DSi power button and volume switch support (#1630)

* Add proper BPTWL interrupts

* Added DSi power button and volume switch hotkeys

* Added hardware reset workaround

* Adjusted syntax to follow guidelines

* Added DSi output volume synchronization

* Fix trivial member function error

12 files changed, 534 insertions, 22 deletions

diff --git a/.gitignore b/.gitignore
index 7bbb40a..e76a094 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,8 @@ compile_commands.json
 *.exe
 
 .DS_Store
+
+.vs
+.vscode
+CMakeFiles
+CMakeCache.txt
diff --git a/src/DSi_I2C.cpp b/src/DSi_I2C.cpp
index b4cfa89..7bb7e1d 100644
--- a/src/DSi_I2C.cpp
+++ b/src/DSi_I2C.cpp
@@ -18,6 +18,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <math.h>
 #include "DSi.h"
 #include "DSi_I2C.h"
 #include "DSi_Camera.h"
@@ -31,6 +32,38 @@ using Platform::LogLevel;
 namespace DSi_BPTWL
 {
 
+// TODO: These are purely approximations
+const double PowerButtonShutdownTime = 0.5;
+const double PowerButtonForcedShutdownTime = 5.0;
+const double VolumeSwitchRepeatStart = 0.5;
+const double VolumeSwitchRepeatRate = 1.0 / 6;
+
+// Could not find a pattern or a decent formula for these,
+// regardless, they're only 64 bytes in size
+const u8 VolumeDownTable[32] =
+{
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x02, 0x03,
+    0x04, 0x05, 0x06, 0x06, 0x07, 0x08, 0x09, 0x0A,
+    0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12,
+    0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A,
+};
+
+const u8 VolumeUpTable[32] =
+{
+    0x02, 0x03, 0x06, 0x07, 0x08, 0x0A, 0x0B, 0x0C,
+    0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14,
+    0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C,
+    0x1D, 0x1E, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F,
+};
+
+double PowerButtonTime = 0.0;
+bool PowerButtonDownFlag = false;
+bool PowerButtonShutdownFlag = false;
+double VolumeSwitchTime = 0.0;
+double VolumeSwitchRepeatTime = 0.0;
+bool VolumeSwitchDownFlag = false;
+u32 VolumeSwitchKeysDown = 0;
+
 u8 Registers[0x100];
 u32 CurPos;
 
@@ -51,9 +84,9 @@ void Reset()
     Registers[0x00] = 0x33; // TODO: support others??
     Registers[0x01] = 0x00;
     Registers[0x02] = 0x50;
-    Registers[0x10] = 0x00; // power btn
+    Registers[0x10] = 0x00; // irq flag
     Registers[0x11] = 0x00; // reset
-    Registers[0x12] = 0x00; // power btn tap
+    Registers[0x12] = 0x00; // irq mode
     Registers[0x20] = 0x8F; // battery
     Registers[0x21] = 0x07;
     Registers[0x30] = 0x13;
@@ -74,6 +107,15 @@ void Reset()
     Registers[0x77] = 0x00;
     Registers[0x80] = 0x10;
     Registers[0x81] = 0x64;
+
+    // Ideally these should be replaced by a proper BPTWL core emulator
+    PowerButtonTime = 0.0;
+    PowerButtonDownFlag = false;
+    PowerButtonShutdownFlag = false;
+    VolumeSwitchTime = 0.0;
+    VolumeSwitchRepeatTime = 0.0;
+    VolumeSwitchKeysDown = 0;
+
 }
 
 void DoSavestate(Savestate* file)
@@ -84,6 +126,12 @@ void DoSavestate(Savestate* file)
     file->Var32(&CurPos);
 }
 
+// TODO: Needs more investigation on the other bits
+inline bool GetIRQMode()
+{
+    return Registers[0x12] & 0x01;
+}
+
 u8 GetBootFlag() { return Registers[0x70]; }
 
