text: /*
   * The MIT License (MIT)
   *
   * Copyright (c) 2019 Ha Thach (tinyusb.org)
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   *
   * This file is part of the TinyUSB stack.
   */
  
  #include "tusb_option.h"
  
  #if TUSB_OPT_DEVICE_ENABLED
  
  #include "tusb.h"
  #include "device/usbd.h"
  #include "device/usbd_pvt.h"
  #include "device/dcd.h"
  
  //--------------------------------------------------------------------+
  // USBD Configuration
  //--------------------------------------------------------------------+
  
  // Debug level of USBD
  #define USBD_DBG   2
  
  #ifndef CFG_TUD_TASK_QUEUE_SZ
    #define CFG_TUD_TASK_QUEUE_SZ   16
  #endif
  
  //--------------------------------------------------------------------+
  // Device Data
  //--------------------------------------------------------------------+
  
  // Invalid driver ID in itf2drv[] ep2drv[][] mapping
  enum { DRVID_INVALID = 0xFFu };
  
  typedef struct
  {
    struct TU_ATTR_PACKED
    {
      volatile uint8_t connected    : 1;
      volatile uint8_t addressed    : 1;
      volatile uint8_t suspended    : 1;
  
      uint8_t remote_wakeup_en      : 1; // enable/disable by host
      uint8_t remote_wakeup_support : 1; // configuration descriptor's attribute
      uint8_t self_powered          : 1; // configuration descriptor's attribute
    };
  
    volatile uint8_t cfg_num; // current active configuration (0x00 is not configured)
    uint8_t speed;
  
    uint8_t itf2drv[16];     // map interface number to driver (0xff is invalid)
    uint8_t ep2drv[CFG_TUD_ENDPPOINT_MAX][2]; // map endpoint to driver ( 0xff is invalid )
  
    struct TU_ATTR_PACKED
    {
      volatile bool busy    : 1;
      volatile bool stalled : 1;
      volatile bool claimed : 1;
  
      // TODO merge ep2drv here, 4-bit should be sufficient
    }ep_status[CFG_TUD_ENDPPOINT_MAX][2];
  
  }usbd_device_t;
  
  static usbd_device_t _usbd_dev;
  
  //--------------------------------------------------------------------+
  // Class Driver
  //--------------------------------------------------------------------+
  #if CFG_TUSB_DEBUG >= 2
    #define DRIVER_NAME(_name)    .name = _name,
  #else
    #define DRIVER_NAME(_name)
  #endif
  
  // Built-in class drivers
  static usbd_class_driver_t const _usbd_driver[] =
  {
    #if CFG_TUD_CDC
    {
      DRIVER_NAME("CDC")
      .init             = cdcd_init,
      .reset            = cdcd_reset,
      .open             = cdcd_open,
      .control_xfer_cb  = cdcd_control_xfer_cb,
      .xfer_cb          = cdcd_xfer_cb,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_MSC
    {
      DRIVER_NAME("MSC")
      .init             = mscd_init,
      .reset            = mscd_reset,
      .open             = mscd_open,
      .control_xfer_cb  = mscd_control_xfer_cb,
      .xfer_cb          = mscd_xfer_cb,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_HID
    {
      DRIVER_NAME("HID")
      .init             = hidd_init,
      .reset            = hidd_reset,
      .open             = hidd_open,
      .control_xfer_cb  = hidd_control_xfer_cb,
      .xfer_cb          = hidd_xfer_cb,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_AUDIO
    {
      DRIVER_NAME("AUDIO")
      .init             = audiod_init,
      .reset            = audiod_reset,
      .open             = audiod_open,
      .control_xfer_cb  = audiod_control_xfer_cb,
      .xfer_cb          = audiod_xfer_cb,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_VIDEO
    {
      DRIVER_NAME("VIDEO")
      .init             = videod_init,
      .reset            = videod_reset,
      .open             = videod_open,
      .control_xfer_cb  = videod_control_xfer_cb,
      .xfer_cb          = videod_xfer_cb,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_MIDI
    {
      DRIVER_NAME("MIDI")
      .init             = midid_init,
      .open             = midid_open,
      .reset            = midid_reset,
      .control_xfer_cb  = midid_control_xfer_cb,
      .xfer_cb          = midid_xfer_cb,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_VENDOR
    {
      DRIVER_NAME("VENDOR")
      .init             = vendord_init,
      .reset            = vendord_reset,
      .open             = vendord_open,
      .control_xfer_cb  = tud_vendor_control_xfer_cb,
      .xfer_cb          = vendord_xfer_cb,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_USBTMC
    {
      DRIVER_NAME("TMC")
      .init             = usbtmcd_init_cb,
      .reset            = usbtmcd_reset_cb,
      .open             = usbtmcd_open_cb,
      .control_xfer_cb  = usbtmcd_control_xfer_cb,
      .xfer_cb          = usbtmcd_xfer_cb,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_DFU_RUNTIME
    {
      DRIVER_NAME("DFU-RUNTIME")
      .init             = dfu_rtd_init,
      .reset            = dfu_rtd_reset,
      .open             = dfu_rtd_open,
      .control_xfer_cb  = dfu_rtd_control_xfer_cb,
      .xfer_cb          = NULL,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_DFU
    {
      DRIVER_NAME("DFU")
      .init             = dfu_moded_init,
      .reset            = dfu_moded_reset,
      .open             = dfu_moded_open,
      .control_xfer_cb  = dfu_moded_control_xfer_cb,
      .xfer_cb          = NULL,
      .sof              = NULL
    },
    #endif
  
    #if CFG_TUD_ECM_RNDIS || CFG_TUD_NCM
    {
      DRIVER_NAME("NET")
      .init             = netd_init,
      .reset            = netd_reset,
      .open             = netd_open,
      .control_xfer_cb  = netd_control_xfer_cb,
      .xfer_cb          = netd_xfer_cb,
      .sof              = NULL,
    },
    #endif
  
    #if CFG_TUD_BTH
    {
      DRIVER_NAME("BTH")
      .init             = btd_init,
      .reset            = btd_reset,
      .open             = btd_open,
      .control_xfer_cb  = btd_control_xfer_cb,
      .xfer_cb          = btd_xfer_cb,
      .sof              = NULL
    },
    #endif
  };
  
  enum { BUILTIN_DRIVER_COUNT = TU_ARRAY_SIZE(_usbd_driver) };
  
