//=================================================================================================
//
// Company:       Paul Scherrer Institut
//                5232 Villigen PSI
//                Switzerland
//
//-------------------------------------------------------------------------------------------------
//
// Project:       Peltier Controller V2
// Author:        Noah Piqué (noah.pique@psi.ch)
//
//-------------------------------------------------------------------------------------------------
//
// Module:        User Flash
// Filename:      USFL_UserFlash.c
// Date:          Handled by Subversion (version control system)
// Revision:      Handled by Subversion (version control system)
// History:       Handled by Subversion (version control system)
//
//-------------------------------------------------------------------------------------------------
//
// Description:   This source file contains all functions dealing with internal flash for User Settings
//
// STM32L432KBUX_FLASH.ld
//
//  DATA    (rwx) : ORIGIN = 0x801F800, LENGTH = 2K
//
// /* Sections */
// SECTIONS
// {
//   /* NOLOAD is required for not ereasing this block */
//   .user_data (NOLOAD) :
//   {
//   . = ALIGN(4);
//   *(.user_data)
//   . = ALIGN(4);
//   } > DATA*/
// ...
//=================================================================================================



//=================================================================================================
// Section:       INCLUDES
// Description:   List of required include files.
//=================================================================================================

#include "USFL_UserFlash.h"

// Toolbox
#include "../Application/VARH_VariableHandler.h"

// include STM32 drivers
#include "stm32l4xx_hal.h"

#include "cmsis_os2.h"

//=================================================================================================
// Section:       DEFINITIONS
// Description:   Definition of local constants (visible by this module only).
//=================================================================================================

#define USERFLASHSIZE (2000/4) // Bytes -> 64 Bits
#define USERFLASHPAGE (63)

#define VARDEF 0xABCDEF

#define STARTDEF (((U64)0xAA01F055 << 32) + (VARDEF << 2))



//=================================================================================================
// Section:       MACROS
// Description:   Definition of local macros (visible by this module only).
//=================================================================================================



//=================================================================================================
// Section:       ENUMERATIONS
// Description:   Definition of local enumerations (visible by this module only).
//=================================================================================================



//=================================================================================================
// Section:       STRUCTURES
// Description:   Definition of local Structures (visible by this module only).
//=================================================================================================
 
FLASH_EraseInitTypeDef stEreaseInit = {
  FLASH_TYPEERASE_PAGES,
  FLASH_BANK_1,
  USERFLASHPAGE,
  1
};


//=================================================================================================
// Section:       LOCAL VARIABLES
// Description:   Definition of local variables (visible by this module only).
//=================================================================================================

U32 u32VarPointer = 0;

//=================================================================================================
// Section:       LOCAL CONSTANTS
// Description:   Definition of local constants (visible by this module only).
//=================================================================================================

__attribute__((__section__(".user_data"))) const U64 UserFlash[USERFLASHSIZE];

//=================================================================================================
// Section:       LOCAL FUNCTIONS (PROTOTYPES)
// Description:   Definition of local functions (visible by this module only).
//=================================================================================================

BOOL vEreaseUserFlash( void );
U32 vFindNextFreePointer( void );
U32 u32FindLastPointer( void );
U8 u8ConvertWordsToDoubleWords( U8 u8Words );

//=================================================================================================
// Section:       GLOBAL FUNCTIONS
// Description:   Definition (implementation) of global functions.
//=================================================================================================

//-------------------------------------------------------------------------------------------------
// Function:      USFL_boInitializeModule
// Description:   Initializes the module. Function must be called once immediately after power-up.
// Parameters:    None
// Returns:       Boolean TRUE if successful
//-------------------------------------------------------------------------------------------------

BOOL USFL_boInitializeModule( VOID )
{
  BOOL boOK = TRUE;

  if( UserFlash[0] != STARTDEF ){
    boOK &= vEreaseUserFlash();
  }



  return( boOK );
}

VARH_UVariable USFL_uGetVariable ( void ){

  if( u32VarPointer == 0 ) u32VarPointer = u32FindLastPointer();

  

}



//=================================================================================================
// Section:       LOCAL FUNCTIONS
// Descriptionn:  Definition (implementation) of local functions.
//=================================================================================================

//-------------------------------------------------------------------------------------------------
// Function:      u32FindNextFreePointer
// Description:   Finds the next free sector in the flash for saving variables
// Parameters:    None
// Returns:       U32 next free pointer
//-------------------------------------------------------------------------------------------------
U32 u32FindNextFreePointer( void ){

  BOOL boFound = FALSE;
  U32 u32Pointer = u32VarPointer;

  while(!boFound){

    if( ( ( UserFlash[u32Pointer] >> 8 ) & 0xFFFFFF ) == VARDEF ){
      U8 u8Size = UserFlash[u32Pointer] & 0xFF;
      if( u8Size == 0 ){
        boFound = TRUE;
      } else {
        u32Pointer += u8ConvertWordsToDoubleWords(u8Size);
      }
    } else {
      u32Pointer += 1;
    }

    if( u32Pointer >= USERFLASHSIZE ){
      u32Pointer = 1;
      break;
    }
  }
  return u32Pointer;
}


//-------------------------------------------------------------------------------------------------
// Function:      u32FindLastPointer
// Description:   Finds the next free sector in the flash for saving variables
// Parameters:    None
// Returns:       U32 next free pointer
//-------------------------------------------------------------------------------------------------
U32 u32FindLastPointer( void ){

  BOOL boFound = FALSE;
  U32 u32Pointer = 0; 
  U8 u8LastSize = 0;

  while(!boFound){

    if( ( UserFlash[u32Pointer] >> 40) == VARDEF ){
      U8 u8Size = UserFlash[u32Pointer] & 0xFF;
      if( u8Size == 0 ){
        boFound = TRUE;
        u32Pointer -= u8ConvertWordsToDoubleWords(u8LastSize);
      } else {
        u32Pointer += u8ConvertWordsToDoubleWords(u8Size);
        u8LastSize = u8Size;
      }
    } else {
      u32Pointer += 1;
    }

    if( u32Pointer >= USERFLASHSIZE ){
      u32Pointer = 1;
      break;
    }
  }
  return u32Pointer;
}


//-------------------------------------------------------------------------------------------------
// Function:      u8ConvertWordsToDoubleWords
// Description:   Converts 32Bit Word size to 64 Bit Double Word size for saving Vars
// Parameters:    U8 u8Words
// Returns:       U8 Double Words
//-------------------------------------------------------------------------------------------------
U8 u8ConvertWordsToDoubleWords( U8 u8Words ) {
  U8 u8DWords;

  u8Words += 1; // + VARDEF
  u8DWords = u8Words / 2;
  u8DWords += u8Words % 2;

  return u8DWords;
}

//-------------------------------------------------------------------------------------------------
// Function:      vEreaseUserFlash
// Description:   Ereases the User Flash Sector
// Parameters:    None
// Returns:       Boolean TRUE if successful
//-------------------------------------------------------------------------------------------------
BOOL vEreaseUserFlash( void ){
  uint32_t u32PageError = 0;

  BOOL boOK = TRUE;

  HAL_FLASH_Unlock();
  boOK &= HAL_FLASHEx_Erase(&stEreaseInit, &u32PageError) == HAL_OK ? TRUE : FALSE;

  if( !boOK ){
    return FALSE;
  }

  HAL_FLASH_Program(FLASH_TYPEPROGRAM_DOUBLEWORD, (U32) &UserFlash[0], STARTDEF);

  HAL_FLASH_Lock();

  return TRUE;
}