/*
 * (C) Copyright 2004 Texas Instruments
 * Jian Zhang <jzhang@ti.com>
 *
 *  Samsung K9F1G08R0AQ0C NAND chip driver for an OMAP2420 board
 * 
 * This file is based on the following u-boot file:
 *	common/cmd_nand.c
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>

#include <asm/arch/sys_proto.h>
#include <asm/arch/sys_info.h>

#ifdef CFG_NAND_K9F1G08R0A

#define K9F1G08R0A_MFR		0xec  /* Samsung */
#define K9F1G08R0A_ID		0xa1  /* part # */

/* Since Micron and Samsung parts are similar in geometry and bus width
 * we can use the same driver. Need to revisit to make this file independent
 * of part/manufacturer
 */
#define MT29F1G_MFR		0x2c  /* Micron */
#define MT29F1G_ID		0xa1  /* x8, 1GiB */
#define MT29F2G_ID      0xba  /* x16, 2GiB */
#define MT29F4G_ID      0xbc  /* x16, 4GiB */

#define ADDR_COLUMN		1          
#define ADDR_PAGE		2             
#define ADDR_COLUMN_PAGE	(ADDR_COLUMN | ADDR_PAGE)

#define ADDR_OOB		(0x4 | ADDR_COLUMN_PAGE) 

#define PAGE_SIZE		2048
#define OOB_SIZE		64
#define MAX_NUM_PAGES		64

#define ECC_CHECK_ENABLE
#define ECC_STEPS		3

#ifdef CFG_SW_ECC_512
#define ECC_BLOCK_SIZE 512
#define ECC_SIZE	12
#else
#define ECC_BLOCK_SIZE 256
#define ECC_SIZE	24
#endif

/*******************************************************
 * Routine: delay
 * Description: spinning delay to use before udelay works
 ******************************************************/
static inline void delay (unsigned long loops)
{
	__asm__ volatile ("1:\n"
					  "subs %0, %0, #1\n"
					  "bne 1b":"=r" (loops):"0" (loops));
}

static int nand_read_page(u_char *buf, ulong page_addr);
static int nand_read_oob(u_char * buf, ulong page_addr);

/* JFFS2 large page layout for 3-byte ECC per 256 bytes ECC layout */
/* This is the only SW ECC supported by u-boot. So to load u-boot 
 * this should be supported */
static u_char ecc_pos[] = 
		{40, 41, 42, 43, 44, 45, 46, 47,
		48, 49, 50, 51, 52, 53, 54, 55,
		56, 57, 58, 59, 60, 61, 62, 63};

static unsigned long chipsize = (256 << 20);

#ifdef NAND_16BIT
static int bus_width = 16;
#else
static int bus_width = 8;
#endif

/* NanD_Command: Send a flash command to the flash chip */
static int NanD_Command(unsigned char command)
{
 	NAND_CTL_SETCLE(NAND_ADDR);

 	WRITE_NAND_COMMAND(command, NAND_ADDR);
 	NAND_CTL_CLRCLE(NAND_ADDR);

  	if(command == NAND_CMD_RESET){
		unsigned char ret_val;
		NanD_Command(NAND_CMD_STATUS);
		do{
			ret_val = READ_NAND(NAND_ADDR);/* wait till ready */
  		} while((ret_val & 0x40) != 0x40);
 	}
 	
	NAND_WAIT_READY();
	return 0;
}


/* NanD_Address: Set the current address for the flash chip */
static int NanD_Address(unsigned int numbytes, unsigned long ofs)
{
	uchar u;

 	NAND_CTL_SETALE(NAND_ADDR);

	if (numbytes == ADDR_COLUMN || numbytes == ADDR_COLUMN_PAGE 
				|| numbytes == ADDR_OOB)
	{
		ushort col = ofs;

		u = col  & 0xff;
		WRITE_NAND_ADDRESS(u, NAND_ADDR);

		u = (col >> 8) & 0x07;
		if (numbytes == ADDR_OOB)
			u = u | ((bus_width == 16) ? (1 << 2) : (1 << 3));
		WRITE_NAND_ADDRESS(u, NAND_ADDR);
	}

	if (numbytes == ADDR_PAGE || numbytes == ADDR_COLUMN_PAGE
				|| numbytes == ADDR_OOB)
	{
		u = (ofs >> 11) & 0xff;
		WRITE_NAND_ADDRESS(u, NAND_ADDR);
		u = (ofs >> 19) & 0xff;
		WRITE_NAND_ADDRESS(u, NAND_ADDR);

		/* One more address cycle for devices > 128MiB */
		if (chipsize > (128 << 20)) {
			u = (ofs >> 27) & 0xff;
			WRITE_NAND_ADDRESS(u, NAND_ADDR);
		}
	}

 	NAND_CTL_CLRALE(NAND_ADDR);

 	NAND_WAIT_READY();
	return 0;
}

/* read chip mfr and id
 * return 0 if they match board config
 * return 1 if not
 */
int nand_chip()
{
	int mfr, id;

 	NAND_ENABLE_CE();

 	if (NanD_Command(NAND_CMD_RESET)) {
 		printf("Err: RESET\n");
 		NAND_DISABLE_CE();   
		return 1;
	}
 
 	if (NanD_Command(NAND_CMD_READID)) {
 		printf("Err: READID\n");
 		NAND_DISABLE_CE();
		return 1;
 	}
 
