nand: make 1-bit software ECC configurable

The software ECC algorithm is not necessary when hardware ECC
is available and can be left out for a smaller image size.
Enable with CONFIG_MTD_ECC_SOFT.

Signed-off-by: Christian Hitz <christian.hitz@aizo.com>
Cc: Scott Wood <scottwood@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 1d1b628..998fc73 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -39,7 +39,7 @@
 COBJS-y += nand_ids.o
 COBJS-y += nand_util.o
 endif
-COBJS-y += nand_ecc.o
+COBJS-$(CONFIG_MTD_ECC_SOFT) += nand_ecc.o
 COBJS-y += nand_base.o
 COBJS-$(CONFIG_NAND_ECC_BCH) += nand_bch.o
 
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 8ab8303..12b960f 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3028,6 +3028,10 @@
 		chip->ecc.mode = NAND_ECC_SOFT;
 
 	case NAND_ECC_SOFT:
+		if (!mtd_nand_has_ecc_soft()) {
+			printk(KERN_WARNING "CONFIG_MTD_ECC_SOFT not enabled\n");
+			return -EINVAL;
+		}
 		chip->ecc.calculate = nand_calculate_ecc;
 		chip->ecc.correct = nand_correct_data;
 		chip->ecc.read_page = nand_read_page_swecc;