Print version number of device 1 on each raw dev.

Only works on HID++ >=2.0 so far. Also solves a race condition where
the wrong response can be sent to a request.

src/logid/CMakeLists.txt

@@ -17,6 +17,10 @@ add_executable(logid
         backend/raw/RawDevice.cpp
         backend/hidpp/Device.cpp
         backend/hidpp/Report.cpp
+        backend/hidpp20/Device.cpp
+        backend/hidpp20/Error.cpp
+        backend/hidpp20/Feature.cpp
+        backend/hidpp20/features/Root.cpp
         backend/dj/Report.cpp
         util/mutex_queue.h)
 

src/logid/DeviceMonitor.cpp

@@ -105,6 +105,9 @@ void DeviceMonitor::addDevice(std::string path)
         auto device = std::make_shared<backend::hidpp::Device>(path, hidpp::DeviceIndex::WirelessDevice1);
         log_printf(DEBUG, "Detected HID++ device at %s", path.c_str());
 
+        auto version = device->version();
+        log_printf(DEBUG, "HID++ version: %d.%d", std::get<0>(version), std::get<1>(version));
+
         auto eventHandler = std::make_shared<backend::hidpp::EventHandler>();
         eventHandler->condition = [device](backend::hidpp::Report& report)->bool
         {

src/logid/backend/dj/defs.h

@@ -0,0 +1,20 @@
+#ifndef LOGID_BACKEND_DJ_DEFS_H
+#define LOGID_BACKEND_DJ_DEFS_H
+
+#include <cstdint>
+
+namespace logid {
+namespace backend {
+namespace dj
+{
+    namespace ReportType
+    {
+        enum ReportType : uint8_t
+        {
+            Short = 0x20,
+            Long = 0x21
+        };
+    }
+}}}
+
+#endif //LOGID_BACKEND_DJ_DEFS_H

src/logid/backend/hidpp/Device.cpp

@@ -1,6 +1,7 @@
 #include <assert.h>
 #include "Device.h"
 #include "Report.h"
+#include "../hidpp20/features/Root.h"
 
 using namespace logid::backend;
 using namespace logid::backend::hidpp;
@@ -29,12 +30,20 @@ Device::Device(const std::string& path, DeviceIndex index):
     if(!supported_reports)
         throw InvalidDevice(InvalidDevice::NoHIDPPReport);
 
+    Report versionRequest(Report::Type::Short, index, hidpp20::FeatureID::ROOT,
+            hidpp20::Root::Ping, LOGID_HIDPP_SOFTWARE_ID);
+
+    ///TODO: Catch error
+    auto versionResponse = sendReport(versionRequest);
+    auto versionResponse_params = versionResponse.paramBegin();
+    _version = std::make_tuple(versionResponse_params[0], versionResponse_params[1]);
+
     // Pass all HID++ events with device index to this device.
     RawEventHandler rawEventHandler;
     rawEventHandler.condition = [index](std::vector<uint8_t>& report)->bool
     {
-        return (report[Offset::Type] == Report::Short ||
-            report[Offset::Type] == Report::Long) && (report[Offset::DeviceIndex] == index);
+        return (report[Offset::Type] == Report::Type::Short ||
+            report[Offset::Type] == Report::Type::Long) && (report[Offset::DeviceIndex] == index);
     };
     rawEventHandler.callback = [this](std::vector<uint8_t>& report)->void
     {
@@ -69,11 +78,11 @@ Report Device::sendReport(Report& report)
 {
     switch(report.type())
     {
-        case Report::Short:
+        case Report::Type::Short:
             if(!(supported_reports & HIDPP_REPORT_SHORT_SUPPORTED))
-                report.setType(Report::Long);
+                report.setType(Report::Type::Long);
             break;
-        case Report::Long:
+        case Report::Type::Long:
             /* Report can be truncated, but that isn't a good idea. */
             assert(supported_reports & HIDPP_REPORT_LONG_SUPPORTED);
     }

src/logid/backend/hidpp/Device.h

@@ -40,6 +40,7 @@ namespace hidpp
 
         std::string devicePath() const { return path; }
         DeviceIndex deviceIndex() const { return index; }
+        std::tuple<uint8_t, uint8_t> version() const { return _version; }
 
         void listen(); // Runs asynchronously
         void stopListening();
@@ -56,6 +57,8 @@ namespace hidpp
         DeviceIndex index;
         uint8_t supported_reports;
 
