/******************** (C) COPYRIGHT 2007 STMicroelectronics ********************
* File Name          : spi_flash.c
* Author             : MCD Application Team
* Version            : V1.0
* Date               : 10/08/2007
* Description        : This file provides a set of functions needed to manage the
*                      communication between SPI peripheral and SPI M25P64 FLASH.
********************************************************************************
* THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
* CONTENT OF SUCH SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*******************************************************************************/

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

/* Private typedef -----------------------------------------------------------*/
#define SPI_FLASH_PageSize 256

#define WRITE      0x02  /* Write to Memory instruction */
#define WRSR       0x01  /* Write Status Register instruction */ 
#define WREN       0x06  /* Write enable instruction */

#define READ       0x03  /* Read from Memory instruction */
#define RDSR       0x05  /* Read Status Register instruction  */
#define RDID       0x9F  /* Read identification */
#define SE         0xD8  /* Sector Erase instruction */
#define BE         0xC7  /* Bulk Erase instruction */

#define WIP_Flag   0x01  /* Write In Progress (WIP) flag */

#define Dummy_Byte 0xA5

/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/

/*******************************************************************************
* Function Name  : SPI_FLASH_Init
* Description    : Initializes the peripherals used by the SPI FLASH driver.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_FLASH_Init(void)
{
  SPI_InitTypeDef  SPI_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;
   
  /* Enable SPI1 and GPIOA clocks */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 | RCC_APB2Periph_GPIOA, ENABLE);
  
  /* Configure SPI1 pins: NSS, SCK, MISO and MOSI */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Configure PA.4 as Output push-pull, used as Flash Chip select */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();

  /* SPI1 configuration */ 
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_Init(SPI1, &SPI_InitStructure);
  
  /* Enable SPI1  */
  SPI_Cmd(SPI1, ENABLE);   
}

/*******************************************************************************
* Function Name  : SPI_FLASH_SectorErase
* Description    : Erases the specified FLASH sector.
* Input          : SectorAddr: address of the sector to erase.
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_FLASH_SectorErase(u32 SectorAddr)
{
  /* Send write enable instruction */
  SPI_FLASH_WriteEnable();

  /* Sector Erase */ 
  /* Select the FLASH: Chip Select low */
  SPI_FLASH_CS_LOW();
  /* Send Sector Erase instruction */
  SPI_FLASH_SendByte(SE);
  /* Send SectorAddr high nibble address byte */
  SPI_FLASH_SendByte((SectorAddr & 0xFF0000) >> 16);
  /* Send SectorAddr medium nibble address byte */
  SPI_FLASH_SendByte((SectorAddr & 0xFF00) >> 8);
  /* Send SectorAddr low nibble address byte */
  SPI_FLASH_SendByte(SectorAddr & 0xFF);
  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();

  /* Wait the end of Flash writing */
  SPI_FLASH_WaitForWriteEnd();
}

/*******************************************************************************
* Function Name  : SPI_FLASH_BulkErase
* Description    : Erases the entire FLASH.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_FLASH_BulkErase(void)
{
  /* Send write enable instruction */
  SPI_FLASH_WriteEnable();

  /* Bulk Erase */ 
  /* Select the FLASH: Chip Select low */
  SPI_FLASH_CS_LOW();
  /* Send Bulk Erase instruction  */
  SPI_FLASH_SendByte(BE);
  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();

  /* Wait the end of Flash writing */
  SPI_FLASH_WaitForWriteEnd();
}

/*******************************************************************************
* Function Name  : SPI_FLASH_PageWrite
* Description    : Writes more than one byte to the FLASH with a single WRITE
*                  cycle(Page WRITE sequence). The number of byte can't exceed
*                  the FLASH page size.
* Input          : - pBuffer : pointer to the buffer  containing the data to be 
*                    written to the FLASH.
*                  - WriteAddr : FLASH's internal address to write to.
*                  - NumByteToWrite : number of bytes to write to the FLASH,
*                    must be equal or less than "SPI_FLASH_PageSize" value. 
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_FLASH_PageWrite(u8* pBuffer, u32 WriteAddr, u16 NumByteToWrite)
{
  /* Enable the write access to the FLASH */
  SPI_FLASH_WriteEnable();
  
  /* Select the FLASH: Chip Select low */
  SPI_FLASH_CS_LOW();
  /* Send "Write to Memory " instruction */
  SPI_FLASH_SendByte(WRITE);
  /* Send WriteAddr high nibble address byte to write to */
  SPI_FLASH_SendByte((WriteAddr & 0xFF0000) >> 16);
  /* Send WriteAddr medium nibble address byte to write to */
  SPI_FLASH_SendByte((WriteAddr & 0xFF00) >> 8);  
  /* Send WriteAddr low nibble address byte to write to */
  SPI_FLASH_SendByte(WriteAddr & 0xFF);
  
  /* while there is data to be written on the FLASH */
  while(NumByteToWrite--) 
  {
    /* Send the current byte */
    SPI_FLASH_SendByte(*pBuffer);
    /* Point on the next byte to be written */
    pBuffer++; 
  }
  
  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();
  
  /* Wait the end of Flash writing */
  SPI_FLASH_WaitForWriteEnd();
}

/*******************************************************************************
* Function Name  : SPI_FLASH_BufferWrite
* Description    : Writes block of data to the FLASH. In this function, the
*                  number of WRITE cycles are reduced, using Page WRITE sequence.
* Input          : - pBuffer : pointer to the buffer  containing the data to be 
*                    written to the FLASH.
*                  - WriteAddr : FLASH's internal address to write to.
*                  - NumByteToWrite : number of bytes to write to the FLASH.
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_FLASH_BufferWrite(u8* pBuffer, u32 WriteAddr, u16 NumByteToWrite)
{
  u8 NumOfPage = 0, NumOfSingle = 0, Addr = 0, count = 0, temp = 0;

  Addr = WriteAddr % SPI_FLASH_PageSize;
  count = SPI_FLASH_PageSize - Addr;
  NumOfPage =  NumByteToWrite / SPI_FLASH_PageSize;
  NumOfSingle = NumByteToWrite % SPI_FLASH_PageSize;
  
  if(Addr == 0) /* WriteAddr is SPI_FLASH_PageSize aligned  */
  {
    if(NumOfPage == 0) /* NumByteToWrite < SPI_FLASH_PageSize */
    {
      SPI_FLASH_PageWrite(pBuffer, WriteAddr, NumByteToWrite);
    }
    else /* NumByteToWrite > SPI_FLASH_PageSize */ 
    {
      while(NumOfPage--)
      {
        SPI_FLASH_PageWrite(pBuffer, WriteAddr, SPI_FLASH_PageSize);
        WriteAddr +=  SPI_FLASH_PageSize;
        pBuffer += SPI_FLASH_PageSize;  
      }    
     
      SPI_FLASH_PageWrite(pBuffer, WriteAddr, NumOfSingle);
   }
  }
  else /* WriteAddr is not SPI_FLASH_PageSize aligned  */
  {
    if(NumOfPage== 0) /* NumByteToWrite < SPI_FLASH_PageSize */
    {
      if(NumOfSingle > count) /* (NumByteToWrite + WriteAddr) > SPI_FLASH_PageSize */
      {
        temp = NumOfSingle - count;
      
        SPI_FLASH_PageWrite(pBuffer, WriteAddr, count);
        WriteAddr +=  count;
        pBuffer += count; 
        
        SPI_FLASH_PageWrite(pBuffer, WriteAddr, temp);
      }
      else
      {