/**
  ******************************************************************************
  * @file    stm32l5xx_hal_flash.c
  * @author  MCD Application Team
  * @brief   FLASH HAL module driver.
  *          This file provides firmware functions to manage the following
  *          functionalities of the internal FLASH memory:
  *           + Program operations functions
  *           + Memory Control functions
  *           + Peripheral Errors functions
  *
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2019 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  @verbatim
  ==============================================================================
                        ##### Flash peripheral features #####
  ==============================================================================

  [..] The Flash memory interface manages CPU AHB C-Bus accesses
       to the Flash memory. It implements the erase and program Flash memory operations
       and the read and write protection mechanisms.

  [..] The Flash memory interface implements the TrustZone security features (TZ) supported
       by ARM Cortex-M33 core (CM33).

  [..] The FLASH main features are:
      (+) Flash memory read operations
      (+) Flash memory program/erase operations
      (+) Read / write protections
      (+) Option bytes programming
	  (+) TrustZone aware
	  (+) Watermark-based area protection including secure hide area
	  (+) Block-based page protection
      (+) Error code correction (ECC) : Data in flash are 72-bits word
          (8 bits added per double word)

                        ##### How to use this driver #####
 ==============================================================================
    [..]
      This driver provides functions and macros to configure and program the FLASH
      memory of all STM32L5xx devices.

      (#) Flash Memory IO Programming functions:
           (++) Lock and Unlock the FLASH interface using HAL_FLASH_Unlock() and
                HAL_FLASH_Lock() functions
           (++) Program functions: double word
           (++) There Two modes of programming :
            (+++) Polling mode using HAL_FLASH_Program() function
            (+++) Interrupt mode using HAL_FLASH_Program_IT() function

      (#) Interrupts and flags management functions :
           (++) Handle FLASH interrupts by calling HAL_FLASH_IRQHandler()
           (++) Callback functions are called when the flash operations are finished :
                HAL_FLASH_EndOfOperationCallback() when everything is ok, otherwise
                HAL_FLASH_OperationErrorCallback()
           (++) Get error flag status by calling HAL_GetError()

      (#) Option bytes management functions :
           (++) Lock and Unlock the option bytes using HAL_FLASH_OB_Unlock() and
                HAL_FLASH_OB_Lock() functions
           (++) Launch the reload of the option bytes using HAL_FLASH_Launch() function.
                In this case, a reset is generated

    [..]
      In addition to these functions, this driver includes a set of macros allowing
      to handle the following operations:
       (+) Set the latency
       (+) Enable/Disable the Flash power-down during low-power run and sleep modes
       (+) Enable/Disable the Flash interrupts
       (+) Monitor the Flash flags status

  @endverbatim
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32l5xx_hal.h"

/** @addtogroup STM32L5xx_HAL_Driver
  * @{
  */

/** @defgroup FLASH FLASH
  * @brief FLASH HAL module driver
  * @{
  */

#ifdef HAL_FLASH_MODULE_ENABLED

/* Private typedef -----------------------------------------------------------*/
/* Private defines -----------------------------------------------------------*/
/* Private macros ------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/** @defgroup FLASH_Private_Variables FLASH Private Variables
 * @{
 */
/**
  * @brief  Variable used for Program/Erase sectors under interruption
  */
FLASH_ProcessTypeDef pFlash = {.Lock = HAL_UNLOCKED, \
                               .ErrorCode = HAL_FLASH_ERROR_NONE, \
                               .ProcedureOnGoing = 0U, \
                               .Address = 0U, \
                               .Bank = FLASH_BANK_1, \
                               .Page = 0U, \
                               .NbPagesToErase = 0U};
/**
  * @}
  */

/* Private function prototypes -----------------------------------------------*/
/** @defgroup FLASH_Private_Functions FLASH Private Functions
 * @{
 */
static void FLASH_Program_DoubleWord(uint32_t Address, uint64_t Data);
/**
  * @}
  */

/* Exported functions --------------------------------------------------------*/
/** @defgroup FLASH_Exported_Functions FLASH Exported Functions
  * @{
  */

/** @defgroup FLASH_Exported_Functions_Group1 Programming Operation functions
 *  @brief   Programming Operation functions
 *
@verbatim
 ===============================================================================
                  ##### Programming Operation functions #####
 ===============================================================================
    [..]
    This subsection provides a set of functions allowing to manage the FLASH
    program operations.

