msm8976-common: lineagehw: Add mDNIe-backed ReadingEnhancement implementation

Change-Id: I88ad232434130382e95f056097cfd1b914211645

BoardConfigCommon.mk

@@ -171,7 +171,8 @@ TARGET_PROVIDES_KEYMASTER := true
 
 # Lineage hardware
 BOARD_HARDWARE_CLASS += \
-    hardware/samsung/lineagehw
+    hardware/samsung/lineagehw \
+    $(VENDOR_PATH)/lineagehw
 
 # Peripheral manager
 TARGET_PER_MGR_ENABLED := true

lineagehw/org/lineage/hardware/ReadingEnhancement.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2018 TeamNexus
+ * Copyright (C) 2018 The LineageOS Project
+ *
+ * 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
+ *
+ *      http://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.
+ */
+
+package org.lineageos.hardware;
+
+import org.lineageos.internal.util.FileUtils;
+
+/**
+ * Reader mode
+ */
+public class ReadingEnhancement {
+
+    private static final String ACCESSIBILITY_FILE =
+            "/sys/devices/virtual/mdnie/mdnie/accessibility";
+
+    public static boolean isSupported() {
+        return FileUtils.isFileWritable(ACCESSIBILITY_FILE);
+    }
+
+    public static boolean setGrayscale(boolean state) {
+        return FileUtils.writeLine(ACCESSIBILITY_FILE, state ? "4" : "0");
+    }
+
+}