  // Additional class drivers implemented by application
  static usbd_class_driver_t const * _app_driver = NULL;
  static uint8_t _app_driver_count = 0;
  
  // virtually joins built-in and application drivers together.
  // Application is positioned first to allow overwriting built-in ones.
  static inline usbd_class_driver_t const * get_driver(uint8_t drvid)
  {
    // Application drivers
    if ( usbd_app_driver_get_cb )
    {
      if ( drvid < _app_driver_count ) return &_app_driver[drvid];
      drvid -= _app_driver_count;
    }
  
    // Built-in drivers
    if (drvid < BUILTIN_DRIVER_COUNT) return &_usbd_driver[drvid];
  
    return NULL;
  }
  
  #define TOTAL_DRIVER_COUNT    (_app_driver_count + BUILTIN_DRIVER_COUNT)
  
  //--------------------------------------------------------------------+
  // DCD Event
  //--------------------------------------------------------------------+
  
  static bool _usbd_initialized = false;
  
  // Event queue
  // OPT_MODE_DEVICE is used by OS NONE for mutex (disable usb isr)
  OSAL_QUEUE_DEF(OPT_MODE_DEVICE, _usbd_qdef, CFG_TUD_TASK_QUEUE_SZ, dcd_event_t);
  static osal_queue_t _usbd_q;
  
  // Mutex for claiming endpoint, only needed when using with preempted RTOS
  #if CFG_TUSB_OS != OPT_OS_NONE
  static osal_mutex_def_t _ubsd_mutexdef;
  static osal_mutex_t _usbd_mutex;
  #endif
  
  
  //--------------------------------------------------------------------+
  // Prototypes
  //--------------------------------------------------------------------+
  static bool process_control_request(uint8_t rhport, tusb_control_request_t const * p_request);
  static bool process_set_config(uint8_t rhport, uint8_t cfg_num);
  static bool process_get_descriptor(uint8_t rhport, tusb_control_request_t const * p_request);
  
  // from usbd_control.c
  void usbd_control_reset(void);
  void usbd_control_set_request(tusb_control_request_t const *request);
  void usbd_control_set_complete_callback( usbd_control_xfer_cb_t fp );
  bool usbd_control_xfer_cb (uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
  
  
  //--------------------------------------------------------------------+
  // Debug
  //--------------------------------------------------------------------+
  #if CFG_TUSB_DEBUG >= 2
  static char const* const _usbd_event_str[DCD_EVENT_COUNT] =
  {
    "Invalid"        ,
    "Bus Reset"      ,
    "Unplugged"      ,
    "SOF"            ,
    "Suspend"        ,
    "Resume"         ,
    "Setup Received" ,
    "Xfer Complete"  ,
    "Func Call"
  };
  
  static char const* const _tusb_std_request_str[] =
  {
    "Get Status"        ,
    "Clear Feature"     ,
    "Reserved"          ,
    "Set Feature"       ,
    "Reserved"          ,
    "Set Address"       ,
    "Get Descriptor"    ,
    "Set Descriptor"    ,
    "Get Configuration" ,
    "Set Configuration" ,
    "Get Interface"     ,
    "Set Interface"     ,
    "Synch Frame"
  };
  
  static char const* const _tusb_speed_str[] = { "Full", "Low", "High" };
  
  // for usbd_control to print the name of control complete driver
  void usbd_driver_print_control_complete_name(usbd_control_xfer_cb_t callback)
  {
    for (uint8_t i = 0; i < TOTAL_DRIVER_COUNT; i++)
    {
      usbd_class_driver_t const * driver = get_driver(i);
      if ( driver->control_xfer_cb == callback )
      {
        TU_LOG2("  %s control complete\r\n", driver->name);
        return;
      }
    }
  }
  
  #endif
  
  //--------------------------------------------------------------------+
  // Application API
  //--------------------------------------------------------------------+
  tusb_speed_t tud_speed_get(void)
  {
    return (tusb_speed_t) _usbd_dev.speed;
  }
  
  bool tud_connected(void)
  {
    return _usbd_dev.connected;
  }
  
  bool tud_mounted(void)
  {
    return _usbd_dev.cfg_num ? true : false;
  }
  
  bool tud_suspended(void)
  {
    return _usbd_dev.suspended;
  }
  
  bool tud_remote_wakeup(void)
  {
    // only wake up host if this feature is supported and enabled and we are suspended
    TU_VERIFY (_usbd_dev.suspended && _usbd_dev.remote_wakeup_support && _usbd_dev.remote_wakeup_en );
    dcd_remote_wakeup(TUD_OPT_RHPORT);
    return true;
  }
  
  bool tud_disconnect(void)
  {
    TU_VERIFY(dcd_disconnect);
    dcd_disconnect(TUD_OPT_RHPORT);
    return true;
  }
  
  bool tud_connect(void)
  {
    TU_VERIFY(dcd_connect);
    dcd_connect(TUD_OPT_RHPORT);
    return true;
  }
  
  //--------------------------------------------------------------------+
  // USBD Task
  //--------------------------------------------------------------------+
  bool tud_inited(void)
  {
    return _usbd_initialized;
  }
  
  bool tud_init (uint8_t rhport)
  {
    // skip if already initialized
    if (_usbd_initialized) return _usbd_initialized;
  
    TU_LOG2("USBD init\r\n");
  
    tu_varclr(&_usbd_dev);
  
  #if CFG_TUSB_OS != OPT_OS_NONE
    // Init device mutex
    _usbd_mutex = osal_mutex_create(&_ubsd_mutexdef);
    TU_ASSERT(_usbd_mutex);
  #endif
  
    // Init device queue & task
    _usbd_q = osal_queue_create(&_usbd_qdef);
    TU_ASSERT(_usbd_q);
  
    // Get application driver if available
    if ( usbd_app_driver_get_cb )
    {
      _app_driver = usbd_app_driver_get_cb(&_app_driver_count);
    }
  
    // Init class drivers
    for (uint8_t i = 0; i < TOTAL_DRIVER_COUNT; i++)
    {
      usbd_class_driver_t const * driver = get_driver(i);
      TU_LOG2("%s init\r\n", driver->name);
      driver->init();
    }
  
