tici: limit brightness with display uptime (#22918)

Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>
old-commit-hash: c9218a55f3

selfdrive/ui/ui.cc

@@ -12,7 +12,7 @@
 
 #define BACKLIGHT_DT 0.05
 #define BACKLIGHT_TS 10.00
-#define BACKLIGHT_OFFROAD 75
+#define BACKLIGHT_OFFROAD 50
 
 
 // Projects a point in car to space to the corresponding point in full frame
@@ -105,6 +105,7 @@ static void update_sockets(UIState *s) {
 static void update_state(UIState *s) {
   SubMaster &sm = *(s->sm);
   UIScene &scene = s->scene;
+  s->running_time = 1e-9 * (nanos_since_boot() - sm["deviceState"].getDeviceState().getStartedMonoTime());
 
   // update engageability and DM icons at 2Hz
   if (sm.frame % (UI_FREQ / 2) == 0) {
@@ -278,8 +279,10 @@ void Device::setAwake(bool on, bool reset) {
 }
 
 void Device::updateBrightness(const UIState &s) {
+  float clipped_brightness = BACKLIGHT_OFFROAD;
+  if (s.scene.started) {
     // Scale to 0% to 100%
-  float clipped_brightness = 100.0 * s.scene.light_sensor;
+    clipped_brightness = 100.0 * s.scene.light_sensor;
 
     // CIE 1931 - https://www.photonstophotos.net/GeneralTopics/Exposure/Psychometric_Lightness_and_Gamma.htm
     if (clipped_brightness <= 8) {
@@ -291,8 +294,15 @@ void Device::updateBrightness(const UIState &s) {
     // Scale back to 10% to 100%
     clipped_brightness = std::clamp(100.0f * clipped_brightness, 10.0f, 100.0f);
 
-  if (!s.scene.started) {
-    clipped_brightness = BACKLIGHT_OFFROAD;
+    // Limit brightness if running for too long
+    if (Hardware::TICI()) {
+      const float MAX_BRIGHTNESS_HOURS = 4;
+      const float HOURLY_BRIGHTNESS_DECREASE = 5;
+      float ui_running_hours = s.running_time / (60*60);
+      float anti_burnin_max_percent = std::clamp(100.0f - HOURLY_BRIGHTNESS_DECREASE * (ui_running_hours - MAX_BRIGHTNESS_HOURS),
+                                                 30.0f, 100.0f);
+      clipped_brightness = std::min(clipped_brightness, anti_burnin_max_percent);
+    }
   }
 
   int brightness = brightness_filter.update(clipped_brightness);

selfdrive/ui/ui.h

@@ -31,7 +31,6 @@ const int header_h = 420;
 const int footer_h = 280;
 
 const int UI_FREQ = 20;   // Hz
-
 typedef cereal::CarControl::HUDControl::AudibleAlert AudibleAlert;
 
 // TODO: this is also hardcoded in common/transformations/camera.py
@@ -149,6 +148,8 @@ typedef struct UIState {
 
   float car_space_transform[6];
   bool wide_camera;
+  
+  float running_time;
 } UIState;