Improve diode LEF files.

 * Add `USE` and `SHAPE` properties.
 * Remove `CORE` class.
 * Fix layer for power pins.

Fixes https://github.com/google/skywater-pdk/issues/141.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>
diff --git a/cells/diode/sky130_fd_sc_ms__diode_2.lef b/cells/diode/sky130_fd_sc_ms__diode_2.lef
new file mode 100644
index 0000000..a99c0c4
--- /dev/null
+++ b/cells/diode/sky130_fd_sc_ms__diode_2.lef
@@ -0,0 +1,83 @@
+# Copyright 2020 The SkyWater PDK Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+VERSION 5.7 ;
+  NOWIREEXTENSIONATPIN ON ;
+  DIVIDERCHAR "/" ;
+  BUSBITCHARS "[]" ;
+MACRO sky130_fd_sc_ms__diode_2
+  CLASS CORE ANTENNACELL ;
+  FOREIGN scs8ms_diode_2 ;
+  ORIGIN  0.000000  0.000000 ;
+  SIZE  0.960000 BY  3.330000 ;
+  SYMMETRY X Y ;
+  SITE unit ;
+  PIN DIODE
+    ANTENNADIFFAREA  0.641700 ;
+    ANTENNAGATEAREA  0.641700 ;
+    DIRECTION INPUT ;
+    USE SIGNAL ;
+    PORT
+      LAYER li1 ;
+        RECT 0.095000 0.265000 0.865000 3.065000 ;
+    END
+  END DIODE
+  PIN VGND
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
+    USE GROUND ;
+    PORT
+      LAYER met1 ;
+        RECT 0.000000 -0.245000 0.960000 0.245000 ;
+    END
+  END VGND
+  PIN VNB
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER pwell ;
+        RECT 0.000000 0.000000 0.960000 0.245000 ;
+    END
+  END VNB
+  PIN VPB
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER nwell ;
+        RECT -0.190000 1.660000 1.150000 3.520000 ;
+    END
+  END VPB
+  PIN VPWR
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
+    USE POWER ;
+    PORT
+      LAYER met1 ;
+        RECT 0.000000 3.085000 0.960000 3.575000 ;
+    END
+  END VPWR
+  OBS
+    LAYER li1 ;
+      RECT 0.000000 -0.085000 0.960000 0.085000 ;
+      RECT 0.000000  3.245000 0.960000 3.415000 ;
+    LAYER mcon ;
+      RECT 0.155000 -0.085000 0.325000 0.085000 ;
+      RECT 0.155000  3.245000 0.325000 3.415000 ;
+      RECT 0.635000 -0.085000 0.805000 0.085000 ;
+      RECT 0.635000  3.245000 0.805000 3.415000 ;
+  END
+END sky130_fd_sc_ms__diode_2
+END LIBRARY
diff --git a/cells/diode/sky130_fd_sc_ms__diode_2.magic.lef b/cells/diode/sky130_fd_sc_ms__diode_2.magic.lef
index e65eef4..43383a8 100644
--- a/cells/diode/sky130_fd_sc_ms__diode_2.magic.lef
+++ b/cells/diode/sky130_fd_sc_ms__diode_2.magic.lef
@@ -19,43 +19,50 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__diode_2
-  CLASS BLOCK ;
+  CLASS CORE ANTENNACELL ;
   FOREIGN sky130_fd_sc_ms__diode_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
+  SYMMETRY X Y ;
+  SITE unit ;
   PIN DIODE
     ANTENNADIFFAREA  0.641700 ;
     ANTENNAGATEAREA  0.641700 ;
     DIRECTION INPUT ;
+    USE SIGNAL ;
     PORT
       LAYER li1 ;
         RECT 0.095000 0.265000 0.865000 3.065000 ;
     END
   END DIODE
-  PIN VNB
-    DIRECTION INPUT ;
-    PORT
-      LAYER pwell ;
-        RECT 0.000000 0.000000 0.960000 0.245000 ;
-    END
-  END VNB
-  PIN VPB
-    DIRECTION INPUT ;
-    PORT
-      LAYER nwell ;
-        RECT -0.190000 1.660000 1.150000 3.520000 ;
-    END
-  END VPB
   PIN VGND
-    DIRECTION INPUT ;
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
     USE GROUND ;
     PORT
       LAYER met1 ;
         RECT 0.000000 -0.245000 0.960000 0.245000 ;
     END
   END VGND
+  PIN VNB
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER pwell ;
+        RECT 0.000000 0.000000 0.960000 0.245000 ;
+    END
+  END VNB
+  PIN VPB
