nand_legacy.c

嵌入式试验箱S3C2410的bootloader源代码

	NAND_ENABLE_CE(nand);  /* set pin low */
	/* Reset the chip */
	if (NanD_Command(nand, NAND_CMD_RESET)) {
#ifdef NAND_DEBUG
		printf("NanD_Command (reset) for %d,%d returned true\n",
		       floor, chip);
#endif
		NAND_DISABLE_CE(nand);  /* set pin high */
		return 0;
	}

	/* Read the NAND chip ID: 1. Send ReadID command */
	if (NanD_Command(nand, NAND_CMD_READID)) {
#ifdef NAND_DEBUG
		printf("NanD_Command (ReadID) for %d,%d returned true\n",
		       floor, chip);
#endif
		NAND_DISABLE_CE(nand);  /* set pin high */
		return 0;
	}

	/* Read the NAND chip ID: 2. Send address byte zero */
	NanD_Address(nand, ADDR_COLUMN, 0);

	/* Read the manufacturer and device id codes from the device */

	mfr = READ_NAND(nand->IO_ADDR);

	id = READ_NAND(nand->IO_ADDR);

	NAND_DISABLE_CE(nand);  /* set pin high */

#ifdef NAND_DEBUG
	printf("NanD_Command (ReadID) got %x %x\n", mfr, id);
#endif
	if (mfr == 0xff || mfr == 0) {
		/* No response - return failure */
		return 0;
	}

	/* Check it's the same as the first chip we identified.
	 * M-Systems say that any given nand_chip device should only
	 * contain _one_ type of flash part, although that's not a
	 * hardware restriction. */
	if (nand->mfr) {
		if (nand->mfr == mfr && nand->id == id) {
			return 1;	/* This is another the same the first */
		} else {
			printf("Flash chip at floor %d, chip %d is different:\n",
			       floor, chip);
		}
	}

	/* Print and store the manufacturer and ID codes. */
	for (i = 0; nand_flash_ids[i].name != NULL; i++) {
		if (mfr == nand_flash_ids[i].manufacture_id &&
		    id == nand_flash_ids[i].model_id) {
#ifdef NAND_DEBUG
			printf("Flash chip found:\n\t Manufacturer ID: 0x%2.2X, "
			       "Chip ID: 0x%2.2X (%s)\n", mfr, id,
			       nand_flash_ids[i].name);
#endif
			if (!nand->mfr) {
				nand->mfr = mfr;
				nand->id = id;
				nand->chipshift =
				    nand_flash_ids[i].chipshift;
				nand->page256 = nand_flash_ids[i].page256;
				nand->eccsize = 256;
				if (nand->page256) {
					nand->oobblock = 256;
					nand->oobsize = 8;
					nand->page_shift = 8;
				} else {
					nand->oobblock = 512;
					nand->oobsize = 16;
					nand->page_shift = 9;
				}
				nand->pageadrlen = nand_flash_ids[i].pageadrlen;
				nand->erasesize  = nand_flash_ids[i].erasesize;
				nand->chips_name = nand_flash_ids[i].name;
				nand->bus16	 = nand_flash_ids[i].bus16;
 				return 1;
			}
			return 0;
		}
	}


#ifdef NAND_DEBUG
	/* We haven't fully identified the chip. Print as much as we know. */
	printf("Unknown flash chip found: %2.2X %2.2X\n",
	       id, mfr);
#endif

	return 0;
}

/* NanD_ScanChips: Find all NAND chips present in a nand_chip, and identify them */

static void NanD_ScanChips(struct nand_chip *nand)
{
	int floor, chip;
	int numchips[NAND_MAX_FLOORS];
	int maxchips = NAND_MAX_CHIPS;
	int ret = 1;

	nand->numchips = 0;
	nand->mfr = 0;
	nand->id = 0;


	/* For each floor, find the number of valid chips it contains */
	for (floor = 0; floor < NAND_MAX_FLOORS; floor++) {
		ret = 1;
		numchips[floor] = 0;
		for (chip = 0; chip < maxchips && ret != 0; chip++) {

			ret = NanD_IdentChip(nand, floor, chip);
			if (ret) {
				numchips[floor]++;
				nand->numchips++;
			}
		}
	}

	/* If there are none at all that we recognise, bail */
	if (!nand->numchips) {
#ifdef NAND_DEBUG
		puts ("No NAND flash chips recognised.\n");
#endif
		return;
	}

