From 785818fa8385fe55dab253e42a4c6728fca61333 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Sat, 29 Apr 2017 11:06:43 +0200 Subject: mtd: nand: add core support for on-die ECC A number of NAND flashes have a capability called "on-die ECC" where the NAND chip itself is capable of detecting and correcting errors. Linux already has support for using the ECC implementation of the NAND controller, or a software based ECC implementation, but not for using the ECC implementation of the NAND controller. However, such an implementation is sometimes useful in situations where the NAND controller provides ECC algorithms that are not strong enough for the NAND chip used on the system. A typical case is a NAND chip that requires a 4-bit ECC, while the NAND controller only provides a 1-bit ECC algorithm. This commit introduces the support for the NAND_ECC_ON_DIE ECC mode: - Parsing of the "on-die" value for the "nand-ecc-mode" Device Tree property - Handling NAND_ECC_ON_DIE case in nand_scan_tail(). The idea is that the vendor specific code for the NAND chip must implement ->read_page() and ->write_page(). It may optionally provide its own ->read_page_raw() and ->write_page_raw() as well. For OOB operation, we assume the standard operations are good enough, but they can be overridden by the vendor specific code if needed. Signed-off-by: Thomas Petazzoni Reviewed-by: Richard Weinberger Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/mtd/nand.h') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 8f67b1581683..603522097ec9 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -116,6 +116,7 @@ typedef enum { NAND_ECC_HW, NAND_ECC_HW_SYNDROME, NAND_ECC_HW_OOB_FIRST, + NAND_ECC_ON_DIE, } nand_ecc_modes_t; enum nand_ecc_algo { -- cgit