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER nwell ;
+        RECT -0.190000 1.660000 1.150000 3.520000 ;
+    END
+  END VPB
   PIN VPWR
-    DIRECTION INPUT ;
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
     USE POWER ;
     PORT
       LAYER met1 ;
diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.lef
new file mode 100644
index 0000000..38cc2b4
--- /dev/null
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.lef
@@ -0,0 +1,75 @@
+# Copyright 2020 The SkyWater PDK Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+VERSION 5.7 ;
+  NOWIREEXTENSIONATPIN ON ;
+  DIVIDERCHAR "/" ;
+  BUSBITCHARS "[]" ;
+MACRO sky130_fd_sc_ms__fill_diode_2
+  CLASS SPACER ;
+  FOREIGN scs8ms_fill_diode_2 ;
+  ORIGIN  0.000000  0.000000 ;
+  SIZE  0.960000 BY  3.330000 ;
+  SYMMETRY X Y ;
+  SITE unit ;
+  PIN VGND
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
+    USE GROUND ;
+    PORT
+      LAYER met1 ;
+        RECT 0.000000 -0.245000 0.960000 0.245000 ;
+    END
+  END VGND
+  PIN VNB
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER pwell ;
+        RECT 0.000000 0.000000 0.960000 0.245000 ;
+    END
+  END VNB
+  PIN VPB
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER nwell ;
+        RECT -0.190000 1.660000 1.150000 3.520000 ;
+    END
+  END VPB
+  PIN VPWR
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
+    USE POWER ;
+    PORT
+      LAYER met1 ;
+        RECT 0.000000 3.085000 0.960000 3.575000 ;
+    END
+  END VPWR
+  OBS
+    LAYER li1 ;
+      RECT 0.000000 -0.085000 0.960000 0.085000 ;
+      RECT 0.000000  3.245000 0.960000 3.415000 ;
+      RECT 0.135000  0.085000 0.825000 0.580000 ;
+      RECT 0.135000  2.750000 0.825000 3.245000 ;
+    LAYER mcon ;
+      RECT 0.155000 -0.085000 0.325000 0.085000 ;
+      RECT 0.155000  3.245000 0.325000 3.415000 ;
+      RECT 0.635000 -0.085000 0.805000 0.085000 ;
+      RECT 0.635000  3.245000 0.805000 3.415000 ;
+  END
+END sky130_fd_sc_ms__fill_diode_2
+END LIBRARY
diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef
index a7dbde3..ae8bc5a 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_2.magic.lef
@@ -19,34 +19,40 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_2
-  CLASS BLOCK ;
+  CLASS SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_diode_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
-  PIN VNB
-    DIRECTION INPUT ;
-    PORT
-      LAYER pwell ;
-        RECT 0.000000 0.000000 0.960000 0.245000 ;
-    END
-  END VNB
-  PIN VPB
-    DIRECTION INPUT ;
-    PORT
-      LAYER nwell ;
-        RECT -0.190000 1.660000 1.150000 3.520000 ;
-    END
-  END VPB
+  SYMMETRY X Y ;
+  SITE unit ;
   PIN VGND
-    DIRECTION INPUT ;
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
     USE GROUND ;
     PORT
       LAYER met1 ;
         RECT 0.000000 -0.245000 0.960000 0.245000 ;
     END
   END VGND
+  PIN VNB
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER pwell ;
+        RECT 0.000000 0.000000 0.960000 0.245000 ;
+    END
+  END VNB
+  PIN VPB
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER nwell ;
+        RECT -0.190000 1.660000 1.150000 3.520000 ;
+    END
+  END VPB
   PIN VPWR
-    DIRECTION INPUT ;
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
     USE POWER ;
     PORT
       LAYER met1 ;
diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.lef
new file mode 100644
index 0000000..8bcae67
--- /dev/null
