add docstring, missing return module

diff --git a/src/soc/alu/rotator.py b/src/soc/alu/rotator.py
index a763021a73485097579d98c31c701422ecc1c62e..05b6b19b908d8a8002229d30dc86ad7e91ec2e00 100644 (file)
--- a/src/soc/alu/rotator.py
+++ b/src/soc/alu/rotator.py
@@ -1,3 +1,6 @@
+# Manual translation and adaptation of rotator.vhdl from microwatt into nmigen
+#
+
 from soc.alu.rotl import ROTL
 
 #note BE bit numbering
@@ -130,3 +133,4 @@ class Rotator(Elaboratable):
         with m.If(output_mode = 0b11):
             comb += carry_out.eq(rs & ~ml)
 
+        return m