/****************************************Copyright (c)**************************************************
**                      
**                          
**                               
**
**--------------File Info-------------------------------------------------------------------------------
** File name:			AT29C04X.h
** Last modified Date:  
** Last Version:		1.0
** Descriptions:		讀寫ATMEL FLASH
**
**------------------------------------------------------------------------------------------------------
** Created by:			潘妙青
** Created date:		2008-2-26
** Version:				1.0
** Descriptions:		The original version
**
**------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
** Version:
** Descriptions:
**
********************************************************************************************************/
#include "config.h"
#include "delay.h"

#define __SRC
#include "AT29C040X.h"
#undef __SRC

#define FLASH_BASE_ADDR		0x82000000
#define MAX_SECTOR_NUMBER	2048
#define SECTOR_SIZE			256
#define TWC					1

void delay_20ms(void)
{
	int i;
	
	for(i = 0;i < 2;i++)
		delay_10ms();
}

void delay_flash()
{
	int i;
	
	for(i = 0; i< TWC; i++)
		delay_10ms();
}

/****************************************************************************
* 名稱：flash_SDP_enable()
* 功能：使能SDP功能
* 入口參數：
* 出口參數：
****************************************************************************/
void flash_SDP_enable(void)
{
	uint8 *flash_addr = NULL;
	
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x5555);
	*flash_addr = 0xAA;
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x2AAA);
	*flash_addr = 0x55;
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x5555);
	*flash_addr = 0xA0;
}

/****************************************************************************
* 名稱：entry_id_mode()
* 功能：進入ID模式
* 入口參數：
* 出口參數：
****************************************************************************/
void entry_id_mode(void)
{
	uint8 *flash_addr = NULL;
	
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x5555);
	*flash_addr = 0xAA;
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x2AAA);
	*flash_addr = 0x55;
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x5555);
	*flash_addr = 0x90;
}

/****************************************************************************
* 名稱：leave_id_mode()
* 功能：退出ID模式
* 入口參數：
* 出口參數：
****************************************************************************/
void leave_id_mode(void)
{
	uint8 *flash_addr = NULL;
	
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x5555);
	*flash_addr = 0xAA;
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x2AAA);
	*flash_addr = 0x55;
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x5555);
	*flash_addr = 0xF0;
}

/****************************************************************************
* 名稱：Init_Flash()
* 功能：初始化FLASH
* 入口參數：
* 出口參數：
****************************************************************************/
int Init_Flash(void)
{
	uint8 flash_id;
	uint8 *flash_addr = NULL;
	
	entry_id_mode();		//進入讀ID模式
	delay_20ms();
	
	flash_addr = (uint8 *)(FLASH_BASE_ADDR + 0x0001);	//ID地址為0X0001
	flash_id = *flash_addr;
	
	leave_id_mode();		//退出讀ID模式
	delay_20ms();
	
	if(flash_id != 0xa4)
		return -1;

/*	
	switch(flash_id)
	{
		case 0x5b:
			sector_size = 512;		//29C040
			twc = 1;
			break;
		case 0xa4:
			sector_size = 256;		//29C040A
			twc = 1;
			break;
		case 0x3b:
			secotr_size = 512;		//29LV040
			twc = 2;
			break;	
		case 0xc4:
			sector_size = 256;		//29LV040A
			twc = 2;
			break;	
		default:
			sector_size = 0;
			twc = 0;		
	}
*/	
	return 0;
}

/****************************************************************************
* 名稱：Write_Flash_Sector()
* 功能：寫數據到一扇區中
* 入口參數：FlashAddr(0x82000000-0x8207FFFF) / length of data is sector_size
*			sector:0-2047
* 出口參數：
****************************************************************************/
int Write_Flash_Sector(uint8 sector, uint8 *data)
{
	int i;
	uint8 *addr = (uint8 *)(FLASH_BASE_ADDR + sector * SECTOR_SIZE);
	
	flash_SDP_enable();		//使能SDP功能,保護數據
	
	for(i = 0; i < SECTOR_SIZE; i++)
		*(addr + i) = *(data + i);
		
	delay_flash();			//DELAY 10ms	
	return 0;	
}

/****************************************************************************
* 名稱：Write_Flash()
* 功能：寫SRAM數據到FLASH中
* 入口參數：FlashAddr(0x82000000-0x8207FFFF)
* 出口參數：
****************************************************************************/
int Write_Flash(uint32 FlashAddr, uint8 *data, int datalen)
{
	int i;
	uint8 sector,offset;
	uint8 sector_buf[SECTOR_SIZE];
	uint8 check_buf[SECTOR_SIZE];
	
	if(data == NULL || datalen == 0)
		return -1;
		
	if(datalen > FlashAddr - FLASH_BASE_ADDR)		//越界
		return -1;	
	
	sector = (FlashAddr - FLASH_BASE_ADDR) >> 8;	//計算起始扇區號
	offset = FlashAddr & 0xFF;						//計算扇區內偏移
	
	while(datalen > 0) {
		Read_Flash((FLASH_BASE_ADDR + sector * SECTOR_SIZE),sector_buf, SECTOR_SIZE);	//讀取當前扇區
		for( i = 0; (i < SECTOR_SIZE - offset) && (datalen > 0); i++, datalen--) {
			data += i;
			sector_buf[offset + i] = *data;
		}	
			
		Write_Flash_Sector(sector, sector_buf);			//寫入一扇區
		
		Read_Flash((FLASH_BASE_ADDR + sector * SECTOR_SIZE),check_buf, SECTOR_SIZE);
		for(i = 0; i < SECTOR_SIZE; i++) {				//驗證
			if(*(check_buf + i) != *(sector_buf + i))
				return -1;
		}
		offset = 0;	
		sector++;
	}	
	
	return 0;
}

/****************************************************************************
* 名稱：Read_Flash()
* 功能：讀取一扇區數據到SRAM中
* 入口參數：FlashAddr(0x82000000-0x8207FFFF)
* 出口參數：
****************************************************************************/
int Read_Flash(uint32 FlashAddr, uint8 *buf, int buflen)
{
	int i;
	uint8 *flash_addr = (uint8 *)FlashAddr;
	
	if(buf == NULL || buflen == 0)
		return -1;
		
	if(buflen > FlashAddr - FLASH_BASE_ADDR)		// 越界
		return -1;
		
	for(i = 0; i < buflen; i++)
		*(buf + i) = *(flash_addr + i);
		
	return 0;		
}