4 files changed, 1086 insertions, 0 deletions
diff --git a/src/input_common/gcadapter/gc_adapter.cpp b/src/input_common/gcadapter/gc_adapter.cpp
new file mode 100644
index 0000000000..d80195c827
--- /dev/null
+++ b/src/input_common/gcadapter/gc_adapter.cpp
@@ -0,0 +1,509 @@
+// Copyright 2014 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <chrono>
+#include <thread>
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4200) // nonstandard extension used : zero-sized array in struct/union
+#endif
+#include <libusb.h>
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+#include "common/logging/log.h"
+#include "common/param_package.h"
+#include "input_common/gcadapter/gc_adapter.h"
+#include "input_common/settings.h"
+
+namespace GCAdapter {
+
+Adapter::Adapter() {
+    if (usb_adapter_handle != nullptr) {
+        return;
+    }
+    LOG_INFO(Input, "GC Adapter Initialization started");
+
+    const int init_res = libusb_init(&libusb_ctx);
+    if (init_res == LIBUSB_SUCCESS) {
+        adapter_scan_thread = std::thread(&Adapter::AdapterScanThread, this);
+    } else {
+        LOG_ERROR(Input, "libusb could not be initialized. failed with error = {}", init_res);
+    }
+}
+
+Adapter::~Adapter() {
+    Reset();
+}
+
+void Adapter::AdapterInputThread() {
+    LOG_DEBUG(Input, "GC Adapter input thread started");
+    s32 payload_size{};
+    AdapterPayload adapter_payload{};
+
+    if (adapter_scan_thread.joinable()) {
+        adapter_scan_thread.join();
+    }
+
+    while (adapter_input_thread_running) {
+        libusb_interrupt_transfer(usb_adapter_handle, input_endpoint, adapter_payload.data(),
+                                  static_cast<s32>(adapter_payload.size()), &payload_size, 16);
+        if (IsPayloadCorrect(adapter_payload, payload_size)) {
+            UpdateControllers(adapter_payload);
+            UpdateVibrations();
+        }
+        std::this_thread::yield();
+    }
+
+    if (restart_scan_thread) {
+        adapter_scan_thread = std::thread(&Adapter::AdapterScanThread, this);
+        restart_scan_thread = false;
+    }
+}
+
+bool Adapter::IsPayloadCorrect(const AdapterPayload& adapter_payload, s32 payload_size) {
+    if (payload_size != static_cast<s32>(adapter_payload.size()) ||
+        adapter_payload[0] != LIBUSB_DT_HID) {
+        LOG_DEBUG(Input, "Error reading payload (size: {}, type: {:02x})", payload_size,
+                  adapter_payload[0]);
+        if (input_error_counter++ > 20) {
+            LOG_ERROR(Input, "GC adapter timeout, Is the adapter connected?");
+            adapter_input_thread_running = false;
+            restart_scan_thread = true;
+        }
+        return false;
+    }
+
+    input_error_counter = 0;
+    return true;
+}
+
+void Adapter::UpdateControllers(const AdapterPayload& adapter_payload) {
+    for (std::size_t port = 0; port < pads.size(); ++port) {
+        const std::size_t offset = 1 + (9 * port);
+        const auto type = static_cast<ControllerTypes>(adapter_payload[offset] >> 4);
+        UpdatePadType(port, type);
+        if (DeviceConnected(port)) {
+            const u8 b1 = adapter_payload[offset + 1];
+            const u8 b2 = adapter_payload[offset + 2];
+            UpdateStateButtons(port, b1, b2);
+            UpdateStateAxes(port, adapter_payload);
+            if (configuring) {
+                UpdateYuzuSettings(port);
+            }
+        }
+    }
+}
+
+void Adapter::UpdatePadType(std::size_t port, ControllerTypes pad_type) {
+    if (pads[port].type == pad_type) {
+        return;
+    }
+    // Device changed reset device and set new type
+    ResetDevice(port);
+    pads[port].type = pad_type;
+}
+
+void Adapter::UpdateStateButtons(std::size_t port, u8 b1, u8 b2) {
+    if (port >= pads.size()) {
+        return;
+    }
+
+    static constexpr std::array<PadButton, 8> b1_buttons{
+        PadButton::ButtonA,    PadButton::ButtonB,     PadButton::ButtonX,    PadButton::ButtonY,
+        PadButton::ButtonLeft, PadButton::ButtonRight, PadButton::ButtonDown, PadButton::ButtonUp,
+    };
+
+    static constexpr std::array<PadButton, 4> b2_buttons{
+        PadButton::ButtonStart,
+        PadButton::TriggerZ,
+        PadButton::TriggerR,
+        PadButton::TriggerL,
+    };
+    pads[port].buttons = 0;
+    for (std::size_t i = 0; i < b1_buttons.size(); ++i) {
+        if ((b1 & (1U << i)) != 0) {
+            pads[port].buttons =
+                static_cast<u16>(pads[port].buttons | static_cast<u16>(b1_buttons[i]));
+            pads[port].last_button = b1_buttons[i];
+        }
+    }
+
+    for (std::size_t j = 0; j < b2_buttons.size(); ++j) {
+        if ((b2 & (1U << j)) != 0) {
+            pads[port].buttons =
