mtd: nand: omap: fix ecc-layout for HAM1 ecc-scheme
As per OMAP3530 TRM referenced below [1]
For large-page NAND, ROM code expects following ecc-layout for HAM1 ecc-scheme
- OOB[1] (offset of 1 *byte* from start of OOB) for x8 NAND device
- OOB[2] (offset of 1 *word* from start of OOB) for x16 NAND device
Thus ecc-layout expected by ROM code for HAM1 ecc-scheme is:
*for x8 NAND Device*
+--------+---------+---------+---------+---------+---------+---------+
| xxxx | ECC[A0] | ECC[A1] | ECC[A2] | ECC[B0] | ECC[B1] | ECC[B2] | ...
+--------+---------+---------+---------+---------+---------+---------+
*for x16 NAND Device*
+--------+--------+---------+---------+---------+---------+---------+---------+
| xxxxx | xxxxx | ECC[A0] | ECC[A1] | ECC[A2] | ECC[B0] | ECC[B1] | ECC[B2] |
+--------+--------+---------+---------+---------+---------+---------+---------+
This patch fixes ecc-layout *only* for HAM1, as required by ROM-code
For other ecc-schemes like (BCH8) ecc-layout is same for x8 or x16 devices.
[1] OMAP3530: http://www.ti.com/product/omap3530
TRM: http://www.ti.com/litv/pdf/spruf98x
Chapter-25: Initialization Sub-topic: Memory Booting
Section: 25.4.7.4 NAND
Figure 25-19. ECC Locations in NAND Spare Areas
Reported-by: Stefan Roese <sr@denx.de>
Signed-off-by: Pekon Gupta <pekon@ti.com>
Tested-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c
index 5e7e6b3..23a961c 100644
--- a/drivers/mtd/nand/omap_gpmc.c
+++ b/drivers/mtd/nand/omap_gpmc.c
@@ -798,8 +798,12 @@
nand->ecc.calculate = omap_calculate_ecc;
/* define ecc-layout */
ecclayout->eccbytes = nand->ecc.bytes * eccsteps;
- for (i = 0; i < ecclayout->eccbytes; i++)
- ecclayout->eccpos[i] = i + BADBLOCK_MARKER_LENGTH;
+ for (i = 0; i < ecclayout->eccbytes; i++) {
+ if (nand->options & NAND_BUSWIDTH_16)
+ ecclayout->eccpos[i] = i + 2;
+ else
+ ecclayout->eccpos[i] = i + 1;
+ }
ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
BADBLOCK_MARKER_LENGTH;