//
// This file is part of the GNU ARM Eclipse distribution.
// Copyright (c) 2014 Liviu Ionescu.
//

// ----------------------------------------------------------------------------

#include "stm32f4xx.h"
#include "stm32f4xx_hal.h"
#include "stm32f4xx_hal_cortex.h"

// ----------------------------------------------------------------------------

// The external clock frequency is specified as a preprocessor definition
// passed to the compiler via a command line option (see the 'C/C++ General' ->
// 'Paths and Symbols' -> the 'Symbols' tab, if you want to change it).
// The value selected during project creation was HSE_VALUE=8000000.
//
// The code to set the clock is at the end.
//
// Note1: The default clock settings assume that the HSE_VALUE is a multiple
// of 1MHz, and try to reach the maximum speed available for the
// board. It does NOT guarantee that the required USB clock of 48MHz is
// available. If you need this, please update the settings of PLL_M, PLL_N,
// PLL_P, PLL_Q to match your needs.
//
// Note2: The external memory controllers are not enabled. If needed, you
// have to define DATA_IN_ExtSRAM or DATA_IN_ExtSDRAM and to configure
// the memory banks in system/src/cmsis/system_stm32f4xx.c to match your needs.

// ----------------------------------------------------------------------------

// Forward declarations.

void
__initialize_hardware(void);

void
SystemClock_Config(void);

// ----------------------------------------------------------------------------

// This is the application hardware initialisation routine,
// redefined to add more inits.
//
// Called early from _start(), right after data & bss init, before
// constructors.
//
// After Reset the Cortex-M processor is in Thread mode,
// priority is Privileged, and the Stack is set to Main.
//
// Warning: The HAL requires the system timer, running at 1000 Hz
// and calling HAL_IncTick().

void
__initialize_hardware(void)
{
  // Initialise the HAL Library; it must be the first function
  // to be executed before the call of any HAL function.
  HAL_Init();

  // Enable HSE Oscillator and activate PLL with HSE as source
  SystemClock_Config();

  // Call the CSMSIS system clock routine to store the clock frequency
  // in the SystemCoreClock global RAM location.
  SystemCoreClockUpdate();
}

// Disable when using RTOSes, since they have their own handler.
#if 0

// This is a sample SysTick handler, use it if you need HAL timings.
void __attribute__ ((section(".after_vectors")))
SysTick_Handler(void)
{
#if defined(USE_HAL_DRIVER)
	HAL_IncTick();
#endif
}

#endif

// ----------------------------------------------------------------------------

/**
 * @brief  System Clock Configuration
 * @param  None
 * @retval None
 */
void
__attribute__((weak))
SystemClock_Config(void)
{
  // Enable Power Control clock
  __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);

//#warning "Please check if the SystemClock_Config() settings match your board!"
  // Comment out the warning after checking and updating.

  RCC_OscInitTypeDef RCC_OscInitStruct;

#if defined(HSE_VALUE) && (HSE_VALUE != 0)
  // Enable HSE Oscillator and activate PLL with HSE as source.
  // This is tuned for STM32F4-DISCOVERY; update it for your board.
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  // This assumes the HSE_VALUE is a multiple of 1 MHz. If this is not
  // your case, you have to recompute these PLL constants.
  RCC_OscInitStruct.PLL.PLLM = (HSE_VALUE/1000000u);
#else
  // Use HSI and activate PLL with HSI as source.
  // This is tuned for NUCLEO-F411; update it for your board.
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  // 16 is the average calibration value, adjust for your own board.
  RCC_OscInitStruct.HSICalibrationValue = 16;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  // This assumes the HSI_VALUE is a multiple of 1 MHz. If this is not
  // your case, you have to recompute these PLL constants.
  RCC_OscInitStruct.PLL.PLLM = (HSI_VALUE/1000000u);
#endif

  RCC_OscInitStruct.PLL.PLLN = 336;
#if defined(STM32F401xC) || defined(STM32F401xE) || defined(STM32F411xE)
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4; /* 84 MHz */
#elif defined(STM32F427xx) || defined(STM32F437xx) || defined(STM32F429xx) || defined(STM32F439xx)
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; /* 168 MHz */
#elif defined(STM32F405xx) || defined(STM32F415xx) || defined(STM32F407xx) || defined(STM32F417xx)
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; /* 168 MHz */
#elif defined(STM32F446xx)
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; /* 168 MHz */
#else
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4; /* 84 MHz, conservative */
#endif
  RCC_OscInitStruct.PLL.PLLQ = 7; /* To make USB work. */
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  // 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;
#if defined(STM32F401xC) || defined(STM32F401xE) || defined(STM32F411xE)
  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);
#else
  // This is expected to work for most large cores.
  // Check and update it for your own configuration.
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);
#endif

  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);

  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
}

// ----------------------------------------------------------------------------