@endverbatim
  * @{
  */

/**
  * @brief  Program double word at a specified address.
  * @param  TypeProgram  Indicate the way to program at a specified address.
  *                           This parameter can be a value of @ref FLASH_Type_Program
  * @param  Address  specifies the address to be programmed.
  * @param  Data specifies the data to be programmed
  *                This parameter is the data for the double word program
  *
  * @retval HAL_StatusTypeDef HAL Status
  */
HAL_StatusTypeDef HAL_FLASH_Program(uint32_t TypeProgram, uint32_t Address, uint64_t Data)
{
  HAL_StatusTypeDef status;
  __IO uint32_t *reg;

  /* Check the parameters */
  assert_param(IS_FLASH_TYPEPROGRAM(TypeProgram));

  /* Process Locked */
  __HAL_LOCK(&pFlash);

  /* Reset error code */
  pFlash.ErrorCode = HAL_FLASH_ERROR_NONE;

  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(FLASH_TIMEOUT_VALUE);

  if(status == HAL_OK)
  {
    pFlash.ProcedureOnGoing = TypeProgram;
    reg = IS_FLASH_SECURE_OPERATION() ? &(FLASH->SECCR) : &(FLASH_NS->NSCR);

    /* Program double-word (64-bit) at a specified address */
    FLASH_Program_DoubleWord(Address, Data);

    /* Wait for last operation to be completed */
    status = FLASH_WaitForLastOperation(FLASH_TIMEOUT_VALUE);

    /* If the program operation is completed, disable the PG Bit */
    CLEAR_BIT((*reg), (pFlash.ProcedureOnGoing & ~(FLASH_NON_SECURE_MASK)));
  }

  /* Process Unlocked */
  __HAL_UNLOCK(&pFlash);

  return status;
}

/**
  * @brief  Program double word at a specified address with interrupt enabled.
  * @param  TypeProgram  Indicate the way to program at a specified address.
  *                           This parameter can be a value of @ref FLASH_Type_Program
  * @param  Address  specifies the address to be programmed.
  * @param  Data specifies the data to be programmed
  *                This parameter is the data for the double word program
  *
  * @retval HAL Status
  */
HAL_StatusTypeDef HAL_FLASH_Program_IT(uint32_t TypeProgram, uint32_t Address, uint64_t Data)
{
  HAL_StatusTypeDef status;
  __IO uint32_t *reg_cr;

  /* Check the parameters */
  assert_param(IS_FLASH_TYPEPROGRAM(TypeProgram));

  /* Process Locked */
  __HAL_LOCK(&pFlash);

  /* Reset error code */
  pFlash.ErrorCode = HAL_FLASH_ERROR_NONE;

  /* Wait for last operation to be completed */
  status = FLASH_WaitForLastOperation(FLASH_TIMEOUT_VALUE);

  if (status != HAL_OK)
  {
    /* Process Unlocked */
    __HAL_UNLOCK(&pFlash);
  }
  else
  {
    /* Set internal variables used by the IRQ handler */
    pFlash.ProcedureOnGoing = TypeProgram;
    pFlash.Address = Address;
    
    /* Access to SECCR or NSCR depends on operation type */
    reg_cr = IS_FLASH_SECURE_OPERATION() ? &(FLASH->SECCR) : &(FLASH_NS->NSCR);

    /* Enable End of Operation and Error interrupts */
    (*reg_cr) |= (FLASH_IT_EOP | FLASH_IT_OPERR);

    /* Program double-word (64-bit) at a specified address */
    FLASH_Program_DoubleWord(Address, Data);
  }

  return status;
}

/**
  * @brief Handle FLASH interrupt request.
  * @retval None
  */
void HAL_FLASH_IRQHandler(void)
{
  uint32_t param = 0U;
  uint32_t error, type;
  __IO uint32_t *reg;
  __IO uint32_t *reg_sr;

  type = (pFlash.ProcedureOnGoing & ~(FLASH_NON_SECURE_MASK));
  reg = IS_FLASH_SECURE_OPERATION() ? &(FLASH->SECCR) : &(FLASH_NS->NSCR);
  reg_sr = IS_FLASH_SECURE_OPERATION() ? &(FLASH->SECSR) : &(FLASH_NS->NSSR);

  /* Save Flash errors */
  error = (*reg_sr) & FLASH_FLAG_SR_ERRORS;
#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
  error |= (FLASH->NSSR & FLASH_FLAG_OPTWERR);
#endif /* __ARM_FEATURE_CMSE */