+                static_cast<u16>(pads[port].buttons | static_cast<u16>(b2_buttons[j]));
+            pads[port].last_button = b2_buttons[j];
+        }
+    }
+}
+
+void Adapter::UpdateStateAxes(std::size_t port, const AdapterPayload& adapter_payload) {
+    if (port >= pads.size()) {
+        return;
+    }
+
+    const std::size_t offset = 1 + (9 * port);
+    static constexpr std::array<PadAxes, 6> axes{
+        PadAxes::StickX,    PadAxes::StickY,      PadAxes::SubstickX,
+        PadAxes::SubstickY, PadAxes::TriggerLeft, PadAxes::TriggerRight,
+    };
+
+    for (const PadAxes axis : axes) {
+        const auto index = static_cast<std::size_t>(axis);
+        const u8 axis_value = adapter_payload[offset + 3 + index];
+        if (pads[port].axis_origin[index] == 255) {
+            pads[port].axis_origin[index] = axis_value;
+        }
+        pads[port].axis_values[index] =
+            static_cast<s16>(axis_value - pads[port].axis_origin[index]);
+    }
+}
+
+void Adapter::UpdateYuzuSettings(std::size_t port) {
+    if (port >= pads.size()) {
+        return;
+    }
+
+    constexpr u8 axis_threshold = 50;
+    GCPadStatus pad_status = {.port = port};
+
+    if (pads[port].buttons != 0) {
+        pad_status.button = pads[port].last_button;
+        pad_queue.Push(pad_status);
+    }
+
+    // Accounting for a threshold here to ensure an intentional press
+    for (std::size_t i = 0; i < pads[port].axis_values.size(); ++i) {
+        const s16 value = pads[port].axis_values[i];
+
+        if (value > axis_threshold || value < -axis_threshold) {
+            pad_status.axis = static_cast<PadAxes>(i);
+            pad_status.axis_value = value;
+            pad_status.axis_threshold = axis_threshold;
+            pad_queue.Push(pad_status);
+        }
+    }
+}
+
+void Adapter::UpdateVibrations() {
+    // Use 8 states to keep the switching between on/off fast enough for
+    // a human to not notice the difference between switching from on/off
+    // More states = more rumble strengths = slower update time
+    constexpr u8 vibration_states = 8;
+
+    vibration_counter = (vibration_counter + 1) % vibration_states;
+
+    for (GCController& pad : pads) {
+        const bool vibrate = pad.rumble_amplitude > vibration_counter;
+        vibration_changed |= vibrate != pad.enable_vibration;
+        pad.enable_vibration = vibrate;
+    }
+    SendVibrations();
+}
+
+void Adapter::SendVibrations() {
+    if (!rumble_enabled || !vibration_changed) {
+        return;
+    }
+    s32 size{};
+    constexpr u8 rumble_command = 0x11;
+    const u8 p1 = pads[0].enable_vibration;
+    const u8 p2 = pads[1].enable_vibration;
+    const u8 p3 = pads[2].enable_vibration;
+    const u8 p4 = pads[3].enable_vibration;
+    std::array<u8, 5> payload = {rumble_command, p1, p2, p3, p4};
+    const int err = libusb_interrupt_transfer(usb_adapter_handle, output_endpoint, payload.data(),
+                                              static_cast<s32>(payload.size()), &size, 16);
+    if (err) {
+        LOG_DEBUG(Input, "Adapter libusb write failed: {}", libusb_error_name(err));
+        if (output_error_counter++ > 5) {
+            LOG_ERROR(Input, "GC adapter output timeout, Rumble disabled");
+            rumble_enabled = false;
+        }
+        return;
+    }
+    output_error_counter = 0;
+    vibration_changed = false;
+}
+
+bool Adapter::RumblePlay(std::size_t port, u8 amplitude) {
+    pads[port].rumble_amplitude = amplitude;
+
+    return rumble_enabled;
+}
+
+void Adapter::AdapterScanThread() {
+    adapter_scan_thread_running = true;
+    adapter_input_thread_running = false;
+    if (adapter_input_thread.joinable()) {
+        adapter_input_thread.join();
+    }
+    ClearLibusbHandle();
+    ResetDevices();
+    while (adapter_scan_thread_running && !adapter_input_thread_running) {
+        Setup();
+        std::this_thread::sleep_for(std::chrono::seconds(1));
+    }
+}
+
+void Adapter::Setup() {
+    usb_adapter_handle = libusb_open_device_with_vid_pid(libusb_ctx, 0x057e, 0x0337);
+
+    if (usb_adapter_handle == NULL) {
+        return;
+    }
+    if (!CheckDeviceAccess()) {
+        ClearLibusbHandle();
+        return;
+    }
+
+    libusb_device* device = libusb_get_device(usb_adapter_handle);
+
+    LOG_INFO(Input, "GC adapter is now connected");
+    // GC Adapter found and accessible, registering it
+    if (GetGCEndpoint(device)) {
+        adapter_scan_thread_running = false;
+        adapter_input_thread_running = true;
+        rumble_enabled = true;
+        input_error_counter = 0;
+        output_error_counter = 0;
+        adapter_input_thread = std::thread(&Adapter::AdapterInputThread, this);
+    }
+}
+
+bool Adapter::CheckDeviceAccess() {
+    // This fixes payload problems from offbrand GCAdapters