+        std::tuple<uint8_t, uint8_t> _version;
+
         std::map<std::string, std::shared_ptr<EventHandler>> event_handlers;
     };
 } } }

src/logid/backend/hidpp/Report.cpp

@@ -96,15 +96,15 @@ const char *Report::InvalidReportLength::what() const noexcept
 Report::Report(Report::Type type, DeviceIndex device_index,
         uint8_t feature_index, uint8_t function, uint8_t sw_id)
 {
-    assert(!(function & functionMask));
-    assert(!(sw_id & swIdMask));
+    assert(function <= functionMask);
+    assert(sw_id <= swIdMask);
 
     switch(type)
     {
-        case Short:
+        case Type::Short:
             _data.resize(HeaderLength + ShortParamLength);
             break;
-        case Long:
+        case Type::Long:
             _data.resize(HeaderLength + LongParamLength);
             break;
         default:
@@ -123,10 +123,10 @@ Report::Report(const std::vector<uint8_t>& data)
 
     switch(_data[Offset::Type])
     {
-        case Short:
+        case Type::Short:
             _data.resize(HeaderLength + ShortParamLength);
             break;
-        case Long:
+        case Type::Long:
             _data.resize(HeaderLength + LongParamLength);
             break;
         default:
@@ -138,10 +138,10 @@ void Report::setType(Report::Type type)
 {
     switch(type)
     {
-        case Short:
+        case Type::Short:
             _data.resize(HeaderLength + ShortParamLength);
             break;
-        case Long:
+        case Type::Long:
             _data.resize(HeaderLength + LongParamLength);
             break;
         default:
@@ -158,3 +158,10 @@ void Report::setParams(const std::vector<uint8_t>& _params)
     for(std::size_t i = 0; i < _params.size(); i++)
         _data[Offset::Parameters + i] = _params[i];
 }
+
+bool Report::isError20(Report::hidpp20_error* error)
+{
+    if(_data[Offset::Type] != Type::Long ||
+        _data[Offset::Feature] != 0xff)
+        return false;
+}

src/logid/backend/hidpp/Report.h

@@ -26,11 +26,7 @@ namespace logid::backend::hidpp
     class Report
     {
     public:
-        enum Type: uint8_t
-        {
-            Short = 0x10,
-            Long = 0x11
-        };
+        typedef ReportType::ReportType Type;
 
         class InvalidReportID: public std::exception
         {
@@ -50,19 +46,26 @@ namespace logid::backend::hidpp
         static constexpr uint8_t swIdMask = 0x0f;
         static constexpr uint8_t functionMask = 0x0f;
 
-        Report(Type type, DeviceIndex device_index,
+        Report(Report::Type type, DeviceIndex device_index,
                 uint8_t feature_index,
                 uint8_t function,
                 uint8_t sw_id);
         explicit Report(const std::vector<uint8_t>& data);
 
-        Type type() const { return static_cast<Type>(_data[Offset::Type]); };
+        Report::Type type() const { return static_cast<Report::Type>(_data[Offset::Type]); };
         void setType(Report::Type type);
 
-        std::vector<uint8_t>::const_iterator paramBegin() const { return _data.begin() + Offset::Parameters; }
-        std::vector<uint8_t>::const_iterator paramEnd() const { return _data.end(); }
+        std::vector<uint8_t>::iterator paramBegin() { return _data.begin() + Offset::Parameters; }
+        std::vector<uint8_t>::iterator paramEnd() { return _data.end(); }
         void setParams(const std::vector<uint8_t>& _params);
 
