sm6250-common: import light HAL from Xiaomi msm8998-common

Change-Id: Ieee4277f15927b4522deaec9a709809cf6db6fea

light/Light.cpp

@@ -0,0 +1,176 @@
+/*
+ * Copyright (C) 2018-2019 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.
+ */
+
+#define LOG_TAG "LightService"
+
+#include <log/log.h>
+
+#include "Light.h"
+
+#include <fstream>
+
+#define LCD_LED         "/sys/class/backlight/panel0-backlight/"
+#define WHITE_LED       "/sys/class/leds/white/"
+
+#define BREATH          "breath"
+#define BRIGHTNESS      "brightness"
+
+#define MAX_LED_BRIGHTNESS    255
+#define MAX_LCD_BRIGHTNESS    4095
+
+namespace {
+/*
+ * Write value to path and close file.
+ */
+static void set(std::string path, std::string value) {
+    std::ofstream file(path);
+
+    if (!file.is_open()) {
+        ALOGW("failed to write %s to %s", value.c_str(), path.c_str());
+        return;
+    }
+
+    file << value;
+}
+
+static void set(std::string path, int value) {
+    set(path, std::to_string(value));
+}
+
+static uint32_t getBrightness(const LightState& state) {
+    uint32_t alpha, red, green, blue;
+
+    /*
+     * Extract brightness from AARRGGBB.
+     */
+    alpha = (state.color >> 24) & 0xFF;
+    red = (state.color >> 16) & 0xFF;
+    green = (state.color >> 8) & 0xFF;
+    blue = state.color & 0xFF;
+
+    /*
+     * Scale RGB brightness if Alpha brightness is not 0xFF.
+     */
+    if (alpha != 0xFF) {
+        red = red * alpha / 0xFF;
+        green = green * alpha / 0xFF;
+        blue = blue * alpha / 0xFF;
+    }
+
+    return (77 * red + 150 * green + 29 * blue) >> 8;
+}
+
+static inline uint32_t scaleBrightness(uint32_t brightness, uint32_t maxBrightness) {
+    return brightness * maxBrightness / 0xFF;
+}
+
+static inline uint32_t getScaledBrightness(const LightState& state, uint32_t maxBrightness) {
+    return scaleBrightness(getBrightness(state), maxBrightness);
+}
+
+static void handleBacklight(const LightState& state) {
+    uint32_t brightness = getScaledBrightness(state, MAX_LCD_BRIGHTNESS);
+    set(LCD_LED BRIGHTNESS, brightness);
+}
+
+static void handleNotification(const LightState& state) {
+    uint32_t whiteBrightness = getScaledBrightness(state, MAX_LED_BRIGHTNESS);
+
+    /* Disable breathing or blinking */
+    set(WHITE_LED BREATH, 0);
+
+    switch (state.flashMode) {
+        case Flash::HARDWARE:
+        case Flash::TIMED:
+            /* Breathing */
+            set(WHITE_LED BREATH, 1);
+            break;
+        case Flash::NONE:
+        default:
+            set(WHITE_LED BRIGHTNESS, whiteBrightness);
+    }
+}
+
+static inline bool isLit(const LightState& state) {
+    return state.color & 0x00ffffff;
+}
+
+/* Keep sorted in the order of importance. */
+static std::vector<LightBackend> backends = {
+    { Type::ATTENTION, handleNotification },
+    { Type::NOTIFICATIONS, handleNotification },
+    { Type::BATTERY, handleNotification },
+    { Type::BACKLIGHT, handleBacklight },
+};
+
+}  // anonymous namespace
+
+namespace android {
+namespace hardware {
+namespace light {
+namespace V2_0 {
+namespace implementation {
+
+Return<Status> Light::setLight(Type type, const LightState& state) {
+    LightStateHandler handler = nullptr;
+
+    /* Lock global mutex until light state is updated. */
+    std::lock_guard<std::mutex> lock(globalLock);
+
+    /* Update the cached state value for the current type. */
+    for (LightBackend& backend : backends) {
+        if (backend.type == type) {
+            backend.state = state;
+            handler = backend.handler;
+        }
+    }
+
+    /* If no handler has been found, then the type is not supported. */
+    if (!handler) {
+        return Status::LIGHT_NOT_SUPPORTED;
+    }
+
+    /* Light up the type with the highest priority that matches the current handler. */
+    for (LightBackend& backend : backends) {
+        if (handler == backend.handler && isLit(backend.state)) {
+            handler(backend.state);
+            return Status::SUCCESS;
+        }
+    }
+
+    /* If no type has been lit up, then turn off the hardware. */
+    handler(state);
+
+    return Status::SUCCESS;
+}
+
+Return<void> Light::getSupportedTypes(getSupportedTypes_cb _hidl_cb) {
+    std::vector<Type> types;
+
+    for (const LightBackend& backend : backends) {
+        types.push_back(backend.type);
+    }
+
+    _hidl_cb(types);
+
+    return Void();
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace light
+}  // namespace hardware
+}  // namespace android