+    const s32 control_transfer_error =
+        libusb_control_transfer(usb_adapter_handle, 0x21, 11, 0x0001, 0, nullptr, 0, 1000);
+    if (control_transfer_error < 0) {
+        LOG_ERROR(Input, "libusb_control_transfer failed with error= {}", control_transfer_error);
+    }
+
+    s32 kernel_driver_error = libusb_kernel_driver_active(usb_adapter_handle, 0);
+    if (kernel_driver_error == 1) {
+        kernel_driver_error = libusb_detach_kernel_driver(usb_adapter_handle, 0);
+        if (kernel_driver_error != 0 && kernel_driver_error != LIBUSB_ERROR_NOT_SUPPORTED) {
+            LOG_ERROR(Input, "libusb_detach_kernel_driver failed with error = {}",
+                      kernel_driver_error);
+        }
+    }
+
+    if (kernel_driver_error && kernel_driver_error != LIBUSB_ERROR_NOT_SUPPORTED) {
+        libusb_close(usb_adapter_handle);
+        usb_adapter_handle = nullptr;
+        return false;
+    }
+
+    const int interface_claim_error = libusb_claim_interface(usb_adapter_handle, 0);
+    if (interface_claim_error) {
+        LOG_ERROR(Input, "libusb_claim_interface failed with error = {}", interface_claim_error);
+        libusb_close(usb_adapter_handle);
+        usb_adapter_handle = nullptr;
+        return false;
+    }
+
+    return true;
+}
+
+bool Adapter::GetGCEndpoint(libusb_device* device) {
+    libusb_config_descriptor* config = nullptr;
+    const int config_descriptor_return = libusb_get_config_descriptor(device, 0, &config);
+    if (config_descriptor_return != LIBUSB_SUCCESS) {
+        LOG_ERROR(Input, "libusb_get_config_descriptor failed with error = {}",
+                  config_descriptor_return);
+        return false;
+    }
+
+    for (u8 ic = 0; ic < config->bNumInterfaces; ic++) {
+        const libusb_interface* interfaceContainer = &config->interface[ic];
+        for (int i = 0; i < interfaceContainer->num_altsetting; i++) {
+            const libusb_interface_descriptor* interface = &interfaceContainer->altsetting[i];
+            for (u8 e = 0; e < interface->bNumEndpoints; e++) {
+                const libusb_endpoint_descriptor* endpoint = &interface->endpoint[e];
+                if ((endpoint->bEndpointAddress & LIBUSB_ENDPOINT_IN) != 0) {
+                    input_endpoint = endpoint->bEndpointAddress;
+                } else {
+                    output_endpoint = endpoint->bEndpointAddress;
+                }
+            }
+        }
+    }
+    // This transfer seems to be responsible for clearing the state of the adapter
+    // Used to clear the "busy" state of when the device is unexpectedly unplugged
+    unsigned char clear_payload = 0x13;
+    libusb_interrupt_transfer(usb_adapter_handle, output_endpoint, &clear_payload,
+                              sizeof(clear_payload), nullptr, 16);
+    return true;
+}
+
+void Adapter::JoinThreads() {
+    restart_scan_thread = false;
+    adapter_input_thread_running = false;
+    adapter_scan_thread_running = false;
+
+    if (adapter_scan_thread.joinable()) {
+        adapter_scan_thread.join();
+    }
+
+    if (adapter_input_thread.joinable()) {
+        adapter_input_thread.join();
+    }
+}
+
+void Adapter::ClearLibusbHandle() {
+    if (usb_adapter_handle) {
+        libusb_release_interface(usb_adapter_handle, 1);
+        libusb_close(usb_adapter_handle);
+        usb_adapter_handle = nullptr;
+    }
+}
+
+void Adapter::ResetDevices() {
+    for (std::size_t i = 0; i < pads.size(); ++i) {
+        ResetDevice(i);
+    }
+}
+
+void Adapter::ResetDevice(std::size_t port) {
+    pads[port].type = ControllerTypes::None;
+    pads[port].enable_vibration = false;
+    pads[port].rumble_amplitude = 0;
+    pads[port].buttons = 0;
+    pads[port].last_button = PadButton::Undefined;
+    pads[port].axis_values.fill(0);
+    pads[port].axis_origin.fill(255);
+}
+
+void Adapter::Reset() {
+    JoinThreads();
+    ClearLibusbHandle();
+    ResetDevices();
+
+    if (libusb_ctx) {
+        libusb_exit(libusb_ctx);
+    }
+}
+
+std::vector<Common::ParamPackage> Adapter::GetInputDevices() const {
+    std::vector<Common::ParamPackage> devices;
+    for (std::size_t port = 0; port < pads.size(); ++port) {
+        if (!DeviceConnected(port)) {
+            continue;
+        }
+        std::string name = fmt::format("Gamecube Controller {}", port + 1);
+        devices.emplace_back(Common::ParamPackage{
+            {"class", "gcpad"},
+            {"display", std::move(name)},
+            {"port", std::to_string(port)},
+        });
+    }
+    return devices;
+}
+
+InputCommon::ButtonMapping Adapter::GetButtonMappingForDevice(
+    const Common::ParamPackage& params) const {
+    // This list is missing ZL/ZR since those are not considered buttons.
