usb_descriptors.c

/* 
 * 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 "unique.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) )

// String Descriptor Index
enum
{
  STRID_LANGID = 0,
  STRID_MANUFACTURER,
  STRID_PRODUCT,
  STRID_SERIAL,
};

//--------------------------------------------------------------------+
// Device Descriptors
//--------------------------------------------------------------------+
tusb_desc_device_t const desc_device =
{
    .bLength            = sizeof(tusb_desc_device_t),
    .bDescriptorType    = TUSB_DESC_DEVICE,
    .bcdUSB             = 0x0200,
    .bDeviceClass       = 0x00,
    .bDeviceSubClass    = 0x00,
    .bDeviceProtocol    = 0x00,
    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,

    .idVendor           = 0xCafe,
    .idProduct          = USB_PID,
    .bcdDevice          = 0x0102,

    .iManufacturer      = STRID_MANUFACTURER,
    .iProduct           = STRID_PRODUCT,
    .iSerialNumber      = STRID_SERIAL,

    .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;
}

//--------------------------------------------------------------------+
// HID Report Descriptor
//--------------------------------------------------------------------+

static uint8_t const desc_hid_report[] =
{
  TUD_HID_REPORT_DESC_GENERIC_INOUT(CFG_TUD_HID_EP_BUFSIZE)
};

// Invoked when received GET HID REPORT DESCRIPTOR
// Application return pointer to descriptor
// Descriptor contents must exist long enough for transfer to complete
uint8_t const * tud_hid_descriptor_report_cb(uint8_t itf)
{
  (void) itf;
  return desc_hid_report;
}

//--------------------------------------------------------------------+
// Configuration Descriptor
//--------------------------------------------------------------------+

enum
{
  ITF_NUM_HID,
  ITF_NUM_CDC_COM,
  ITF_NUM_CDC_DATA,
  ITF_NUM_TOTAL
};

#define  CONFIG_TOTAL_LEN  (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_HID_INOUT_DESC_LEN)

#define EPNUM_HID       0x01
#define EPNUM_CDC_NOTIF 0x83
#define EPNUM_CDC_OUT   0x02
#define EPNUM_CDC_IN    0x82

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, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),

  // Interface number, string index, protocol, report descriptor len, EP In & Out address, size & polling interval
  TUD_HID_INOUT_DESCRIPTOR(ITF_NUM_HID, 0, HID_ITF_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, 0x80 | EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 1),

  // Interface number, string index, EP notification address and size, EP data address (out, in) and size.
  TUD_CDC_DESCRIPTOR(ITF_NUM_CDC_COM, 0, EPNUM_CDC_NOTIF, 64, EPNUM_CDC_OUT, EPNUM_CDC_IN, 64),
};

// 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 [] =
{
  [STRID_LANGID]       = (const char[]) { 0x09, 0x04 }, // supported language is English (0x0409)
  [STRID_MANUFACTURER] = "TinyUSB",                     // Manufacturer
  [STRID_PRODUCT]      = PRODUCT_PREFIX "CMSIS-DAP",    // Product
};
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;

  uint8_t chr_count = 0;

  if (STRID_LANGID == index)
  {
    memcpy(&_desc_str[1], string_desc_arr[STRID_LANGID], 2);
    chr_count = 1;
  } else if (STRID_SERIAL == index)
  {
    chr_count = get_unique_id(_desc_str + 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 = TU_MIN(strlen(str), 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] = (TUSB_DESC_STRING << 8 ) | (2*chr_count + 2);

  return _desc_str;
}