/* 
 * 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 "stm32f4xx_hal.h"

//--------------------------------------------------------------------+
// Forward USB interrupt events to TinyUSB IRQ Handler
//--------------------------------------------------------------------+
void OTG_FS_IRQHandler(void)
{
  tud_int_handler(0);
}

//--------------------------------------------------------------------+
// MACRO TYPEDEF CONSTANT ENUM
//--------------------------------------------------------------------+

#define LED_PORT              GPIOE
#define LED_PIN               GPIO_PIN_2
#define LED_STATE_ON          0

#define BUTTON_PORT           GPIOA
#define BUTTON_PIN            GPIO_PIN_0
#define BUTTON_STATE_ACTIVE   1

// Enable PA2 as the debug log UART
#define UARTx                 USART2
#define UART_GPIO_PORT        GPIOA
#define UART_GPIO_AF          GPIO_AF7_USART2
#define UART_TX_PIN           GPIO_PIN_2
#define UART_RX_PIN           GPIO_PIN_3

UART_HandleTypeDef UartHandle;

// enable all LED, Button, Uart, USB clock
static void all_rcc_clk_enable(void)
{
  __HAL_RCC_GPIOA_CLK_ENABLE();  // USB D+, D-, Button
  __HAL_RCC_GPIOE_CLK_ENABLE();  // LED
  __HAL_RCC_USART2_CLK_ENABLE(); // Uart module
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow :
  *            System Clock source            = PLL (HSE)
  *            SYSCLK(Hz)                     = 100000000
  *            HCLK(Hz)                       = 100000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSE Frequency(Hz)              = 8000000
  *            PLL_M                          = HSE_VALUE/1000000
  *            PLL_N                          = 200
  *            PLL_P                          = 2
  *            PLL_Q                          = 7
  *            PLL_R                          = 2
  *            VDD(V)                         = 3.3
  *            Main regulator output voltage  = Scale1 mode
  *            Flash Latency(WS)              = 3
  *         The USB clock configuration from PLLI2S:
  *            PLLI2SM                        = 8
  *            PLLI2SN                        = 192
  *            PLLI2SQ                        = 4
  * @param  None
  * @retval None
  */
static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;

  /* Enable Power Control clock */
  __HAL_RCC_PWR_CLK_ENABLE();

  /* The voltage scaling allows optimizing the power consumption when the
   * device is clocked below the maximum system frequency, to update the
   * voltage scaling value regarding system frequency refer to product
   * datasheet.  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /* Enable HSE Oscillator and activate PLL with HSE as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = HSE_VALUE/1000000;
  RCC_OscInitStruct.PLL.PLLN = 200;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  RCC_OscInitStruct.PLL.PLLR = 2;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  /* Select PLLSAI output as USB clock source */
  PeriphClkInitStruct.PLLI2S.PLLI2SM = 8;
  PeriphClkInitStruct.PLLI2S.PLLI2SQ = 4;
  PeriphClkInitStruct.PLLI2S.PLLI2SN = 192;
  PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_CK48;
  PeriphClkInitStruct.Clk48ClockSelection = RCC_CK48CLKSOURCE_PLLI2SQ;
  PeriphClkInitStruct.PLLI2SSelection = RCC_PLLI2SCLKSOURCE_PLLSRC;
  PeriphClkInitStruct.PLLI2S.PLLI2SR = 7;
  HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);

  /* 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_3);
}

void board_init(void)
{
  SystemClock_Config();
  all_rcc_clk_enable();

#if CFG_TUSB_OS == OPT_OS_NONE
  // 1ms tick timer
  SysTick_Config(SystemCoreClock / 1000);
#elif CFG_TUSB_OS == OPT_OS_FREERTOS
  // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
  //NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
#endif

  GPIO_InitTypeDef  GPIO_InitStruct;

  // LED
  GPIO_InitStruct.Pin = LED_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FAST;
  HAL_GPIO_Init(LED_PORT, &GPIO_InitStruct);

  board_led_write(false);

  // Button
  GPIO_InitStruct.Pin = BUTTON_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLDOWN;
  GPIO_InitStruct.Speed = GPIO_SPEED_FAST;
  HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);

  /* Configure USB FS GPIOs */
  /* Configure USB D+ D- Pins */
  GPIO_InitStruct.Pin = GPIO_PIN_11 | GPIO_PIN_12;
  GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Alternate = GPIO_AF10_OTG_FS;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* Configure VBUS Pin */
  GPIO_InitStruct.Pin = GPIO_PIN_9;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* ID Pin */
  GPIO_InitStruct.Pin = GPIO_PIN_10;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
  GPIO_InitStruct.Alternate = GPIO_AF10_OTG_FS;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* Configure POWER_SWITCH IO pin */
  __HAL_RCC_GPIOG_CLK_ENABLE();
  GPIO_InitStruct.Pin = GPIO_PIN_8;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOG, &GPIO_InitStruct);
  GPIO_InitStruct.Pin       = UART_TX_PIN | UART_RX_PIN;
  GPIO_InitStruct.Mode      = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull      = GPIO_PULLUP;
  GPIO_InitStruct.Speed     = GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.Alternate = UART_GPIO_AF;
  HAL_GPIO_Init(UART_GPIO_PORT, &GPIO_InitStruct);

  UartHandle = (UART_HandleTypeDef){
    .Instance        = UARTx,
    .Init.BaudRate   = CFG_BOARD_UART_BAUDRATE,
    .Init.WordLength = UART_WORDLENGTH_8B,
    .Init.StopBits   = UART_STOPBITS_1,
    .Init.Parity     = UART_PARITY_NONE,
    .Init.HwFlowCtl  = UART_HWCONTROL_NONE,
    .Init.Mode       = UART_MODE_TX_RX,
    .Init.OverSampling = UART_OVERSAMPLING_16
  };
  HAL_UART_Init(&UartHandle);

  // Enable USB OTG clock
  __HAL_RCC_USB_OTG_FS_CLK_ENABLE();

  // Enable VBUS sense (B device) via pin PA9
  USB_OTG_FS->GCCFG |= USB_OTG_GCCFG_VBDEN;
}

//--------------------------------------------------------------------+
// 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)
{
  HAL_UART_Transmit(&UartHandle, (uint8_t*) buf, len, 0xffff);
  return len;
}

#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)
{

}