+    // We will add those afterwards
+    // This list also excludes any button that can't be really mapped
+    static constexpr std::array<std::pair<Settings::NativeButton::Values, PadButton>, 12>
+        switch_to_gcadapter_button = {
+            std::pair{Settings::NativeButton::A, PadButton::ButtonA},
+            {Settings::NativeButton::B, PadButton::ButtonB},
+            {Settings::NativeButton::X, PadButton::ButtonX},
+            {Settings::NativeButton::Y, PadButton::ButtonY},
+            {Settings::NativeButton::Plus, PadButton::ButtonStart},
+            {Settings::NativeButton::DLeft, PadButton::ButtonLeft},
+            {Settings::NativeButton::DUp, PadButton::ButtonUp},
+            {Settings::NativeButton::DRight, PadButton::ButtonRight},
+            {Settings::NativeButton::DDown, PadButton::ButtonDown},
+            {Settings::NativeButton::SL, PadButton::TriggerL},
+            {Settings::NativeButton::SR, PadButton::TriggerR},
+            {Settings::NativeButton::R, PadButton::TriggerZ},
+        };
+    if (!params.Has("port")) {
+        return {};
+    }
+
+    InputCommon::ButtonMapping mapping{};
+    for (const auto& [switch_button, gcadapter_button] : switch_to_gcadapter_button) {
+        Common::ParamPackage button_params({{"engine", "gcpad"}});
+        button_params.Set("port", params.Get("port", 0));
+        button_params.Set("button", static_cast<int>(gcadapter_button));
+        mapping.insert_or_assign(switch_button, std::move(button_params));
+    }
+
+    // Add the missing bindings for ZL/ZR
+    static constexpr std::array<std::pair<Settings::NativeButton::Values, PadAxes>, 2>
+        switch_to_gcadapter_axis = {
+            std::pair{Settings::NativeButton::ZL, PadAxes::TriggerLeft},
+            {Settings::NativeButton::ZR, PadAxes::TriggerRight},
+        };
+    for (const auto& [switch_button, gcadapter_axis] : switch_to_gcadapter_axis) {
+        Common::ParamPackage button_params({{"engine", "gcpad"}});
+        button_params.Set("port", params.Get("port", 0));
+        button_params.Set("button", static_cast<s32>(PadButton::Stick));
+        button_params.Set("axis", static_cast<s32>(gcadapter_axis));
+        button_params.Set("threshold", 0.5f);
+        button_params.Set("direction", "+");
+        mapping.insert_or_assign(switch_button, std::move(button_params));
+    }
+    return mapping;
+}
+
+InputCommon::AnalogMapping Adapter::GetAnalogMappingForDevice(
+    const Common::ParamPackage& params) const {
+    if (!params.Has("port")) {
+        return {};
+    }
+
+    InputCommon::AnalogMapping mapping = {};
+    Common::ParamPackage left_analog_params;
+    left_analog_params.Set("engine", "gcpad");
+    left_analog_params.Set("port", params.Get("port", 0));
+    left_analog_params.Set("axis_x", static_cast<int>(PadAxes::StickX));
+    left_analog_params.Set("axis_y", static_cast<int>(PadAxes::StickY));
+    mapping.insert_or_assign(Settings::NativeAnalog::LStick, std::move(left_analog_params));
+    Common::ParamPackage right_analog_params;
+    right_analog_params.Set("engine", "gcpad");
+    right_analog_params.Set("port", params.Get("port", 0));
+    right_analog_params.Set("axis_x", static_cast<int>(PadAxes::SubstickX));
+    right_analog_params.Set("axis_y", static_cast<int>(PadAxes::SubstickY));
+    mapping.insert_or_assign(Settings::NativeAnalog::RStick, std::move(right_analog_params));
+    return mapping;
+}
+
+bool Adapter::DeviceConnected(std::size_t port) const {
+    return pads[port].type != ControllerTypes::None;
+}
+
+void Adapter::BeginConfiguration() {
+    pad_queue.Clear();
+    configuring = true;
+}
+
+void Adapter::EndConfiguration() {
+    pad_queue.Clear();
+    configuring = false;
+}
+
+Common::SPSCQueue<GCPadStatus>& Adapter::GetPadQueue() {
+    return pad_queue;
+}
+
+const Common::SPSCQueue<GCPadStatus>& Adapter::GetPadQueue() const {
+    return pad_queue;
+}
+
+GCController& Adapter::GetPadState(std::size_t port) {
+    return pads.at(port);
+}
+
+const GCController& Adapter::GetPadState(std::size_t port) const {
+    return pads.at(port);
+}
+
+} // namespace GCAdapter
diff --git a/src/input_common/gcadapter/gc_adapter.h b/src/input_common/gcadapter/gc_adapter.h
new file mode 100644
index 0000000000..f1256c9dad
--- /dev/null
+++ b/src/input_common/gcadapter/gc_adapter.h
@@ -0,0 +1,167 @@
+// Copyright 2014 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+#include <algorithm>
+#include <functional>
+#include <mutex>
+#include <thread>
+#include <unordered_map>
+#include "common/common_types.h"
+#include "common/threadsafe_queue.h"
+#include "input_common/main.h"
+
+struct libusb_context;
+struct libusb_device;
+struct libusb_device_handle;
+
+namespace GCAdapter {
+
+enum class PadButton {
+    Undefined = 0x0000,
+    ButtonLeft = 0x0001,
+    ButtonRight = 0x0002,
+    ButtonDown = 0x0004,
+    ButtonUp = 0x0008,