    // Init device controller driver
    dcd_init(rhport);
    dcd_int_enable(rhport);
  
    _usbd_initialized = true;
  
    return true;
  }
  
  static void configuration_reset(uint8_t rhport)
  {
    for ( uint8_t i = 0; i < TOTAL_DRIVER_COUNT; i++ )
    {
      get_driver(i)->reset(rhport);
    }
  
    tu_varclr(&_usbd_dev);
    memset(_usbd_dev.itf2drv, DRVID_INVALID, sizeof(_usbd_dev.itf2drv)); // invalid mapping
    memset(_usbd_dev.ep2drv , DRVID_INVALID, sizeof(_usbd_dev.ep2drv )); // invalid mapping
  }
  
  static void usbd_reset(uint8_t rhport)
  {
    configuration_reset(rhport);
    usbd_control_reset();
  }
  
  bool tud_task_event_ready(void)
  {
    // Skip if stack is not initialized
    if ( !tusb_inited() ) return false;
  
    return !osal_queue_empty(_usbd_q);
  }
  
  /* USB Device Driver task
   * This top level thread manages all device controller event and delegates events to class-specific drivers.
   * This should be called periodically within the mainloop or rtos thread.
   *
     @code
      int main(void)
      {
        application_init();
        tusb_init();
  
        while(1) // the mainloop
        {
          application_code();
          tud_task(); // tinyusb device task
        }
      }
      @endcode
   */
  void tud_task (void)
  {
    // Skip if stack is not initialized
    if ( !tusb_inited() ) return;
  
    // Loop until there is no more events in the queue
    while (1)
    {
      dcd_event_t event;
  
      if ( !osal_queue_receive(_usbd_q, &event) ) return;
  
  #if CFG_TUSB_DEBUG >= 2
      if (event.event_id == DCD_EVENT_SETUP_RECEIVED) TU_LOG2("\r\n"); // extra line for setup
      TU_LOG2("USBD %s ", event.event_id < DCD_EVENT_COUNT ? _usbd_event_str[event.event_id] : "CORRUPTED");
  #endif
  
      switch ( event.event_id )
      {
        case DCD_EVENT_BUS_RESET:
          TU_LOG2(": %s Speed\r\n", _tusb_speed_str[event.bus_reset.speed]);
          usbd_reset(event.rhport);
          _usbd_dev.speed = event.bus_reset.speed;
        break;
  
        case DCD_EVENT_UNPLUGGED:
          TU_LOG2("\r\n");
          usbd_reset(event.rhport);
  
          // invoke callback
          if (tud_umount_cb) tud_umount_cb();
        break;
  
        case DCD_EVENT_SETUP_RECEIVED:
          TU_LOG2_VAR(&event.setup_received);
          TU_LOG2("\r\n");
  
          // Mark as connected after receiving 1st setup packet.
          // But it is easier to set it every time instead of wasting time to check then set
          _usbd_dev.connected = 1;
  
          // mark both in & out control as free
          _usbd_dev.ep_status[0][TUSB_DIR_OUT].busy = false;
          _usbd_dev.ep_status[0][TUSB_DIR_OUT].claimed = 0;
          _usbd_dev.ep_status[0][TUSB_DIR_IN ].busy = false;
          _usbd_dev.ep_status[0][TUSB_DIR_IN ].claimed = 0;
  
          // Process control request
          if ( !process_control_request(event.rhport, &event.setup_received) )
          {
            TU_LOG2("  Stall EP0\r\n");
            // Failed -> stall both control endpoint IN and OUT
            dcd_edpt_stall(event.rhport, 0);
            dcd_edpt_stall(event.rhport, 0 | TUSB_DIR_IN_MASK);
          }
        break;
  
        case DCD_EVENT_XFER_COMPLETE:
        {
          // Invoke the class callback associated with the endpoint address
          uint8_t const ep_addr = event.xfer_complete.ep_addr;
          uint8_t const epnum   = tu_edpt_number(ep_addr);
          uint8_t const ep_dir  = tu_edpt_dir(ep_addr);
  
          TU_LOG2("on EP %02X with %u bytes\r\n", ep_addr, (unsigned int) event.xfer_complete.len);
  
          _usbd_dev.ep_status[epnum][ep_dir].busy = false;
          _usbd_dev.ep_status[epnum][ep_dir].claimed = 0;
  
          if ( 0 == epnum )
          {
            usbd_control_xfer_cb(event.rhport, ep_addr, (xfer_result_t)event.xfer_complete.result, event.xfer_complete.len);
          }
          else
          {
            usbd_class_driver_t const * driver = get_driver( _usbd_dev.ep2drv[epnum][ep_dir] );
            TU_ASSERT(driver, );
  
            TU_LOG2("  %s xfer callback\r\n", driver->name);
            driver->xfer_cb(event.rhport, ep_addr, (xfer_result_t)event.xfer_complete.result, event.xfer_complete.len);
          }
        }
        break;
  
        case DCD_EVENT_SUSPEND:
          // NOTE: When plugging/unplugging device, the D+/D- state are unstable and
          // can accidentally meet the SUSPEND condition ( Bus Idle for 3ms ), which result in a series of event
          // e.g suspend -> resume -> unplug/plug. Skip suspend/resume if not connected
          if ( _usbd_dev.connected )
          {
            TU_LOG2(": Remote Wakeup = %u\r\n", _usbd_dev.remote_wakeup_en);
            if (tud_suspend_cb) tud_suspend_cb(_usbd_dev.remote_wakeup_en);
          }else
          {
            TU_LOG2(" Skipped\r\n");
          }
        break;
  
        case DCD_EVENT_RESUME:
          if ( _usbd_dev.connected )
          {
            TU_LOG2("\r\n");
            if (tud_resume_cb) tud_resume_cb();
          }else
          {
            TU_LOG2(" Skipped\r\n");
          }
        break;
  
        case DCD_EVENT_SOF:
          TU_LOG2("\r\n");
          for ( uint8_t i = 0; i < TOTAL_DRIVER_COUNT; i++ )
          {
            usbd_class_driver_t const * driver = get_driver(i);
            if ( driver->sof ) driver->sof(event.rhport);
          }
        break;
  
        case USBD_EVENT_FUNC_CALL:
          TU_LOG2("\r\n");
          if ( event.func_call.func ) event.func_call.func(event.func_call.param);
        break;
  
        default:
          TU_BREAKPOINT();
        break;
      }
    }
  }
  
  //--------------------------------------------------------------------+
  // Control Request Parser & Handling
  //--------------------------------------------------------------------+
  
