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.
   *
   */
  
  #include "tusb.h"
  #include "class/dfu/dfu_rt_device.h"
  
  /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
   * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
   *
   * Auto ProductID layout's Bitmap:
   *   [MSB]         HID | MSC | CDC          [LSB]
   */
  #define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
  #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
                             _PID_MAP(MIDI, 3) | _PID_MAP(VENDOR, 4) )
  
  //--------------------------------------------------------------------+
  // Device Descriptors
  //--------------------------------------------------------------------+
  tusb_desc_device_t const desc_device =
  {
      .bLength            = sizeof(tusb_desc_device_t),
      .bDescriptorType    = TUSB_DESC_DEVICE,
      .bcdUSB             = 0x0200,
  
    #if CFG_TUD_CDC
      // Use Interface Association Descriptor (IAD) for CDC
      // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
      .bDeviceClass       = TUSB_CLASS_MISC,
      .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
      .bDeviceProtocol    = MISC_PROTOCOL_IAD,
    #else
      .bDeviceClass       = 0x00,
      .bDeviceSubClass    = 0x00,
      .bDeviceProtocol    = 0x00,
    #endif
  
      .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
  
      .idVendor           = 0xCafe,
      .idProduct          = USB_PID,
      .bcdDevice          = 0x0100,
  
      .iManufacturer      = 0x01,
      .iProduct           = 0x02,
      .iSerialNumber      = 0x03,
  
      .bNumConfigurations = 0x01
  };
  
  // Invoked when received GET DEVICE DESCRIPTOR
  // Application return pointer to descriptor
  uint8_t const * tud_descriptor_device_cb(void)
  {
    return (uint8_t const *) &desc_device;
  }
  
  //--------------------------------------------------------------------+
  // Configuration Descriptor
  //--------------------------------------------------------------------+
  
  enum
  {
    ITF_NUM_DFU_RT,
    ITF_NUM_TOTAL
  };
  
  #define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_DFU_RT_DESC_LEN)
  
  uint8_t const desc_configuration[] =
  {
    // Config number, interface count, string index, total length, attribute, power in mA
    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
  
    // Interface number, string index, attributes, detach timeout, transfer size */
    TUD_DFU_RT_DESCRIPTOR(ITF_NUM_DFU_RT, 4, 0x0d, 1000, 4096),
  };
  
  
  // Invoked when received GET CONFIGURATION DESCRIPTOR
  // Application return pointer to descriptor
  // Descriptor contents must exist long enough for transfer to complete
  uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
  {
    (void) index; // for multiple configurations
    return desc_configuration;
  }
  
  //--------------------------------------------------------------------+
  // String Descriptors
  //--------------------------------------------------------------------+
  
  // array of pointer to string descriptors
  char const* string_desc_arr [] =
  {
    (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
    "TinyUSB",                     // 1: Manufacturer
    "TinyUSB Device",              // 2: Product
    "123456",                      // 3: Serials, should use chip ID
    "TinyUSB DFU runtime",         // 4: DFU runtime
  };
  
  static uint16_t _desc_str[32];
  
  // Invoked when received GET STRING DESCRIPTOR request
  // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
  uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
  {
    (void) langid;
  
    size_t chr_count;
  
    if ( index == 0)
    {
      memcpy(&_desc_str[1], string_desc_arr[0], 2);
      chr_count = 1;
    }
    else
    {
      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
  
      if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
  
      const char* str = string_desc_arr[index];
  
      // Cap at max char
      chr_count = strlen(str);
      if ( chr_count > 31 ) {
        chr_count = 31;
      }
  
      // Convert ASCII string into UTF-16
      for(uint8_t i=0; i<chr_count; i++)
      {
        _desc_str[1+i] = str[i];
      }
    }
  
    // first byte is length (including header), second byte is string type
    _desc_str[0] = (uint16_t)((((uint16_t)TUSB_DESC_STRING) << 8 ) | (2u*chr_count + 2u));
  
    return _desc_str;
  }
  