 bool GetBatteryCharging() { return Registers[0x20] >> 7; }
@@ -97,6 +145,242 @@ void SetBatteryLevel(u8 batteryLevel)
 {
     Registers[0x20] = ((Registers[0x20] & 0xF0) | (batteryLevel & 0x0F));
     SPI_Powerman::SetBatteryLevelOkay(batteryLevel > batteryLevel_Low ? true : false);
+
+    if (batteryLevel <= 1)
+    {
+        SetIRQ(batteryLevel ? IRQ_BatteryLow : IRQ_BatteryEmpty);
+    }
+
+}
+
+u8 GetVolumeLevel() { return Registers[0x40]; }
+void SetVolumeLevel(u8 volume)
+{
+    Registers[0x40] = volume & 0x1F;
+}
+
+u8 GetBacklightLevel() { return Registers[0x41]; }
+void SetBacklightLevel(u8 backlight)
+{
+    Registers[0x41] = backlight > 4 ? 4 : backlight;
+}
+
+
+void ResetButtonState()
+{
+    PowerButtonTime = 0.0;
+    PowerButtonDownFlag = false;
+    PowerButtonShutdownFlag = false;
+
+    VolumeSwitchKeysDown = 0;
+    VolumeSwitchDownFlag = false;
+    VolumeSwitchTime = 0.0;
+    VolumeSwitchRepeatTime = 0.0;
+}
+
+void DoHardwareReset(bool direct)
+{
+    ResetButtonState();
+
+    Log(LogLevel::Debug, "BPTWL: soft-reset\n");
+
+    if (direct)
+    {
+        // TODO: This doesn't seem to stop the SPU
+        DSi::SoftReset();
+        return;
+    }
+
+    // TODO: soft-reset might need to be scheduled later!
+    // TODO: this has been moved for the JIT to work, nothing is confirmed here
+    NDS::ARM7->Halt(4);
+}
+
+void DoShutdown()
+{
+    ResetButtonState();
+    NDS::Stop();
+}
+
+
+void SetPowerButtonHeld(double time)
+{
+    if (!PowerButtonDownFlag)
+    {
+        PowerButtonDownFlag = true;
+        PowerButtonTime = time;
+        DoPowerButtonPress();
+        return;
+    }
+
+    double elapsed = time - PowerButtonTime;
+    if (elapsed < 0)
+        return;
+
+    if (elapsed >= PowerButtonForcedShutdownTime)
+    {
+        Log(LogLevel::Debug, "Force power off via DSi power button\n");
+        DoPowerButtonForceShutdown();
+        return;
+    }
+
+    if (elapsed >= PowerButtonShutdownTime)
+    {
+        DoPowerButtonShutdown();
+    }
+}
+
+void SetPowerButtonReleased(double time)
+{
+    double elapsed = time - PowerButtonTime;
+    if (elapsed >= 0 && elapsed < PowerButtonShutdownTime)
+    {
+        DoPowerButtonReset();
+    }
+
+    PowerButtonTime = 0.0;
+    PowerButtonDownFlag = false;
+    PowerButtonShutdownFlag = false;
+}
+
+void SetVolumeSwitchHeld(u32 key)
+{
+    VolumeSwitchKeysDown |= (1 << key);
+}
+
+void SetVolumeSwitchReleased(u32 key)
+{
+    VolumeSwitchKeysDown &= ~(1 << key);
+    VolumeSwitchDownFlag = false;
+    VolumeSwitchTime = 0.0;
+    VolumeSwitchRepeatTime = 0.0;
+}
+
+inline bool CheckVolumeSwitchKeysValid()
+{
+    bool up = VolumeSwitchKeysDown & (1 << volumeKey_Up);
+    bool down = VolumeSwitchKeysDown & (1 << volumeKey_Down);
+
+    return up != down;
+}
+
+s32 ProcessVolumeSwitchInput(double time)
+{
+    if (!CheckVolumeSwitchKeysValid())
+        return -1;
+
+    s32 key = VolumeSwitchKeysDown & (1 << volumeKey_Up) ? volumeKey_Up : volumeKey_Down;
+
+    // Always fire an IRQ when first pressed
+    if (!VolumeSwitchDownFlag)
+    {
+        VolumeSwitchDownFlag = true;
+        VolumeSwitchTime = time;
+        DoVolumeSwitchPress(key);
+        return key;
+    }
+
+    // Handle key repetition mechanic
+    if (VolumeSwitchRepeatTime == 0)
+    {
+        double elapsed = time - VolumeSwitchTime;
+        if (elapsed < VolumeSwitchRepeatStart)
+            return -1;
+
+        VolumeSwitchRepeatTime = time;
+        DoVolumeSwitchPress(key);
+        return key;
+    }
+
+    double elapsed = time - VolumeSwitchRepeatTime;
+    if (elapsed < VolumeSwitchRepeatRate)
+        return -1;
+
+    double rem = fmod(elapsed, VolumeSwitchRepeatRate);
+    VolumeSwitchRepeatTime = time - rem;
+    DoVolumeSwitchPress(key);
+    return key;
+}
+
+
+void DoPowerButtonPress()
+{
+    // Set button pressed IRQ
+    SetIRQ(IRQ_PowerButtonPressed);
+
+    // There is no default hardware behavior for pressing the power button
+}
+
+void DoPowerButtonReset()
+{
+    // Reset via IRQ, handled by software
+    SetIRQ(IRQ_PowerButtonReset);
+
+    // Reset automatically via hardware
+    if (!GetIRQMode())
+    {
+        // Assumes this isn't called during normal CPU execution
+        DoHardwareReset(true);
+    }
+}
+
+void DoPowerButtonShutdown()
+{
+    // Shutdown via IRQ, handled by software
+    if (!PowerButtonShutdownFlag)
+    {
+        SetIRQ(IRQ_PowerButtonShutdown);
+    }
+
+    PowerButtonShutdownFlag = true;
+
+    // Shutdown automatically via hardware
+    if (!GetIRQMode())
+    {
+        DoShutdown();
+    }
+
+    // The IRQ is only fired once (hence the need for an if guard),
+    // but the hardware shutdown is continuously triggered.
+    // That way when switching the IRQ mode while holding
+    // down the power button, the DSi will still shut down
+}
+
+void DoPowerButtonForceShutdown()
+{
+    DoShutdown();
+}
+
+void DoVolumeSwitchPress(u32 key)
+{
+    u8 volume = Registers[0x40];
+
+    switch (key)
+    {
+
+    case volumeKey_Up:
+        volume = VolumeUpTable[volume];
+        break;
+
+    case volumeKey_Down:
+        volume = VolumeDownTable[volume];
+        break;
+
+    }
+
+    Registers[0x40] = volume;
+
+    SetIRQ(IRQ_VolumeSwitchPressed);
+}
+
+void SetIRQ(u8 irqFlag)
+{
+    Registers[0x10] |= irqFlag & IRQ_ValidMask;
+
+    if (GetIRQMode())
+    {
+        NDS::SetIRQ2(NDS::IRQ2_DSi_BPTWL);
+    }
 }
 