 	NanD_Address(ADDR_COLUMN, 0);

 	mfr = READ_NAND(NAND_ADDR);
	id = READ_NAND(NAND_ADDR);

	NAND_DISABLE_CE();

	/* Check Micron part or Samsung part */
	if ((mfr == MT29F1G_MFR && (id == MT29F1G_ID || id == MT29F2G_ID || id == MT29F4G_ID)) ||
	    (mfr == K9F1G08R0A_MFR && (id == K9F1G08R0A_ID)) ){
		   return 0;
	}
	return 1;
}

/* read a block data to buf
 * return 1 if the block is bad or ECC error can't be corrected for any page
 * return 0 on sucess
 */ 
int nand_read_block(unsigned char *buf, ulong block_addr)
{
	int i, offset = 0;

#ifdef ECC_CHECK_ENABLE
	u16 oob_buf[OOB_SIZE >> 1];
 	
	/* check bad block */
	/* 0th word in spare area needs be 0xff */
	if (nand_read_oob((u_char *)oob_buf, block_addr) || (oob_buf[0] & 0xff) != 0xff){
		printf("Skipped bad block at 0x%x\n", block_addr);
		return 1;    /* skip bad block */
	}
#endif
	/* read the block page by page*/
	for (i=0; i<MAX_NUM_PAGES; i++){
		if (nand_read_page(buf+offset, block_addr + offset))
			return 1;
		offset += PAGE_SIZE;
	}

	return 0;
}

static int count = 0;

/* read a page with ECC */
static int nand_read_page(u_char *buf, ulong page_addr)
{
#ifdef ECC_CHECK_ENABLE
 	u_char ecc_code[ECC_SIZE];
	u_char ecc_calc[ECC_STEPS];
	u_char oob_buf[OOB_SIZE];
#endif
	u16 val;
	int cntr;
	int len;

#ifdef NAND_16BIT
	u16 *p;
#else
	u_char *p;
#endif

	NAND_ENABLE_CE();   
	NanD_Command(NAND_CMD_READ0);
	NanD_Address(ADDR_COLUMN_PAGE, page_addr);
	NanD_Command(NAND_CMD_READSTART);
	NAND_WAIT_READY();

	/* A delay seems to be helping here. needs more investigation */
	delay(10000);
	len = (bus_width == 16) ? PAGE_SIZE >> 1 : PAGE_SIZE;

#ifdef NAND_16BIT
	p = (u16 *)buf;
#else
	p = buf;
#endif
	for (cntr = 0; cntr < len; cntr++){
		*p++ = READ_NAND(NAND_ADDR);
		delay(10);
   	}
	
#ifdef ECC_CHECK_ENABLE
#ifdef NAND_16BIT
	p = (u16 *)oob_buf;
#else
	p = oob_buf;
#endif
        len = (bus_width == 16) ? OOB_SIZE >> 1 : OOB_SIZE;
	for (cntr = 0; cntr < len; cntr++){
		*p++ = READ_NAND(NAND_ADDR);
		delay(10);
 	}
	count = 0;
 	NAND_DISABLE_CE();  /* set pin high */

 	/* Pick the ECC bytes out of the oob data */
	for (cntr = 0; cntr < ECC_SIZE; cntr++)
		ecc_code[cntr] =  oob_buf[ecc_pos[cntr]];

	for (count = 0, cntr = 0; cntr < PAGE_SIZE / ECC_BLOCK_SIZE;
					cntr++, count += ECC_STEPS) {
 		nand_calculate_ecc (buf, &ecc_calc[0]);
		if (nand_correct_data (buf, &ecc_code[count], &ecc_calc[0]) == -1) {
 			printf ("ECC Failed, page 0x%08x\n", page_addr);
			for (val = 0; val < ECC_BLOCK_SIZE; val++)
				printf("%x ", buf[val]);
			printf("\n");
			for (;;);
  			return 1;
 		}
		buf += ECC_BLOCK_SIZE;
		page_addr += ECC_BLOCK_SIZE;
	}
#endif	
	return 0;
}

/* read from the 16 bytes of oob data that correspond to a 512 / 2048 byte page.
 */
static int nand_read_oob(u_char *buf, ulong page_addr)
{
	int cntr;
	int len;

#ifdef NAND_16BIT
	u16 *p = (u16 *)buf;
#else
	u_char *p = buf;
#endif
        len = (bus_width == 16) ? OOB_SIZE >> 1 : OOB_SIZE;

  	NAND_ENABLE_CE();  /* set pin low */
	NanD_Command(NAND_CMD_READ0);
 	NanD_Address(ADDR_OOB, page_addr);
	NanD_Command(NAND_CMD_READSTART);
	NAND_WAIT_READY();

	/* A delay seems to be helping here. needs more investigation */
	delay(10000);
	for (cntr = 0; cntr < len; cntr++)
		*p++ = READ_NAND(NAND_ADDR);
  
	NAND_WAIT_READY();
	NAND_DISABLE_CE();  /* set pin high */

	return 0;
}

#endif