  /* Set parameter of the callback */
  if(type == FLASH_TYPEERASE_PAGES)
  {
    param = pFlash.Page;
  }
  else if(type == FLASH_TYPEERASE_MASSERASE)
  {
    param = pFlash.Bank;
  }
  else if(type == FLASH_TYPEPROGRAM_DOUBLEWORD)
  {
    param = pFlash.Address;
  }
  else
  {
    /* Empty statement (to be compliant MISRA 15.7) */
  }

  /* Clear bit on the on-going procedure */
  CLEAR_BIT((*reg), type);

  /* Check FLASH operation error flags */
  if(error != 0U)
  {
    /* Save the error code */
    pFlash.ErrorCode |= error;

    /* Clear error programming flags */
    (*reg_sr) = error;
#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
    if ((error & FLASH_FLAG_OPTWERR) != 0U)
    {
      FLASH->NSSR = FLASH_FLAG_OPTWERR;
    }
#endif /* __ARM_FEATURE_CMSE */

    /* Stop the procedure ongoing */
    pFlash.ProcedureOnGoing = 0U;

    /* FLASH error interrupt user callback */
    HAL_FLASH_OperationErrorCallback(param);
  }

  /* Check FLASH End of Operation flag  */
  if (((*reg_sr) & FLASH_FLAG_EOP) != 0U)
  {
    /* Clear FLASH End of Operation pending bit */
    (*reg_sr) = FLASH_FLAG_EOP;

    if(type == FLASH_TYPEERASE_PAGES)
    {
      /* Nb of pages to erased can be decreased */
      pFlash.NbPagesToErase--;

      /* Check if there are still pages to erase*/
      if(pFlash.NbPagesToErase != 0U)
      {
        /* Increment page number */
        pFlash.Page++;
        FLASH_PageErase(pFlash.Page, pFlash.Bank);
      }
      else
      {
        /* No more pages to Erase */
        pFlash.ProcedureOnGoing = 0U;
        param = 0xFFFFFFFFU;
      }
    }
    else
    {
      /*Clear the procedure ongoing*/
      pFlash.ProcedureOnGoing = 0U;
    }

    /* FLASH EOP interrupt user callback */
    HAL_FLASH_EndOfOperationCallback(param);
  }

  if(pFlash.ProcedureOnGoing == 0U)
  {
    /* Disable End of Operation and Error interrupts */
    (*reg) &= ~(FLASH_IT_EOP | FLASH_IT_OPERR);

    /* Process Unlocked */
    __HAL_UNLOCK(&pFlash);
  }
}

/**
  * @brief  FLASH end of operation interrupt callback.
  * @param  ReturnValue The value saved in this parameter depends on the ongoing procedure :
  *                  @arg Mass Erase: Bank number which has been requested to erase
  *                  @arg Page Erase: Page which has been erased
  *                       (if 0xFFFFFFFF, it means that all the selected pages have been erased)
  *                  @arg Program: Address which was selected for data program
  * @retval None
  */
__weak void HAL_FLASH_EndOfOperationCallback(uint32_t ReturnValue)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(ReturnValue);

  /* NOTE : This function should not be modified, when the callback is needed,
            the HAL_FLASH_EndOfOperationCallback could be implemented in the user file
   */
}

/**
  * @brief  FLASH operation error interrupt callback.
  * @param  ReturnValue The value saved in this parameter depends on the ongoing procedure :
  *                 @arg Mass Erase: Bank number which has been requested to erase
  *                 @arg Page Erase: Page number which returned an error
  *                 @arg Program: Address which was selected for data program
  * @retval None
  */
__weak void HAL_FLASH_OperationErrorCallback(uint32_t ReturnValue)
{
  /* Prevent unused argument(s) compilation warning */
  UNUSED(ReturnValue);

  /* NOTE : This function should not be modified, when the callback is needed,
            the HAL_FLASH_OperationErrorCallback could be implemented in the user file
   */
}

/**
  * @}
  */

/** @defgroup FLASH_Exported_Functions_Group2 Peripheral Control functions
 *  @brief   Management functions
 *
@verbatim
 ===============================================================================
                      ##### Peripheral Control functions #####
 ===============================================================================
    [..]
    This subsection provides a set of functions allowing to control the FLASH
    memory operations.