+        struct hidpp20_error
+        {
+            uint8_t feature_index, function, software_id, error_code;
+        };
+
+        bool isError20(hidpp20_error* error);
+
         logid::backend::hidpp::DeviceIndex deviceIndex()
         {
             return static_cast<DeviceIndex>(_data[Offset::DeviceIndex]);

src/logid/backend/hidpp/defs.h

@@ -5,6 +5,15 @@
 
 namespace logid::backend::hidpp
 {
+    namespace ReportType
+    {
+        enum ReportType : uint8_t
+        {
+            Short = 0x10,
+            Long = 0x11
+        };
+    }
+
     enum DeviceIndex: uint8_t
     {
         DefaultDevice = 0,

src/logid/backend/hidpp20/Device.cpp

@@ -0,0 +1,25 @@
+#include <cassert>
+
+#include "Device.h"
+#include "../hidpp/defs.h"
+
+using namespace logid::backend::hidpp20;
+
+std::vector<uint8_t> Device::callFunction(uint8_t feature_index,
+        uint8_t function, std::vector<uint8_t>& params)
+{
+    hidpp::Report::Type type;
+
+    assert(params.size() <= hidpp::LongParamLength);
+    if(params.size() <= hidpp::ShortParamLength)
+        type = hidpp::Report::Type::Short;
+    else if(params.size() <= hidpp::LongParamLength)
+        type = hidpp::Report::Type::Long;
+
+    hidpp::Report request(type, deviceIndex(), feature_index, function,
+            LOGID_HIDPP_SOFTWARE_ID);
+    std::copy(params.begin(), params.end(), request.paramBegin());
+
+    auto response = this->sendReport(request);
+    return std::vector<uint8_t>(response.paramBegin(), response.paramEnd());
+}

src/logid/backend/hidpp20/Device.h

@@ -0,0 +1,19 @@
+#ifndef LOGID_HIDPP20_DEVICE_H
+#define LOGID_HIDPP20_DEVICE_H
+
+#include "../hidpp/Device.h"
+#include <cstdint>
+
+namespace logid {
+namespace backend {
+namespace hidpp20 {
+    class Device : public hidpp::Device
+    {
+    public:
+        std::vector<uint8_t> callFunction(uint8_t feature_index,
+                uint8_t function,
+                std::vector<uint8_t>& params);
+    };
+}}}
+
+#endif //LOGID_HIDPP20_DEVICE_H

src/logid/backend/hidpp20/Error.cpp

@@ -0,0 +1,46 @@
+#include <cassert>
+#include <cstring>
+#include "Error.h"
+
+using namespace logid::backend::hidpp20;
+
+Error::Error(uint8_t code) : _code (code)
+{
+    assert(_code != NoError);
+}
+
+const char* Error::what() const noexcept
+{
+    switch(_code)
+    {
+        case NoError:
+            return "No error";
+        case Unknown:
+            return "Unknown";
+        case InvalidArgument:
+            return "Invalid argument";
+        case OutOfRange:
+            return "Out of range";
+        case HardwareError:
+            return "Hardware error";
+        case LogitechInternal:
+            return "Logitech internal feature";
+        case InvalidFeatureIndex:
+            return "Invalid feature index";
+        case InvalidFunctionID:
+            return "Invalid function ID";
+        case Busy:
+            return "Busy";
+        case Unsupported:
+            return "Unsupported";
+        case UnknownDevice:
+            return "Unknown device";
+        default:
+            return std::string("Unknown error code " + std::to_string(_code)).c_str();
+    }
+}
+
+uint8_t Error::code() const noexcept
+{
+    return _code;
+}

