flash_stm32.c

//#include "libmaple.h"
#include "libmaple/util.h"
#include "libmaple/flash.h"
#include "flash_stm32.h"

#define FLASH_KEY1			((uint32)0x45670123)
#define FLASH_KEY2			((uint32)0xCDEF89AB)

/* Delay definition */
#define EraseTimeout		((uint32)0x00000FFF)
#define ProgramTimeout		((uint32)0x0000001F)

/**
  * @brief  Inserts a time delay.
  * @param  None
  * @retval None
  */
static void delay(void)
{
	__IO uint32 i = 0;
	for(i = 0xFF; i != 0; i--) { }
}

/**
  * @brief  Returns the FLASH Status.
  * @param  None
  * @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PG,
  *   FLASH_ERROR_WRP or FLASH_COMPLETE
  */
FLASH_Status FLASH_GetStatus(void)
{
	if ((FLASH_BASE->SR & FLASH_SR_BSY) == FLASH_SR_BSY)
		return FLASH_BUSY;

	if ((FLASH_BASE->SR & FLASH_SR_PGERR) != 0)
		return FLASH_ERROR_PG;

	if ((FLASH_BASE->SR & FLASH_SR_WRPRTERR) != 0 )
		return FLASH_ERROR_WRP;

	if ((FLASH_BASE->SR & FLASH_OBR_OPTERR) != 0 )
		return FLASH_ERROR_OPT;

	return FLASH_COMPLETE;
}

/**
  * @brief  Waits for a Flash operation to complete or a TIMEOUT to occur.
  * @param  Timeout: FLASH progamming Timeout
  * @retval FLASH Status: The returned value can be: FLASH_ERROR_PG,
  *   FLASH_ERROR_WRP, FLASH_COMPLETE or FLASH_TIMEOUT.
  */
FLASH_Status FLASH_WaitForLastOperation(uint32 Timeout)
{ 
	FLASH_Status status;

	/* Check for the Flash Status */
	status = FLASH_GetStatus();
	/* Wait for a Flash operation to complete or a TIMEOUT to occur */
	while ((status == FLASH_BUSY) && (Timeout != 0x00))
	{
		delay();
		status = FLASH_GetStatus();
		Timeout--;
	}
	if (Timeout == 0)
		status = FLASH_TIMEOUT;
	/* Return the operation status */
	return status;
}

/**
  * @brief  Erases a specified FLASH page.
  * @param  Page_Address: The page address to be erased.
  * @retval FLASH Status: The returned value can be: FLASH_BUSY, FLASH_ERROR_PG,
  *   FLASH_ERROR_WRP, FLASH_COMPLETE or FLASH_TIMEOUT.
  */
FLASH_Status FLASH_ErasePage(uint32 Page_Address)
{
	FLASH_Status status = FLASH_COMPLETE;
	/* Check the parameters */
	ASSERT(IS_FLASH_ADDRESS(Page_Address));
	/* Wait for last operation to be completed */
	status = FLASH_WaitForLastOperation(EraseTimeout);
  
	if(status == FLASH_COMPLETE)
	{
		/* if the previous operation is completed, proceed to erase the page */
		FLASH_BASE->CR |= FLASH_CR_PER;
		FLASH_BASE->AR = Page_Address;
		FLASH_BASE->CR |= FLASH_CR_STRT;

		/* Wait for last operation to be completed */
		status = FLASH_WaitForLastOperation(EraseTimeout);
		if(status != FLASH_TIMEOUT)
		{
			/* if the erase operation is completed, disable the PER Bit */
			FLASH_BASE->CR &= ~FLASH_CR_PER;
		}
		FLASH_BASE->SR = (FLASH_SR_EOP | FLASH_SR_PGERR | FLASH_SR_WRPRTERR);
	}
	/* Return the Erase Status */
	return status;
}

/**
  * @brief  Programs a half word at a specified address.
  * @param  Address: specifies the address to be programmed.
  * @param  Data: specifies the data to be programmed.
  * @retval FLASH Status: The returned value can be: FLASH_ERROR_PG,
  *   FLASH_ERROR_WRP, FLASH_COMPLETE or FLASH_TIMEOUT. 
  */
FLASH_Status FLASH_ProgramHalfWord(uint32 Address, uint16 Data)
{
	FLASH_Status status = FLASH_BAD_ADDRESS;

	if (IS_FLASH_ADDRESS(Address))
	{
		/* Wait for last operation to be completed */
		status = FLASH_WaitForLastOperation(ProgramTimeout);
		if(status == FLASH_COMPLETE)
		{
			/* if the previous operation is completed, proceed to program the new data */
			FLASH_BASE->CR |= FLASH_CR_PG;
			*(__IO uint16*)Address = Data;
			/* Wait for last operation to be completed */
			status = FLASH_WaitForLastOperation(ProgramTimeout);
			if(status != FLASH_TIMEOUT)
			{
				/* if the program operation is completed, disable the PG Bit */
				FLASH_BASE->CR &= ~FLASH_CR_PG;
			}
			FLASH_BASE->SR = (FLASH_SR_EOP | FLASH_SR_PGERR | FLASH_SR_WRPRTERR);
		}
	}
	return status;
}

/**
  * @brief  Unlocks the FLASH Program Erase Controller.
  * @param  None
  * @retval None
  */
void FLASH_Unlock(void)
{
	/* Authorize the FPEC Access */
	FLASH_BASE->KEYR = FLASH_KEY1;
	FLASH_BASE->KEYR = FLASH_KEY2;
}

/**
  * @brief  Locks the FLASH Program Erase Controller.
  * @param  None
  * @retval None
  */
void FLASH_Lock(void)
{
	/* Set the Lock Bit to lock the FPEC and the FCR */
	FLASH_BASE->CR |= FLASH_CR_LOCK;
}