diff --git a/src/amd/registers/canonicalize.py b/src/amd/registers/canonicalize.py
index 958f4389433..a1b7023a201 100644
--- a/src/amd/registers/canonicalize.py
+++ b/src/amd/registers/canonicalize.py
@@ -68,24 +68,25 @@ def deduce_missing_register_types(regdb):
                 regmap.type_ref = regtypename
 
 
-def main():
-    regdb_filename = sys.argv[1]
-    with open(regdb_filename, 'r') as filp:
-        regdb = RegisterDatabase.from_json(json.load(filp))
+def json_canonicalize(filp, chips = None):
+    regdb = RegisterDatabase.from_json(json.load(filp))
 
-    if len(sys.argv) > 2:
+    if chips is not None:
         for regmap in regdb.register_mappings():
             assert not hasattr(regmap, 'chips')
-            regmap.chips = [sys.argv[2]]
+            regmap.chips = [chips]
 
     deduplicate_enums(regdb)
     deduplicate_register_types(regdb)
     deduce_missing_register_types(regdb)
     regdb.garbage_collect()
 
-    print(regdb.encode_json_pretty())
+    return regdb.encode_json_pretty()
 
 
+def main():
+    print(json_canonicalize(open(sys.argv[1], 'r'), sys.argv[2]))
+
 if __name__ == '__main__':
     main()