nand_read.c

2410实验指导书 详尽的实验说明院程序

/* 
 * 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: 2002/08/14 10:26:47 $
 *
 * $Revision: 1.6 $
 * $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
 *
 */

//#include <config.h>

#define __REGb(x)	(*(volatile unsigned char *)(x))
#define __REGi(x)	(*(volatile unsigned int *)(x))
#define NF_BASE		0x4e000000
#define NFCONF		__REGi(NF_BASE + 0x0)
#define NFCMD		__REGb(NF_BASE + 0x4)
#define NFADDR		__REGb(NF_BASE + 0x8)
#define NFDATA		__REGb(NF_BASE + 0xc)
#define NFSTAT		__REGb(NF_BASE + 0x10)

#define BUSY 1
inline void wait_idle(void) {
    int i;

    while(!(NFSTAT & BUSY))
      for(i=0; i<10; i++);
}

#define NAND_SECTOR_SIZE	512
#define NAND_BLOCK_MASK		(NAND_SECTOR_SIZE - 1)

/* low level nand read function */
int
nand_read_ll(unsigned char *buf, unsigned long start_addr, int size)
{
    int i, j;

    if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
        return -1;	/* invalid alignment */
    }

    /* chip Enable */
    NFCONF &= ~0x800;
    for(i=0; i<10; i++);

    for(i=start_addr; i < (start_addr + size);) {
      /* READ0 */
      NFCMD = 0;

      /* Write Address */
      NFADDR = i & 0xff;
      NFADDR = (i >> 9) & 0xff;
      NFADDR = (i >> 17) & 0xff;
      NFADDR = (i >> 25) & 0xff;

      wait_idle();

      for(j=0; j < NAND_SECTOR_SIZE; j++, i++) {
	*buf = (NFDATA & 0xff);
	buf++;
      }
    }

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

    return 0;
}