 void Start()
@@ -107,7 +391,15 @@ void Start()
 u8 Read(bool last)
 {
     //printf("BPTWL: read %02X -> %02X @ %08X\n", CurPos, Registers[CurPos], NDS::GetPC(1));
-    u8 ret = Registers[CurPos++];
+    u8 ret = Registers[CurPos];
+
+    // IRQ flags are automatically cleared upon read
+    if (CurPos == 0x10)
+    {
+        Registers[0x10] = 0;
+    }
+
+    CurPos++;
 
     if (last)
     {
@@ -134,19 +426,29 @@ void Write(u8 val, bool last)
 
     if (CurPos == 0x11 && val == 0x01)
     {
-        Log(LogLevel::Debug, "BPTWL: soft-reset\n");
+        // Assumes this is called during normal CPU execution
+        DoHardwareReset(false);
         val = 0; // checkme
-        // TODO: soft-reset might need to be scheduled later!
-        // TODO: this has been moved for the JIT to work, nothing is confirmed here
-        NDS::ARM7->Halt(4);
         CurPos = -1;
         return;
     }
 
+    // Mask volume level
+    if (CurPos == 0x40)
+    {
+        val &= 0x1F;
+    }
+
+    // Clamp backlight level
+    if (CurPos == 0x41)
+    {
+        val = val > 4 ? 4 : val;
+    }
+
     if (CurPos == 0x11 || CurPos == 0x12 ||
         CurPos == 0x21 ||
         CurPos == 0x30 || CurPos == 0x31 ||
-        CurPos == 0x40 || CurPos == 0x31 ||
+        CurPos == 0x40 || CurPos == 0x41 ||
         CurPos == 0x60 || CurPos == 0x63 ||
         (CurPos >= 0x70 && CurPos <= 0x77) ||
         CurPos == 0x80 || CurPos == 0x81)
diff --git a/src/DSi_I2C.h b/src/DSi_I2C.h
index 48c8e88..8a54a2c 100644
--- a/src/DSi_I2C.h
+++ b/src/DSi_I2C.h
@@ -42,6 +42,56 @@ enum
 
