arch/s3c2440/nand_read.c

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/**************************
* s3c2440 nandflash driver
* modified from vivi
*
* arch/s3c2440/head.s
* author: book chen
* date: 2008.08.20
****************************
*/
#include "includes.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 NFCONT    __REGi(NF_BASE + 0x4)
#define NFCMD   __REGb(NF_BASE + 0x8)
#define NFADDR    __REGb(NF_BASE + 0xC)
#define NFDATA    __REGb(NF_BASE + 0x10)
#define NFSTAT    __REGb(NF_BASE + 0x20)
*/

//#define GPDAT   __REGi(GPIO_CTL_BASE+oGPIO_F+oGPIO_DAT)

#define NAND_CHIP_ENABLE  (NFCONT &= ~(1<<1))
#define NAND_CHIP_DISABLE (NFCONT |=  (1<<1))
#define NAND_CLEAR_RB   (NFSTAT |=  (1<<2))
#define NAND_DETECT_RB    { while(! (NFSTAT&(1<<2)) );}

#define BUSY 4
inline void wait_idle(void) {
  while(!(NFSTAT & BUSY));
  NFSTAT |= BUSY;
}

#define NAND_CMD_READ0    0
#define NAND_CMD_READSTART  0x30
#define NAND_CMD_READOOB  0x50
#define NAND_CMD_READID   0x90

#define PAGESPERSBLOCK      (32)
#define BYTESPERSPAGE       (512)
#define NAND_BLOCK_SMASK    (512 - 1)
#define PAGESPERLBLOCK      (64)
#define NAND_BLOCK_LMASK    (2048 - 1)

#ifndef LARGEPAGE_FLASH
#define NAND_SECTOR_SIZE        512
#else
#define NAND_SECTOR_SIZE        2048
#endif
#define NAND_BLOCK_MASK   (NAND_SECTOR_SIZE - 1)

void PrintChar(char msg);

//static int maf_id,dev_id;
/* low level nand read function */
int nand_block_checkbad_ll(unsigned long addr);
void PrintChar(char msg);

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

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

  NAND_CHIP_ENABLE;

  baddr=start_addr;
  while(size>0) {
    if (!nand_block_checkbad_ll(baddr)) {
      for (j=0;j<size;j+=NAND_SECTOR_SIZE) {
        /* READ0 */
        NAND_CLEAR_RB;
        NFCMD = NAND_CMD_READ0;
    
        addr = baddr+j;
        /* Write Address */
#ifndef LARGEPAGE_FLASH
        NFADDR = addr & 0xff;
        NFADDR = (addr >> 9) & 0xff;
        NFADDR = (addr >> 17) & 0xff;
        NFADDR = (addr >> 25) & 0xff;
#else
        NFADDR = addr & 0xff;
        NFADDR = (addr >> 8) & 0x07;
        NFADDR = (addr >> 11) & 0xff;
        NFADDR = (addr >> 19) & 0xff;
        NFADDR = (addr >> 27) & 0x3;
  
        NFCMD = NAND_CMD_READSTART;
#endif
        NAND_DETECT_RB;
    
        for(n=0; n<NAND_SECTOR_SIZE; n++) {
          *buf = (NFDATA & 0xff);
          buf++;
        }
      }
      size -= j;
    } //else PrintChar('e');
    baddr += (BYTESPERSPAGE*PAGESPERSBLOCK);
  }
  NAND_CHIP_DISABLE;
  return 0;
}

/* low level nand read function */
int nand_block_checkbad_ll(unsigned long addr)
{
    int i;
    //char data;

    /* READOOB */
    NAND_CLEAR_RB;
#ifndef LARGEPAGE_FLASH
    NFCMD = NAND_CMD_READOOB;
#else
    NFCMD = NAND_CMD_READ0;../../include/
#endif

    /* Write Address */
#ifndef LARGEPAGE_FLASH
      addr &= ~0x3fff;
      NFADDR = 5;
      NFADDR = (addr >> 9) & 0xff;
      NFADDR = (addr >> 17) & 0xff;
      NFADDR = (addr >> 25) & 0xff;
#else
      addr &= ~0x1ffff;

      NFADDR = 0;
      NFADDR = 0x08;
      NFADDR = (addr >> 11) & 0xff;
      NFADDR = (addr >> 19) & 0xff;
      NFADDR = (addr >> 27) & 0x3;

      NFCMD = NAND_CMD_READSTART;
#endif

    NAND_DETECT_RB;
    for (i=0;i<1000;i++);

    if ((NFDATA & 0xff)!=0xff) {
      return 1;
    }
    return 0;
}

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