pico-keys-sdk/src/usb/usb_descriptors.c

/* 
 * This file is part of the Pico CCID distribution (https://github.com/polhenarejos/pico-ccid).
 * Copyright (c) 2022 Pol Henarejos.
 * 
 * This program is free software: you can redistribute it and/or modify  
 * it under the terms of the GNU General Public License as published by  
 * the Free Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "tusb.h"
#include "usb_descriptors.h"
#include "ccid.h"
#include "pico/unique_id.h"
#include "version.h"


#ifndef USB_VID
#define USB_VID   0xFEFF
#endif
#ifndef USB_PID
#define USB_PID   0xFCFD
#endif

#define USB_BCD   0x0200

#define USB_CONFIG_ATT_ONE TU_BIT(7)

#define	MAX_USB_POWER		1


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

    .bDeviceClass       = 0x00,
    .bDeviceSubClass    = 0,
    .bDeviceProtocol    = 0,
    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,

    .idVendor           = (USB_VID),
    .idProduct          = (USB_PID),
    .bcdDevice          = CCID_VERSION,

    .iManufacturer      = 1,
    .iProduct           = 2,
    .iSerialNumber      = 3,

    .bNumConfigurations = 1
};

uint8_t const * tud_descriptor_device_cb(void)
{
    return (uint8_t const *) &desc_device;
}

tusb_desc_interface_t const desc_interface = 
{
    .bLength            = sizeof(tusb_desc_interface_t),
    .bDescriptorType    = TUSB_DESC_INTERFACE,
    .bInterfaceNumber   = 0,
    .bAlternateSetting  = 0,
    .bNumEndpoints      = 2,
    .bInterfaceClass    = TUSB_CLASS_SMART_CARD,
    .bInterfaceSubClass = 0,
    .bInterfaceProtocol = 0,
    .iInterface         = 5,
};

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

tusb_desc_configuration_t const desc_config  = 
{
    .bLength             = sizeof(tusb_desc_configuration_t),
  	.bDescriptorType     = TUSB_DESC_CONFIGURATION,
    .wTotalLength        = (sizeof(tusb_desc_configuration_t) + sizeof(tusb_desc_interface_t) + sizeof(struct ccid_class_descriptor) + 2*sizeof(tusb_desc_endpoint_t)),
  	.bNumInterfaces      = 1,
  	.bConfigurationValue = 1,
  	.iConfiguration      = 4,
  	.bmAttributes        = USB_CONFIG_ATT_ONE | TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP,
  	.bMaxPower           = TUSB_DESC_CONFIG_POWER_MA(MAX_USB_POWER+1),
};

tusb_desc_endpoint_t const desc_ep1 = 
{
    .bLength             = sizeof(tusb_desc_endpoint_t),
	.bDescriptorType     = TUSB_DESC_ENDPOINT,
	.bEndpointAddress    = TUSB_DIR_IN_MASK | 1,
	.bmAttributes.xfer   = TUSB_XFER_BULK,
	.wMaxPacketSize.size = (64),
	.bInterval           = 0
};

tusb_desc_endpoint_t const desc_ep2 = 
{
    .bLength             = sizeof(tusb_desc_endpoint_t),
	.bDescriptorType     = TUSB_DESC_ENDPOINT,
	.bEndpointAddress    = 2,
	.bmAttributes.xfer   = TUSB_XFER_BULK,
	.wMaxPacketSize.size = (64),
	.bInterval           = 0
};

static uint8_t desc_config_extended[sizeof(tusb_desc_configuration_t) + sizeof(tusb_desc_interface_t) + sizeof(struct ccid_class_descriptor) + 2*sizeof(tusb_desc_endpoint_t)];

uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
{
    (void) index; // for multiple configurations
  
    static uint8_t initd = 0;
    if (initd == 0)
    {
        uint8_t *p = desc_config_extended;
        memcpy(p, &desc_config, sizeof(tusb_desc_configuration_t)); p += sizeof(tusb_desc_configuration_t);
        memcpy(p, &desc_interface, sizeof(tusb_desc_interface_t)); p += sizeof(tusb_desc_interface_t);
        memcpy(p, &desc_ccid, sizeof(struct ccid_class_descriptor)); p += sizeof(struct ccid_class_descriptor);
        memcpy(p, &desc_ep1, sizeof(tusb_desc_endpoint_t)); p += sizeof(tusb_desc_endpoint_t);
        memcpy(p, &desc_ep2, sizeof(tusb_desc_endpoint_t)); p += sizeof(tusb_desc_endpoint_t);
        initd = 1;
    }
    return (const uint8_t *)desc_config_extended;
}

#define BOS_TOTAL_LEN      (TUD_BOS_DESC_LEN)

#define MS_OS_20_DESC_LEN  0xB2

uint8_t const desc_bos[] =
{
    // total length, number of device caps
    TUD_BOS_DESCRIPTOR(BOS_TOTAL_LEN, 2)
};

uint8_t const * tud_descriptor_bos_cb(void)
{
    return desc_bos;
}

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

// array of pointer to string descriptors
char const* string_desc_arr [] =
{
    (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
    "Pol Henarejos",                     // 1: Manufacturer
    "Pico HSM",                       // 2: Product
    "11223344",                      // 3: Serials, should use chip ID
    "Pico HSM Config",               // 4: Vendor Interface
    "Pico HSM Interface"
};

static uint16_t _desc_str[32];

uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
{
    (void) langid;

    uint8_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];
        char unique_id_str[2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1];
        if (index == 3) {
            pico_unique_board_id_t unique_id;
            pico_get_unique_board_id(&unique_id);
            pico_get_unique_board_id_string(unique_id_str, 2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1);
            str = unique_id_str;
        }

        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];
        }
    }

    _desc_str[0] = (TUSB_DESC_STRING << 8 ) | (2*chr_count + 2);

    return _desc_str;
}