nand_read.c

上一次项目的vivi 代码

/* 
 * 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>
#include "sizes.h"
#include "mtd/mtd.h"
#include "mtd/nand.h"

//#define LARGEPAGE_FLASH

#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++);
}

#ifndef LARGEPAGE_FLASH
#define NAND_SECTOR_SIZE        512
#else
#define NAND_SECTOR_SIZE        2048
#endif
#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)) 
    if ((start_addr & NAND_BLOCK_MASK) /*|| (size > SZ_1M)*/) {
        return -1;      /* invalid alignment */
    }

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

    for(i=start_addr; i < (start_addr + size);) {
      /* READ0 */
      NFCMD = NAND_CMD_READ0;

      /* Write Address */
#ifndef LARGEPAGE_FLASH
      NFADDR = i & 0xff;
      NFADDR = (i >> 9) & 0xff;
      NFADDR = (i >> 17) & 0xff;
      NFADDR = (i >> 25) & 0xff;
#else
      NFADDR = i & 0xff;
      NFADDR = (i >> 8) & 0x07;
      NFADDR = (i >> 11) & 0xff;
      NFADDR = (i >> 19) & 0xff;
      NFADDR = (i >> 27) & 0x3;
      
      NFCMD = NAND_CMD_READSTART;
#endif
      wait_idle();

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

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

    return 0;
}