src/logid/backend/hidpp20/Error.h

@@ -0,0 +1,39 @@
+#ifndef LOGID_BACKEND_HIDPP20_ERROR_H
+#define LOGID_BACKEND_HIDPP20_ERROR_H
+
+#include <stdexcept>
+#include <cstdint>
+
+namespace logid {
+namespace backend {
+namespace hidpp20 {
+    static constexpr uint8_t ErrorID = 0xFF;
+
+    class Error: public std::exception
+    {
+    public:
+        enum ErrorCode: uint8_t {
+            NoError = 0,
+            Unknown = 1,
+            InvalidArgument = 2,
+            OutOfRange = 3,
+            HardwareError = 4,
+            LogitechInternal = 5,
+            InvalidFeatureIndex = 6,
+            InvalidFunctionID = 7,
+            Busy = 8,
+            Unsupported = 9,
+            UnknownDevice = 10
+        };
+
+        Error(uint8_t code);
+
+        virtual const char* what() const noexcept;
+        uint8_t code() const noexcept;
+
+    private:
+        uint8_t _code;
+    };
+}}}
+
+#endif //LOGID_BACKEND_HIDPP20_ERROR_H

src/logid/backend/hidpp20/Feature.cpp

@@ -0,0 +1,28 @@
+#include "Feature.h"
+
+using namespace logid::backend::hidpp20;
+
+const char* Feature::UnsupportedFeature::what() const noexcept
+{
+    return "Unsupported feature";
+}
+
+uint16_t Feature::UnsupportedFeature::code() const noexcept
+{
+    return _f_id;
+}
+
+std::vector<uint8_t> Feature::callFunction(uint8_t function_id, std::vector<uint8_t>& params)
+{
+    return _device->callFunction(_index, function_id, params);
+}
+
+Feature::Feature(Device* dev, uint16_t _id) : _device (dev), _index (0xff)
+{
+    ///TODO: Set index
+}
+
+Feature::Feature(Device* dev, uint8_t _index) : _device (dev), _index (_index)
+{
+
+}

src/logid/backend/hidpp20/Feature.h

@@ -0,0 +1,37 @@
+#ifndef LOGID_HIDPP20_FEATURE_H
+#define LOGID_HIDPP20_FEATURE_H
+
+#include <cstdint>
+#include "Device.h"
+
+namespace logid {
+namespace backend {
+namespace hidpp20 {
+    class Feature
+    {
+    class UnsupportedFeature : public std::exception
+    {
+    public:
+        explicit UnsupportedFeature(uint16_t ID) : _f_id (ID) {}
+        virtual const char* what() const noexcept;
+        uint16_t code() const noexcept;
+    private:
+        uint16_t _f_id;
+    };
+
+    public:
+        static const uint16_t ID;
+        virtual uint16_t getID() = 0;
+
+    protected:
+        explicit Feature(Device* dev, uint16_t _id);
+        explicit Feature(Device* dev, uint8_t _index);
+        std::vector<uint8_t> callFunction(uint8_t function_id,
+            std::vector<uint8_t>& params);
+    private:
+        Device* _device;
+        uint8_t _index;
+    };
+}}}
+
+#endif //LOGID_HIDPP20_FEATURE_H

