text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2019 Damien P. George
   *
   * 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 "samd_soc.h"
  #include "tusb.h"
  
  #define USBD_VID (0xf055)
  #define USBD_PID (0x9802)
  
  #define USBD_DESC_LEN (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN)
  #define USBD_MAX_POWER_MA (250)
  
  #define USBD_ITF_CDC (0) // needs 2 interfaces
  #define USBD_ITF_MAX (2)
  
  #define USBD_CDC_EP_CMD (0x81)
  #define USBD_CDC_EP_OUT (0x02)
  #define USBD_CDC_EP_IN (0x82)
  #define USBD_CDC_CMD_MAX_SIZE (8)
  
  #define USBD_STR_0 (0x00)
  #define USBD_STR_MANUF (0x01)
  #define USBD_STR_PRODUCT (0x02)
  #define USBD_STR_SERIAL (0x03)
  #define USBD_STR_CDC (0x04)
  
  // Note: descriptors returned from callbacks must exist long enough for transfer to complete
  
  static const tusb_desc_device_t usbd_desc_device = {
      .bLength = sizeof(tusb_desc_device_t),
      .bDescriptorType = TUSB_DESC_DEVICE,
      .bcdUSB = 0x0200,
      .bDeviceClass = TUSB_CLASS_MISC,
      .bDeviceSubClass = MISC_SUBCLASS_COMMON,
      .bDeviceProtocol = MISC_PROTOCOL_IAD,
      .bMaxPacketSize0 = CFG_TUD_ENDOINT0_SIZE,
      .idVendor = USBD_VID,
      .idProduct = USBD_PID,
      .bcdDevice = 0x0100,
      .iManufacturer = USBD_STR_MANUF,
      .iProduct = USBD_STR_PRODUCT,
      .iSerialNumber = USBD_STR_SERIAL,
      .bNumConfigurations = 1,
  };
  
  static const uint8_t usbd_desc_cfg[USBD_DESC_LEN] = {
      TUD_CONFIG_DESCRIPTOR(USBD_ITF_MAX, USBD_STR_0, USBD_DESC_LEN,
          TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, USBD_MAX_POWER_MA),
  
      TUD_CDC_DESCRIPTOR(USBD_ITF_CDC, USBD_STR_CDC, USBD_CDC_EP_CMD,
          USBD_CDC_CMD_MAX_SIZE, USBD_CDC_EP_OUT, USBD_CDC_EP_IN, CFG_TUD_CDC_RX_BUFSIZE),
  };
  
  static const char *const usbd_desc_str[] = {
      [USBD_STR_MANUF] = "MicroPython",
      [USBD_STR_PRODUCT] = "Board in FS mode",
      [USBD_STR_SERIAL] = "000000000000", // TODO
      [USBD_STR_CDC] = "Board CDC",
  };
  
  const uint8_t *tud_descriptor_device_cb(void) {
      return (const uint8_t *)&usbd_desc_device;
  }
  
  const uint8_t *tud_descriptor_configuration_cb(uint8_t index) {
      (void)index;
      return usbd_desc_cfg;
  }
  
  const uint16_t *tud_descriptor_string_cb(uint8_t index) {
      #define DESC_STR_MAX (20)
      static uint16_t desc_str[DESC_STR_MAX];
  
      uint8_t len;
      if (index == 0) {
          desc_str[1] = 0x0409; // supported language is English
          len = 1;
      } else {
          if (index >= sizeof(usbd_desc_str) / sizeof(usbd_desc_str[0])) {
              return NULL;
          }
          const char *str = usbd_desc_str[index];
          for (len = 0; len < DESC_STR_MAX - 1 && str[len]; ++len) {
              desc_str[1 + len] = str[len];
          }
      }
  
      // first byte is length (including header), second byte is string type
      desc_str[0] = (TUSB_DESC_STRING << 8 ) | (2 * len + 2);
  
      return desc_str;
  }
  
  #if defined(MCU_SAMD21)
  
  void USB_Handler_wrapper(void) {
      USB_Handler();
      tud_task();
  }
  
  #elif defined(MCU_SAMD51)
  
  void USB_0_Handler_wrapper(void) {
      USB_0_Handler();
      tud_task();
  }
  
  void USB_1_Handler_wrapper(void) {
      USB_1_Handler();
      tud_task();
  }
  
  void USB_2_Handler_wrapper(void) {
      USB_2_Handler();
      tud_task();
  }
  
  void USB_3_Handler_wrapper(void) {
      USB_3_Handler();
      tud_task();
  }
  
  #endif
  