 u8 GetBatteryLevel();
 void SetBatteryLevel(u8 batteryLevel);
+
+// 0-31
+u8 GetVolumeLevel();
+void SetVolumeLevel(u8 volume);
+
+// 0-4
+u8 GetBacklightLevel();
+void SetBacklightLevel(u8 backlight);
+
+void DoHardwareReset(bool direct);
+void DoShutdown();
+
+enum
+{
+    volumeKey_Up,
+    volumeKey_Down,
+};
+
+// Used by hotkeys
+void SetPowerButtonHeld(double time);
+void SetPowerButtonReleased(double time);
+void SetVolumeSwitchHeld(u32 key);
+void SetVolumeSwitchReleased(u32 key);
+s32 ProcessVolumeSwitchInput(double time);
+
+void DoPowerButtonPress();
+void DoPowerButtonReset();
+void DoPowerButtonShutdown();
+void DoPowerButtonForceShutdown();
+void DoVolumeSwitchPress(u32 key);
+
+enum
+{
+    IRQ_PowerButtonReset    = 0x01, // Triggered after releasing the power button quickly
+    IRQ_PowerButtonShutdown = 0x02, // Triggered after holding the power button for less than a second
+    IRQ_PowerButtonPressed  = 0x08, // Triggered after pressing the power button
+    IRQ_BatteryEmpty        = 0x10, //
+    IRQ_BatteryLow          = 0x20, // Triggered when the battery level reaches 1
+    IRQ_VolumeSwitchPressed = 0x40, // Triggered once when the volume sliders are first pressed and repeatedly when held down
+    /*
+        Bit 2 (0x04) could be set when holding the power button for more than 5 seconds? (forced power off)
+        It is unknown whether it is set as the console powers off immediately.
+        Bit 7 (0x80) is unused?
+        Both bits are never used by the official ARM7 libraries, but could have some undocumented hardware functionality (?).
+    */
+    IRQ_ValidMask           = 0x7B,
+};
+
+void SetIRQ(u8 irqFlag);
+
 }
 
 namespace DSi_I2C
diff --git a/src/NDS.h b/src/NDS.h
index 824c2bc..dc7809e 100644
--- a/src/NDS.h
+++ b/src/NDS.h
@@ -110,7 +110,7 @@ enum
     IRQ2_DSi_Unused3,
     IRQ2_DSi_GPIO33_0,
     IRQ2_DSi_Headphone,
-    IRQ2_DSi_PowerButton,
+    IRQ2_DSi_BPTWL,
     IRQ2_DSi_GPIO33_3, // "sound enable input"
     IRQ2_DSi_SDMMC,
     IRQ2_DSi_SD_Data1,
diff --git a/src/frontend/qt_sdl/AudioSettingsDialog.cpp b/src/frontend/qt_sdl/AudioSettingsDialog.cpp
index 4beefaf..198c06b 100644
--- a/src/frontend/qt_sdl/AudioSettingsDialog.cpp
+++ b/src/frontend/qt_sdl/AudioSettingsDialog.cpp
@@ -22,6 +22,8 @@
 #include "types.h"
 #include "Platform.h"
 #include "Config.h"
+#include "NDS.h"
+#include "DSi_I2C.h"
 
 #include "AudioSettingsDialog.h"
 #include "ui_AudioSettingsDialog.h"
@@ -32,7 +34,7 @@ AudioSettingsDialog* AudioSettingsDialog::currentDlg = nullptr;
 extern std::string EmuDirectory;
 
 
-AudioSettingsDialog::AudioSettingsDialog(QWidget* parent) : QDialog(parent), ui(new Ui::AudioSettingsDialog)
+AudioSettingsDialog::AudioSettingsDialog(QWidget* parent, bool emuActive) : QDialog(parent), ui(new Ui::AudioSettingsDialog)
 {
     ui->setupUi(this);
     setAttribute(Qt::WA_DeleteOnClose);
@@ -40,6 +42,7 @@ AudioSettingsDialog::AudioSettingsDialog(QWidget* parent) : QDialog(parent), ui(
     oldInterp = Config::AudioInterp;
     oldBitrate = Config::AudioBitrate;
     oldVolume = Config::AudioVolume;
+    oldDSiSync = Config::DSiVolumeSync;
 
     ui->cbInterpolation->addItem("None");
     ui->cbInterpolation->addItem("Linear");
@@ -52,7 +55,21 @@ AudioSettingsDialog::AudioSettingsDialog(QWidget* parent) : QDialog(parent), ui(
     ui->cbBitrate->addItem("16-bit");
     ui->cbBitrate->setCurrentIndex(Config::AudioBitrate);
 
