/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2019 William D. Jones (thor0505@comcast.net),
 * 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 "stm32h7xx.h"
#include "stm32h7xx_hal_conf.h"

#define LED_PORT              GPIOB
#define LED_PIN               GPIO_PIN_0
#define LED_STATE_ON          1

#define BUTTON_PORT           GPIOC
#define BUTTON_PIN            GPIO_PIN_13
#define BUTTON_STATE_ACTIVE   1

// enable all LED, Button, Uart, USB clock
static void all_rcc_clk_enable(void)
{
  __HAL_RCC_GPIOA_CLK_ENABLE();  // USB D+, D-
  __HAL_RCC_GPIOB_CLK_ENABLE();  // LED
  __HAL_RCC_GPIOC_CLK_ENABLE();  // Button
//  __HAL_RCC_GPIOD_CLK_ENABLE();  // Uart tx, rx
//  __HAL_RCC_USART3_CLK_ENABLE(); // Uart module
}

/* PWR, RCC, GPIO (All): AHB4 (D3 domain)
   USB{1,2} OTG_{H,F}S: AHB1 (D2 domain)
*/

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follows :
  *            System Clock source            = PLL (HSE)
  *            SYSCLK(Hz)                     = 168000000
  *            ACLK(Hz)                       = 168000000
  *            HCLK(Hz)                       = 168000000
  *            AHB1-4 Prescaler               = 1
  *            APB1 Prescaler (Domain 2)      = 2
  *            APB2 Prescaler (Domain 2)      = 2
  *            APB3 Prescaler (Domain 1)      = 2
  *            APB4 Prescaler (Domain 3)      = 2
  *            HSE Frequency(Hz)              = 8000000
  *            PLL1_M                         = 8
  *            PLL1_N                         = 336
  *            PLL1_P                         = 2
  *            PLL1_Q                         = 7
  *            PLL1_R                         = Unused (TODO: figure out how
  *                                             to gate from HAL?)
  *            VDD(V)                         = 3.3
  *            Main regulator output voltage  = Scale3 mode
  *            Flash Latency(WS)              = 4
  * @param  None
  * @retval None
  */
static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;

  /* The PWR block is always enabled on the H7 series- there is no clock
     enable. For now, use the default VOS3 scale mode (lowest) and limit clock
     frequencies to avoid potential current draw problems from bus
     power when using the max clock speeds throughout the chip. */

  /* Enable HSE Oscillator and activate PLL1 with HSE as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSIState = RCC_HSI_OFF;
  RCC_OscInitStruct.CSIState = RCC_CSI_OFF;
  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 = 336;
  RCC_OscInitStruct.PLL.PLLP = 2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_0;
  RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOMEDIUM;
  RCC_OscInitStruct.PLL.PLLFRACN = 0;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | \
    RCC_CLOCKTYPE_D1PCLK1 | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2 | \
    RCC_CLOCKTYPE_D3PCLK1);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV1;

  /* Unlike on the STM32F4 family, it appears the maximum APB frequencies are
     device-dependent- 120 MHz for this board according to Figure 2 of
     the datasheet. Dividing by half will be safe for now. */
  RCC_ClkInitStruct.APB3CLKDivider = RCC_APB3_DIV2;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_APB2_DIV2;
  RCC_ClkInitStruct.APB4CLKDivider = RCC_APB4_DIV2;

  /* 4 wait states required for 168MHz and VOS3. */
  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4);

  /* Like on F4, on H7, USB's actual peripheral clock and bus clock are
     separate. However, the main system PLL (PLL1) doesn't have a direct
     connection to the USB peripheral clock to generate 48 MHz, so we do this
     dance. This will connect PLL1's Q output to the USB peripheral clock. */
  RCC_PeriphCLKInitTypeDef RCC_PeriphCLKInitStruct;

  RCC_PeriphCLKInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB;
  RCC_PeriphCLKInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_PLL;
  HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphCLKInitStruct);
}

void board_init(void)
{
  #if CFG_TUSB_OS  == OPT_OS_NONE
    // 1ms tick timer
    SysTick_Config(SystemCoreClock / 1000);
  #endif

  SystemClock_Config();
  SystemCoreClockUpdate();
  all_rcc_clk_enable();

  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_FREQ_HIGH;
  HAL_GPIO_Init(LED_PORT, &GPIO_InitStruct);

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

  // USB Pin Init
  // PA9- VUSB, PA10- ID, PA11- DM, PA12- DP

  /* Configure DM DP Pins */
  GPIO_InitStruct.Pin = GPIO_PIN_11 | GPIO_PIN_12;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Alternate = GPIO_AF10_OTG2_HS;
  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);

  /* This for ID line debug */
  GPIO_InitStruct.Pin = GPIO_PIN_10;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.Alternate = GPIO_AF10_OTG2_HS;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  // https://community.st.com/s/question/0D50X00009XkYZLSA3/stm32h7-nucleo-usb-fs-cdc
  // TODO: Board init actually works fine without this line.
  HAL_PWREx_EnableUSBVoltageDetector();
  __HAL_RCC_USB2_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);
}

uint32_t board_button_read(void)
{
  return 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)
{

}
