Preserve datatype markers when emitting dts format

If datatype markers are present in the property value, use them to
output the data in the correct format instead of trying to guess the
datatype. This also will preserve data grouping, such as in an
interrupts list.

This is a step forward for preserving and using datatype information
when processing DTS/DTB files. Schema validation tools can use the
datatype information to make sure a DT is correctly formed and
intepreted.

Signed-off-by: Grant Likely <grant.likely@arm.com>
[robh: rework marker handling and fix label output]
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

tests/run_tests.sh

@@ -551,6 +551,13 @@ dtc_tests () {
 	run_test dtbs_equal_ordered $tree odts_$tree.test.dtb
     done
 
+    # Check -Odts preserving type information
+    for tree in type-preservation.dts; do
+        run_dtc_test -I dts -O dts -o $tree.test.dts $tree
+        run_dtc_test -I dts -O dts $tree.test.dts
+        run_wrap_test cmp $tree $tree.test.dts
+    done
+
     # Check version conversions
     for tree in test_tree1.dtb ; do
 	 for aver in 1 2 3 16 17; do

tests/type-preservation.dts

@@ -0,0 +1,28 @@
+/dts-v1/;
+
+/ {
+	#address-cells = < 0x01 >;
+	#size-cells = < 0x00 >;
+
+	sub1: subnode@1 {
+		prop_label: compatible = value_label: "subnode1";
+		reg = < 0x01 >;
+		int-array = < 0x00 0x01 >, int_value_label: < 0x02 0x03 >;
+		int8 = [ 56 ];
+		int8-array = [ 00 12 34 56 label: ];
+		int16 = /bits/ 16 < 0x3210 >;
+		int16-array = /bits/ 16 < 0x1234 0x5678 0x90ab 0xcdef >;
+		int16-matrix = /bits/ 16 < 0x1234 0x5678 >, < 0x90ab 0xcdef >;
+		int64 = /bits/ 64 < 0x200000000 >;
+		int64-array = /bits/ 64 < 0x100000000 0x00 int64_array_label_end: >;
+		a-string-with-nulls = "foo\0bar", "baz";
+
+		subsub1: subsubnode {
+			compatible = "subsubnode1", "subsubnode";
+
+			subsubsub1: subsubsubnode {
+				compatible = "subsubsubnode1", < 0x1234 >, valuea: valueb: "subsubsubnode";
+			};
+		};
+	};
+};