  // Helper to invoke class driver control request handler
  static bool invoke_class_control(uint8_t rhport, usbd_class_driver_t const * driver, tusb_control_request_t const * request)
  {
    usbd_control_set_complete_callback(driver->control_xfer_cb);
    TU_LOG2("  %s control request\r\n", driver->name);
    return driver->control_xfer_cb(rhport, CONTROL_STAGE_SETUP, request);
  }
  
  // This handles the actual request and its response.
  // return false will cause its caller to stall control endpoint
  static bool process_control_request(uint8_t rhport, tusb_control_request_t const * p_request)
  {
    usbd_control_set_complete_callback(NULL);
  
    TU_ASSERT(p_request->bmRequestType_bit.type < TUSB_REQ_TYPE_INVALID);
  
    // Vendor request
    if ( p_request->bmRequestType_bit.type == TUSB_REQ_TYPE_VENDOR )
    {
      TU_VERIFY(tud_vendor_control_xfer_cb);
  
      usbd_control_set_complete_callback(tud_vendor_control_xfer_cb);
      return tud_vendor_control_xfer_cb(rhport, CONTROL_STAGE_SETUP, p_request);
    }
  
  #if CFG_TUSB_DEBUG >= 2
    if (TUSB_REQ_TYPE_STANDARD == p_request->bmRequestType_bit.type && p_request->bRequest <= TUSB_REQ_SYNCH_FRAME)
    {
      TU_LOG2("  %s", _tusb_std_request_str[p_request->bRequest]);
      if (TUSB_REQ_GET_DESCRIPTOR != p_request->bRequest) TU_LOG2("\r\n");
    }
  #endif
  
    switch ( p_request->bmRequestType_bit.recipient )
    {
      //------------- Device Requests e.g in enumeration -------------//
      case TUSB_REQ_RCPT_DEVICE:
        if ( TUSB_REQ_TYPE_CLASS == p_request->bmRequestType_bit.type )
        {
          uint8_t const itf = tu_u16_low(p_request->wIndex);
          TU_VERIFY(itf < TU_ARRAY_SIZE(_usbd_dev.itf2drv));
  
          usbd_class_driver_t const * driver = get_driver(_usbd_dev.itf2drv[itf]);
          TU_VERIFY(driver);
  
          // forward to class driver: "non-STD request to Interface"
          return invoke_class_control(rhport, driver, p_request);
        }
  
        if ( TUSB_REQ_TYPE_STANDARD != p_request->bmRequestType_bit.type )
        {
          // Non standard request is not supported
          TU_BREAKPOINT();
          return false;
        }
  
        switch ( p_request->bRequest )
        {
          case TUSB_REQ_SET_ADDRESS:
            // Depending on mcu, status phase could be sent either before or after changing device address,
            // or even require stack to not response with status at all
            // Therefore DCD must take full responsibility to response and include zlp status packet if needed.
            usbd_control_set_request(p_request); // set request since DCD has no access to tud_control_status() API
            dcd_set_address(rhport, (uint8_t) p_request->wValue);
            // skip tud_control_status()
            _usbd_dev.addressed = 1;
          break;
  
          case TUSB_REQ_GET_CONFIGURATION:
          {
            uint8_t cfg_num = _usbd_dev.cfg_num;
            tud_control_xfer(rhport, p_request, &cfg_num, 1);
          }
          break;
  
          case TUSB_REQ_SET_CONFIGURATION:
          {
            uint8_t const cfg_num = (uint8_t) p_request->wValue;
  
            // Only process if new configure is different
            if (_usbd_dev.cfg_num != cfg_num)
            {
              if ( _usbd_dev.cfg_num )
              {
                // already configured: need to clear all endpoints and driver first
                TU_LOG(USBD_DBG, "  Clear current Configuration (%u) before switching\r\n", _usbd_dev.cfg_num);
  
                // close all non-control endpoints, cancel all pending transfers if any
                dcd_edpt_close_all(rhport);
  
                // close all drivers and current configured state except bus speed
                uint8_t const speed = _usbd_dev.speed;
                configuration_reset(rhport);
  
                _usbd_dev.speed = speed; // restore speed
              }
  
              // switch to new configuration if not zero
              if ( cfg_num ) TU_ASSERT( process_set_config(rhport, cfg_num) );
            }
  
            _usbd_dev.cfg_num = cfg_num;
            tud_control_status(rhport, p_request);
          }
          break;
  
          case TUSB_REQ_GET_DESCRIPTOR:
            TU_VERIFY( process_get_descriptor(rhport, p_request) );
          break;
  
          case TUSB_REQ_SET_FEATURE:
            // Only support remote wakeup for device feature
            TU_VERIFY(TUSB_REQ_FEATURE_REMOTE_WAKEUP == p_request->wValue);
  
            TU_LOG(USBD_DBG, "    Enable Remote Wakeup\r\n");
  
            // Host may enable remote wake up before suspending especially HID device
            _usbd_dev.remote_wakeup_en = true;
            tud_control_status(rhport, p_request);
          break;
  
          case TUSB_REQ_CLEAR_FEATURE:
            // Only support remote wakeup for device feature
            TU_VERIFY(TUSB_REQ_FEATURE_REMOTE_WAKEUP == p_request->wValue);
  
            TU_LOG(USBD_DBG, "    Disable Remote Wakeup\r\n");
  
            // Host may disable remote wake up after resuming
            _usbd_dev.remote_wakeup_en = false;
            tud_control_status(rhport, p_request);
          break;
  
          case TUSB_REQ_GET_STATUS:
          {
            // Device status bit mask
            // - Bit 0: Self Powered
            // - Bit 1: Remote Wakeup enabled
            uint16_t status = (_usbd_dev.self_powered ? 1 : 0) | (_usbd_dev.remote_wakeup_en ? 2 : 0);
            tud_control_xfer(rhport, p_request, &status, 2);
          }
          break;
  
          // Unknown/Unsupported request
          default: TU_BREAKPOINT(); return false;
        }
      break;
  
