Merge pull request #1005 from makermelissa/libgpiod-fix

[Adafruit_Blinka-hackapet.git] / src / adafruit_blinka / __init__.py

diff --git a/src/adafruit_blinka/__init__.py b/src/adafruit_blinka/__init__.py
old mode 100644 (file)
new mode 100755 (executable)
index 0e52a3c..3624475
--- a/src/adafruit_blinka/__init__.py
+++ b/src/adafruit_blinka/__init__.py
@@ -1,9 +1,20 @@
-"""Module providing runtime utility objects to support the Micro/CircuitPython api"""
+# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+"""
+`adafruit_blinka` - Runtime utility objects for re-implementation of CircuitPython API
+======================================================================================
 
-class Enum(object):
+* Author(s): cefn
+"""
+
+import os
+
+
+class Enum:
     """
-        Object supporting CircuitPython-style of static symbols
-        as seen with Direction.OUTPUT, Pull.UP
+    Object supporting CircuitPython-style of static symbols
+    as seen with Direction.OUTPUT, Pull.UP
     """
 
     def __repr__(self):
@@ -21,34 +32,96 @@ class Enum(object):
     @classmethod
     def iteritems(cls):
         """
-            Inspects attributes of the class for instances of the class
-            and returns as key,value pairs mirroring dict#iteritems
+        Inspects attributes of the class for instances of the class
+        and returns as key,value pairs mirroring dict#iteritems
         """
         for key in dir(cls):
             val = getattr(cls, key)
-            if type(val) is cls:
+            if isinstance(cls, val):
                 yield (key, val)
 
 
 class ContextManaged:
+    """An object that automatically deinitializes hardware with a context manager."""
+
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_value, traceback):
         self.deinit()
 
-def Lockable(ContextManaged):
+    # pylint: disable=no-self-use
+    def deinit(self):
+        """Free any hardware used by the object."""
+        return
+
+    # pylint: enable=no-self-use
+
+
+class Lockable(ContextManaged):
+    """An object that must be locked to prevent collisions on a microcontroller resource."""
+
     _locked = False
 
     def try_lock(self):
+        """Attempt to grab the lock. Return True on success, False if the lock is already taken."""
         if self._locked:
             return False
-        else:
-            self._locked=True
-            return True
+        self._locked = True
+        return True
 
     def unlock(self):
+        """Release the lock so others may use the resource."""
         if self._locked:
             self._locked = False
-        else:
-            raise ValueError("Not locked")
+
+
+def load_settings_toml():
+    """Load values from settings.toml into os.environ, so that os.getenv returns them.
+    Note: This does not work in MicroPython because of the tomllib module not being available.
+    """
+    try:
+        import tomllib
+    except ImportError:
+        import toml as tomllib
+
+    if not os.path.isfile("settings.toml"):
+        raise FileNotFoundError("settings.toml not found in current directory.")
+
+    print("settings.toml found. Updating environment variables:")
+    with open("settings.toml", "rb") as toml_file:
+        try:
+            settings = tomllib.load(toml_file)
+        except tomllib.TOMLDecodeError as e:
+            raise tomllib.TOMLDecodeError("Error with settings.toml file.") from e
+
+    invalid_types = set()
+    for key, value in settings.items():
+        if not isinstance(value, (bool, int, float, str)):
+            invalid_types.add(type(value).__name__)
+    if invalid_types:
+        invalid_types_string = ", ".join(invalid_types)
+        raise ValueError(
+            f"The types: '{invalid_types_string}' are not supported in settings.toml."
+        )
+
+    for key, value in settings.items():
+        key = str(key)
+        if key in os.environ:
+            print(f" - {key} already exists in environment")
+            continue
+        os.environ[key] = str(value)
+        print(f" - {key} added")
+
+    return settings
+
+
+def patch_system():
+    """Patch modules that may be different due to the platform."""
+    # pylint: disable=import-outside-toplevel
+    import sys
+    from adafruit_blinka.agnostic import time
+
+    # pylint: enable=import-outside-toplevel
+
+    sys.modules["time"] = time