src/logid/backend/hidpp20/feature_defs.h

@@ -6,97 +6,108 @@
 namespace logid {
 namespace backend {
 namespace hidpp20 {
-    enum FeatureID : uint16_t
-    {
-        ROOT = 0x0000,
-        FEATURE_SET = 0x0001,
-        FEATURE_INFO = 0x0002,
-        FW_VERSION = 0x0003,
-        DEVICE_NAME = 0x0005,
-        DEVICE_GROUPS = 0x0006,
-        DEVICE_FRIENDLY_NAME = 0x0007,
-        RESET = 0x0020,
-        CRYPTO_IDENTIFIER = 0x0021,
-        DFUCONTROL = 0x00c0,
-        DFUCONTROL_V2 = 0x00c1,
-        DFUCONTROL_V3 = 0x00c2,
-        DFU = 0xd000,
-        BATTERY_STATUS = 0x1000,
-        BATTERY_VOLTAGE = 0x1001,
-        CHARGING_CONTROL = 0x1010,
-        LED_CONTROL = 0x1300,
-        GENERIC_TEST = 0x1800,
-        DEVICE_RESET = 0x1802,
-        OOB_STATE = 0x1805,
-        CONFIGURABLE_DEVICE_PROPERTIES = 0x1806,
-        CHANGE_HOST = 0x1814,
-        HOSTS_INFO = 0x1815,
-        BACKLIGHT = 0x1981,
-        BACKLIGHT_V2 = 0x1982,
-        BACKLIGHT_V3 = 0x1983,
-        PRESENTER_CONTROL = 0x1a00,
-        SENSOR_3D = 0x1a01,
-        REPROG_CONTROLS = 0x1b00,
-        REPROG_CONTROLS_V2 = 0x1b01,
-        REPROG_CONTROLS_V2_2 = 0x1b02,
-        REPROG_CONTROLS_V3 = 0x1b03,
-        REPROG_CONTROLS_V4 = 0x1b04,
-        PERSISTENT_REMAPPABLE_ACTION = 0x1bc0,
-        WIRELESS_DEVICE_STATUS = 0x1d4b,
-        ENABLE_HIDDEN_FEATURE = 0x1e00,
-        FIRMWARE_PROPERTIES = 0x1f1f,
-        ADC_MEASUREMENT = 0x1f20,
-        LEFT_RIGHT_SWAP = 0x2001,
-        SWAP_BUTTON = 0x2005,
-        POINTER_AXES_ORIENTATION = 0x2006,
-        VERTICAL_SCROLLING = 0x2100,
-        SMART_SHIFT = 0x2110,
-        HIRES_SCROLLING = 0x2120,
-        HIRES_SCROLLING_V2 = 0x2121, // Referred to as Hi-res wheel in cvuchener/hidpp, seems to be V2?
-        LORES_SCROLLING = 0x2130,
-        MOUSE_POINTER = 0x2200, // Possibly predecessor to 0x2201?
-        ADJUSTABLE_DPI = 0x2201,
-        ANGLE_SNAPPING = 0x2230,
-        SURFACE_TUNING = 0x2240,
-        HYBRID_TRACKING = 0x2400,
-        FN_INVERSION = 0x40a0,
-        FN_INVERSION_V2 = 0x40a2, // Is 0x40a1 skipped?
-        FN_INVERSION_V3 = 0x40a3,
-        ENCRYPTION = 0x4100,
-        LOCK_KEY_STATE = 0x4220,
-        SOLAR_DASHBOARD = 0x4301,
-        KEYBOARD_LAYOUT = 0x4520,
-        KEYBOARD_DISABLE = 0x4521,
-        DISABLE_KEYS = 0x4522,
-        MULTIPLATFORM = 0x4530, // Dual platform only?
-        MULTIPLATFORM_V2 = 0x4531,
-        KEYBOARD_LAYOUT_V2 = 0x4540,
-        CROWN = 0x4600,
-        TOUCHPAD_FW = 0x6010,
-        TOUCHPAD_SW = 0x6011,
-        TOUCHPAD_FW_WIN8 = 0x6012,
-        TOUCHMOUSE_RAW = 0x6100,
-        // TOUCHMOUSE_6120 = 0x6120, (Keeping this commented out until a better name is found)
-        GESTURE = 0x6500,
-        GESTURE_V2 = 0x6501,
-        G_KEY = 0x8010,
-        M_KEY = 0x8020,
-        // MR = 0x8030, (Keeping this commented out until a better name is found)
-        BRIGHTNESS_CONTROL = 0x8040,
-        REPORT_RATE = 0x8060,
-        RGB_EFFECTS = 0x8070,
-        RGB_EFFECTS_V2 = 0x8071,
-        PER_KEY_LIGHTING = 0x8080,
-        PER_KEY_LIGHTING_V2 = 0x8081,
-        MODE_STATUS = 0x8100,
-        MOUSE_BUTTON_SPY = 0x8110,
-        LATENCY_MONITORING = 0x8111,
-        GAMING_ATTACHMENTS = 0x8120,
-        FORCE_FEEDBACK = 0x8123,
-        SIDETONE = 0x8300,
-        EQUALIZER = 0x8310,
-        HEADSET_OUT = 0x8320
+    struct feature_info {
+        uint16_t feature_id;
+        bool obsolete;
+        bool internal;
+        bool hidden;
     };
+
+    namespace FeatureID
+    {
+        enum FeatureID : uint16_t
+        {
