From 305b81cdf5d11c0ab16c42316cc1b0a18bc64f8c Mon Sep 17 00:00:00 2001
From: Konsta <konsta09@gmail.com>
Date: Fri, 2 May 2025 13:39:37 +0300
Subject: [PATCH] light: support more backlight paths

* I2C address for the panel regulator driver depends on the device and
  DSI port the display is connected on. Add more backlight paths to support
  different hardware configurations. Also add path for legacy rpi_backlight
  driver to make testing easier.
---
 light/Lights.cpp                            | 33 ++++++++++++++++-----
 light/android.hardware.light-service.rpi.rc |  8 +++++
 sepolicy/genfs_contexts                     |  8 +++--
 3 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/light/Lights.cpp b/light/Lights.cpp
index f4e3d65..a1144bf 100644
--- a/light/Lights.cpp
+++ b/light/Lights.cpp
@@ -15,9 +15,12 @@
  * limitations under the License.
  */
 
+#define LOG_TAG "android.hardware.light-service.rpi"
+
 #include "Lights.h"
 
 #include <android-base/file.h>
+#include <android-base/logging.h>
 
 using ::android::base::ReadFileToString;
 using ::android::base::WriteStringToFile;
@@ -26,8 +29,13 @@ namespace aidl::android::hardware::light {
 
 static const uint32_t defaultMaxBrightness = 255;
 
-static const std::string backlightBrightnessPath = "/sys/class/backlight/11-0045/brightness";
-static const std::string backlightMaxBrightnessPath = "/sys/class/backlight/11-0045/max_brightness";
+static const std::string backlightBasePath = "/sys/class/backlight/";
+
+static const std::string backlightPaths[] = {
+    "10-0045",
+    "11-0045",
+    "rpi_backlight",
+};
 
 static const std::vector<HwLight> availableLights = {
     {.id = (int)LightType::BACKLIGHT, .type = LightType::BACKLIGHT, .ordinal = 0}
@@ -36,10 +44,15 @@ static const std::vector<HwLight> availableLights = {
 Lights::Lights() {
     maxBrightness = defaultMaxBrightness;
 
-    if (!access(backlightMaxBrightnessPath.c_str(), R_OK)) {
-        std::string maxBrightnessValue;
-        if (ReadFileToString(backlightMaxBrightnessPath, &maxBrightnessValue)) {
-            maxBrightness = std::stoi(maxBrightnessValue);
+    for (auto &path : backlightPaths) {
+        std::string backlightMaxBrightnessPath = backlightBasePath + path + "/max_brightness";
+        if (!access(backlightMaxBrightnessPath.c_str(), R_OK)) {
+            std::string maxBrightnessValue;
+            if (ReadFileToString(backlightMaxBrightnessPath, &maxBrightnessValue)) {
+                maxBrightness = std::stoi(maxBrightnessValue);
+                LOG(INFO) << backlightMaxBrightnessPath << " = " << maxBrightnessValue;
+                break;
+            }
         }
     }
 }
@@ -50,8 +63,12 @@ ndk::ScopedAStatus Lights::setLightState(int id, const HwLightState& state) {
 
     switch (light.type) {
         case LightType::BACKLIGHT:
-            if (!access(backlightBrightnessPath.c_str(), W_OK)) {
-                WriteStringToFile(brightness, backlightBrightnessPath);
+            for (auto &path : backlightPaths) {
+                std::string backlightBrightnessPath = backlightBasePath + path + "/brightness";
+                if (!access(backlightBrightnessPath.c_str(), W_OK)) {
+                   WriteStringToFile(brightness, backlightBrightnessPath);
+                   break;
+                }
             }
             break;
         default:
diff --git a/light/android.hardware.light-service.rpi.rc b/light/android.hardware.light-service.rpi.rc
index 01917b7..6a8acc5 100644
--- a/light/android.hardware.light-service.rpi.rc
+++ b/light/android.hardware.light-service.rpi.rc
@@ -1,8 +1,16 @@
 on early-boot
+    chown system system /sys/class/backlight/10-0045/brightness
+    chown system system /sys/class/backlight/10-0045/max_brightness
     chown system system /sys/class/backlight/11-0045/brightness
     chown system system /sys/class/backlight/11-0045/max_brightness
+    chown system system /sys/class/backlight/rpi_backlight/brightness
+    chown system system /sys/class/backlight/rpi_backlight/max_brightness
+    chmod 660 /sys/class/backlight/10-0045/brightness
+    chmod 440 /sys/class/backlight/10-0045/max_brightness
     chmod 660 /sys/class/backlight/11-0045/brightness
     chmod 440 /sys/class/backlight/11-0045/max_brightness
+    chmod 660 /sys/class/backlight/rpi_backlight/brightness
+    chmod 440 /sys/class/backlight/rpi_backlight/max_brightness
 
 service vendor.light-rpi /apex/com.android.hardware.light.rpi5/bin/hw/android.hardware.light-service.rpi
     class hal
diff --git a/sepolicy/genfs_contexts b/sepolicy/genfs_contexts
index e174d46..18605c9 100644
--- a/sepolicy/genfs_contexts
+++ b/sepolicy/genfs_contexts
@@ -7,8 +7,12 @@ genfscon sysfs /devices/platform/axi/1002000000.v3d  u:object_r:sysfs_gpu:s0
 genfscon sysfs /devices/platform/axi/axi:gpu         u:object_r:sysfs_gpu:s0
 
 # Lights
-genfscon sysfs /class/backlight/11-0045/brightness      u:object_r:sysfs_leds:s0
-genfscon sysfs /class/backlight/11-0045/max_brightness  u:object_r:sysfs_leds:s0
+genfscon sysfs /class/backlight/10-0045/brightness            u:object_r:sysfs_leds:s0
+genfscon sysfs /class/backlight/10-0045/max_brightness        u:object_r:sysfs_leds:s0
+genfscon sysfs /class/backlight/11-0045/brightness            u:object_r:sysfs_leds:s0
+genfscon sysfs /class/backlight/11-0045/max_brightness        u:object_r:sysfs_leds:s0
+genfscon sysfs /class/backlight/rpi_backlight/brightness      u:object_r:sysfs_leds:s0
+genfscon sysfs /class/backlight/rpi_backlight/max_brightness  u:object_r:sysfs_leds:s0
 
 # Serial number
 genfscon sysfs /firmware/devicetree/base/serial-number  u:object_r:sysfs_dt_firmware_android:s0