+    TriggerZ = 0x0010,
+    TriggerR = 0x0020,
+    TriggerL = 0x0040,
+    ButtonA = 0x0100,
+    ButtonB = 0x0200,
+    ButtonX = 0x0400,
+    ButtonY = 0x0800,
+    ButtonStart = 0x1000,
+    // Below is for compatibility with "AxisButton" type
+    Stick = 0x2000,
+};
+
+enum class PadAxes : u8 {
+    StickX,
+    StickY,
+    SubstickX,
+    SubstickY,
+    TriggerLeft,
+    TriggerRight,
+    Undefined,
+};
+
+enum class ControllerTypes {
+    None,
+    Wired,
+    Wireless,
+};
+
+struct GCPadStatus {
+    std::size_t port{};
+
+    PadButton button{PadButton::Undefined}; // Or-ed PAD_BUTTON_* and PAD_TRIGGER_* bits
+
+    PadAxes axis{PadAxes::Undefined};
+    s16 axis_value{};
+    u8 axis_threshold{50};
+};
+
+struct GCController {
+    ControllerTypes type{};
+    bool enable_vibration{};
+    u8 rumble_amplitude{};
+    u16 buttons{};
+    PadButton last_button{};
+    std::array<s16, 6> axis_values{};
+    std::array<u8, 6> axis_origin{};
+};
+
+class Adapter {
+public:
+    Adapter();
+    ~Adapter();
+
+    /// Request a vibration for a controller
+    bool RumblePlay(std::size_t port, u8 amplitude);
+
+    /// Used for polling
+    void BeginConfiguration();
+    void EndConfiguration();
+
+    Common::SPSCQueue<GCPadStatus>& GetPadQueue();
+    const Common::SPSCQueue<GCPadStatus>& GetPadQueue() const;
+
+    GCController& GetPadState(std::size_t port);
+    const GCController& GetPadState(std::size_t port) const;
+
+    /// Returns true if there is a device connected to port
+    bool DeviceConnected(std::size_t port) const;
+
+    /// Used for automapping features
+    std::vector<Common::ParamPackage> GetInputDevices() const;
+    InputCommon::ButtonMapping GetButtonMappingForDevice(const Common::ParamPackage& params) const;
+    InputCommon::AnalogMapping GetAnalogMappingForDevice(const Common::ParamPackage& params) const;
+
+private:
+    using AdapterPayload = std::array<u8, 37>;
+
+    void UpdatePadType(std::size_t port, ControllerTypes pad_type);
+    void UpdateControllers(const AdapterPayload& adapter_payload);
+    void UpdateYuzuSettings(std::size_t port);
+    void UpdateStateButtons(std::size_t port, u8 b1, u8 b2);
+    void UpdateStateAxes(std::size_t port, const AdapterPayload& adapter_payload);
+    void UpdateVibrations();
+
+    void AdapterInputThread();
+
+    void AdapterScanThread();
+
+    bool IsPayloadCorrect(const AdapterPayload& adapter_payload, s32 payload_size);
+
+    // Updates vibration state of all controllers
+    void SendVibrations();
+
+    /// For use in initialization, querying devices to find the adapter
+    void Setup();
+
+    /// Resets status of all GC controller devices to a disconected state
+    void ResetDevices();
+
+    /// Resets status of device connected to a disconected state
+    void ResetDevice(std::size_t port);
+
+    /// Returns true if we successfully gain access to GC Adapter
+    bool CheckDeviceAccess();
+
+    /// Captures GC Adapter endpoint address
+    /// Returns true if the endpoind was set correctly
+    bool GetGCEndpoint(libusb_device* device);
+
+    /// For shutting down, clear all data, join all threads, release usb
+    void Reset();
+
+    // Join all threads
+    void JoinThreads();
+
+    // Release usb handles
+    void ClearLibusbHandle();
+
+    libusb_device_handle* usb_adapter_handle = nullptr;
+    std::array<GCController, 4> pads;
+    Common::SPSCQueue<GCPadStatus> pad_queue;
+
+    std::thread adapter_input_thread;
+    std::thread adapter_scan_thread;
+    bool adapter_input_thread_running;
+    bool adapter_scan_thread_running;
+    bool restart_scan_thread;
+
+    libusb_context* libusb_ctx;
+
+    u8 input_endpoint{0};
+    u8 output_endpoint{0};
+    u8 input_error_counter{0};
+    u8 output_error_counter{0};
+    int vibration_counter{0};
+
+    bool configuring{false};
+    bool rumble_enabled{true};
+    bool vibration_changed{true};
+};
+} // namespace GCAdapter
diff --git a/src/input_common/gcadapter/gc_poller.cpp b/src/input_common/gcadapter/gc_poller.cpp
new file mode 100644
index 0000000000..4d1052414c
--- /dev/null
+++ b/src/input_common/gcadapter/gc_poller.cpp
@@ -0,0 +1,332 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <atomic>
+#include <list>
+#include <mutex>
+#include <utility>
+#include "common/assert.h"
+#include "common/threadsafe_queue.h"
+#include "input_common/gcadapter/gc_adapter.h"
+#include "input_common/gcadapter/gc_poller.h"
+
+namespace InputCommon {
+
+class GCButton final : public Input::ButtonDevice {
+public:
+    explicit GCButton(u32 port_, s32 button_, const GCAdapter::Adapter* adapter)
+        : port(port_), button(button_), gcadapter(adapter) {}
+
+    ~GCButton() override;
+
+    bool GetStatus() const override {
+        if (gcadapter->DeviceConnected(port)) {
+            return (gcadapter->GetPadState(port).buttons & button) != 0;
+        }