@endverbatim
  * @{
  */

/**
  * @brief  Unlock the FLASH control register access.
  * @retval HAL Status
  */
HAL_StatusTypeDef HAL_FLASH_Unlock(void)
{
  HAL_StatusTypeDef status = HAL_OK;

  if(READ_BIT(FLASH->NSCR, FLASH_NSCR_NSLOCK) != 0u)
  {
    /* Authorize the FLASH Registers access */
    WRITE_REG(FLASH->NSKEYR, FLASH_KEY1);
    WRITE_REG(FLASH->NSKEYR, FLASH_KEY2);

    /* verify Flash is unlocked */
    if (READ_BIT(FLASH->NSCR, FLASH_NSCR_NSLOCK) != 0u)
    {
      status = HAL_ERROR;
    }
  }

#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
  if (status == HAL_OK)
  {
    if(READ_BIT(FLASH->SECCR, FLASH_SECCR_SECLOCK) != 0u)
    {
      /* Authorize the FLASH Registers access */
      WRITE_REG(FLASH->SECKEYR, FLASH_KEY1);
      WRITE_REG(FLASH->SECKEYR, FLASH_KEY2);

      /* verify Flash is unlocked */
      if (READ_BIT(FLASH->SECCR, FLASH_SECCR_SECLOCK) != 0u)
      {
        status = HAL_ERROR;
      }
    }
  }
#endif

  return status;
}

/**
  * @brief  Lock the FLASH control register access.
  * @retval HAL Status
  */
HAL_StatusTypeDef HAL_FLASH_Lock(void)
{
  HAL_StatusTypeDef status = HAL_ERROR;

  /* Set the LOCK Bit to lock the FLASH Registers access */
  SET_BIT(FLASH->NSCR, FLASH_NSCR_NSLOCK);

  /* verify Flash is locked */
  if (READ_BIT(FLASH->NSCR, FLASH_NSCR_NSLOCK) != 0u)
  {
    status = HAL_OK;
  }

#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
  if (status == HAL_OK)
  {
    SET_BIT(FLASH->SECCR, FLASH_SECCR_SECLOCK);

    /* verify Flash is locked */
    if (READ_BIT(FLASH->SECCR, FLASH_SECCR_SECLOCK) != 0u)
    {
      status = HAL_OK;
    }
  }
#endif

  return status;
}

/**
  * @brief  Unlock the FLASH Option Bytes Registers access.
  * @retval HAL Status
  */
HAL_StatusTypeDef HAL_FLASH_OB_Unlock(void)
{
  if(READ_BIT(FLASH->NSCR, FLASH_NSCR_OPTLOCK) != 0u)
  {
    /* Authorizes the Option Byte register programming */
    WRITE_REG(FLASH->OPTKEYR, FLASH_OPTKEY1);
    WRITE_REG(FLASH->OPTKEYR, FLASH_OPTKEY2);

    /* Verify that the Option Bytes are unlocked */
    if (READ_BIT(FLASH->NSCR, FLASH_NSCR_OPTLOCK) != 0u)
    {
      return HAL_ERROR;
    }
  }

  return HAL_OK;
}

/**
  * @brief  Lock the FLASH Option Bytes Registers access.
  * @retval HAL Status
  */
HAL_StatusTypeDef HAL_FLASH_OB_Lock(void)
{
  /* Set the OPTLOCK Bit to lock the FLASH Option Byte Registers access */
  SET_BIT(FLASH->NSCR, FLASH_NSCR_OPTLOCK);

  /* Verify that the Option Bytes are locked */
  if (READ_BIT(FLASH->NSCR, FLASH_NSCR_OPTLOCK) != 0u)
  {
    return HAL_OK;
  }

  return HAL_ERROR;
}

/**
  * @brief  Launch the option byte loading.
  * @retval HAL Status
  */
HAL_StatusTypeDef HAL_FLASH_OB_Launch(void)
{
  /* Set the bit to force the option byte reloading */
  SET_BIT(FLASH->NSCR, FLASH_NSCR_OBL_LAUNCH);

  /* We should not reach here : Option byte launch generates Option byte reset
     so return error */
  return HAL_ERROR;
}

/**
  * @}
  */

/** @defgroup FLASH_Exported_Functions_Group3 Peripheral State and Errors functions
 *  @brief   Peripheral Errors functions
 *
@verbatim
 ===============================================================================
                ##### Peripheral Errors functions #####
 ===============================================================================
    [..]
    This subsection permits to get in run-time Errors of the FLASH peripheral.