	/* Allocate an array to hold the information for each chip */
	nand->chips = malloc(sizeof(struct Nand) * nand->numchips);
	if (!nand->chips) {
		puts ("No memory for allocating chip info structures\n");
		return;
	}

	ret = 0;

	/* Fill out the chip array with {floor, chipno} for each
	 * detected chip in the device. */
	for (floor = 0; floor < NAND_MAX_FLOORS; floor++) {
		for (chip = 0; chip < numchips[floor]; chip++) {
			nand->chips[ret].floor = floor;
			nand->chips[ret].chip = chip;
			nand->chips[ret].curadr = 0;
			nand->chips[ret].curmode = 0x50;
			ret++;
		}
	}

	/* Calculate and print the total size of the device */
	nand->totlen = nand->numchips * (1 << nand->chipshift);

#ifdef NAND_DEBUG
	printf("%d flash chips found. Total nand_chip size: %ld MB\n",
	       nand->numchips, nand->totlen >> 20);
#endif
}

/* we need to be fast here, 1 us per read translates to 1 second per meg */
static void NanD_ReadBuf (struct nand_chip *nand, u_char * data_buf, int cntr)
{
	unsigned long nandptr = nand->IO_ADDR;

	NanD_Command (nand, NAND_CMD_READ0);

	if (nand->bus16) {
		u16 val;

		while (cntr >= 16) {
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			cntr -= 16;
		}

		while (cntr > 0) {
			val = READ_NAND (nandptr);
			*data_buf++ = val & 0xff;
			*data_buf++ = val >> 8;
			cntr -= 2;
		}
	} else {
		while (cntr >= 16) {
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			*data_buf++ = READ_NAND (nandptr);
			cntr -= 16;
		}

		while (cntr > 0) {
			*data_buf++ = READ_NAND (nandptr);
			cntr--;
		}
	}
}

/*
 * NAND read with ECC
 */
static int nand_read_ecc(struct nand_chip *nand, size_t start, size_t len,
		 size_t * retlen, u_char *buf, u_char *ecc_code)
{
	int col, page;
	int ecc_status = 0;
#ifdef CONFIG_MTD_NAND_ECC
	int j;
	int ecc_failed = 0;
	u_char *data_poi;
	u_char ecc_calc[6];
#endif

	/* Do not allow reads past end of device */
	if ((start + len) > nand->totlen) {
		printf ("%s: Attempt read beyond end of device %x %x %x\n",
			__FUNCTION__, (uint) start, (uint) len, (uint) nand->totlen);
		*retlen = 0;
		return -1;
	}

	/* First we calculate the starting page */
	/*page = shr(start, nand->page_shift);*/
	page = start >> nand->page_shift;

	/* Get raw starting column */
	col = start & (nand->oobblock - 1);

	/* Initialize return value */
	*retlen = 0;

	/* Select the NAND device */
	NAND_ENABLE_CE(nand);  /* set pin low */

	/* Loop until all data read */
	while (*retlen < len) {

#ifdef CONFIG_MTD_NAND_ECC
		/* Do we have this page in cache ? */
		if (nand->cache_page == page)
			goto readdata;
		/* Send the read command */
		NanD_Command(nand, NAND_CMD_READ0);
		if (nand->bus16) {
 			NanD_Address(nand, ADDR_COLUMN_PAGE,
				     (page << nand->page_shift) + (col >> 1));
		} else {
 			NanD_Address(nand, ADDR_COLUMN_PAGE,
				     (page << nand->page_shift) + col);
		}

		/* Read in a page + oob data */
		NanD_ReadBuf(nand, nand->data_buf, nand->oobblock + nand->oobsize);

		/* copy data into cache, for read out of cache and if ecc fails */
		if (nand->data_cache) {
			memcpy (nand->data_cache, nand->data_buf,
				nand->oobblock + nand->oobsize);
		}

		/* Pick the ECC bytes out of the oob data */
		for (j = 0; j < 6; j++) {
			ecc_code[j] = nand->data_buf[(nand->oobblock + oob_config.ecc_pos[j])];
		}

