nand_read.c

SMDK2440 boot code, base on vivi

/* 
 * vivi/s3c2410/nand_read.c: Simple NAND read functions for booting from NAND
 *
 * Copyright (C) 2002 MIZI Research, Inc.
 *
 * Author: Hwang, Chideok <[e-mail]>
 * Date  : $Date: 2004/03/25 04:42:41 $
 *
 * $Revision: 1.12 $
 * $Id: param.c,v 1.9 2002/07/11 06:17:20 nandy Exp 
 *
 * History
 *
 * 2002-05-xx: Hwang, Chideok <[e-mail]>
 *    - 瞪芭扼绊 抄叼俊霸 淋.
 *
 * 2002-05-xx: Chan Gyun Jeong <[e-mail]>
 *    - 抄叼狼 何殴阑 罐绊 力措肺 悼累窍档废 荐沥.
 *
 * 2002-08-10: Yong-iL Joh <[e-mail]>
 *    - SECTOR_SIZE啊 512牢 仇篮 促 佬档废 荐沥
 *
 * 2003-04-08: Janghoon Lyu <[e-mail]>
 *    - Check bad block when vivi copy itself. 
 *    - Add a function called nand_read_oob_ll()
 *
 * NOTE: Don't use printk()
 */

#include <config.h>
#include <machine.h>
#include <memory.h>

/* 
 * 构 汗棱窍变 窍瘤父, 捞犯霸扼档 东户篮 且 荐 乐嚼聪促.
 * 弊贰档 8M俊辑绰 悼累救钦聪促. 恐 弊繁瘤 葛福摆嚼聪促.
 */
#undef CONFIG_SMC_SUPPORT_8M

#if defined(CONFIG_SMC_SUPPORT_8M)
#define CONFIG_SMC_3CYCLE_ADDRESSING
#define VIVI_BLOCKS		(16)
#else
#define CONFIG_SMC_4CYCLE_ADDRESSING
#define VIVI_BLOCKS		(8)
#endif

#ifdef CONFIG_SMC_SUPPORT_8M
#define NAND_PAGES_IN_BLOCK	(16)
#else
#define NAND_PAGES_IN_BLOCK	(32)
#endif
#define NAND_PAGE_SIZE		(512)
#define NAND_PAGE_MASK		(NAND_PAGE_SIZE - 1)
#define NAND_BLOCK_SIZE		(NAND_PAGE_SIZE*NAND_PAGES_IN_BLOCK)
#define NAND_BLOCK_MASK		(NAND_BLOCK_SIZE - 1)
#define NAND_OOB_SIZE		(16)

#define TAKE_SOME_DELAY		({ for(i=0; i<10; i++); })

#define BUSY 1
static inline void 
wait_idle(void) 
{
	int i;
	for(i=0; i<10; i++);
	while(!(NFSTAT & BUSY)) ;
}

static void
set_address(unsigned long addr)
{
	NFADDR = addr & 0xff;
	NFADDR = (addr >> 9) & 0xff;
	NFADDR = (addr >> 17) & 0xff;
#ifdef CONFIG_SMC_4CYCLE_ADDRESSING
	NFADDR = (addr >> 25) & 0xff;
#endif
}

static int
nand_read_page_ll(unsigned char *buf, unsigned long addr)
{
	int i;

	if (addr & NAND_PAGE_MASK) {
		return -1;	/* invalid alignment */
	}

	/* chip Enable */
	NFCONF &= ~0x800;
	TAKE_SOME_DELAY;

	/* READ0 */
	NFCMD = 0;

	/* Write Address */
	set_address(addr);

	wait_idle();

	/* Read data */
	for(i=0; i < NAND_PAGE_SIZE; i++) {
		*buf = (NFDATA & 0xff);
		buf++;
	}

	/* chip Disable */
	NFCONF |= 0x800;

	return 0;
}

/* low level nand read function */
static int
nand_read_oob_ll(char *buf, unsigned long addr)
{
	int i;

	if ((addr & NAND_BLOCK_MASK)) {
		return -1;	/* invalid alignment */
	}

	/* Chip Enable */
	NFCONF &= ~0x800;
	TAKE_SOME_DELAY;

	/* READOOB */
	NFCMD = 0x50;

	/* Write Address */
	set_address(addr);

	wait_idle();

	/* Read oob data */
	for(i=0; i < NAND_OOB_SIZE; i++) {
		*buf = (NFDATA & 0xff);
		buf++;
	}

	/* Chip Disable */
	NFCONF |= 0x800;

	return 0;
}

static int
is_bad_block(unsigned long addr)
{
	char oob_buf[16];

	nand_read_oob_ll((char *)oob_buf, addr);

	if (oob_buf[5] != 0xff)
		return 1;
	else
		return 0;
}

/*
 * Read data from NAND.
 */
int
nandll_read_blocks(unsigned long dst_addr, unsigned long src_addr, int size)
{
	char *buf = (char *)dst_addr;	
	int i;

	if ((src_addr & NAND_BLOCK_MASK) || (size & NAND_PAGE_MASK))
		return -1;	/* invalid alignment */

	while (size > 0) {
		/* If this block is bad, go next block */
		if (is_bad_block(src_addr)) {
			src_addr += NAND_BLOCK_SIZE;
			continue;
		}

		/* Read block */
		for (i = 0; i < NAND_PAGES_IN_BLOCK; i++) {
			nand_read_page_ll((char *)buf, src_addr);
			buf += NAND_PAGE_SIZE;
			src_addr += NAND_PAGE_SIZE;
			size -= NAND_PAGE_SIZE;
			if (size == 0) break;
		}
	}

	return 0;
}

static void
nandll_reset(void)
{
	NFCONF = 0xf830;		/* initial value */
	NFCONF &= ~(0x800);		/* enable chip */
	NFCMD = 0xff;			/* RESET command */

	wait_idle();

	NFCONF |= (0x800);		/* disable chip */
}

int
copy_vivi_to_ram(void)
{
	nandll_reset();
	/* Copy vivi to ram. 128k is enough. */
	return nandll_read_blocks(VIVI_BASE, 0x0, (VIVI_BLOCKS*NAND_BLOCK_SIZE));
}