scripts: ci: Add CI bindings style checker

Implement a check in the CI pipeline to enforce
that property names in device tree bindings do
not contain underscores.

Signed-off-by: James Roy <[email protected]>

scripts/ci/bindings_propertys_name_wl.yaml

@@ -0,0 +1,11 @@
+# This file is a YAML whitelist of property names that are allowed to
+# bypass the underscore check in bindings. These properties are exempt
+# from the rule that requires using '-' instead of '_'.
+#
+# The file content can be as shown below:
+# - propname1
+# - propname2
+# - ...
+
+- mmc-hs200-1_8v
+- mmc-hs400-1_8v

scripts/ci/check_compliance.py

@@ -22,6 +22,7 @@
 import shutil
 import textwrap
 import unidiff
+import yaml
 
 from yamllint import config, linter
 
@@ -36,6 +37,28 @@
 import list_boards
 import list_hardware
 
+sys.path.insert(0, os.path.join(str(Path(__file__).resolve().parents[2]),
+                                'scripts/dts/python-devicetree/src'))
+from devicetree import edtlib
+
+
+# Let the user run this script as ./scripts/ci/check_compliance.py without
+# making them set ZEPHYR_BASE.
+ZEPHYR_BASE = os.environ.get('ZEPHYR_BASE')
+if not ZEPHYR_BASE:
+    ZEPHYR_BASE = str(Path(__file__).resolve().parents[2])
+    # Propagate this decision to child processes.
+    os.environ['ZEPHYR_BASE'] = ZEPHYR_BASE
+
+# Initialize the propertys name whitelist
+BINDINGS_PROPERTYS_WL = None
+with open(Path(__file__).parent / 'bindings_propertys_name_wl.yaml', 'r') as f:
+    wl = yaml.safe_load(f.read())
+    if wl is not None:
+        BINDINGS_PROPERTYS_WL = set(wl)
+    else:
+        BINDINGS_PROPERTYS_WL = {'',}
+
 logger = None
 
 def git(*args, cwd=None, ignore_non_zero=False):
@@ -335,32 +358,75 @@ class DevicetreeBindingsCheck(ComplianceTest):
     path_hint = "<zephyr-base>"
 
     def run(self, full=True):
-        dts_bindings = self.parse_dt_bindings()
-
-        for dts_binding in dts_bindings:
-            self.required_false_check(dts_binding)
+        bindings_diff, bindings = self.get_yaml_bindings()
 
-    def parse_dt_bindings(self):
+        # If no bindings are changed, skip this check.
+        try:
+            subprocess.check_call(['git', 'diff', '--quiet', COMMIT_RANGE]
+                                  + bindings_diff)
+            nodiff = True
+        except subprocess.CalledProcessError:
+            nodiff = False
+        if nodiff:
+            self.skip('no changes to bindings were made')
+
+        for binding in bindings:
+            self.check(binding, self.check_yaml_property_name)
+            self.check(binding, self.required_false_check)
+
+    @staticmethod
+    def check(binding, callback):
+        while binding is not None:
+            callback(binding)
+            binding = binding.child_binding
+
+    def get_yaml_bindings(self):
         """
-        Returns a list of dts/bindings/**/*.yaml files
+        Returns a list of 'dts/bindings/**/*.yaml'
         """
+        from glob import glob
+        BINDINGS_PATH = 'dts/bindings/'
+        bindings_diff_dir, bindings = set(), []
 
-        dt_bindings = []
-        for file_name in get_files(filter="d"):
-            if 'dts/bindings/' in file_name and file_name.endswith('.yaml'):
-                dt_bindings.append(file_name)
+        for file_name in get_files(filter='d'):
+            if BINDINGS_PATH in file_name:
+                p = file_name.partition(BINDINGS_PATH)
+                bindings_diff_dir.add(os.path.join(p[0], p[1]))
 
-        return dt_bindings
+        for path in bindings_diff_dir:
+            yamls = glob(f'{os.fspath(path)}/**/*.yaml', recursive=True)
+            bindings.extend(yamls)
 
-    def required_false_check(self, dts_binding):
-        with open(dts_binding) as file:
-            for line_number, line in enumerate(file, 1):
-                if 'required: false' in line:
-                    self.fmtd_failure(
-                        'warning', 'Devicetree Bindings', dts_binding,
-                        line_number, col=None,
-                        desc="'required: false' is redundant, please remove")
+        bindings = edtlib.bindings_from_paths(bindings, ignore_errors=True)
+        return list(bindings_diff_dir), bindings
+
+    def check_yaml_property_name(self, binding):
+        """
+        Checks if the property names in the binding file contain underscores.
+        """
+        for prop_name in binding.prop2specs:
+            if '_' in prop_name and prop_name not in BINDINGS_PROPERTYS_WL:
+                better_prop = prop_name.replace('_', '-')
+                print(f"Required: In '{binding.path}', "
+                      f"the property '{prop_name}' "
+                      f"should be renamed to '{better_prop}'.")
+                self.failure(
+                    f"{binding.path}: property '{prop_name}' contains underscores.\n"
+                    f"\tUse '{better_prop}' instead unless this property name is from Linux.\n"
+                    "Or another authoritative upstream source of bindings for "
+                    f"compatible '{binding.compatible}'.\n"
+                    "\tHint: update 'bindings_propertys_name_wl.yaml' if you need to "
+                    "override this check for this property."
+                )
 
+    def required_false_check(self, binding):
+        raw_props = binding.raw.get('properties', {})
+        for prop_name, raw_prop in raw_props.items():
+            if raw_prop.get('required') is False:
+                self.failure(
+                    f'{binding.path}: property "{prop_name}": '
+                    "'required: false' is redundant, please remove"
+                )
 
 class KconfigCheck(ComplianceTest):
     """
@@ -1802,16 +1868,6 @@ def _main(args):
     # The "real" main(), which is wrapped to catch exceptions and report them
     # to GitHub. Returns the number of test failures.
 
-    global ZEPHYR_BASE
-    ZEPHYR_BASE = os.environ.get('ZEPHYR_BASE')
-    if not ZEPHYR_BASE:
-        # Let the user run this script as ./scripts/ci/check_compliance.py without
-        #  making them set ZEPHYR_BASE.
-        ZEPHYR_BASE = str(Path(__file__).resolve().parents[2])
-
-        # Propagate this decision to child processes.
-        os.environ['ZEPHYR_BASE'] = ZEPHYR_BASE
-
     # The absolute path of the top-level git directory. Initialize it here so
     # that issues running Git can be reported to GitHub.
     global GIT_TOP