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.lef
@@ -0,0 +1,79 @@
+# Copyright 2020 The SkyWater PDK Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+VERSION 5.7 ;
+  NOWIREEXTENSIONATPIN ON ;
+  DIVIDERCHAR "/" ;
+  BUSBITCHARS "[]" ;
+MACRO sky130_fd_sc_ms__fill_diode_4
+  CLASS SPACER ;
+  FOREIGN scs8ms_fill_diode_4 ;
+  ORIGIN  0.000000  0.000000 ;
+  SIZE  1.920000 BY  3.330000 ;
+  SYMMETRY X Y ;
+  SITE unit ;
+  PIN VGND
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
+    USE GROUND ;
+    PORT
+      LAYER met1 ;
+        RECT 0.000000 -0.245000 1.920000 0.245000 ;
+    END
+  END VGND
+  PIN VNB
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER pwell ;
+        RECT 0.000000 0.000000 1.920000 0.245000 ;
+    END
+  END VNB
+  PIN VPB
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER nwell ;
+        RECT -0.190000 1.660000 2.110000 3.520000 ;
+    END
+  END VPB
+  PIN VPWR
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
+    USE POWER ;
+    PORT
+      LAYER met1 ;
+        RECT 0.000000 3.085000 1.920000 3.575000 ;
+    END
+  END VPWR
+  OBS
+    LAYER li1 ;
+      RECT 0.000000 -0.085000 1.920000 0.085000 ;
+      RECT 0.000000  3.245000 1.920000 3.415000 ;
+      RECT 0.135000  0.085000 1.785000 0.580000 ;
+      RECT 0.135000  2.750000 1.785000 3.245000 ;
+    LAYER mcon ;
+      RECT 0.155000 -0.085000 0.325000 0.085000 ;
+      RECT 0.155000  3.245000 0.325000 3.415000 ;
+      RECT 0.635000 -0.085000 0.805000 0.085000 ;
+      RECT 0.635000  3.245000 0.805000 3.415000 ;
+      RECT 1.115000 -0.085000 1.285000 0.085000 ;
+      RECT 1.115000  3.245000 1.285000 3.415000 ;
+      RECT 1.595000 -0.085000 1.765000 0.085000 ;
+      RECT 1.595000  3.245000 1.765000 3.415000 ;
+  END
+END sky130_fd_sc_ms__fill_diode_4
+END LIBRARY
diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef
index 4fc71ef..b8b4101 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_4.magic.lef
@@ -19,34 +19,40 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_4
-  CLASS BLOCK ;
+  CLASS SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_diode_4 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.920000 BY  3.330000 ;
-  PIN VNB
-    DIRECTION INPUT ;
-    PORT
-      LAYER pwell ;
-        RECT 0.000000 0.000000 1.920000 0.245000 ;
-    END
-  END VNB
-  PIN VPB
-    DIRECTION INPUT ;
-    PORT
-      LAYER nwell ;
-        RECT -0.190000 1.660000 2.110000 3.520000 ;
-    END
-  END VPB
+  SYMMETRY X Y ;
+  SITE unit ;
   PIN VGND
-    DIRECTION INPUT ;
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
     USE GROUND ;
     PORT
       LAYER met1 ;
         RECT 0.000000 -0.245000 1.920000 0.245000 ;
     END
   END VGND
+  PIN VNB
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER pwell ;
+        RECT 0.000000 0.000000 1.920000 0.245000 ;
+    END
+  END VNB
+  PIN VPB
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER nwell ;
+        RECT -0.190000 1.660000 2.110000 3.520000 ;
+    END
+  END VPB
   PIN VPWR
-    DIRECTION INPUT ;
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
     USE POWER ;
     PORT
       LAYER met1 ;
diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.lef
new file mode 100644
index 0000000..35fbee3
--- /dev/null
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.lef
@@ -0,0 +1,87 @@
+# Copyright 2020 The SkyWater PDK Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+VERSION 5.7 ;
+  NOWIREEXTENSIONATPIN ON ;
