tinyUSB/examples/device/video_capture/src/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 "bsp/board_api.h"
#include "tusb.h"
#include "usb_descriptors.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]  VIDEO | AUDIO | MIDI | 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(AUDIO, 4) | _PID_MAP(VIDEO, 5) | _PID_MAP(VENDOR, 6) )

#define USB_VID   0xCafe
#define USB_BCD   0x0200

//--------------------------------------------------------------------+
// Device Descriptors
//--------------------------------------------------------------------+
tusb_desc_device_t const desc_device = {
    .bLength            = sizeof(tusb_desc_device_t),
    .bDescriptorType    = TUSB_DESC_DEVICE,
    .bcdUSB             = USB_BCD,

    // Use Interface Association Descriptor (IAD) for Video
    // 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,

    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,

    .idVendor           = USB_VID,
    .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
//--------------------------------------------------------------------+

// Select appropriate endpoint number
#if TU_CHECK_MCU(OPT_MCU_LPC175X_6X, OPT_MCU_LPC177X_8X, OPT_MCU_LPC40XX)
  // LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
  // 0 control, 1 In, 2 Bulk, 3 Iso, 4 In, 5 Bulk etc ...
  #define EPNUM_VIDEO_IN    (CFG_TUD_VIDEO_STREAMING_BULK ? 0x82 : 0x83)
#elif TU_CHECK_MCU(OPT_MCU_NRF5X)
  // nRF5x ISO can only be endpoint 8
  #define EPNUM_VIDEO_IN    (CFG_TUD_VIDEO_STREAMING_BULK ? 0x81 : 0x88)
#else
  #define EPNUM_VIDEO_IN    0x81
#endif

// For mcus that does not have enough SRAM for frame buffer, we use fixed frame data.
// To further reduce the size, we use MJPEG format instead of YUY2.
// Select interface descriptor and length accordingly.
#if defined(CFG_EXAMPLE_VIDEO_READONLY) && !defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
  #if CFG_TUD_VIDEO_STREAMING_BULK
    #define ITF_VIDEO_DESC(epsize)  TUD_VIDEO_CAPTURE_DESCRIPTOR_MJPEG_BULK(4, EPNUM_VIDEO_IN, FRAME_WIDTH, FRAME_HEIGHT, FRAME_RATE, epsize)
    #define ITF_VIDEO_LEN           TUD_VIDEO_CAPTURE_DESC_MJPEG_BULK_LEN
  #else
    #define ITF_VIDEO_DESC(epsize)  TUD_VIDEO_CAPTURE_DESCRIPTOR_MJPEG(4, EPNUM_VIDEO_IN, FRAME_WIDTH, FRAME_HEIGHT, FRAME_RATE, epsize)
    #define ITF_VIDEO_LEN           TUD_VIDEO_CAPTURE_DESC_MJPEG_LEN
  #endif
#else
  #if CFG_TUD_VIDEO_STREAMING_BULK
    #define ITF_VIDEO_DESC(epsize)  TUD_VIDEO_CAPTURE_DESCRIPTOR_UNCOMPR_BULK(4, EPNUM_VIDEO_IN, FRAME_WIDTH, FRAME_HEIGHT, FRAME_RATE, epsize)
    #define ITF_VIDEO_LEN           TUD_VIDEO_CAPTURE_DESC_UNCOMPR_BULK_LEN
  #else
    #define ITF_VIDEO_DESC(epsize)  TUD_VIDEO_CAPTURE_DESCRIPTOR_UNCOMPR(4, EPNUM_VIDEO_IN, FRAME_WIDTH, FRAME_HEIGHT, FRAME_RATE, epsize)
    #define ITF_VIDEO_LEN           TUD_VIDEO_CAPTURE_DESC_UNCOMPR_LEN
  #endif
#endif

#define CONFIG_TOTAL_LEN (TUD_CONFIG_DESC_LEN + ITF_VIDEO_LEN)

// full speed descriptor
uint8_t const desc_fs_configuration[] = {
    // Config number, interface count, string index, total length, attribute, power in mA
    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0, 500),

    // IAD for Video Control
    ITF_VIDEO_DESC(CFG_TUD_VIDEO_STREAMING_BULK ? 64 : CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE)
};

#if TUD_OPT_HIGH_SPEED
// Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration
uint8_t const desc_hs_configuration[] = {
  // Config number, interface count, string index, total length, attribute, power in mA
  TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0, 500),

  // IAD for Video Control
  ITF_VIDEO_DESC(CFG_TUD_VIDEO_STREAMING_BULK ? 512 : CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE)
};

// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
tusb_desc_device_qualifier_t const desc_device_qualifier = {
  .bLength            = sizeof(tusb_desc_device_t),
  .bDescriptorType    = TUSB_DESC_DEVICE,
  .bcdUSB             = USB_BCD,

  .bDeviceClass       = TUSB_CLASS_MISC,
  .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
  .bDeviceProtocol    = MISC_PROTOCOL_IAD,

  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
  .bNumConfigurations = 0x01,
  .bReserved          = 0x00
};

// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
// device_qualifier descriptor describes information about a high-speed capable device that would
// change if the device were operating at the other speed. If not highspeed capable stall this request.
uint8_t const* tud_descriptor_device_qualifier_cb(void) {
  return (uint8_t const*) &desc_device_qualifier;
}

// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index) {
  (void) index; // for multiple configurations
  // if link speed is high return fullspeed config, and vice versa
  return (tud_speed_get() == TUSB_SPEED_HIGH) ?  desc_fs_configuration : desc_hs_configuration;
}
#endif // highspeed

// 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

#if TUD_OPT_HIGH_SPEED
  // Although we are highspeed, host may be fullspeed.
  return (tud_speed_get() == TUSB_SPEED_HIGH) ?  desc_hs_configuration : desc_fs_configuration;
#else
  return desc_fs_configuration;
#endif
}

//--------------------------------------------------------------------+
// String Descriptors
//--------------------------------------------------------------------+

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

// 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
    NULL,                          // 3: Serials will use unique ID if possible
    "TinyUSB UVC",                 // 4: UVC Interface
};

static uint16_t _desc_str[32 + 1];

// 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;

  switch (index) {
    case STRID_LANGID:
      memcpy(&_desc_str[1], string_desc_arr[0], 2);
      chr_count = 1;
      break;

    case STRID_SERIAL:
      chr_count = board_usb_get_serial(_desc_str + 1, 32);
      break;

    default:
      // 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);
      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
      if (chr_count > max_count) chr_count = max_count;

      // Convert ASCII string into UTF-16
      for (size_t i = 0; i < chr_count; i++) {
        _desc_str[1 + i] = str[i];
      }
      break;
  }

  // first byte is length (including header), second byte is string type
  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));

  return _desc_str;
}