@endverbatim
  * @{
  */

/**
  * @brief  Get the specific FLASH error flag.
  * @retval FLASH_ErrorCode The returned value can be:
  *            @arg HAL_FLASH_ERROR_NONE: No error set
  *            @arg HAL_FLASH_ERROR_OP: FLASH Operation error
  *            @arg HAL_FLASH_ERROR_PROG: FLASH Programming error
  *            @arg HAL_FLASH_ERROR_WRP: FLASH Write protection error
  *            @arg HAL_FLASH_ERROR_PGA: FLASH Programming alignment error
  *            @arg HAL_FLASH_ERROR_SIZ: FLASH Size error
  *            @arg HAL_FLASH_ERROR_PGS: FLASH Programming sequence error
  *            @arg HAL_FLASH_ERROR_OPTW: FLASH Option modification error
  */
uint32_t HAL_FLASH_GetError(void)
{
   return pFlash.ErrorCode;
}

/**
  * @}
  */

/**
  * @}
  */

/* Private functions ---------------------------------------------------------*/

/** @addtogroup FLASH_Private_Functions
  * @{
  */

/**
  * @brief  Wait for a FLASH operation to complete.
  * @param  Timeout maximum flash operation timeout
  * @retval HAL_StatusTypeDef HAL Status
  */
HAL_StatusTypeDef FLASH_WaitForLastOperation(uint32_t Timeout)
{
  /* Wait for the FLASH operation to complete by polling on BUSY flag to be reset.
     Even if the FLASH operation fails, the BUSY flag will be reset and an error
     flag will be set */

  uint32_t timeout = HAL_GetTick() + Timeout;
  uint32_t error;
  __IO uint32_t *reg_sr;

  while(__HAL_FLASH_GET_FLAG(FLASH_FLAG_BSY))
  {
    if(Timeout != HAL_MAX_DELAY)
    {
      if(HAL_GetTick() >= timeout)
      {
        return HAL_TIMEOUT;
      }
    }
  }
  
  /* Access to SECSR or NSSR registers depends on operation type */
  reg_sr = IS_FLASH_SECURE_OPERATION() ? &(FLASH->SECSR) : &(FLASH_NS->NSSR);

  /* Check FLASH operation error flags */
  error = ((*reg_sr) & FLASH_FLAG_SR_ERRORS);
#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
  error |= (FLASH->NSSR & FLASH_FLAG_OPTWERR);
#endif /* __ARM_FEATURE_CMSE */ 

  if(error != 0u)
  {
    /*Save the error code*/
    pFlash.ErrorCode |= error;

    /* Clear error programming flags */
    (*reg_sr) = error;
#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
    if ((error & FLASH_FLAG_OPTWERR) != 0U)
    {
      FLASH->NSSR = FLASH_FLAG_OPTWERR;
    }
#endif /* __ARM_FEATURE_CMSE */

    return HAL_ERROR;
  }

  /* Check FLASH End of Operation flag  */
  if (((*reg_sr) & FLASH_FLAG_EOP) != 0U)
  {
    /* Clear FLASH End of Operation pending bit */
    (*reg_sr) = FLASH_FLAG_EOP;
  }

  /* If there is an error flag set */
  return HAL_OK;
}

/**
  * @brief  Program double-word (64-bit) at a specified address.
  * @param  Address specifies the address to be programmed.
  * @param  Data specifies the data to be programmed.
  * @retval None
  */
static void FLASH_Program_DoubleWord(uint32_t Address, uint64_t Data)
{
  uint32_t primask_bit;
  __IO uint32_t *reg;
  /* Check the parameters */
  assert_param(IS_FLASH_PROGRAM_ADDRESS(Address));
  
  /* Access to SECCR or NSCR registers depends on operation type */
  reg = IS_FLASH_SECURE_OPERATION() ? &(FLASH->SECCR) : &(FLASH_NS->NSCR);

  /* Disable interrupts to avoid any interruption during the double word programming */
  primask_bit = __get_PRIMASK();
  __disable_irq();

  /* Set PG bit */
  SET_BIT((*reg), FLASH_NSCR_NSPG);

  /* Program first word */
  *(uint32_t*)Address = (uint32_t)Data;

  /* Barrier to ensure programming is performed in 2 steps, in right order
    (independently of compiler optimization behavior) */
  __ISB();

  /* Program second word */
  *(uint32_t*)(Address+4U) = (uint32_t)(Data >> 32U);

  /* Re-enable the interrupts */
  __set_PRIMASK(primask_bit);
}

/**
  * @}
  */

#endif /* HAL_FLASH_MODULE_ENABLED */

/**
  * @}
  */

/**
  * @}
  */