+    bool state = ui->slVolume->blockSignals(true);
     ui->slVolume->setValue(Config::AudioVolume);
+    ui->slVolume->blockSignals(state);
+
+    ui->chkSyncDSiVolume->setChecked(Config::DSiVolumeSync);
+
+    // Setup volume slider accordingly
+    if (emuActive && NDS::ConsoleType == 1)
+    {
+        on_chkSyncDSiVolume_clicked(Config::DSiVolumeSync);
+    }
+    else
+    {
+        ui->chkSyncDSiVolume->setEnabled(false);
+    }
 
     grpMicMode = new QButtonGroup(this);
     grpMicMode->addButton(ui->rbMicNone,     0);
@@ -88,6 +105,22 @@ AudioSettingsDialog::~AudioSettingsDialog()
     delete ui;
 }
 
+void AudioSettingsDialog::onSyncVolumeLevel()
+{
+    if (Config::DSiVolumeSync && NDS::ConsoleType == 1)
+    {
+        bool state = ui->slVolume->blockSignals(true);
+        ui->slVolume->setValue(DSi_BPTWL::GetVolumeLevel());
+        ui->slVolume->blockSignals(state);
+    }
+}
+
+void AudioSettingsDialog::onConsoleReset()
+{
+    on_chkSyncDSiVolume_clicked(Config::DSiVolumeSync);
+    ui->chkSyncDSiVolume->setEnabled(NDS::ConsoleType == 1);
+}
+
 void AudioSettingsDialog::on_AudioSettingsDialog_accepted()
 {
     Config::MicInputType = grpMicMode->checkedId();
@@ -102,6 +135,7 @@ void AudioSettingsDialog::on_AudioSettingsDialog_rejected()
     Config::AudioInterp = oldInterp;
     Config::AudioBitrate = oldBitrate;
     Config::AudioVolume = oldVolume;
+    Config::DSiVolumeSync = oldDSiSync;
 
     closeDlg();
 }
@@ -128,9 +162,38 @@ void AudioSettingsDialog::on_cbInterpolation_currentIndexChanged(int idx)
 
 void AudioSettingsDialog::on_slVolume_valueChanged(int val)
 {
+    if (Config::DSiVolumeSync && NDS::ConsoleType == 1)
+    {
+        DSi_BPTWL::SetVolumeLevel(val);
+        return;
+    }
+
     Config::AudioVolume = val;
 }
 
+void AudioSettingsDialog::on_chkSyncDSiVolume_clicked(bool checked)
+{
+    Config::DSiVolumeSync = checked;
+
+    bool state = ui->slVolume->blockSignals(true);
+    if (Config::DSiVolumeSync && NDS::ConsoleType == 1)
+    {
+        ui->slVolume->setMaximum(31);
+        ui->slVolume->setValue(DSi_BPTWL::GetVolumeLevel());
+        ui->slVolume->setPageStep(4);
+        ui->slVolume->setTickPosition(QSlider::TicksBelow);
+    }
+    else
+    {
+        Config::AudioVolume = oldVolume;
+        ui->slVolume->setMaximum(256);
+        ui->slVolume->setValue(Config::AudioVolume);
+        ui->slVolume->setPageStep(16);
+        ui->slVolume->setTickPosition(QSlider::NoTicks);
+    }
+    ui->slVolume->blockSignals(state);
+}
+
 void AudioSettingsDialog::onChangeMicMode(int mode)
 {
     bool iswav = (mode == 3);
diff --git a/src/frontend/qt_sdl/AudioSettingsDialog.h b/src/frontend/qt_sdl/AudioSettingsDialog.h
index 498c152..14d1ad3 100644
--- a/src/frontend/qt_sdl/AudioSettingsDialog.h
+++ b/src/frontend/qt_sdl/AudioSettingsDialog.h
@@ -30,11 +30,11 @@ class AudioSettingsDialog : public QDialog
     Q_OBJECT
 
 public:
-    explicit AudioSettingsDialog(QWidget* parent);
+    explicit AudioSettingsDialog(QWidget* parent, bool emuActive);
     ~AudioSettingsDialog();
 
     static AudioSettingsDialog* currentDlg;
-    static AudioSettingsDialog* openDlg(QWidget* parent)
+    static AudioSettingsDialog* openDlg(QWidget* parent, bool emuActive)
     {
         if (currentDlg)
         {
@@ -42,7 +42,7 @@ public:
             return currentDlg;
         }
 