+            ROOT = 0x0000,
+            FEATURE_SET = 0x0001,
+            FEATURE_INFO = 0x0002,
+            FW_VERSION = 0x0003,
+            DEVICE_NAME = 0x0005,
+            DEVICE_GROUPS = 0x0006,
+            DEVICE_FRIENDLY_NAME = 0x0007,
+            RESET = 0x0020,
+            CRYPTO_IDENTIFIER = 0x0021,
+            DFUCONTROL = 0x00c0,
+            DFUCONTROL_V2 = 0x00c1,
+            DFUCONTROL_V3 = 0x00c2,
+            DFU = 0xd000,
+            BATTERY_STATUS = 0x1000,
+            BATTERY_VOLTAGE = 0x1001,
+            CHARGING_CONTROL = 0x1010,
+            LED_CONTROL = 0x1300,
+            GENERIC_TEST = 0x1800,
+            DEVICE_RESET = 0x1802,
+            OOB_STATE = 0x1805,
+            CONFIGURABLE_DEVICE_PROPERTIES = 0x1806,
+            CHANGE_HOST = 0x1814,
+            HOSTS_INFO = 0x1815,
+            BACKLIGHT = 0x1981,
+            BACKLIGHT_V2 = 0x1982,
+            BACKLIGHT_V3 = 0x1983,
+            PRESENTER_CONTROL = 0x1a00,
+            SENSOR_3D = 0x1a01,
+            REPROG_CONTROLS = 0x1b00,
+            REPROG_CONTROLS_V2 = 0x1b01,
+            REPROG_CONTROLS_V2_2 = 0x1b02,
+            REPROG_CONTROLS_V3 = 0x1b03,
+            REPROG_CONTROLS_V4 = 0x1b04,
+            PERSISTENT_REMAPPABLE_ACTION = 0x1bc0,
+            WIRELESS_DEVICE_STATUS = 0x1d4b,
+            ENABLE_HIDDEN_FEATURE = 0x1e00,
+            FIRMWARE_PROPERTIES = 0x1f1f,
+            ADC_MEASUREMENT = 0x1f20,
+            LEFT_RIGHT_SWAP = 0x2001,
+            SWAP_BUTTON = 0x2005,
+            POINTER_AXES_ORIENTATION = 0x2006,
+            VERTICAL_SCROLLING = 0x2100,
+            SMART_SHIFT = 0x2110,
+            HIRES_SCROLLING = 0x2120,
+            HIRES_SCROLLING_V2 = 0x2121, // Referred to as Hi-res wheel in cvuchener/hidpp, seems to be V2?
+            LORES_SCROLLING = 0x2130,
+            MOUSE_POINTER = 0x2200, // Possibly predecessor to 0x2201?
+            ADJUSTABLE_DPI = 0x2201,
+            ANGLE_SNAPPING = 0x2230,
+            SURFACE_TUNING = 0x2240,
+            HYBRID_TRACKING = 0x2400,
+            FN_INVERSION = 0x40a0,
+            FN_INVERSION_V2 = 0x40a2, // Is 0x40a1 skipped?
+            FN_INVERSION_V3 = 0x40a3,
+            ENCRYPTION = 0x4100,
+            LOCK_KEY_STATE = 0x4220,
+            SOLAR_DASHBOARD = 0x4301,
+            KEYBOARD_LAYOUT = 0x4520,
+            KEYBOARD_DISABLE = 0x4521,
+            DISABLE_KEYS = 0x4522,
+            MULTIPLATFORM = 0x4530, // Dual platform only?
+            MULTIPLATFORM_V2 = 0x4531,
+            KEYBOARD_LAYOUT_V2 = 0x4540,
+            CROWN = 0x4600,
+            TOUCHPAD_FW = 0x6010,
+            TOUCHPAD_SW = 0x6011,
+            TOUCHPAD_FW_WIN8 = 0x6012,
+            TOUCHMOUSE_RAW = 0x6100,
+            // TOUCHMOUSE_6120 = 0x6120, (Keeping this commented out until a better name is found)
+            GESTURE = 0x6500,
+            GESTURE_V2 = 0x6501,
+            G_KEY = 0x8010,
+            M_KEY = 0x8020,
+            // MR = 0x8030, (Keeping this commented out until a better name is found)
+            BRIGHTNESS_CONTROL = 0x8040,
+            REPORT_RATE = 0x8060,
+            RGB_EFFECTS = 0x8070,
+            RGB_EFFECTS_V2 = 0x8071,
+            PER_KEY_LIGHTING = 0x8080,
+            PER_KEY_LIGHTING_V2 = 0x8081,
+            MODE_STATUS = 0x8100,
+            MOUSE_BUTTON_SPY = 0x8110,
+            LATENCY_MONITORING = 0x8111,
+            GAMING_ATTACHMENTS = 0x8120,
+            FORCE_FEEDBACK = 0x8123,
+            SIDETONE = 0x8300,
+            EQUALIZER = 0x8310,
+            HEADSET_OUT = 0x8320
+        };
+    }
+
 }}}
 
