display backlight and bluetooth reference counting (#639)

Tactility/Source/app/boot/Boot.cpp

@@ -99,6 +99,7 @@ void setupDisplay() {
         } else {
             LOG_E(TAG, "Failed to set brightness of %s", backlight->name);
         }
+        device_put(backlight);
     } else {
         LOG_I(TAG, "No backlight for %s", display->name);
     }

Tactility/Source/app/display/Display.cpp

@@ -74,6 +74,7 @@ void onBacklightSliderEvent(lv_event_t* event) {
     ctx->displaySettings.backlightDuty = static_cast<uint8_t>(slider_value);
     ctx->displaySettingsUpdated = true;
     backlight_set_brightness(backlight, ctx->displaySettings.backlightDuty);
+    device_put(backlight);
 }
 
 void onOrientationSet(lv_event_t* event) {
@@ -184,6 +185,8 @@ void createWidgets(lv_obj_t* parent, void* userData) {
 
             lv_slider_set_value(brightness_slider, ctx->displaySettings.backlightDuty, LV_ANIM_OFF);
         }
+        // Only compared against nullptr below, never dereferenced again, so releasing it here is safe.
+        device_put(backlight);
     }
 
     // Orientation

Tactility/Source/bluetooth/Bluetooth.cpp

@@ -138,20 +138,23 @@ static void bt_event_bridge(BtEvent event) {
                             }
                         } else if (has_hid_device_auto) {
                             LOG_I(TAG, "HID device auto-start (bonded peer found)");
-                            if (Device* dev = bluetooth_hid_device_get_device()) {
+                            if (Device* dev = bluetooth_hid_device_get()) {
                                 bluetooth_hid_device_start(dev, BT_HID_DEVICE_MODE_KEYBOARD);
+                                device_put(dev);
                             }
                         } else {
                             if (settings::shouldSppAutoStart()) {
                                 LOG_I(TAG, "Auto-starting SPP server");
-                                if (Device* dev = bluetooth_serial_get_device()) {
+                                if (Device* dev = bluetooth_serial_get()) {
                                     bluetooth_serial_start(dev);
+                                    device_put(dev);
                                 }
                             }
                             if (settings::shouldMidiAutoStart()) {
                                 LOG_I(TAG, "Auto-starting MIDI server");
-                                if (Device* dev = bluetooth_midi_get_device()) {
+                                if (Device* dev = bluetooth_midi_get()) {
                                     bluetooth_midi_start(dev);
+                                    device_put(dev);
                                 }
                             }
                         }
@@ -476,18 +479,21 @@ void connect(const std::array<uint8_t, 6>& addr, int profileId) {
     if (profileId == BT_PROFILE_HID_HOST) {
         hidHostConnect(addr);
     } else if (profileId == BT_PROFILE_HID_DEVICE) {
-        if (Device* dev = bluetooth_hid_device_get_device()) {
+        if (Device* dev = bluetooth_hid_device_get()) {
             bluetooth_hid_device_start(dev, BT_HID_DEVICE_MODE_KEYBOARD);
+            device_put(dev);
         }
     } else if (profileId == BT_PROFILE_SPP) {
-        if (Device* dev = bluetooth_serial_get_device()) {
+        if (Device* dev = bluetooth_serial_get()) {
             bluetooth_serial_start(dev);
             settings::setSppAutoStart(true);
+            device_put(dev);
         }
     } else if (profileId == BT_PROFILE_MIDI) {
-        if (Device* dev = bluetooth_midi_get_device()) {
+        if (Device* dev = bluetooth_midi_get()) {
             bluetooth_midi_start(dev);
             settings::setMidiAutoStart(true);
+            device_put(dev);
         }
     }
 }
@@ -497,8 +503,9 @@ void disconnect(const std::array<uint8_t, 6>& addr, int profileId) {
     if (profileId == BT_PROFILE_HID_HOST) {
         hidHostDisconnect();
     } else if (profileId == BT_PROFILE_HID_DEVICE) {
-        if (Device* dev = bluetooth_hid_device_get_device()) {
+        if (Device* dev = bluetooth_hid_device_get()) {
             bluetooth_hid_device_stop(dev);
+            device_put(dev);
         }
     } else {
         Device* dev;

Tactility/Source/service/displayidle/DisplayIdle.cpp

@@ -38,7 +38,6 @@ static void setBacklightBrightness(uint8_t brightness) {
     if (device_get_first_active_by_type(&DISPLAY_TYPE, &display) == ERROR_NONE) {
         ::Device* backlight;
         if (display_get_backlight(display, &backlight) == ERROR_NONE) {
-            device_get(backlight);
             backlight_set_brightness(backlight, brightness);
             device_put(backlight);
         }
@@ -53,6 +52,7 @@ static bool hasDisplayWithBacklight() {
         ::Device* backlight;
         if (display_get_backlight(display, &backlight) == ERROR_NONE) {
             result = true;
+            device_put(backlight);
         }
         device_put(display);
     }

Tactility/Source/service/statusbar/Statusbar.cpp

@@ -178,10 +178,16 @@ class StatusbarService final : public Service {
             }
         }
 
-        Device* serial_dev = bluetooth_serial_get_device();
-        Device* midi_dev = bluetooth_midi_get_device();
+        Device* serial_dev = bluetooth_serial_get();
+        Device* midi_dev = bluetooth_midi_get();
         bool connected = (serial_dev && bluetooth_serial_is_connected(serial_dev)) ||
                          (midi_dev && bluetooth_midi_is_connected(midi_dev));
+        if (serial_dev) {
+            device_put(serial_dev);
+        }
+        if (midi_dev) {
+            device_put(midi_dev);
+        }
         const char* desired_icon = getBluetoothStatusIcon(radio_state, scanning, connected);
         if (bt_last_icon != desired_icon) {
             if (desired_icon != nullptr) {