Add lights support for Nook Glowlight 4 Plus (bnrv1300)

Split bnrv1300 out of the NOOK_GL4 device ID into a new NOOK_GL4PLUS ID
with a dedicated NookGL4plusController. Brightness is set via
Settings.System (SELinux blocks direct sysfs access from the app
process); warmth is set via `su -c echo` to the lm3630a_led color sysfs
node (0=cold, 10=warm), which requires the user to grant root access
once via Magisk.

Fixes koreader/koreader#14574

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: backcountrymountains

app/src/main/java/org/koreader/launcher/device/DeviceInfo.kt

@@ -78,6 +78,7 @@ object DeviceInfo {
         NABUK,
         NOOK,
         NOOK_GL4,
+        NOOK_GL4PLUS,
         NOOK_GLPLUS,
         OBOOK_P10D,
         OBOOK_P78D,
@@ -358,9 +359,13 @@ object DeviceInfo {
             MANUFACTURER == "onyx" && MODEL == "nabukreg_hd"
             -> Id.NABUK
 
-            // Nook Glowlight 4 (4/4e/4plus)
-            (MANUFACTURER == "barnesandnoble")
-            && (MODEL == "bnrv1000" || MODEL == "bnrv1100" || MODEL == "bnrv1300")
+            // Nook Glowlight 4 Plus
+            MANUFACTURER == "barnesandnoble" && MODEL == "bnrv1300"
+            -> Id.NOOK_GL4PLUS
+
+            // Nook Glowlight 4 / 4e
+            MANUFACTURER == "barnesandnoble"
+            && (MODEL == "bnrv1000" || MODEL == "bnrv1100")
             -> Id.NOOK_GL4
 
             // Nook Glowlight plus 7.8" (2019)

app/src/main/java/org/koreader/launcher/device/LightsFactory.kt

@@ -106,6 +106,11 @@ object LightsFactory {
                     logController("TolinoNTXNoWarmth")
                     TolinoNtxNoWarmthController()
                 }
+                DeviceInfo.Id.NOOK_GL4PLUS,
+                -> {
+                    logController("NookGL4plus")
+                    NookGL4plusController()
+                }
                 DeviceInfo.Id.NOOK_GL4,
                 DeviceInfo.Id.TOLINO_EPOS2,
                 -> {

app/src/main/java/org/koreader/launcher/device/lights/NookGL4plusController.kt

@@ -0,0 +1,84 @@
+package org.koreader.launcher.device.lights
+
+import android.app.Activity
+import android.provider.Settings
+import android.util.Log
+import org.koreader.launcher.device.LightsInterface
+
+/* Controller for Nook Glowlight 4 Plus (bnrv1300) on Android 8.1.
+ * Brightness via Settings.System (SELinux blocks direct sysfs writes from the app process).
+ * Warmth via 'su -c echo' to sysfs color file (SELinux blocks direct ioctl from the app process).
+ * see https://github.com/koreader/koreader/issues/14574
+ */
+class NookGL4plusController : LightsInterface {
+
+    companion object {
+        private const val TAG = "Lights"
+        private const val BRIGHTNESS_MAX = 100
+        private const val WARMTH_MAX = 10
+        private const val MIN = 0
+        private const val COLOR_FILE = "/sys/class/backlight/lm3630a_led/color"
+    }
+
+    private var currentWarmth: Int? = null
+
+    override fun getPlatform(): String = "nook"
+    override fun hasFallback(): Boolean = false
+    override fun hasWarmth(): Boolean = true
+    override fun needsPermission(): Boolean = false
+    override fun hasStandaloneWarmth(): Boolean = false
+
+    override fun enableFrontlightSwitch(activity: Activity): Int = 1
+
+    override fun getBrightness(activity: Activity): Int {
+        return try {
+            Settings.System.getInt(activity.applicationContext.contentResolver,
+                Settings.System.SCREEN_BRIGHTNESS)
+        } catch (e: Exception) {
+            Log.w(TAG, e.toString())
+            0
+        }
+    }
+
+    override fun getWarmth(activity: Activity): Int {
+        return currentWarmth ?: MIN
+    }
+
+    override fun setBrightness(activity: Activity, brightness: Int) {
+        if (brightness < MIN || brightness > BRIGHTNESS_MAX) {
+            Log.w(TAG, "brightness value out of range: $brightness")
+            return
+        }
+        Log.v(TAG, "Setting brightness to $brightness")
+        try {
+            Settings.System.putInt(activity.applicationContext.contentResolver,
+                Settings.System.SCREEN_BRIGHTNESS, brightness)
+        } catch (e: Exception) {
+            Log.w(TAG, "$e")
+        }
+    }
+
+    override fun setWarmth(activity: Activity, warmth: Int) {
+        if (warmth < MIN || warmth > WARMTH_MAX) {
+            Log.w(TAG, "warmth value out of range: $warmth")
+            return
+        }
+        Log.v(TAG, "Setting warmth to $warmth of $WARMTH_MAX")
+        try {
+            val process = Runtime.getRuntime().exec(arrayOf("su", "-c", "echo $warmth > $COLOR_FILE"))
+            val exitCode = process.waitFor()
+            if (exitCode == 0) {
+                currentWarmth = warmth
+            } else {
+                Log.w(TAG, "su failed (exit $exitCode)")
+            }
+        } catch (e: Exception) {
+            Log.w(TAG, "setWarmth: $e")
+        }
+    }
+
+    override fun getMinBrightness(): Int = MIN
+    override fun getMaxBrightness(): Int = BRIGHTNESS_MAX
+    override fun getMinWarmth(): Int = MIN
+    override fun getMaxWarmth(): Int = WARMTH_MAX
+}