 #endif //LOGID_BACKEND_HIDPP20_FEATUREDEFS

src/logid/backend/hidpp20/features/Root.cpp

@@ -0,0 +1,25 @@
+#include "Root.h"
+
+using namespace logid::backend::hidpp20;
+
+Root::Root(Device* dev) : Feature(dev, ID)
+{
+
+}
+
+feature_info Root::getFeature(uint16_t feature_id)
+{
+    feature_info info;
+    std::vector<uint8_t> params(2);
+    params[0] = feature_id & 0xff;
+    params[1] = (feature_id >> 8) & 0xff;
+
+    auto response = this->callFunction(Function::Ping, params);
+
+    info.feature_id = response[0];
+    info.hidden = response[1] & FeatureFlag::Hidden;
+    info.obsolete = response[1] & FeatureFlag::Obsolete;
+    info.internal = response[1] & FeatureFlag::Internal;
+
+    return info;
+}

src/logid/backend/hidpp20/features/Root.h

@@ -0,0 +1,37 @@
+#ifndef LOGID_BACKEND_HIDPP20_FEATURE_ROOT_H
+#define LOGID_BACKEND_HIDPP20_FEATURE_ROOT_H
+
+#include "../Feature.h"
+#include "../feature_defs.h"
+
+namespace logid {
+namespace backend {
+namespace hidpp20
+{
+    class Root : public Feature
+    {
+    public:
+        static const uint16_t ID = FeatureID::ROOT;
+        virtual uint16_t getID() { return ID; }
+
+        enum Function : uint8_t
+        {
+            GetFeature = 0,
+            Ping = 1
+        };
+
+        Root(Device* device);
+
+        feature_info getFeature (uint16_t feature_id);
+        void ping();
+    private:
+        enum FeatureFlag : uint8_t
+        {
+            Obsolete = 1<<7,
+            Hidden = 1<<6,
+            Internal = 1<<5
+        };
+    };
+}}}
+
+#endif //LOGID_BACKEND_HIDPP20_FEATURE_ROOT_H

src/logid/backend/raw/RawDevice.cpp

@@ -1,5 +1,7 @@
 #include "RawDevice.h"
 #include "../Error.h"
+#include "../hidpp/defs.h"
+#include "../dj/defs.h"
 
 #include <string>
 #include <system_error>
@@ -16,9 +18,16 @@ extern "C"
 }
 
 using namespace logid::backend::raw;
+using namespace logid::backend;
 using namespace std::chrono;
 
-RawDevice::RawDevice(std::string path) : path (path)
+bool RawDevice::supportedReportID(uint8_t id)
+{
+    return (hidpp::ReportType::Short == id) || (hidpp::ReportType::Long == id) ||
+           (dj::ReportType::Short == id) || (dj::ReportType::Long == id);
+}
+
+RawDevice::RawDevice(std::string path) : path (path), continue_listen (false)
 {
     int ret;
 
