omap: gpmc: 'nandecc sw' can use HAM1 or BCH8

The 'nandecc sw' command selects a software-based error correction
algorithm.  By default, this is OMAP_ECC_HAM1_CODE_SW but some
platforms use OMAP_ECC_BCH8_CODE_HW_DETECTION_SW as their
software-based correction algorithm.  Allow a user to be specific e.g.
 # nandecc sw <hamming|bch8>
where 'hamming' is still the default.

Note: we don't just use CONFIG_NAND_OMAP_ECCSCHEME as it might be set
      to a hardware-based ECC scheme---a little strange when the user
      has requested 'sw' ECC.

Signed-off-by: Ash Charles <ashcharles@gmail.com>
diff --git a/arch/arm/cpu/armv7/omap3/board.c b/arch/arm/cpu/armv7/omap3/board.c
index 347947c..dd53b20 100644
--- a/arch/arm/cpu/armv7/omap3/board.c
+++ b/arch/arm/cpu/armv7/omap3/board.c
@@ -347,7 +347,16 @@
 				goto usage;
 		}
 	} else if (strncmp(argv[1], "sw", 2) == 0) {
-		omap_nand_switch_ecc(0, 0);
+		if (argc == 2) {
+			omap_nand_switch_ecc(0, 1);
+		} else {
+			if (strncmp(argv[2], "hamming", 7) == 0)
+				omap_nand_switch_ecc(0, 1);
+			else if (strncmp(argv[2], "bch8", 4) == 0)
+				omap_nand_switch_ecc(0, 8);
+			else
+				goto usage;
+		}
 	} else {
 		goto usage;
 	}
diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c
index f8b0063..610f969 100644
--- a/drivers/mtd/nand/omap_gpmc.c
+++ b/drivers/mtd/nand/omap_gpmc.c
@@ -912,8 +912,18 @@
 			return -EINVAL;
 		}
 	} else {
-		err = omap_select_ecc_scheme(nand, OMAP_ECC_HAM1_CODE_SW,
+		if (eccstrength == 1) {
+			err = omap_select_ecc_scheme(nand,
+					OMAP_ECC_HAM1_CODE_SW,
 					mtd->writesize, mtd->oobsize);
+		} else if (eccstrength == 8) {
+			err = omap_select_ecc_scheme(nand,
+					OMAP_ECC_BCH8_CODE_HW_DETECTION_SW,
+					mtd->writesize, mtd->oobsize);
+		} else {
+			printf("nand: error: unsupported ECC scheme\n");
+			return -EINVAL;
+		}
 	}
 
 	/* Update NAND handling after ECC mode switch */