X-Git-Url: https://git.ayoreis.com/Adafruit_Blinka-hackapet.git/blobdiff_plain/15891fa3df5ef5bc97c020fc72c34dc43348b253..3f5c764d453b12a5524cd5a7b6183441e98eaee0:/src/adafruit_blinka/microcontroller/amlogic/meson_g12_common/pin.py

diff --git a/src/adafruit_blinka/microcontroller/amlogic/meson_g12_common/pin.py b/src/adafruit_blinka/microcontroller/amlogic/meson_g12_common/pin.py
index 82fa6ea..41cf8f2 100644
--- a/src/adafruit_blinka/microcontroller/amlogic/meson_g12_common/pin.py
+++ b/src/adafruit_blinka/microcontroller/amlogic/meson_g12_common/pin.py
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
 """
 G12A, G12B, and SM1 Common Definitions
 Ref:
@@ -8,6 +11,8 @@ Linux kernel 5.4.y (mainline)
     linux/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi
 """
 
+from typing import Optional
+import os
 import re
 import gpiod
 from adafruit_blinka.microcontroller.generic_linux.libgpiod_pin import Pin
@@ -107,18 +112,18 @@ UART1_RX = GPIOX_13
 uartPorts = ((1, UART1_TX, UART1_RX),)
 
 
-def get_dts_alias(device: str) -> str:
+def get_dts_alias(device: str) -> Optional[str]:
     """Get the Device Tree Alias"""
     uevent_path = "/sys/bus/platform/devices/" + device + "/uevent"
-    with open(uevent_path, "r") as fd:
-        pattern = r"^OF_ALIAS_0=(.*)$"
-        uevent = fd.read().split("\n")
-        for line in uevent:
-            match = re.search(pattern, line)
-            if match:
-                return match.group(1).upper()
-
-        return None
+    if os.path.exists(uevent_path):
+        with open(uevent_path, "r", encoding="utf-8") as fd:
+            pattern = r"^OF_ALIAS_0=(.*)$"
+            uevent = fd.read().split("\n")
+            for line in uevent:
+                match = re.search(pattern, line)
+                if match:
+                    return match.group(1).upper()
+    return None
 
 
 # ordered as i2cId, sclId, sdaId