __init of_selftest_overlay(void)
 {
 	struct device_node *bus_np = NULL;
@@ -1433,6 +1469,9 @@
 	of_selftest_overlay_6();
 	of_selftest_overlay_8();
 
+	of_selftest_overlay_10();
+	of_selftest_overlay_11();
+
 out:
 	of_node_put(bus_np);
 }