text: /* 
   * The MIT License (MIT)
   *
   * Copyright (c) 2020, 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.
   *
   * This file is part of the TinyUSB stack.
   */
  
  #include "../../board.h"
  #include "board.h"
  
  #include "esp_rom_gpio.h"
  #include "hal/gpio_ll.h"
  #include "hal/usb_hal.h"
  #include "soc/usb_periph.h"
  
  #include "driver/periph_ctrl.h"
  #include "driver/rmt.h"
  
  #ifdef NEOPIXEL_PIN
  #include "led_strip.h"
  static led_strip_t *strip;
  #endif
  
  //--------------------------------------------------------------------+
  // MACRO TYPEDEF CONSTANT ENUM DECLARATION
  //--------------------------------------------------------------------+
  
  static void configure_pins(usb_hal_context_t *usb);
  
  // Initialize on-board peripherals : led, button, uart and USB
  void board_init(void)
  {
  
  #ifdef NEOPIXEL_PIN
    #ifdef NEOPIXEL_POWER_PIN
    gpio_reset_pin(NEOPIXEL_POWER_PIN);
    gpio_set_direction(NEOPIXEL_POWER_PIN, GPIO_MODE_OUTPUT);
    gpio_set_level(NEOPIXEL_POWER_PIN, NEOPIXEL_POWER_STATE);
    #endif
  
    // WS2812 Neopixel driver with RMT peripheral
    rmt_config_t config = RMT_DEFAULT_CONFIG_TX(NEOPIXEL_PIN, RMT_CHANNEL_0);
    config.clk_div = 2; // set counter clock to 40MHz
  
    rmt_config(&config);
    rmt_driver_install(config.channel, 0, 0);
  
    led_strip_config_t strip_config = LED_STRIP_DEFAULT_CONFIG(1, (led_strip_dev_t) config.channel);
    strip = led_strip_new_rmt_ws2812(&strip_config);
    strip->clear(strip, 100); // off led
  #endif
  
    // Button
    gpio_pad_select_gpio(BUTTON_PIN);
    gpio_set_direction(BUTTON_PIN, GPIO_MODE_INPUT);
    gpio_set_pull_mode(BUTTON_PIN, BUTTON_STATE_ACTIVE ? GPIO_PULLDOWN_ONLY : GPIO_PULLUP_ONLY);
  
    // USB Controller Hal init
    periph_module_reset(PERIPH_USB_MODULE);
    periph_module_enable(PERIPH_USB_MODULE);
  
    usb_hal_context_t hal = {
      .use_external_phy = false // use built-in PHY
    };
    usb_hal_init(&hal);
    configure_pins(&hal);
  }
  
  static void configure_pins(usb_hal_context_t *usb)
  {
    /* usb_periph_iopins currently configures USB_OTG as USB Device.
     * Introduce additional parameters in usb_hal_context_t when adding support
     * for USB Host.
     */
    for (const usb_iopin_dsc_t *iopin = usb_periph_iopins; iopin->pin != -1; ++iopin) {
      if ((usb->use_external_phy) || (iopin->ext_phy_only == 0)) {
        esp_rom_gpio_pad_select_gpio(iopin->pin);
        if (iopin->is_output) {
          esp_rom_gpio_connect_out_signal(iopin->pin, iopin->func, false, false);
        } else {
          esp_rom_gpio_connect_in_signal(iopin->pin, iopin->func, false);
          if ((iopin->pin != GPIO_FUNC_IN_LOW) && (iopin->pin != GPIO_FUNC_IN_HIGH)) {
            gpio_ll_input_enable(&GPIO, iopin->pin);
          }
        }
        esp_rom_gpio_pad_unhold(iopin->pin);
      }
    }
    if (!usb->use_external_phy) {
      gpio_set_drive_capability(USBPHY_DM_NUM, GPIO_DRIVE_CAP_3);
      gpio_set_drive_capability(USBPHY_DP_NUM, GPIO_DRIVE_CAP_3);
    }
  }
  
  // Turn LED on or off
  void board_led_write(bool state)
  {
  #ifdef NEOPIXEL_PIN
    strip->set_pixel(strip, 0, (state ? 0x88 : 0x00), 0x00, 0x00);
    strip->refresh(strip, 100);
  #endif
  }
  
  // Get the current state of button
  // a '1' means active (pressed), a '0' means inactive.
  uint32_t board_button_read(void)
  {
    return gpio_get_level(BUTTON_PIN) == BUTTON_STATE_ACTIVE;
  }
  
  // Get characters from UART
  int board_uart_read(uint8_t* buf, int len)
  {
    (void) buf; (void) len;
    return 0;
  }
  
  // Send characters to UART
  int board_uart_write(void const * buf, int len)
  {
    (void) buf; (void) len;
    return 0;
  }
  
  