-        currentDlg = new AudioSettingsDialog(parent);
+        currentDlg = new AudioSettingsDialog(parent, emuActive);
         currentDlg->show();
         return currentDlg;
     }
@@ -51,6 +51,9 @@ public:
         currentDlg = nullptr;
     }
 
+    void onSyncVolumeLevel();
+    void onConsoleReset();
+
 signals:
     void updateAudioSettings();
 
@@ -61,6 +64,7 @@ private slots:
     void on_cbInterpolation_currentIndexChanged(int idx);
     void on_cbBitrate_currentIndexChanged(int idx);
     void on_slVolume_valueChanged(int val);
+    void on_chkSyncDSiVolume_clicked(bool checked);
     void onChangeMicMode(int mode);
     void on_btnMicWavBrowse_clicked();
 
@@ -70,6 +74,7 @@ private:
     int oldInterp;
     int oldBitrate;
     int oldVolume;
+    bool oldDSiSync;
     QButtonGroup* grpMicMode;
 };
 
diff --git a/src/frontend/qt_sdl/AudioSettingsDialog.ui b/src/frontend/qt_sdl/AudioSettingsDialog.ui
index 8fc38d9..862042f 100644
--- a/src/frontend/qt_sdl/AudioSettingsDialog.ui
+++ b/src/frontend/qt_sdl/AudioSettingsDialog.ui
@@ -59,6 +59,16 @@
         </property>
        </widget>
       </item>
+      <item row="3" column="1">
+        <widget class="QCheckBox" name="chkSyncDSiVolume">
+         <property name="whatsThis">
+          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Synchronizes the output volume with the DSi hardware volume.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+         </property>
+         <property name="text">
+          <string>Sync with DSi volume</string>
+         </property>
+        </widget>
+      </item>
       <item row="0" column="0">
        <widget class="QLabel" name="label_2">
         <property name="text">
diff --git a/src/frontend/qt_sdl/Config.cpp b/src/frontend/qt_sdl/Config.cpp
index 4e00046..49c41a1 100644
--- a/src/frontend/qt_sdl/Config.cpp
+++ b/src/frontend/qt_sdl/Config.cpp
@@ -118,6 +118,7 @@ bool SavestateRelocSRAM;
 int AudioInterp;
 int AudioBitrate;
 int AudioVolume;
+bool DSiVolumeSync;
 int MicInputType;
 std::string MicWavPath;
 
@@ -187,6 +188,9 @@ ConfigEntry ConfigFile[] =
     {"HKKey_SolarSensorDecrease", 0, &HKKeyMapping[HK_SolarSensorDecrease], -1, true},
     {"HKKey_SolarSensorIncrease", 0, &HKKeyMapping[HK_SolarSensorIncrease], -1, true},
     {"HKKey_FrameStep",           0, &HKKeyMapping[HK_FrameStep],           -1, true},
+    {"HKKey_PowerButton",         0, &HKKeyMapping[HK_PowerButton],         -1, true},
+    {"HKKey_VolumeUp",            0, &HKKeyMapping[HK_VolumeUp],            -1, true},
+    {"HKKey_VolumeDown",          0, &HKKeyMapping[HK_VolumeDown],          -1, true},
 
     {"HKJoy_Lid",                 0, &HKJoyMapping[HK_Lid],                 -1, true},
     {"HKJoy_Mic",                 0, &HKJoyMapping[HK_Mic],                 -1, true},
@@ -200,6 +204,9 @@ ConfigEntry ConfigFile[] =
     {"HKJoy_SolarSensorDecrease", 0, &HKJoyMapping[HK_SolarSensorDecrease], -1, true},
     {"HKJoy_SolarSensorIncrease", 0, &HKJoyMapping[HK_SolarSensorIncrease], -1, true},
     {"HKJoy_FrameStep",           0, &HKJoyMapping[HK_FrameStep],           -1, true},
+    {"HKJoy_PowerButton",         0, &HKJoyMapping[HK_PowerButton],         -1, true},
+    {"HKJoy_VolumeUp",            0, &HKJoyMapping[HK_VolumeUp],            -1, true},
+    {"HKJoy_VolumeDown",          0, &HKJoyMapping[HK_VolumeDown],          -1, true},
 