+        return false;
+    }
+
+private:
+    const u32 port;
+    const s32 button;
+    const GCAdapter::Adapter* gcadapter;
+};
+
+class GCAxisButton final : public Input::ButtonDevice {
+public:
+    explicit GCAxisButton(u32 port_, u32 axis_, float threshold_, bool trigger_if_greater_,
+                          const GCAdapter::Adapter* adapter)
+        : port(port_), axis(axis_), threshold(threshold_), trigger_if_greater(trigger_if_greater_),
+          gcadapter(adapter) {}
+
+    bool GetStatus() const override {
+        if (gcadapter->DeviceConnected(port)) {
+            const float current_axis_value = gcadapter->GetPadState(port).axis_values.at(axis);
+            const float axis_value = current_axis_value / 128.0f;
+            if (trigger_if_greater) {
+                // TODO: Might be worthwile to set a slider for the trigger threshold. It is
+                // currently always set to 0.5 in configure_input_player.cpp ZL/ZR HandleClick
+                return axis_value > threshold;
+            }
+            return axis_value < -threshold;
+        }
+        return false;
+    }
+
+private:
+    const u32 port;
+    const u32 axis;
+    float threshold;
+    bool trigger_if_greater;
+    const GCAdapter::Adapter* gcadapter;
+};
+
+GCButtonFactory::GCButtonFactory(std::shared_ptr<GCAdapter::Adapter> adapter_)
+    : adapter(std::move(adapter_)) {}
+
+GCButton::~GCButton() = default;
+
+std::unique_ptr<Input::ButtonDevice> GCButtonFactory::Create(const Common::ParamPackage& params) {
+    const auto button_id = params.Get("button", 0);
+    const auto port = static_cast<u32>(params.Get("port", 0));
+
+    constexpr s32 PAD_STICK_ID = static_cast<s32>(GCAdapter::PadButton::Stick);
+
+    // button is not an axis/stick button
+    if (button_id != PAD_STICK_ID) {
+        return std::make_unique<GCButton>(port, button_id, adapter.get());
+    }
+
+    // For Axis buttons, used by the binary sticks.
+    if (button_id == PAD_STICK_ID) {
+        const int axis = params.Get("axis", 0);
+        const float threshold = params.Get("threshold", 0.25f);
+        const std::string direction_name = params.Get("direction", "");
+        bool trigger_if_greater;
+        if (direction_name == "+") {
+            trigger_if_greater = true;
+        } else if (direction_name == "-") {
+            trigger_if_greater = false;
+        } else {
+            trigger_if_greater = true;
+            LOG_ERROR(Input, "Unknown direction {}", direction_name);
+        }
+        return std::make_unique<GCAxisButton>(port, axis, threshold, trigger_if_greater,
+                                              adapter.get());
+    }
+
+    return nullptr;
+}
+
+Common::ParamPackage GCButtonFactory::GetNextInput() const {
+    Common::ParamPackage params;
+    GCAdapter::GCPadStatus pad;
+    auto& queue = adapter->GetPadQueue();
+    while (queue.Pop(pad)) {
+        // This while loop will break on the earliest detected button
+        params.Set("engine", "gcpad");
+        params.Set("port", static_cast<s32>(pad.port));
+        if (pad.button != GCAdapter::PadButton::Undefined) {
+            params.Set("button", static_cast<u16>(pad.button));
+        }
+
+        // For Axis button implementation
+        if (pad.axis != GCAdapter::PadAxes::Undefined) {
+            params.Set("axis", static_cast<u8>(pad.axis));
+            params.Set("button", static_cast<u16>(GCAdapter::PadButton::Stick));
+            params.Set("threshold", "0.25");
+            if (pad.axis_value > 0) {
+                params.Set("direction", "+");
+            } else {
+                params.Set("direction", "-");
+            }
+            break;
+        }
+    }
+    return params;
+}
+
+void GCButtonFactory::BeginConfiguration() {
+    polling = true;
+    adapter->BeginConfiguration();
+}
+
+void GCButtonFactory::EndConfiguration() {
+    polling = false;
+    adapter->EndConfiguration();
+}
+
+class GCAnalog final : public Input::AnalogDevice {
+public:
+    explicit GCAnalog(u32 port_, u32 axis_x_, u32 axis_y_, float deadzone_,
+                      const GCAdapter::Adapter* adapter, float range_)
+        : port(port_), axis_x(axis_x_), axis_y(axis_y_), deadzone(deadzone_), gcadapter(adapter),
+          range(range_) {}
+
+    float GetAxis(u32 axis) const {
+        if (gcadapter->DeviceConnected(port)) {
+            std::lock_guard lock{mutex};
+            const auto axis_value =
+                static_cast<float>(gcadapter->GetPadState(port).axis_values.at(axis));
+            return (axis_value) / (100.0f * range);
+        }
+        return 0.0f;
+    }
+
+    std::pair<float, float> GetAnalog(u32 analog_axis_x, u32 analog_axis_y) const {
+        float x = GetAxis(analog_axis_x);
+        float y = GetAxis(analog_axis_y);
+
+        // Make sure the coordinates are in the unit circle,
+        // otherwise normalize it.