      //------------- Class/Interface Specific Request -------------//
      case TUSB_REQ_RCPT_INTERFACE:
      {
        uint8_t const itf = tu_u16_low(p_request->wIndex);
        TU_VERIFY(itf < TU_ARRAY_SIZE(_usbd_dev.itf2drv));
  
        usbd_class_driver_t const * driver = get_driver(_usbd_dev.itf2drv[itf]);
        TU_VERIFY(driver);
  
        // all requests to Interface (STD or Class) is forwarded to class driver.
        // notable requests are: GET HID REPORT DESCRIPTOR, SET_INTERFACE, GET_INTERFACE
        if ( !invoke_class_control(rhport, driver, p_request) )
        {
          // For GET_INTERFACE and SET_INTERFACE, it is mandatory to respond even if the class
          // driver doesn't use alternate settings or implement this
          TU_VERIFY(TUSB_REQ_TYPE_STANDARD == p_request->bmRequestType_bit.type);
  
          switch(p_request->bRequest)
          {
            case TUSB_REQ_GET_INTERFACE:
            case TUSB_REQ_SET_INTERFACE:
              // Clear complete callback if driver set since it can also stall the request.
              usbd_control_set_complete_callback(NULL);
  
              if (TUSB_REQ_GET_INTERFACE == p_request->bRequest)
              {
                uint8_t alternate = 0;
                tud_control_xfer(rhport, p_request, &alternate, 1);
              }else
              {
                tud_control_status(rhport, p_request);
              }
            break;
  
            default: return false;
          }
        }
      }
      break;
  
      //------------- Endpoint Request -------------//
      case TUSB_REQ_RCPT_ENDPOINT:
      {
        uint8_t const ep_addr = tu_u16_low(p_request->wIndex);
        uint8_t const ep_num  = tu_edpt_number(ep_addr);
        uint8_t const ep_dir  = tu_edpt_dir(ep_addr);
  
        TU_ASSERT(ep_num < TU_ARRAY_SIZE(_usbd_dev.ep2drv) );
  
        usbd_class_driver_t const * driver = get_driver(_usbd_dev.ep2drv[ep_num][ep_dir]);
  
        if ( TUSB_REQ_TYPE_STANDARD != p_request->bmRequestType_bit.type )
        {
          // Forward class request to its driver
          TU_VERIFY(driver);
          return invoke_class_control(rhport, driver, p_request);
        }
        else
        {
          // Handle STD request to endpoint
          switch ( p_request->bRequest )
          {
            case TUSB_REQ_GET_STATUS:
            {
              uint16_t status = usbd_edpt_stalled(rhport, ep_addr) ? 0x0001 : 0x0000;
              tud_control_xfer(rhport, p_request, &status, 2);
            }
            break;
  
            case TUSB_REQ_CLEAR_FEATURE:
            case TUSB_REQ_SET_FEATURE:
            {
              if ( TUSB_REQ_FEATURE_EDPT_HALT == p_request->wValue )
              {
                if ( TUSB_REQ_CLEAR_FEATURE ==  p_request->bRequest )
                {
                  usbd_edpt_clear_stall(rhport, ep_addr);
                }else
                {
                  usbd_edpt_stall(rhport, ep_addr);
                }
              }
  
              if (driver)
              {
                // Some classes such as USBTMC needs to clear/re-init its buffer when receiving CLEAR_FEATURE request
                // We will also forward std request targeted endpoint to class drivers as well
  
                // STD request must always be ACKed regardless of driver returned value
                // Also clear complete callback if driver set since it can also stall the request.
                (void) invoke_class_control(rhport, driver, p_request);
                usbd_control_set_complete_callback(NULL);
  
                // skip ZLP status if driver already did that
                if ( !_usbd_dev.ep_status[0][TUSB_DIR_IN].busy ) tud_control_status(rhport, p_request);
              }
            }
            break;
  
            // Unknown/Unsupported request
            default: TU_BREAKPOINT(); return false;
          }
        }
      }
      break;
  
      // Unknown recipient
      default: TU_BREAKPOINT(); return false;
    }
  
    return true;
  }
  
  // Process Set Configure Request
  // This function parse configuration descriptor & open drivers accordingly
  static bool process_set_config(uint8_t rhport, uint8_t cfg_num)
  {
    // index is cfg_num-1
    tusb_desc_configuration_t const * desc_cfg = (tusb_desc_configuration_t const *) tud_descriptor_configuration_cb(cfg_num-1);
    TU_ASSERT(desc_cfg != NULL && desc_cfg->bDescriptorType == TUSB_DESC_CONFIGURATION);
  
    // Parse configuration descriptor
    _usbd_dev.remote_wakeup_support = (desc_cfg->bmAttributes & TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP) ? 1 : 0;
    _usbd_dev.self_powered          = (desc_cfg->bmAttributes & TUSB_DESC_CONFIG_ATT_SELF_POWERED ) ? 1 : 0;
  
    // Parse interface descriptor
    uint8_t const * p_desc   = ((uint8_t const*) desc_cfg) + sizeof(tusb_desc_configuration_t);
    uint8_t const * desc_end = ((uint8_t const*) desc_cfg) + tu_le16toh(desc_cfg->wTotalLength);
  
    while( p_desc < desc_end )
    {
      uint8_t assoc_itf_count = 1;
  
      // Class will always starts with Interface Association (if any) and then Interface descriptor
      if ( TUSB_DESC_INTERFACE_ASSOCIATION == tu_desc_type(p_desc) )
      {
        tusb_desc_interface_assoc_t const * desc_iad = (tusb_desc_interface_assoc_t const *) p_desc;
        assoc_itf_count = desc_iad->bInterfaceCount;
  
        p_desc = tu_desc_next(p_desc); // next to Interface
  
        // IAD's first interface number and class should match with opened interface
        //TU_ASSERT(desc_iad->bFirstInterface == desc_itf->bInterfaceNumber &&
        //          desc_iad->bFunctionClass  == desc_itf->bInterfaceClass);
      }
  
      TU_ASSERT( TUSB_DESC_INTERFACE == tu_desc_type(p_desc) );
      tusb_desc_interface_t const * desc_itf = (tusb_desc_interface_t const*) p_desc;
  
