text: /* 
   * 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.
   *
   * This file is part of the TinyUSB stack.
   */
  
  #include "../board.h"
  
  #include "stm32f3xx_hal.h"
  
  #define LED_PORT              GPIOE
  #define LED_PIN               GPIO_PIN_9
  #define LED_STATE_ON          1
  
  #define BUTTON_PORT           GPIOA
  #define BUTTON_PIN            GPIO_PIN_0
  #define BUTTON_STATE_ACTIVE   1
  
  
  /**
    * @brief  System Clock Configuration
    *         The system Clock is configured as follow :
    *            System Clock source            = PLL (HSE)
    *            SYSCLK(Hz)                     = 72000000
    *            HCLK(Hz)                       = 72000000
    *            AHB Prescaler                  = 1
    *            APB1 Prescaler                 = 2
    *            APB2 Prescaler                 = 1
    *            HSE Frequency(Hz)              = 8000000
    *            HSE PREDIV                     = 1
    *            PLLMUL                         = RCC_PLL_MUL9 (9)
    *            Flash Latency(WS)              = 2
    * @param  None
    * @retval None
    */
  static void SystemClock_Config(void)
  {
    RCC_ClkInitTypeDef RCC_ClkInitStruct;
    RCC_OscInitTypeDef RCC_OscInitStruct;
    RCC_PeriphCLKInitTypeDef  RCC_PeriphClkInit;
  
    /* Enable HSE Oscillator and activate PLL with HSE as source */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
    RCC_OscInitStruct.HSEState = RCC_HSE_ON;
    RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
    RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
    HAL_RCC_OscConfig(&RCC_OscInitStruct);
  
    /* Configures the USB clock */
    HAL_RCCEx_GetPeriphCLKConfig(&RCC_PeriphClkInit);
    RCC_PeriphClkInit.USBClockSelection = RCC_USBCLKSOURCE_PLL_DIV1_5;
    HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphClkInit);
  
    /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2
    clocks dividers */
    RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
    HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2);
  
    /* Enable Power Clock */
    __HAL_RCC_PWR_CLK_ENABLE();
  }
  
  void board_init(void)
  {
    SystemClock_Config();
  
    #if CFG_TUSB_OS  == OPT_OS_NONE
    // 1ms tick timer
    SysTick_Config(SystemCoreClock / 1000);
    #endif
  
    // LED
    __HAL_RCC_GPIOE_CLK_ENABLE();
    GPIO_InitTypeDef  GPIO_InitStruct;
    GPIO_InitStruct.Pin = LED_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(LED_PORT, &GPIO_InitStruct);
  
    // Button
    __HAL_RCC_GPIOA_CLK_ENABLE();
    GPIO_InitStruct.Pin = BUTTON_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_PULLDOWN;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);
  
    /* Configure USB DM and DP pins */
    __HAL_RCC_GPIOA_CLK_ENABLE();
    GPIO_InitStruct.Pin = (GPIO_PIN_11 | GPIO_PIN_12);
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF14_USB;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  
    // Enable USB clock
    __HAL_RCC_USB_CLK_ENABLE();
  }
  
  //--------------------------------------------------------------------+
  // Board porting API
  //--------------------------------------------------------------------+
  
  void board_led_write(bool state)
  {
    HAL_GPIO_WritePin(LED_PORT, LED_PIN, state ? LED_STATE_ON : (1-LED_STATE_ON));
  }
  
  uint32_t board_button_read(void)
  {
    return BUTTON_STATE_ACTIVE == HAL_GPIO_ReadPin(BUTTON_PORT, BUTTON_PIN);
  }
  
  int board_uart_read(uint8_t* buf, int len)
  {
    (void) buf; (void) len;
    return 0;
  }
  
  int board_uart_write(void const * buf, int len)
  {
    (void) buf; (void) len;
    return 0;
  }
  
  #if CFG_TUSB_OS  == OPT_OS_NONE
  volatile uint32_t system_ticks = 0;
  void SysTick_Handler (void)
  {
    system_ticks++;
  }
  
  uint32_t board_millis(void)
  {
    return system_ticks;
  }
  #endif
  
  void HardFault_Handler (void)
  {
    asm("bkpt");
  }
  
  // Required by __libc_init_array in startup code if we are compiling using
  // -nostdlib/-nostartfiles.
  void _init(void)
  {
  
  }
  