+        float r = x * x + y * y;
+        if (r > 1.0f) {
+            r = std::sqrt(r);
+            x /= r;
+            y /= r;
+        }
+
+        return {x, y};
+    }
+
+    std::tuple<float, float> GetStatus() const override {
+        const auto [x, y] = GetAnalog(axis_x, axis_y);
+        const float r = std::sqrt((x * x) + (y * y));
+        if (r > deadzone) {
+            return {x / r * (r - deadzone) / (1 - deadzone),
+                    y / r * (r - deadzone) / (1 - deadzone)};
+        }
+        return {0.0f, 0.0f};
+    }
+
+    bool GetAnalogDirectionStatus(Input::AnalogDirection direction) const override {
+        const auto [x, y] = GetStatus();
+        const float directional_deadzone = 0.5f;
+        switch (direction) {
+        case Input::AnalogDirection::RIGHT:
+            return x > directional_deadzone;
+        case Input::AnalogDirection::LEFT:
+            return x < -directional_deadzone;
+        case Input::AnalogDirection::UP:
+            return y > directional_deadzone;
+        case Input::AnalogDirection::DOWN:
+            return y < -directional_deadzone;
+        }
+        return false;
+    }
+
+private:
+    const u32 port;
+    const u32 axis_x;
+    const u32 axis_y;
+    const float deadzone;
+    const GCAdapter::Adapter* gcadapter;
+    const float range;
+    mutable std::mutex mutex;
+};
+
+/// An analog device factory that creates analog devices from GC Adapter
+GCAnalogFactory::GCAnalogFactory(std::shared_ptr<GCAdapter::Adapter> adapter_)
+    : adapter(std::move(adapter_)) {}
+
+/**
+ * Creates analog device from joystick axes
+ * @param params contains parameters for creating the device:
+ *     - "port": the nth gcpad on the adapter
+ *     - "axis_x": the index of the axis to be bind as x-axis
+ *     - "axis_y": the index of the axis to be bind as y-axis
+ */
+std::unique_ptr<Input::AnalogDevice> GCAnalogFactory::Create(const Common::ParamPackage& params) {
+    const auto port = static_cast<u32>(params.Get("port", 0));
+    const auto axis_x = static_cast<u32>(params.Get("axis_x", 0));
+    const auto axis_y = static_cast<u32>(params.Get("axis_y", 1));
+    const auto deadzone = std::clamp(params.Get("deadzone", 0.0f), 0.0f, 1.0f);
+    const auto range = std::clamp(params.Get("range", 1.0f), 0.50f, 1.50f);
+
+    return std::make_unique<GCAnalog>(port, axis_x, axis_y, deadzone, adapter.get(), range);
+}
+
+void GCAnalogFactory::BeginConfiguration() {
+    polling = true;
+    adapter->BeginConfiguration();
+}
+
+void GCAnalogFactory::EndConfiguration() {
+    polling = false;
+    adapter->EndConfiguration();
+}
+
+Common::ParamPackage GCAnalogFactory::GetNextInput() {
+    GCAdapter::GCPadStatus pad;
+    Common::ParamPackage params;
+    auto& queue = adapter->GetPadQueue();
+    while (queue.Pop(pad)) {
+        if (pad.button != GCAdapter::PadButton::Undefined) {
+            params.Set("engine", "gcpad");
+            params.Set("port", static_cast<s32>(pad.port));
+            params.Set("button", static_cast<u16>(pad.button));
+            return params;
+        }
+        if (pad.axis == GCAdapter::PadAxes::Undefined ||
+            std::abs(static_cast<float>(pad.axis_value) / 128.0f) < 0.1f) {
+            continue;
+        }
+        // An analog device needs two axes, so we need to store the axis for later and wait for
+        // a second input event. The axes also must be from the same joystick.