      // Find driver for this interface
      uint16_t const remaining_len = desc_end-p_desc;
      uint8_t drv_id;
      for (drv_id = 0; drv_id < TOTAL_DRIVER_COUNT; drv_id++)
      {
        usbd_class_driver_t const *driver = get_driver(drv_id);
        uint16_t const drv_len = driver->open(rhport, desc_itf, remaining_len);
  
        if ( (sizeof(tusb_desc_interface_t) <= drv_len)  && (drv_len <= remaining_len) )
        {
          // Open successfully
          TU_LOG2("  %s opened\r\n", driver->name);
  
          // Some drivers use 2 or more interfaces but may not have IAD e.g MIDI (always) or
          // BTH (even CDC) with class in device descriptor (single interface)
          if ( assoc_itf_count == 1)
          {
            #if CFG_TUD_CDC
            if ( driver->open == cdcd_open ) assoc_itf_count = 2;
            #endif
  
            #if CFG_TUD_MIDI
            if ( driver->open == midid_open ) assoc_itf_count = 2;
            #endif
  
            #if CFG_TUD_BTH && CFG_TUD_BTH_ISO_ALT_COUNT
            if ( driver->open == btd_open ) assoc_itf_count = 2;
            #endif
          }
  
          // bind (associated) interfaces to found driver
          for(uint8_t i=0; i<assoc_itf_count; i++)
          {
            uint8_t const itf_num = desc_itf->bInterfaceNumber+i;
  
            // Interface number must not be used already
            TU_ASSERT(DRVID_INVALID == _usbd_dev.itf2drv[itf_num]);
            _usbd_dev.itf2drv[itf_num] = drv_id;
          }
  
          // bind all endpoints to found driver
          tu_edpt_bind_driver(_usbd_dev.ep2drv, desc_itf, drv_len, drv_id);
  
          // next Interface
          p_desc += drv_len;
  
          break; // exit driver find loop
        }
      }
  
      // Failed if there is no supported drivers
      TU_ASSERT(drv_id < TOTAL_DRIVER_COUNT);
    }
  
    // invoke callback
    if (tud_mount_cb) tud_mount_cb();
  
    return true;
  }
  
  // return descriptor's buffer and update desc_len
  static bool process_get_descriptor(uint8_t rhport, tusb_control_request_t const * p_request)
  {
    tusb_desc_type_t const desc_type = (tusb_desc_type_t) tu_u16_high(p_request->wValue);
    uint8_t const desc_index = tu_u16_low( p_request->wValue );
  
    switch(desc_type)
    {
      case TUSB_DESC_DEVICE:
      {
        TU_LOG2(" Device\r\n");
  
        void* desc_device = (void*) (uintptr_t) tud_descriptor_device_cb();
  
        // Only response with exactly 1 Packet if: not addressed and host requested more data than device descriptor has.
        // This only happens with the very first get device descriptor and EP0 size = 8 or 16.
        if ((CFG_TUD_ENDPOINT0_SIZE < sizeof(tusb_desc_device_t)) && !_usbd_dev.addressed &&
            ((tusb_control_request_t const*) p_request)->wLength > sizeof(tusb_desc_device_t))
        {
          // Hack here: we modify the request length to prevent usbd_control response with zlp
          // since we are responding with 1 packet & less data than wLength.
          tusb_control_request_t mod_request = *p_request;
          mod_request.wLength = CFG_TUD_ENDPOINT0_SIZE;
  
          return tud_control_xfer(rhport, &mod_request, desc_device, CFG_TUD_ENDPOINT0_SIZE);
        }else
        {
          return tud_control_xfer(rhport, p_request, desc_device, sizeof(tusb_desc_device_t));
        }
      }
      // break; // unreachable
  
      case TUSB_DESC_BOS:
      {
        TU_LOG2(" BOS\r\n");
  
        // requested by host if USB > 2.0 ( i.e 2.1 or 3.x )
        if (!tud_descriptor_bos_cb) return false;
  
        uintptr_t desc_bos = (uintptr_t) tud_descriptor_bos_cb();
        TU_ASSERT(desc_bos);
  
        // Use offsetof to avoid pointer to the odd/misaligned address
        uint16_t const total_len = tu_le16toh( tu_unaligned_read16((const void*) (desc_bos + offsetof(tusb_desc_bos_t, wTotalLength))) );
  
        return tud_control_xfer(rhport, p_request, (void*) desc_bos, total_len);
      }
      // break; // unreachable
  
      case TUSB_DESC_CONFIGURATION:
      case TUSB_DESC_OTHER_SPEED_CONFIG:
      {
        uintptr_t desc_config;
  
        if ( desc_type == TUSB_DESC_CONFIGURATION )
        {
          TU_LOG2(" Configuration[%u]\r\n", desc_index);
          desc_config = (uintptr_t) tud_descriptor_configuration_cb(desc_index);
        }else
        {
          // Host only request this after getting Device Qualifier descriptor
          TU_LOG2(" Other Speed Configuration\r\n");
          TU_VERIFY( tud_descriptor_other_speed_configuration_cb );
          desc_config = (uintptr_t) tud_descriptor_other_speed_configuration_cb(desc_index);
        }
  
        TU_ASSERT(desc_config);
  
        // Use offsetof to avoid pointer to the odd/misaligned address
        uint16_t const total_len = tu_le16toh( tu_unaligned_read16((const void*) (desc_config + offsetof(tusb_desc_configuration_t, wTotalLength))) );
  
        return tud_control_xfer(rhport, p_request, (void*) desc_config, total_len);
      }
      // break; // unreachable
  
      case TUSB_DESC_STRING:
      {
        TU_LOG2(" String[%u]\r\n", desc_index);
  
        // String Descriptor always uses the desc set from user
        uint8_t const* desc_str = (uint8_t const*) tud_descriptor_string_cb(desc_index, tu_le16toh(p_request->wIndex));
        TU_VERIFY(desc_str);
  
        // first byte of descriptor is its size
        return tud_control_xfer(rhport, p_request, (void*) (uintptr_t) desc_str, tu_desc_len(desc_str));
      }
      // break; // unreachable
  
      case TUSB_DESC_DEVICE_QUALIFIER:
      {
        TU_LOG2(" Device Qualifier\r\n");
  
