Commit 6a623e07 authored by Alexander Couzens's avatar Alexander Couzens Committed by Brian Norris
Browse files

mtd: nand: add ooblayout for old hamming layout 



The old 1-bit hamming layout requires ECC data to be placed at a
fixed offset, and not necessarily at the end of the OOB area.
Add this old layout back in order to fix legacy setups.

Fixes: 41b207a7 ("mtd: nand: implement the default mtd_ooblayout_ops")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAlexander Couzens <lynxis@fe80.eu>
Acked-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent b98e1995

drivers/mtd/nand/nand_base.c

+69 −1
Original line number Diff line number Diff line
@@ -139,6 +139,74 @@ const struct mtd_ooblayout_ops nand_ooblayout_lp_ops = { 
};

EXPORT_SYMBOL_GPL(nand_ooblayout_lp_ops);



/*

 * Support the old "large page" layout used for 1-bit Hamming ECC where ECC

 * are placed at a fixed offset.

 */

static int nand_ooblayout_ecc_lp_hamming(struct mtd_info *mtd, int section,

					 struct mtd_oob_region *oobregion)

{

	struct nand_chip *chip = mtd_to_nand(mtd);

	struct nand_ecc_ctrl *ecc = &chip->ecc;



	if (section)

		return -ERANGE;



	switch (mtd->oobsize) {

	case 64:

		oobregion->offset = 40;

		break;

	case 128:

		oobregion->offset = 80;

		break;

	default:

		return -EINVAL;

	}



	oobregion->length = ecc->total;

	if (oobregion->offset + oobregion->length > mtd->oobsize)

		return -ERANGE;



	return 0;

}



static int nand_ooblayout_free_lp_hamming(struct mtd_info *mtd, int section,

					  struct mtd_oob_region *oobregion)

{

	struct nand_chip *chip = mtd_to_nand(mtd);

	struct nand_ecc_ctrl *ecc = &chip->ecc;

	int ecc_offset = 0;



	if (section < 0 || section > 1)

		return -ERANGE;



	switch (mtd->oobsize) {

	case 64:

		ecc_offset = 40;

		break;

	case 128:

		ecc_offset = 80;

		break;

	default:

		return -EINVAL;

	}



	if (section == 0) {

		oobregion->offset = 2;

		oobregion->length = ecc_offset - 2;

	} else {

		oobregion->offset = ecc_offset + ecc->total;

		oobregion->length = mtd->oobsize - oobregion->offset;

	}



	return 0;

}



const struct mtd_ooblayout_ops nand_ooblayout_lp_hamming_ops = {

	.ecc = nand_ooblayout_ecc_lp_hamming,

	.free = nand_ooblayout_free_lp_hamming,

};



static int check_offs_len(struct mtd_info *mtd,

					loff_t ofs, uint64_t len)

{
@@ -4559,7 +4627,7 @@ int nand_scan_tail(struct mtd_info *mtd) 
			break;

		case 64:

		case 128:

			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);

			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_hamming_ops);

			break;

		default:

			WARN(1, "No oob scheme defined for oobsize %d\n",

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