+        const u8 axis = static_cast<u8>(pad.axis);
+        if (axis == 0 || axis == 1) {
+            analog_x_axis = 0;
+            analog_y_axis = 1;
+            controller_number = static_cast<s32>(pad.port);
+            break;
+        }
+        if (axis == 2 || axis == 3) {
+            analog_x_axis = 2;
+            analog_y_axis = 3;
+            controller_number = static_cast<s32>(pad.port);
+            break;
+        }
+
+        if (analog_x_axis == -1) {
+            analog_x_axis = axis;
+            controller_number = static_cast<s32>(pad.port);
+        } else if (analog_y_axis == -1 && analog_x_axis != axis &&
+                   controller_number == static_cast<s32>(pad.port)) {
+            analog_y_axis = axis;
+            break;
+        }
+    }
+    if (analog_x_axis != -1 && analog_y_axis != -1) {
+        params.Set("engine", "gcpad");
+        params.Set("port", controller_number);
+        params.Set("axis_x", analog_x_axis);
+        params.Set("axis_y", analog_y_axis);
+        analog_x_axis = -1;
+        analog_y_axis = -1;
+        controller_number = -1;
+        return params;
+    }
+    return params;
+}
+
+class GCVibration final : public Input::VibrationDevice {
+public:
+    explicit GCVibration(u32 port_, GCAdapter::Adapter* adapter)
+        : port(port_), gcadapter(adapter) {}
+
+    u8 GetStatus() const override {
+        return gcadapter->RumblePlay(port, 0);
+    }
+
+    bool SetRumblePlay(f32 amp_low, [[maybe_unused]] f32 freq_low, f32 amp_high,
+                       [[maybe_unused]] f32 freq_high) const override {
+        const auto mean_amplitude = (amp_low + amp_high) * 0.5f;
+        const auto processed_amplitude =
+            static_cast<u8>((mean_amplitude + std::pow(mean_amplitude, 0.3f)) * 0.5f * 0x8);
+
+        return gcadapter->RumblePlay(port, processed_amplitude);
+    }
+
+private:
+    const u32 port;
+    GCAdapter::Adapter* gcadapter;
+};
+
+/// An vibration device factory that creates vibration devices from GC Adapter
+GCVibrationFactory::GCVibrationFactory(std::shared_ptr<GCAdapter::Adapter> adapter_)
+    : adapter(std::move(adapter_)) {}
+
+/**
+ * Creates a vibration device from a joystick
+ * @param params contains parameters for creating the device:
+ *     - "port": the nth gcpad on the adapter
+ */
+std::unique_ptr<Input::VibrationDevice> GCVibrationFactory::Create(
+    const Common::ParamPackage& params) {
+    const auto port = static_cast<u32>(params.Get("port", 0));
+
+    return std::make_unique<GCVibration>(port, adapter.get());
+}
+
+} // namespace InputCommon
diff --git a/src/input_common/gcadapter/gc_poller.h b/src/input_common/gcadapter/gc_poller.h
new file mode 100644
index 0000000000..d1271e3ead
--- /dev/null
+++ b/src/input_common/gcadapter/gc_poller.h
@@ -0,0 +1,78 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include "core/frontend/input.h"
+#include "input_common/gcadapter/gc_adapter.h"
+
+namespace InputCommon {
+
+/**
+ * A button device factory representing a gcpad. It receives gcpad events and forward them
+ * to all button devices it created.
+ */
+class GCButtonFactory final : public Input::Factory<Input::ButtonDevice> {
+public:
+    explicit GCButtonFactory(std::shared_ptr<GCAdapter::Adapter> adapter_);
+
+    /**
+     * Creates a button device from a button press
+     * @param params contains parameters for creating the device:
+     *     - "code": the code of the key to bind with the button
+     */
+    std::unique_ptr<Input::ButtonDevice> Create(const Common::ParamPackage& params) override;
+
+    Common::ParamPackage GetNextInput() const;
+
+    /// For device input configuration/polling
+    void BeginConfiguration();
+    void EndConfiguration();
+
+    bool IsPolling() const {
+        return polling;
+    }
+
+private:
+    std::shared_ptr<GCAdapter::Adapter> adapter;
+    bool polling = false;
+};
+
+/// An analog device factory that creates analog devices from GC Adapter
+class GCAnalogFactory final : public Input::Factory<Input::AnalogDevice> {
+public:
+    explicit GCAnalogFactory(std::shared_ptr<GCAdapter::Adapter> adapter_);
+
+    std::unique_ptr<Input::AnalogDevice> Create(const Common::ParamPackage& params) override;
+    Common::ParamPackage GetNextInput();
+
+    /// For device input configuration/polling
+    void BeginConfiguration();
+    void EndConfiguration();
+
+    bool IsPolling() const {
+        return polling;
+    }
+
+private:
+    std::shared_ptr<GCAdapter::Adapter> adapter;
+    int analog_x_axis = -1;
+    int analog_y_axis = -1;
+    int controller_number = -1;
+    bool polling = false;
+};
+
+/// A vibration device factory creates vibration devices from GC Adapter
+class GCVibrationFactory final : public Input::Factory<Input::VibrationDevice> {
+public:
+    explicit GCVibrationFactory(std::shared_ptr<GCAdapter::Adapter> adapter_);
+
+    std::unique_ptr<Input::VibrationDevice> Create(const Common::ParamPackage& params) override;
+
+private:
+    std::shared_ptr<GCAdapter::Adapter> adapter;
+};
+
+} // namespace InputCommon