        TU_VERIFY( tud_descriptor_device_qualifier_cb );
  
        uint8_t const* desc_qualifier = tud_descriptor_device_qualifier_cb();
        TU_VERIFY(desc_qualifier);
  
        // first byte of descriptor is its size
        return tud_control_xfer(rhport, p_request, (void*) (uintptr_t) desc_qualifier, tu_desc_len(desc_qualifier));
      }
      // break; // unreachable
  
      default: return false;
    }
  }
  
  //--------------------------------------------------------------------+
  // DCD Event Handler
  //--------------------------------------------------------------------+
  void dcd_event_handler(dcd_event_t const * event, bool in_isr)
  {
    switch (event->event_id)
    {
      case DCD_EVENT_UNPLUGGED:
        _usbd_dev.connected  = 0;
        _usbd_dev.addressed  = 0;
        _usbd_dev.cfg_num    = 0;
        _usbd_dev.suspended  = 0;
        osal_queue_send(_usbd_q, event, in_isr);
      break;
  
      case DCD_EVENT_SUSPEND:
        // NOTE: When plugging/unplugging device, the D+/D- state are unstable and
        // can accidentally meet the SUSPEND condition ( Bus Idle for 3ms ).
        // In addition, some MCUs such as SAMD or boards that haven no VBUS detection cannot distinguish
        // suspended vs disconnected. We will skip handling SUSPEND/RESUME event if not currently connected
        if ( _usbd_dev.connected )
        {
          _usbd_dev.suspended = 1;
          osal_queue_send(_usbd_q, event, in_isr);
        }
      break;
  
      case DCD_EVENT_RESUME:
        // skip event if not connected (especially required for SAMD)
        if ( _usbd_dev.connected )
        {
          _usbd_dev.suspended = 0;
          osal_queue_send(_usbd_q, event, in_isr);
        }
      break;
  
      case DCD_EVENT_SOF:
        // Some MCUs after running dcd_remote_wakeup() does not have way to detect the end of remote wakeup
        // which last 1-15 ms. DCD can use SOF as a clear indicator that bus is back to operational
        if ( _usbd_dev.suspended )
        {
          _usbd_dev.suspended = 0;
          dcd_event_t const event_resume = { .rhport = event->rhport, .event_id = DCD_EVENT_RESUME };
          osal_queue_send(_usbd_q, &event_resume, in_isr);
        }
      break;
  
      default:
        osal_queue_send(_usbd_q, event, in_isr);
      break;
    }
  }
  
  void dcd_event_bus_signal (uint8_t rhport, dcd_eventid_t eid, bool in_isr)
  {
    dcd_event_t event = { .rhport = rhport, .event_id = eid };
    dcd_event_handler(&event, in_isr);
  }
  
  void dcd_event_bus_reset (uint8_t rhport, tusb_speed_t speed, bool in_isr)
  {
    dcd_event_t event = { .rhport = rhport, .event_id = DCD_EVENT_BUS_RESET };
    event.bus_reset.speed = speed;
    dcd_event_handler(&event, in_isr);
  }
  
  void dcd_event_setup_received(uint8_t rhport, uint8_t const * setup, bool in_isr)
  {
    dcd_event_t event = { .rhport = rhport, .event_id = DCD_EVENT_SETUP_RECEIVED };
    memcpy(&event.setup_received, setup, 8);
  
    dcd_event_handler(&event, in_isr);
  }
  
  void dcd_event_xfer_complete (uint8_t rhport, uint8_t ep_addr, uint32_t xferred_bytes, uint8_t result, bool in_isr)
  {
    dcd_event_t event = { .rhport = rhport, .event_id = DCD_EVENT_XFER_COMPLETE };
  
    event.xfer_complete.ep_addr = ep_addr;
    event.xfer_complete.len     = xferred_bytes;
    event.xfer_complete.result  = result;
  
    dcd_event_handler(&event, in_isr);
  }
  
  //--------------------------------------------------------------------+
  // USBD API For Class Driver
  //--------------------------------------------------------------------+
  
  // Parse consecutive endpoint descriptors (IN & OUT)
  bool usbd_open_edpt_pair(uint8_t rhport, uint8_t const* p_desc, uint8_t ep_count, uint8_t xfer_type, uint8_t* ep_out, uint8_t* ep_in)
  {
    for(int i=0; i<ep_count; i++)
    {
      tusb_desc_endpoint_t const * desc_ep = (tusb_desc_endpoint_t const *) p_desc;
  
      TU_ASSERT(TUSB_DESC_ENDPOINT == desc_ep->bDescriptorType && xfer_type == desc_ep->bmAttributes.xfer);
      TU_ASSERT(usbd_edpt_open(rhport, desc_ep));
  
      if ( tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN )
      {
        (*ep_in) = desc_ep->bEndpointAddress;
      }else
      {
        (*ep_out) = desc_ep->bEndpointAddress;
      }
  
      p_desc = tu_desc_next(p_desc);
    }
  
    return true;
  }
  
  // Helper to defer an isr function
  void usbd_defer_func(osal_task_func_t func, void* param, bool in_isr)
  {
    dcd_event_t event =
    {
        .rhport   = 0,
        .event_id = USBD_EVENT_FUNC_CALL,
    };
  
    event.func_call.func  = func;
    event.func_call.param = param;
  
    dcd_event_handler(&event, in_isr);
  }
  
  //--------------------------------------------------------------------+
  // USBD Endpoint API
  //--------------------------------------------------------------------+
  
  bool usbd_edpt_open(uint8_t rhport, tusb_desc_endpoint_t const * desc_ep)
  {
    TU_ASSERT(tu_edpt_number(desc_ep->bEndpointAddress) < CFG_TUD_ENDPPOINT_MAX);
    TU_ASSERT(tu_edpt_validate(desc_ep, (tusb_speed_t) _usbd_dev.speed));
  
    return dcd_edpt_open(rhport, desc_ep);
  }
  
  bool usbd_edpt_claim(uint8_t rhport, uint8_t ep_addr)
  {
    (void) rhport;
  
    // TODO add this check later, also make sure we don't starve an out endpoint while suspending
    // TU_VERIFY(tud_ready());
  