     {"JoystickID", 0, &JoystickID, 0, true},
 
@@ -291,6 +298,7 @@ ConfigEntry ConfigFile[] =
     {"AudioInterp", 0, &AudioInterp, 0, false},
     {"AudioBitrate", 0, &AudioBitrate, 0, false},
     {"AudioVolume", 0, &AudioVolume, 256, true},
+    {"DSiVolumeSync", 0, &DSiVolumeSync, 0, true},
     {"MicInputType", 0, &MicInputType, 1, false},
     {"MicWavPath", 2, &MicWavPath, (std::string)"", false},
 
diff --git a/src/frontend/qt_sdl/Config.h b/src/frontend/qt_sdl/Config.h
index 42b0a6a..2d4022e 100644
--- a/src/frontend/qt_sdl/Config.h
+++ b/src/frontend/qt_sdl/Config.h
@@ -36,6 +36,9 @@ enum
     HK_SolarSensorDecrease,
     HK_SolarSensorIncrease,
     HK_FrameStep,
+    HK_PowerButton,
+    HK_VolumeUp,
+    HK_VolumeDown,
     HK_MAX
 };
 
@@ -163,6 +166,7 @@ extern bool SavestateRelocSRAM;
 extern int AudioInterp;
 extern int AudioBitrate;
 extern int AudioVolume;
+extern bool DSiVolumeSync;
 extern int MicInputType;
 extern std::string MicWavPath;
 
diff --git a/src/frontend/qt_sdl/InputConfig/InputConfigDialog.h b/src/frontend/qt_sdl/InputConfig/InputConfigDialog.h
index 76112e8..53ea876 100644
--- a/src/frontend/qt_sdl/InputConfig/InputConfigDialog.h
+++ b/src/frontend/qt_sdl/InputConfig/InputConfigDialog.h
@@ -52,7 +52,10 @@ static constexpr std::initializer_list<int> hk_general =
     HK_Lid,
     HK_Mic,
     HK_SwapScreens,
-    HK_SwapScreenEmphasis
+    HK_SwapScreenEmphasis,
+    HK_PowerButton,
+    HK_VolumeUp,
+    HK_VolumeDown
 };
 
 static constexpr std::initializer_list<const char*> hk_general_labels =
@@ -66,7 +69,10 @@ static constexpr std::initializer_list<const char*> hk_general_labels =
     "Close/open lid",
     "Microphone",
     "Swap screens",
-    "Swap screen emphasis"
+    "Swap screen emphasis",
+    "DSi Power button",
+    "DSi Volume up",
+    "DSi Volume down"
 };
 
 static_assert(hk_general.size() == hk_general_labels.size());
diff --git a/src/frontend/qt_sdl/main.cpp b/src/frontend/qt_sdl/main.cpp
index 803d1f1..7015c6d 100644
--- a/src/frontend/qt_sdl/main.cpp
+++ b/src/frontend/qt_sdl/main.cpp
@@ -88,6 +88,7 @@
 #include "Platform.h"
 #include "LocalMP.h"
 #include "Config.h"
+#include "DSi_I2C.h"
 
 #include "Savestate.h"
 
@@ -581,6 +582,7 @@ void EmuThread::run()
     double lastMeasureTime = lastTime;
 
     u32 winUpdateCount = 0, winUpdateFreq = 1;
+    u8 dsiVolumeLevel = 0x1F;
 
     char melontitle[100];
 
@@ -620,6 +622,42 @@ void EmuThread::run()
             }
         }
 
+        if (NDS::ConsoleType == 1)
+        {
+            double currentTime = SDL_GetPerformanceCounter() * perfCountsSec;
+
+            // Handle power button
+            if (Input::HotkeyDown(HK_PowerButton))
+            {
+                DSi_BPTWL::SetPowerButtonHeld(currentTime);
+            }
+            else if (Input::HotkeyReleased(HK_PowerButton))
+            {
+                DSi_BPTWL::SetPowerButtonReleased(currentTime);
+            }
+
+            // Handle volume buttons
+            if (Input::HotkeyDown(HK_VolumeUp))
+            {
+                DSi_BPTWL::SetVolumeSwitchHeld(DSi_BPTWL::volumeKey_Up);
+            }
+            else if (Input::HotkeyReleased(HK_VolumeUp))
+            {
+                DSi_BPTWL::SetVolumeSwitchReleased(DSi_BPTWL::volumeKey_Up);
+            }
+
+            if (Input::HotkeyDown(HK_VolumeDown))
+            {
+                DSi_BPTWL::SetVolumeSwitchHeld(DSi_BPTWL::volumeKey_Down);
+            }
+            else if (Input::HotkeyReleased(HK_VolumeDown))
+            {
+                DSi_BPTWL::SetVolumeSwitchReleased(DSi_BPTWL::volumeKey_Down);
+            }
+
+            DSi_BPTWL::ProcessVolumeSwitchInput(currentTime);
+        }
+
         if (EmuRunning == 1 || EmuRunning == 3)
         {
             EmuStatus = 1;
@@ -739,6 +777,18 @@ void EmuThread::run()
                 oglContext->SetSwapInterval(0);
             }
 
