descriptors_control.c

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/*
 * SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#include <string.h>
#include "esp_log.h"
#include "descriptors_control.h"
 
static const char *TAG = "tusb_desc";
static tusb_desc_device_t s_device_descriptor;
static const uint8_t *s_configuration_descriptor;
static char *s_str_descriptor[USB_STRING_DESCRIPTOR_ARRAY_SIZE];
#define MAX_DESC_BUF_SIZE 32
 
// =============================================================================
// CALLBACKS
// =============================================================================

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

uint8_t const *tud_descriptor_configuration_cb(uint8_t index)
{
    (void)index; // for multiple configurations
    return s_configuration_descriptor;
}
 
static uint16_t _desc_str[MAX_DESC_BUF_SIZE];
 
// 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;
 
    if ( index == 0) {
        memcpy(&_desc_str[1], s_str_descriptor[0], 2);
        chr_count = 1;
    } else {
        // Convert ASCII string into UTF-16
 
        if ( index >= sizeof(s_str_descriptor) / sizeof(s_str_descriptor[0]) ) {
            ESP_LOGE(TAG, "String index (%u) is out of bounds, check your string descriptor", index);
            return NULL;
        }
 
        if (s_str_descriptor[index] == NULL) {
            ESP_LOGE(TAG, "String index (%u) points to NULL, check your string descriptor", index);
            return NULL;
        }
 
        const char *str = s_str_descriptor[index];
 
        // Cap at max char
        chr_count = strlen(str);
        if ( chr_count > MAX_DESC_BUF_SIZE - 1 ) {
            chr_count = MAX_DESC_BUF_SIZE - 1;
        }
 
        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;
}
 
// =============================================================================
// Driver functions
// =============================================================================
 
void tusb_set_descriptor(const tusb_desc_device_t *dev_desc, const char **str_desc, const uint8_t *cfg_desc)
{
    ESP_LOGI(TAG, "\n"
             "┌─────────────────────────────────┐\n"
             "│  USB Device Descriptor Summary  │\n"
             "├───────────────────┬─────────────┤\n"
             "│bDeviceClass       │ %-4u        │\n"
             "├───────────────────┼─────────────┤\n"
             "│bDeviceSubClass    │ %-4u        │\n"
             "├───────────────────┼─────────────┤\n"
             "│bDeviceProtocol    │ %-4u        │\n"
             "├───────────────────┼─────────────┤\n"
             "│bMaxPacketSize0    │ %-4u        │\n"
             "├───────────────────┼─────────────┤\n"
             "│idVendor           │ %-#10x  │\n"
             "├───────────────────┼─────────────┤\n"
             "│idProduct          │ %-#10x  │\n"
             "├───────────────────┼─────────────┤\n"
             "│bcdDevice          │ %-#10x  │\n"
             "├───────────────────┼─────────────┤\n"
             "│iManufacturer      │ %-#10x  │\n"
             "├───────────────────┼─────────────┤\n"
             "│iProduct           │ %-#10x  │\n"
             "├───────────────────┼─────────────┤\n"
             "│iSerialNumber      │ %-#10x  │\n"
             "├───────────────────┼─────────────┤\n"
             "│bNumConfigurations │ %-#10x  │\n"
             "└───────────────────┴─────────────┘",
             dev_desc->bDeviceClass, dev_desc->bDeviceSubClass,
             dev_desc->bDeviceProtocol, dev_desc->bMaxPacketSize0,
             dev_desc->idVendor, dev_desc->idProduct, dev_desc->bcdDevice,
             dev_desc->iManufacturer, dev_desc->iProduct, dev_desc->iSerialNumber,
             dev_desc->bNumConfigurations);
    s_device_descriptor = *dev_desc;
    s_configuration_descriptor = cfg_desc;
 
    if (str_desc != NULL) {
        memcpy(s_str_descriptor, str_desc,
               sizeof(s_str_descriptor[0])*USB_STRING_DESCRIPTOR_ARRAY_SIZE);
    }
}
 
tusb_desc_device_t *tusb_get_active_desc(void)
{
    return &s_device_descriptor;
}
 
char **tusb_get_active_str_desc(void)
{
    return s_str_descriptor;
}
 
void tusb_clear_descriptor(void)
{
    memset(&s_device_descriptor, 0, sizeof(s_device_descriptor));
    memset(&s_str_descriptor, 0, sizeof(s_str_descriptor));
}