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
  #if CFG_TUSB_OS != OPT_OS_NONE
    // pre-check to help reducing mutex lock
    TU_VERIFY((_usbd_dev.ep_status[epnum][dir].busy == 0) && (_usbd_dev.ep_status[epnum][dir].claimed == 0));
    osal_mutex_lock(_usbd_mutex, OSAL_TIMEOUT_WAIT_FOREVER);
  #endif
  
    // can only claim the endpoint if it is not busy and not claimed yet.
    bool const ret = (_usbd_dev.ep_status[epnum][dir].busy == 0) && (_usbd_dev.ep_status[epnum][dir].claimed == 0);
    if (ret)
    {
      _usbd_dev.ep_status[epnum][dir].claimed = 1;
    }
  
  #if CFG_TUSB_OS != OPT_OS_NONE
    osal_mutex_unlock(_usbd_mutex);
  #endif
  
    return ret;
  }
  
  bool usbd_edpt_release(uint8_t rhport, uint8_t ep_addr)
  {
    (void) rhport;
  
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
  #if CFG_TUSB_OS != OPT_OS_NONE
    osal_mutex_lock(_usbd_mutex, OSAL_TIMEOUT_WAIT_FOREVER);
  #endif
  
    // can only release the endpoint if it is claimed and not busy
    bool const ret = (_usbd_dev.ep_status[epnum][dir].busy == 0) && (_usbd_dev.ep_status[epnum][dir].claimed == 1);
    if (ret)
    {
      _usbd_dev.ep_status[epnum][dir].claimed = 0;
    }
  
  #if CFG_TUSB_OS != OPT_OS_NONE
    osal_mutex_unlock(_usbd_mutex);
  #endif
  
    return ret;
  }
  
  bool usbd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t total_bytes)
  {
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
    // TODO skip ready() check for now since enumeration also use this API
    // TU_VERIFY(tud_ready());
  
    TU_LOG2("  Queue EP %02X with %u bytes ...\r\n", ep_addr, total_bytes);
  
    // Attempt to transfer on a busy endpoint, sound like an race condition !
    TU_ASSERT(_usbd_dev.ep_status[epnum][dir].busy == 0);
  
    // Set busy first since the actual transfer can be complete before dcd_edpt_xfer()
    // could return and USBD task can preempt and clear the busy
    _usbd_dev.ep_status[epnum][dir].busy = true;
  
    if ( dcd_edpt_xfer(rhport, ep_addr, buffer, total_bytes) )
    {
      return true;
    }else
    {
      // DCD error, mark endpoint as ready to allow next transfer
      _usbd_dev.ep_status[epnum][dir].busy = false;
      _usbd_dev.ep_status[epnum][dir].claimed = 0;
      TU_LOG2("FAILED\r\n");
      TU_BREAKPOINT();
      return false;
    }
  }
  
  // The number of bytes has to be given explicitly to allow more flexible control of how many
  // bytes should be written and second to keep the return value free to give back a boolean
  // success message. If total_bytes is too big, the FIFO will copy only what is available
  // into the USB buffer!
  bool usbd_edpt_xfer_fifo(uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16_t total_bytes)
  {
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
    TU_LOG2("  Queue ISO EP %02X with %u bytes ... ", ep_addr, total_bytes);
  
    // Attempt to transfer on a busy endpoint, sound like an race condition !
    TU_ASSERT(_usbd_dev.ep_status[epnum][dir].busy == 0);
  
    // Set busy first since the actual transfer can be complete before dcd_edpt_xfer() could return
    // and usbd task can preempt and clear the busy
    _usbd_dev.ep_status[epnum][dir].busy = true;
  
    if (dcd_edpt_xfer_fifo(rhport, ep_addr, ff, total_bytes))
    {
      TU_LOG2("OK\r\n");
      return true;
    }else
    {
      // DCD error, mark endpoint as ready to allow next transfer
      _usbd_dev.ep_status[epnum][dir].busy = false;
      _usbd_dev.ep_status[epnum][dir].claimed = 0;
      TU_LOG2("failed\r\n");
      TU_BREAKPOINT();
      return false;
    }
  }
  
  bool usbd_edpt_busy(uint8_t rhport, uint8_t ep_addr)
  {
    (void) rhport;
  
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
    return _usbd_dev.ep_status[epnum][dir].busy;
  }
  
  void usbd_edpt_stall(uint8_t rhport, uint8_t ep_addr)
  {
  
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
    // only stalled if currently cleared
    if ( !_usbd_dev.ep_status[epnum][dir].stalled )
    {
      TU_LOG(USBD_DBG, "    Stall EP %02X\r\n", ep_addr);
      dcd_edpt_stall(rhport, ep_addr);
      _usbd_dev.ep_status[epnum][dir].stalled = true;
      _usbd_dev.ep_status[epnum][dir].busy = true;
    }
  }
  
  void usbd_edpt_clear_stall(uint8_t rhport, uint8_t ep_addr)
  {
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
    // only clear if currently stalled
    if ( _usbd_dev.ep_status[epnum][dir].stalled )
    {
      TU_LOG(USBD_DBG, "    Clear Stall EP %02X\r\n", ep_addr);
      dcd_edpt_clear_stall(rhport, ep_addr);
      _usbd_dev.ep_status[epnum][dir].stalled = false;
      _usbd_dev.ep_status[epnum][dir].busy = false;
    }
  }
  
  bool usbd_edpt_stalled(uint8_t rhport, uint8_t ep_addr)
  {
    (void) rhport;
  
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
    return _usbd_dev.ep_status[epnum][dir].stalled;
  }
  
  /**
   * usbd_edpt_close will disable an endpoint.
   *
   * In progress transfers on this EP may be delivered after this call.
   *
   */
  void usbd_edpt_close(uint8_t rhport, uint8_t ep_addr)
  {
    TU_ASSERT(dcd_edpt_close, /**/);
    TU_LOG2("  CLOSING Endpoint: 0x%02X\r\n", ep_addr);
  
    uint8_t const epnum = tu_edpt_number(ep_addr);
    uint8_t const dir   = tu_edpt_dir(ep_addr);
  
    dcd_edpt_close(rhport, ep_addr);
    _usbd_dev.ep_status[epnum][dir].stalled = false;
    _usbd_dev.ep_status[epnum][dir].busy = false;
    _usbd_dev.ep_status[epnum][dir].claimed = false;
  
    return;
  }
  
  #endif
  