dm: core: Add a way to copy a node

Add a function to copy a node to another place under a new name. This is
useful at least for testing, since copying a test node with existing
properties is easier than writing the code to generate it all afresh.

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

drivers/core/ofnode.c

@@ -1802,3 +1802,23 @@ int ofnode_copy_props(ofnode dst, ofnode src)
 
 	return 0;
 }
+
+int ofnode_copy_node(ofnode dst_parent, const char *name, ofnode src,
+		     ofnode *nodep)
+{
+	ofnode node;
+	int ret;
+
+	ret = ofnode_add_subnode(dst_parent, name, &node);
+	if (ret) {
+		if (ret == -EEXIST)
+			*nodep = node;
+		return log_msg_ret("add", ret);
+	}
+	ret = ofnode_copy_props(node, src);
+	if (ret)
+		return log_msg_ret("cpy", ret);
+	*nodep = node;
+
+	return 0;
+}

include/dm/ofnode.h

@@ -1620,4 +1620,19 @@ int ofnode_add_subnode(ofnode parent, const char *name, ofnode *nodep);
  */
 int ofnode_copy_props(ofnode dst, ofnode src);
 
+/**
+ * ofnode_copy_node() - Copy a node to another place
+ *
+ * If a node with this name already exists in dst_parent, this returns an
+ * .error
+ *
+ * @dst_parent: Parent of the newly copied node
+ * @name: Name to give the new node
+ * @src: Source node to copy
+ * @nodep: Returns the new node, or the existing node if there is one
+ * Return: 0 if OK, -EEXIST if dst_parent already has a node with this parent
+ */
+int ofnode_copy_node(ofnode dst_parent, const char *name, ofnode src,
+		     ofnode *nodep);
+
 #endif

test/dm/ofnode.c

@@ -1362,3 +1362,66 @@ static int dm_test_oftree_new(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_oftree_new, UT_TESTF_SCAN_FDT);
+
+static int check_copy_node(struct unit_test_state *uts, ofnode dst, ofnode src,
+			   ofnode *nodep)
+{
+	u32 reg[2], val;
+	ofnode node;
+
+	ut_assertok(ofnode_copy_node(dst, "copy-test", src, &node));
+
+	ut_assertok(ofnode_read_u32(node, "ping-expect", &val));
+	ut_asserteq(3, val);
+
+	ut_asserteq_str("denx,u-boot-fdt-test",
+			ofnode_read_string(node, "compatible"));
+
+	/* check that a property with the same name is overwritten */
+	ut_assertok(ofnode_read_u32_array(node, "reg", reg, ARRAY_SIZE(reg)));
+	ut_asserteq(3, reg[0]);
+	ut_asserteq(1, reg[1]);
+
+	/* reset the compatible so the live tree does not change */
+	ut_assertok(ofnode_write_string(node, "compatible", "nothing"));
+	*nodep = node;
+
+	return 0;
+}
+
+static int dm_test_ofnode_copy_node(struct unit_test_state *uts)
+{
+	ofnode src, dst, node, try;
+
+	/*
+	 * These nodes are chosen so that the src node is before the destination
+	 * node in the tree. This doesn't matter with livetree, but with
+	 * flattree any attempt to insert a property earlier in the tree will
+	 * mess up the offsets after it.
+	 */
+	src = ofnode_path("/b-test");
+	dst = ofnode_path("/some-bus");
+
+	ut_assertok(check_copy_node(uts, dst, src, &node));
+
+	/* check trying to copy over an existing node */
+	ut_asserteq(-EEXIST, ofnode_copy_node(dst, "copy-test", src, &try));
+	ut_asserteq(try.of_offset, node.of_offset);
+
+	return 0;
+}
+DM_TEST(dm_test_ofnode_copy_node, UT_TESTF_SCAN_FDT);
+
+/* test ofnode_copy_node() with the 'other' tree */
+static int dm_test_ofnode_copy_node_ot(struct unit_test_state *uts)
+{
+	oftree otree = get_other_oftree(uts);
+	ofnode src, dst, node;
+
+	src = ofnode_path("/b-test");
+	dst = oftree_path(otree, "/node/subnode2");
+	ut_assertok(check_copy_node(uts, dst, src, &node));
+
+	return 0;
+}
+DM_TEST(dm_test_ofnode_copy_node_ot, UT_TESTF_SCAN_FDT | UT_TESTF_OTHER_FDT);