5 files changed, 43 insertions(+), 5 deletions(-)

M README.md
A patch/attiny85.yaml
A patch/common/ac.yaml
A patch/common/ac/acsr.yaml
M patch/svdpatch.py

@@ 44,6 44,17 @@ Via the feature you can select which chip you want the register specifications f
 ### Adding a new Chip
 To add a new chip, download the *atdf* from <http://packs.download.atmel.com/> and place it in `vendor/`.  Be sure to name it like the Rust module that should be generated.  Next, you need to integrate it into the base crate and build system.  Follow what was done in [this commit](https://github.com/Rahix/avr-device/commit/8b1679a89704f5a303a1578b261aa2aee53e1251).  Please adhere to the alphabetical sorting that is present so far.
 
+If patches need to be applied, create a `<chipname>.yaml` in `patch/`. The patching format is compatible to the [YAML patching format of stm32](https://github.com/stm32-rs/stm32-rs/#device-and-peripheral-yaml-format), except that you do not need to provide the path to the svd file (`_svd: ...`) since it is generated in the build process. Additionally, the following patching was added:
+```yaml
+PERIPHERIAL:
+    REGISTER:
+        FIELD:
+            # Replaces the enumeratedValues definition for this field.
+            # If it does not exist yet, it is created.
+            _replace_enum:
+                NAME: [VALUE, DESCRIPTION]
+```
+
 ## License
 *avr-device* is licensed under either of
 

@@ 0,0 1,2 @@
+_include:
+    - "common/ac.yaml"

@@ 0,0 1,2 @@
+_include:
+    - "ac/acsr.yaml"

@@ 0,0 1,11 @@
+AC:
+    ACSR:
+        _modify:
+            ACIS:
+                description: "Analog Comparator Interrupt Mode Select"
+        ACIS:
+            _replace_enum:
+                ON_TOGGLE: [0, "Interrupt on Toggle"]
+                # Leaving [1, 'Reserved'] out
+                ON_FALLING_EDGE: [2, "Interrupt on Falling Edge"]
+                ON_RISING_EDGE: [3, "Interrupt on Rising Edge"]

@@ 6,6 6,9 @@ Licensed under the MIT and Apache 2.0 licenses. See LICENSE files for details.
 
 This script was adapted from stm32-rs (https://github.com/stm32-rs/stm32-rs/blob/master/scripts/svdpatch.py).
 To be integrated into the build system, support for an input / output svd argument is added.
+
+Additional changes:
+    - Support for _replace_enum to overwrite existing <enumeratedValues>
 """
 
 import copy


@@ 595,6 598,11 @@ def process_register_split(rtag, fspec):
 
 def process_field_enum(pname, rtag, fspec, field, usage="read-write"):
     """Add an enumeratedValues given by field to all fspec in rtag."""
+    replace_if_exists = False
+    if "_replace_enum" in field:
+        field = field["_replace_enum"]
+        replace_if_exists = True
+
     derived = None
     for ftag in iter_fields(rtag, fspec):
         name = ftag.find('name').text


@@ 603,12 611,16 @@ def process_field_enum(pname, rtag, fspec, field, usage="read-write"):
             enum_name = enum.find('name').text
             enum_usage = enum.find('usage').text
             for ev in ftag.iter('enumeratedValues'):
-                ev_usage = ev.find('usage').text
+                ev_usage_tag = ev.find('usage')
+                ev_usage = ev_usage_tag.text if ev_usage_tag is not None else 'read-write'
                 if ev_usage == enum_usage or ev_usage == "read-write":
-                    print(pname, fspec, field)
-                    raise SvdPatchError(
-                        "{}: field {} already has enumeratedValues for {}"
-                        .format(pname, name, ev_usage))
+                    if replace_if_exists:
+                        ftag.remove(ev)
+                    else:
+                        print(pname, fspec, field)
+                        raise SvdPatchError(
+                            "{}: field {} already has enumeratedValues for {}. Use '_replace_enum' to overwrite."
+                            .format(pname, name, ev_usage))
             ftag.append(enum)
             derived = make_derived_enumerated_values(enum_name)
         else: