From 8429bb3975ef81c114cde4da111e64d224d19f83 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Tue, 3 Dec 2013 15:51:09 -0800 Subject: mtd: nand: support Micron READ RETRY Micron provides READ RETRY support via the ONFI vendor-specific parameter block (to indicate how many read-retry modes are available) and the ONFI {GET,SET}_FEATURES commands with a vendor-specific feature address (to support reading/switching the current read-retry mode). The recommended sequence is as follows: 1. Perform PAGE_READ operation 2. If no ECC error, we are done 3. Run SET_FEATURES with feature address 89h, mode 1 4. Retry PAGE_READ operation 5. If ECC error and there are remaining supported modes, increment the mode and return to step 3. Otherwise, this is a true ECC error. 6. Run SET_FEATURES with feature address 89h, mode 0, to return to the default state. This patch implements the chip->setup_read_retry() callback for Micron and fills in the chip->read_retries. Tested on Micron MT29F32G08CBADA, which supports 8 read-retry modes. The Micron vendor-specific table was checked against the datasheets for the following Micron NAND: Needs retry Cell-type Part number Vendor revision Byte 180 ----------- --------- ---------------- --------------- ------------ No SLC MT29F16G08ABABA 1 Reserved (0) No MLC MT29F32G08CBABA 1 Reserved (0) No SLC MT29F1G08AACWP 1 0 Yes MLC MT29F32G08CBADA 1 08h Yes MLC MT29F64G08CBABA 2 08h Signed-off-by: Brian Norris Acked-by: Huang Shijie --- include/linux/mtd/nand.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/mtd') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 267d61dd89dd..3080a8c8b62e 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -219,6 +219,9 @@ struct nand_chip; /* ONFI feature address */ #define ONFI_FEATURE_ADDR_TIMING_MODE 0x1 +/* Vendor-specific feature address (Micron) */ +#define ONFI_FEATURE_ADDR_READ_RETRY 0x89 + /* ONFI subfeature parameters length */ #define ONFI_SUBFEATURE_PARAM_LEN 4 -- cgit v1.2.3