#include "s3c2440_soc.h"
#include "printf.h"

#define  TACLS   0
#define  TWRPH0  1
#define  TWRPH1  0
void nand_init(void)
{
	/*设置NAND FLASH的时序*/
	NFCONF = (TACLS<<12) | (TWRPH0<<8) | (TWRPH1<<4);
	/*使能NAND FLASH控制器,初始化ECC，禁止片选*/
	NFCONT = (1<<4) | (1<<1) | (1<<0);
}

void nand_select(void)
{
	/*使能片选*/
	NFCONT &=~(1<<1);
}

void nand_deselect(void)
{
	/*禁止片选*/
	NFCONT |= (1<<1);
}

void nand_cmd(unsigned char cmd)
{
	volatile int i;
	NFCCMD = cmd;
	for(i=0; i<10; i++);
}

void nand_addr_byte(unsigned char addr)
{
	volatile int i;
	NFADDR = addr;
	for(i=0; i<10; i++);
}

unsigned char nand_data(void)
{
	return	NFDATA;
}

void nand_w_data(unsigned char val)
{
	NFDATA = val;
}

void wait_ready(void)
{
	while (!(NFSTAT & 1));
}

/* read id command:0x90
 * address:0x00
 */
void nand_chip_id(void)
{ 
	unsigned char buf[5]={0};
	
	nand_select(); 
	nand_cmd(0x90);
	nand_addr_byte(0x00);

	buf[0] = nand_data();
	buf[1] = nand_data();	
	buf[2] = nand_data();
	buf[3] = nand_data();
	buf[4] = nand_data();	
	nand_deselect(); 	

	printf("maker   id  = 0x%x\n\r",buf[0]);
	printf("device  id  = 0x%x\n\r",buf[1]);	
	printf("3rd byte    = 0x%x\n\r",buf[2]);		
	printf("4th byte    = 0x%x\n\r",buf[3]);			
	printf("page  size  = %d kb\n\r",1  <<  (buf[3] & 0x03));	
	printf("block size  = %d kb\n\r",64 << ((buf[3] >> 4) & 0x03));	
	printf("5th byte    = 0x%x\n\r",buf[4]);
}

/* 将地址转化为对应的块，实际上是擦出整块 */
int nand_erase(unsigned int addr, unsigned int len)
{
	int page = addr / 2048;

	if (addr & (0x1FFFF))
	{
		printf("nand_erase err, addr is not block align\n\r");
		return -1;
	}
	
	if (len & (0x1FFFF))
	{
		printf("nand_erase err, len is not block align\n\r");
		return -1;
	}
	
	nand_select(); 

	while (1)
	{
		page = addr / 2048;
		
		nand_cmd(0x60);
		
		/* row/page addr */
		nand_addr_byte(page & 0xff);
		nand_addr_byte((page>>8) & 0xff);
		nand_addr_byte((page>>16) & 0xff);

		nand_cmd(0xD0);

		wait_ready();

		len -= (128*1024);
		if (len == 0)
			break;
		addr += (128*1024);
	}
	
	nand_deselect(); 	

	return 0;
}


void nand_read(unsigned int addr, unsigned char *buf, unsigned int len)
{
	int i = 0;
	int page = addr / 2048;
	int col  = addr & (2048 - 1);
	
	nand_select(); 

	while (i < len)
	{
		/* 发出00h命令 */
		nand_cmd(00);

		/* 发出地址 */
		/* col addr */
		nand_addr_byte(col & 0xff);
		nand_addr_byte((col>>8) & 0xff);

		/* row/page addr */
		nand_addr_byte(page & 0xff);
		nand_addr_byte((page>>8) & 0xff);
		nand_addr_byte((page>>16) & 0xff);

		/* 发出30h命令 */
		nand_cmd(0x30);

		/* 等待就绪 */
		wait_ready();

		/* 读数据 */
		for (; (col < 2048) && (i < len); col++)
		{
			buf[i++] = nand_data();			
		}
		if (i == len)
			break;

		col = 0;
		page++;
	}
	
	nand_deselect(); 	
}

void nand_write(unsigned int addr, unsigned char *buf, unsigned int len)
{
	int page = addr / 2048;
	int col  = addr & (2048 - 1);
	int i = 0;

	nand_select(); 

	while (1)
	{
		nand_cmd(0x80);

		/* 发出地址 */
		/* col addr */
		nand_addr_byte(col & 0xff);
		nand_addr_byte((col>>8) & 0xff);
		
		/* row/page addr */
		nand_addr_byte(page & 0xff);
		nand_addr_byte((page>>8) & 0xff);
		nand_addr_byte((page>>16) & 0xff);

		/* 发出数据 */
		for (; (col < 2048) && (i < len); )
		{
			nand_w_data(buf[i++]);
		}
		nand_cmd(0x10);
		wait_ready();

		if (i == len)
			break;
		else
		{
			/* 开始下一个循环page */
			col = 0;
			page++;
		}
		
	}
	
	nand_deselect(); 	
}

void do_read_nand_flash(void)
{
	unsigned int addr;
	volatile unsigned char *p;
	int i, j;
	unsigned char c;
	unsigned char str[16];
	unsigned char buf[64];
	
	/* 获得地址 */
	printf("Enter the address to read: ");
	addr = get_uint();

	nand_read(addr, buf, 64);
	p = (volatile unsigned char *)buf;

	printf("Data : \n\r");
	/* 长度固定为64 */
	for (i = 0; i < 4; i++)
	{
		/* 每行打印16个数据 */
		for (j = 0; j < 16; j++)
		{
			/* 先打印数值 */
			c = *p++;
			str[j] = c;
			printf("%02x ", c);
		}

		printf("   ; ");

		for (j = 0; j < 16; j++)
		{
			/* 后打印字符 */
			if (str[j] < 0x20 || str[j] > 0x7e)  /* 不可视字符 */
				putchar('.');
			else
				putchar(str[j]);
		}
		printf("\n\r");
	}
}

void do_erase_nand_flash(void)
{
	unsigned int addr;
	
	/* 获得地址 */
	printf("Enter the address of sector to erase: ");
	addr = get_uint();

	printf("erasing ...\n\r");
	nand_erase(addr, 128*1024);
}


void do_write_nand_flash(void)
{
	unsigned int addr;
	unsigned char str[100];
	int i, j;
	unsigned int val;
	
	/* 获得地址 */
	printf("Enter the address of sector to write: ");
	addr = get_uint();

	printf("Enter the string to write: ");
	gets(str);

	printf("writing ...\n\r");
	nand_write(addr, str, strlen(str)+1);

}

void nand_flash_test(void)
{
	char c;

	while (1)
	{
		/* 打印菜单, 供我们选择测试内容 */
		printf("[s] Scan nand flash\n\r");
		printf("[e] Erase nand flash\n\r");
		printf("[w] Write nand flash\n\r");
		printf("[r] Read nand flash\n\r");
		printf("[q] quit\n\r");
		printf("Enter selection: ");

		c = getchar();
		printf("%c\n\r", c);

		/* 测试内容:
		 * 1. 识别nand flash
		 * 2. 擦除nand flash某个扇区
		 * 3. 编写某个地址
		 * 4. 读某个地址
		 */
		switch (c)		 
		{
			case 'q':
			case 'Q':
				return;
				break;
				
			case 's':
			case 'S':
				nand_chip_id();
				break;

			case 'e':
			case 'E':
				do_erase_nand_flash();
				break;

			case 'w':
			case 'W':
				do_write_nand_flash();
				break;

			case 'r':
			case 'R':
				do_read_nand_flash();
				break;
			default:
				break;
		}
	}
}