nand_read.c

来自「针对基于LINUX的S3C2410下的BOOTLOADER,u-boot1.1.」· C语言 代码 · 共 61 行

#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;
}