sdm660-common: Support button backlight

Change-Id: Id13a42976df428c95c19eae49e1c114f057510bb

3 files changed, 36 insertions, 0 deletions

diff --git a/light/Light.cpp b/light/Light.cpp
index 0286b6a..1702603 100644
--- a/light/Light.cpp
+++ b/light/Light.cpp
@@ -24,6 +24,7 @@
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
+#include <unistd.h>
 
 namespace {
 
@@ -35,6 +36,8 @@ namespace {
 #define LEDS(x) PPCAT(/sys/class/leds, x)
 #define LCD_ATTR(x) STRINGIFY(PPCAT(LEDS(lcd-backlight), x))
 #define WHITE_ATTR(x) STRINGIFY(PPCAT(LEDS(white), x))
+#define BUTTON_ATTR(x) STRINGIFY(PPCAT(LEDS(button-backlight), x))
+#define BUTTON1_ATTR(x) STRINGIFY(PPCAT(LEDS(button-backlight1), x))
 
 using ::android::base::ReadFileToString;
 using ::android::base::WriteStringToFile;
@@ -125,6 +128,24 @@ Light::Light() {
         max_led_brightness_ = kDefaultMaxLedBrightness;
         LOG(ERROR) << "Failed to read max LED brightness, fallback to " << kDefaultMaxLedBrightness;
     }
+
+    if (!access(BUTTON_ATTR(brightness), W_OK)) {
+        lights_.emplace(std::make_pair(Type::BUTTONS,
+                                       [this](auto&&... args) { setLightButtons(args...); }));
+        buttons_.emplace_back(BUTTON_ATTR(brightness));
+
+        if (!access(BUTTON1_ATTR(brightness), W_OK)) {
+            buttons_.emplace_back(BUTTON1_ATTR(brightness));
+        }
+
+        if (ReadFileToString(BUTTON_ATTR(max_brightness), &buf)) {
+            max_button_brightness_ = std::stoi(buf);
+        } else {
+            max_button_brightness_ = kDefaultMaxLedBrightness;
+            LOG(ERROR) << "Failed to read max button brightness, fallback to "
+                       << kDefaultMaxLedBrightness;
+        }
+    }
 }
 
 Return<Status> Light::setLight(Type type, const LightState& state) {
@@ -154,6 +175,13 @@ void Light::setLightBacklight(Type /*type*/, const LightState& state) {
     WriteToFile(LCD_ATTR(brightness), brightness);
 }
 
+void Light::setLightButtons(Type /*type*/, const LightState& state) {
+    uint32_t brightness = RgbaToBrightness(state.color, max_button_brightness_);
+    for (auto&& button : buttons_) {
+        WriteToFile(button, brightness);
+    }
+}
+
 void Light::setLightNotification(Type type, const LightState& state) {
     bool found = false;
     for (auto&& [cur_type, cur_state] : notif_states_) {
diff --git a/light/Light.h b/light/Light.h
index 7acefa7..1a28589 100644
--- a/light/Light.h
+++ b/light/Light.h
@@ -41,9 +41,11 @@ class Light : public ILight {
 
   private:
     void setLightBacklight(Type type, const LightState& state);
+    void setLightButtons(Type type, const LightState& state);
     void setLightNotification(Type type, const LightState& state);
     void applyNotificationState(const LightState& state);
 
+    uint32_t max_button_brightness_;
     uint32_t max_led_brightness_;
     uint32_t max_screen_brightness_;
 
@@ -57,6 +59,8 @@ class Light : public ILight {
             {Type::NOTIFICATIONS, {}},
             {Type::BATTERY, {}},
     }};
+
+    std::vector<std::string> buttons_;
 };
 
 }  // namespace implementation
diff --git a/light/android.hardware.light@2.0-service.xiaomi_sdm660.rc b/light/android.hardware.light@2.0-service.xiaomi_sdm660.rc
index 969bdac..46a2e62 100644
--- a/light/android.hardware.light@2.0-service.xiaomi_sdm660.rc
+++ b/light/android.hardware.light@2.0-service.xiaomi_sdm660.rc
@@ -9,6 +9,10 @@ on boot
     chown system system /sys/class/leds/white/ramp_step_ms
     chown system system /sys/class/leds/white/start_idx
 
+    chown system system /sys/class/leds/button-backlight/max_brightness
+    chown system system /sys/class/leds/button-backlight1/brightness
+    chown system system /sys/class/leds/button-backlight1/max_brightness
+
     chown system system /sys/class/leds/lcd-backlight/max_brightness
 
     start vendor.light-hal-2-0