+            if (Config::DSiVolumeSync && NDS::ConsoleType == 1)
+            {
+                u8 volumeLevel = DSi_BPTWL::GetVolumeLevel();
+                if (volumeLevel != dsiVolumeLevel)
+                {
+                    dsiVolumeLevel = volumeLevel;
+                    emit syncVolumeLevel();
+                }
+
+                Config::AudioVolume = volumeLevel * (256.0 / 31.0);
+            }
+
             if (Config::AudioSync && !fastforward && audioDevice)
             {
                 SDL_LockMutex(audioSyncLock);
@@ -2583,7 +2633,7 @@ void MainWindow::onBootFirmware()
     }
 
     if (!ROMManager::LoadBIOS())
-{
+    {
         // TODO: better error reporting?
         QMessageBox::critical(this, "melonDS", "This firmware is not bootable.");
         emuThread->emuUnpause();
@@ -3027,7 +3077,9 @@ void MainWindow::onCameraSettingsFinished(int res)
 
 void MainWindow::onOpenAudioSettings()
 {
-    AudioSettingsDialog* dlg = AudioSettingsDialog::openDlg(this);
+    AudioSettingsDialog* dlg = AudioSettingsDialog::openDlg(this, emuThread->emuIsActive());
+    connect(emuThread, &EmuThread::syncVolumeLevel, dlg, &AudioSettingsDialog::onSyncVolumeLevel);
+    connect(emuThread, &EmuThread::windowEmuStart, dlg, &AudioSettingsDialog::onConsoleReset);
     connect(dlg, &AudioSettingsDialog::updateAudioSettings, this, &MainWindow::onUpdateAudioSettings);
     connect(dlg, &AudioSettingsDialog::finished, this, &MainWindow::onAudioSettingsFinished);
 }
@@ -3270,7 +3322,8 @@ void MainWindow::onTitleUpdate(QString title)
     setWindowTitle(title);
 }
 
-void ToggleFullscreen(MainWindow* mainWindow) {
+void ToggleFullscreen(MainWindow* mainWindow)
+{
     if (!mainWindow->isFullScreen())
     {
         mainWindow->showFullScreen();
@@ -3289,11 +3342,15 @@ void MainWindow::onFullscreenToggled()
     ToggleFullscreen(this);
 }
 
-void MainWindow::onScreenEmphasisToggled() {
+void MainWindow::onScreenEmphasisToggled()
+{
     int currentSizing = Config::ScreenSizing;
-    if (currentSizing == screenSizing_EmphTop) {
+    if (currentSizing == screenSizing_EmphTop)
+    {
         Config::ScreenSizing = screenSizing_EmphBot;
-    } else if (currentSizing == screenSizing_EmphBot) {
+    }
+    else if (currentSizing == screenSizing_EmphBot)
+    {
         Config::ScreenSizing = screenSizing_EmphTop;
     }
 
@@ -3436,7 +3493,7 @@ int main(int argc, char** argv)
     }
 
     SDL_JoystickEventState(SDL_ENABLE);
-    
+
     SDL_InitSubSystem(SDL_INIT_VIDEO);
     SDL_EnableScreenSaver(); SDL_DisableScreenSaver();
 
diff --git a/src/frontend/qt_sdl/main.h b/src/frontend/qt_sdl/main.h
index f9baea7..8a902ee 100644
--- a/src/frontend/qt_sdl/main.h
+++ b/src/frontend/qt_sdl/main.h
@@ -87,6 +87,8 @@ signals:
     void swapScreensToggle();
     void screenEmphasisToggle();
 
+    void syncVolumeLevel();
+
 private:
     void drawScreenGL();
     void initOpenGL();