@@ -80,24 +89,81 @@ RawDevice::~RawDevice()
 
 std::vector<uint8_t> RawDevice::sendReport(const std::vector<uint8_t>& report)
 {
-    std::packaged_task<std::vector<uint8_t>()> task(
-            [=]() {
-        _sendReport(report);
-        std::vector<uint8_t> response;
-        _readReport(response, MAX_DATA_LENGTH);
-        return response;
-    });
+    assert(supportedReportID(report[0]));
 
-    /* If the listener will stop, handle I/O manually.
+        /* If the listener will stop, handle I/O manually.
      * Otherwise, push to queue and wait for result. */
     if(continue_listen)
     {
+        std::packaged_task<std::vector<uint8_t>()> task( [this, report]() {
+            return this->_respondToReport(report);
+        });
         auto f = task.get_future();
         write_queue.push(&task);
         return f.get();
     }
     else
-        return task.get_future().get();
+        return _respondToReport(report);
+}
+
+std::vector<uint8_t> RawDevice::_respondToReport
+    (const std::vector<uint8_t>& request)
+{
+    _sendReport(request);
+    while(true)
+    {
+        std::vector<uint8_t> response;
+        _readReport(response, MAX_DATA_LENGTH);
+
+        // All reports have the device index at byte 2
+        if(response[1] != request[1])
+        {
+            std::thread([this](std::vector<uint8_t> report) {
+                this->handleEvent(report);
+            }, request).detach();
+            continue;
+        }
+
+        if(hidpp::ReportType::Short == request[0] ||
+            hidpp::ReportType::Long == request[0])
+        {
+            if(hidpp::ReportType::Short != response[0] &&
+               hidpp::ReportType::Long != response[0])
+            {
+                std::thread([this](std::vector<uint8_t> report) {
+                    this->handleEvent(report);
+                }, request).detach();
+                continue;
+            }
+
+            // Error; leave to device to handle
+            if(response[2] == 0x8f || response[2] == 0xff)
+                return response;
+
+            bool others_match = true;
+            for(int i = 2; i < 4; i++)
+            {
+                if(response[i] != request[i])
+                    others_match = false;
+            }
+
+            if(others_match)
+                return response;
+        }
+        else if(dj::ReportType::Short == request[0] ||
+            dj::ReportType::Long == request[0])
+        {
+            //Error; leave to device ot handle
+            if(0x7f == response[2])
+                return response;
+            else if(response[2] == request[2])
+                return response;
+        }
+
+        std::thread([this](std::vector<uint8_t> report) {
+            this->handleEvent(report);
+        }, request).detach();
+    }
 }
 
 int RawDevice::_sendReport(const std::vector<uint8_t>& report)

src/logid/backend/raw/RawDevice.h

@@ -7,6 +7,7 @@
 #include <map>
 #include <atomic>
 #include <future>
+#include <set>
 
 #include "../defs.h"
 #include "../../util/mutex_queue.h"
@@ -20,12 +21,13 @@ namespace raw
     class RawDevice
     {
     public:
+        static bool supportedReportID(uint8_t id);
+
         RawDevice(std::string path);
         ~RawDevice();
         std::string hidrawPath() const { return path; }
         std::vector<uint8_t> reportDescriptor() const { return rdesc; }
 
-        /// TODO: Process reports in a queue.
         std::vector<uint8_t> sendReport(const std::vector<uint8_t>& report);
         void interruptRead();
 
@@ -55,6 +57,8 @@ namespace raw
         int _sendReport(const std::vector<uint8_t>& report);
         int _readReport(std::vector<uint8_t>& report, std::size_t maxDataLength);
 
+        std::vector<uint8_t> _respondToReport(const std::vector<uint8_t>& request);
+
         mutex_queue<std::packaged_task<std::vector<uint8_t>()>*> write_queue;
     };
 }}}