lights: We have only single color led.

Also add additional steps to duty cycle to make notif light fade
smoother.
Also detect maximum brightness dynamically

light/Light.cpp

@@ -24,34 +24,30 @@
 
 #define LEDS            "/sys/class/leds/"
 
-#define BUTTON1_LED     LEDS "button-backlight1/"
-#define BUTTON_LED      LEDS "button-backlight/"
 #define LCD_LED         LEDS "lcd-backlight/"
-#define WHITE_LED       LEDS "white/"
+#define WHITE_LED       LEDS "red/"
 
 #define BLINK           "blink"
 #define BRIGHTNESS      "brightness"
+#define MAX_BRIGHTNESS  "max_brightness"
 #define DUTY_PCTS       "duty_pcts"
 #define PAUSE_HI        "pause_hi"
 #define PAUSE_LO        "pause_lo"
 #define RAMP_STEP_MS    "ramp_step_ms"
 #define START_IDX       "start_idx"
 
-#define MAX_LED_BRIGHTNESS    255
-#define MAX_LCD_BRIGHTNESS    4095
-
 /*
  * 8 duty percent steps.
  */
-#define RAMP_STEPS 8
+#define RAMP_STEPS 15
 /*
  * Each step will stay on for 50ms by default.
  */
-#define RAMP_STEP_DURATION 50
+#define RAMP_STEP_DURATION 150
 /*
  * Each value represents a duty percent (0 - 100) for the led pwm.
  */
-static int32_t BRIGHTNESS_RAMP[RAMP_STEPS] = {0, 12, 25, 37, 50, 72, 85, 100};
+static int32_t BRIGHTNESS_RAMP[RAMP_STEPS] = {0, 12, 25, 37, 50, 72, 85, 100, 85, 72, 50, 37, 25, 12, 0};
 
 namespace {
 /*
@@ -72,6 +68,25 @@ static void set(std::string path, int value) {
     set(path, std::to_string(value));
 }
 
+static int get(std::string path) {
+    std::ifstream file(path);
+    int value;
+
+    if (!file.is_open()) {
+        ALOGW("failed to read from %s", path.c_str());
+        return 0;
+    }
+
+    file >> value;
+    return value;
+}
+
+static int getMaxBrightness(std::string path) {
+    int value = get(path);
+    ALOGW("Got max brightness %d", value);
+    return value;
+}
+
 static uint32_t getBrightness(const LightState& state) {
     uint32_t alpha, red, green, blue;
 
@@ -104,16 +119,10 @@ static inline uint32_t getScaledBrightness(const LightState& state, uint32_t max
 }
 
 static void handleBacklight(Type /* type */, const LightState& state) {
-    uint32_t brightness = getScaledBrightness(state, MAX_LCD_BRIGHTNESS);
+    uint32_t brightness = getScaledBrightness(state, getMaxBrightness(LCD_LED MAX_BRIGHTNESS));
     set(LCD_LED BRIGHTNESS, brightness);
 }
 
-static void handleButtons(Type /* type */, const LightState& state) {
-    uint32_t brightness = getScaledBrightness(state, MAX_LED_BRIGHTNESS);
-    set(BUTTON_LED BRIGHTNESS, brightness);
-    set(BUTTON1_LED BRIGHTNESS, brightness);
-}
-
 /*
  * Scale each value of the brightness ramp according to the
  * brightness of the color.
@@ -130,7 +139,7 @@ static std::string getScaledRamp(uint32_t brightness) {
 }
 
 static void setNotification(const LightState& state) {
-    uint32_t whiteBrightness = getScaledBrightness(state, MAX_LED_BRIGHTNESS);
+    uint32_t whiteBrightness = getScaledBrightness(state, getMaxBrightness(WHITE_LED MAX_BRIGHTNESS));
 
     /* Disable blinking */
     set(WHITE_LED BLINK, 0);
@@ -146,7 +155,7 @@ static void setNotification(const LightState& state) {
         int32_t pauseLo = state.flashOffMs;
 
         if (pauseHi < 0) {
-            stepDuration = state.flashOnMs / (RAMP_STEPS * 2);
+            //stepDuration = state.flashOnMs / (RAMP_STEPS * 2);
             pauseHi = 0;
         }
 
@@ -179,33 +188,28 @@ static std::vector<std::pair<Type, LightState>> notificationStates = {
 };
 
 static void handleNotification(Type type, const LightState& state) {
-    bool handled = false;
-
-    for (auto it : notificationStates) {
+    for(auto it : notificationStates) {
         if (it.first == type) {
             it.second = state;
         }
 
-        if (!handled && isLit(it.second)) {
+        if  (isLit(it.second)) {
             setNotification(it.second);
-            handled = true;
+            return;
         }
     }
 
-    if (!handled) {
-        setNotification(offState);
-    }
+    setNotification(offState);
 }
 
-static std::map<Type, std::function<void(Type, const LightState&)>> lights = {
+static std::map<Type, std::function<void(Type type, const LightState&)>> lights = {
     { Type::ATTENTION, handleNotification },
     { Type::NOTIFICATIONS, handleNotification },
     { Type::BATTERY, handleNotification },
     { Type::BACKLIGHT, handleBacklight },
-    { Type::BUTTONS, handleButtons },
 };
 
-}  // anonymous namespace
+} // anonymous namespace
 
 namespace android {
 namespace hardware {