+  DIVIDERCHAR "/" ;
+  BUSBITCHARS "[]" ;
+MACRO sky130_fd_sc_ms__fill_diode_8
+  CLASS SPACER ;
+  FOREIGN scs8ms_fill_diode_8 ;
+  ORIGIN  0.000000  0.000000 ;
+  SIZE  3.840000 BY  3.330000 ;
+  SYMMETRY X Y ;
+  SITE unit ;
+  PIN VGND
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
+    USE GROUND ;
+    PORT
+      LAYER met1 ;
+        RECT 0.000000 -0.245000 3.840000 0.245000 ;
+    END
+  END VGND
+  PIN VNB
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER pwell ;
+        RECT 0.000000 0.000000 3.840000 0.245000 ;
+    END
+  END VNB
+  PIN VPB
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER nwell ;
+        RECT -0.190000 1.660000 4.030000 3.520000 ;
+    END
+  END VPB
+  PIN VPWR
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
+    USE POWER ;
+    PORT
+      LAYER met1 ;
+        RECT 0.000000 3.085000 3.840000 3.575000 ;
+    END
+  END VPWR
+  OBS
+    LAYER li1 ;
+      RECT 0.000000 -0.085000 3.840000 0.085000 ;
+      RECT 0.000000  3.245000 3.840000 3.415000 ;
+      RECT 0.135000  0.085000 3.705000 0.580000 ;
+      RECT 0.135000  2.750000 3.705000 3.245000 ;
+    LAYER mcon ;
+      RECT 0.155000 -0.085000 0.325000 0.085000 ;
+      RECT 0.155000  3.245000 0.325000 3.415000 ;
+      RECT 0.635000 -0.085000 0.805000 0.085000 ;
+      RECT 0.635000  3.245000 0.805000 3.415000 ;
+      RECT 1.115000 -0.085000 1.285000 0.085000 ;
+      RECT 1.115000  3.245000 1.285000 3.415000 ;
+      RECT 1.595000 -0.085000 1.765000 0.085000 ;
+      RECT 1.595000  3.245000 1.765000 3.415000 ;
+      RECT 2.075000 -0.085000 2.245000 0.085000 ;
+      RECT 2.075000  3.245000 2.245000 3.415000 ;
+      RECT 2.555000 -0.085000 2.725000 0.085000 ;
+      RECT 2.555000  3.245000 2.725000 3.415000 ;
+      RECT 3.035000 -0.085000 3.205000 0.085000 ;
+      RECT 3.035000  3.245000 3.205000 3.415000 ;
+      RECT 3.515000 -0.085000 3.685000 0.085000 ;
+      RECT 3.515000  3.245000 3.685000 3.415000 ;
+  END
+END sky130_fd_sc_ms__fill_diode_8
+END LIBRARY
diff --git a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef
index 2af700b..7733ad8 100644
--- a/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef
+++ b/cells/fill_diode/sky130_fd_sc_ms__fill_diode_8.magic.lef
@@ -19,34 +19,40 @@
   DIVIDERCHAR "/" ;
   BUSBITCHARS "[]" ;
 MACRO sky130_fd_sc_ms__fill_diode_8
-  CLASS BLOCK ;
+  CLASS SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_diode_8 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  3.840000 BY  3.330000 ;
-  PIN VNB
-    DIRECTION INPUT ;
-    PORT
-      LAYER pwell ;
-        RECT 0.000000 0.000000 3.840000 0.245000 ;
-    END
-  END VNB
-  PIN VPB
-    DIRECTION INPUT ;
-    PORT
-      LAYER nwell ;
-        RECT -0.190000 1.660000 4.030000 3.520000 ;
-    END
-  END VPB
+  SYMMETRY X Y ;
+  SITE unit ;
   PIN VGND
-    DIRECTION INPUT ;
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
     USE GROUND ;
     PORT
       LAYER met1 ;
         RECT 0.000000 -0.245000 3.840000 0.245000 ;
     END
   END VGND
+  PIN VNB
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER pwell ;
+        RECT 0.000000 0.000000 3.840000 0.245000 ;
+    END
+  END VNB
+  PIN VPB
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER nwell ;
+        RECT -0.190000 1.660000 4.030000 3.520000 ;
+    END
+  END VPB
   PIN VPWR
-    DIRECTION INPUT ;
+    DIRECTION INOUT ;
+    SHAPE ABUTMENT ;
     USE POWER ;
     PORT
       LAYER met1 ;