		/* Calculate the ECC and verify it */
		/* If block was not written with ECC, skip ECC */
		if (oob_config.eccvalid_pos != -1 &&
		    (nand->data_buf[nand->oobblock + oob_config.eccvalid_pos] & 0x0f) != 0x0f) {

			nand_calculate_ecc (&nand->data_buf[0], &ecc_calc[0]);
			switch (nand_correct_data (&nand->data_buf[0], &ecc_code[0], &ecc_calc[0])) {
			case -1:
				printf ("%s: Failed ECC read, page 0x%08x\n", __FUNCTION__, page);
				ecc_failed++;
				break;
			case 1:
			case 2:	/* transfer ECC corrected data to cache */
				if (nand->data_cache)
					memcpy (nand->data_cache, nand->data_buf, 256);
				break;
			}
		}

		if (oob_config.eccvalid_pos != -1 &&
		    nand->oobblock == 512 && (nand->data_buf[nand->oobblock + oob_config.eccvalid_pos] & 0xf0) != 0xf0) {

			nand_calculate_ecc (&nand->data_buf[256], &ecc_calc[3]);
			switch (nand_correct_data (&nand->data_buf[256], &ecc_code[3], &ecc_calc[3])) {
			case -1:
				printf ("%s: Failed ECC read, page 0x%08x\n", __FUNCTION__, page);
				ecc_failed++;
				break;
			case 1:
			case 2:	/* transfer ECC corrected data to cache */
				if (nand->data_cache)
					memcpy (&nand->data_cache[256], &nand->data_buf[256], 256);
				break;
			}
		}
readdata:
		/* Read the data from ECC data buffer into return buffer */
		data_poi = (nand->data_cache) ? nand->data_cache : nand->data_buf;
		data_poi += col;
		if ((*retlen + (nand->oobblock - col)) >= len) {
			memcpy (buf + *retlen, data_poi, len - *retlen);
			*retlen = len;
		} else {
			memcpy (buf + *retlen, data_poi,  nand->oobblock - col);
			*retlen += nand->oobblock - col;
		}
		/* Set cache page address, invalidate, if ecc_failed */
		nand->cache_page = (nand->data_cache && !ecc_failed) ? page : -1;

		ecc_status += ecc_failed;
		ecc_failed = 0;

#else
		/* Send the read command */
		NanD_Command(nand, NAND_CMD_READ0);
		if (nand->bus16) {
			NanD_Address(nand, ADDR_COLUMN_PAGE,
				     (page << nand->page_shift) + (col >> 1));
		} else {
			NanD_Address(nand, ADDR_COLUMN_PAGE,
				     (page << nand->page_shift) + col);
		}

		/* Read the data directly into the return buffer */
		if ((*retlen + (nand->oobblock - col)) >= len) {
			NanD_ReadBuf(nand, buf + *retlen, len - *retlen);
			*retlen = len;
			/* We're done */
			continue;
		} else {
			NanD_ReadBuf(nand, buf + *retlen, nand->oobblock - col);
			*retlen += nand->oobblock - col;
			}
#endif
		/* For subsequent reads align to page boundary. */
		col = 0;
		/* Increment page address */
		page++;
	}

	/* De-select the NAND device */
	NAND_DISABLE_CE(nand);  /* set pin high */

	/*
	 * Return success, if no ECC failures, else -EIO
	 * fs driver will take care of that, because
	 * retlen == desired len and result == -EIO
	 */
	return ecc_status ? -1 : 0;
}

/*
 *	Nand_page_program function is used for write and writev !
 *  Change By www.arm9.net, if ecc_code is null, write without ECC
 */
static int nand_write_page (struct nand_chip *nand,
			    int page, int col, int last, u_char * ecc_code)
{

	int i;
	unsigned long nandptr = nand->IO_ADDR;
    int writecnt;

#ifdef CONFIG_MTD_NAND_ECC
#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
	int ecc_bytes = (nand->oobblock == 512) ? 6 : 3;
#endif
#endif
	/* pad oob area */
	for (i = nand->oobblock; i < nand->oobblock + nand->oobsize; i++)
		nand->data_buf[i] = 0xff;

#ifdef CONFIG_MTD_NAND_ECC
	/* Zero out the ECC array */
    if (ecc_code)   /* www.arm9.net */
    	for (i = 0; i < 6; i++)
    		ecc_code[i] = 0x00;

	/* Read back previous written data, if col > 0 */
	if (col) {
		NanD_Command (nand, NAND_CMD_READ0);
		if (nand->bus16) {
			NanD_Address (nand, ADDR_COLUMN_PAGE,
				      (page << nand->page_shift) + (col >> 1));