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;
diff --git a/include/linux/mtd/nand_ecc.h b/include/linux/mtd/nand_ecc.h
index 090da50..9715a53 100644
--- a/include/linux/mtd/nand_ecc.h
+++ b/include/linux/mtd/nand_ecc.h
@@ -15,6 +15,10 @@
struct mtd_info;
+#if defined(CONFIG_MTD_ECC_SOFT)
+
+static inline int mtd_nand_has_ecc_soft(void) { return 1; }
+
/*
* Calculate 3 byte ECC code for 256 byte block
*/
@@ -25,4 +29,25 @@
*/
int nand_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc, u_char *calc_ecc);
+#else
+
+static inline int mtd_nand_has_ecc_soft(void) { return 0; }
+
+static inline int
+nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code)
+{
+ return -1;
+}
+
+static inline int
+nand_correct_data(struct mtd_info *mtd,
+ u_char *dat,
+ u_char *read_ecc,
+ u_char *calc_ecc)
+{
+ return -1;
+}
+
+#endif
+
#endif /* __MTD_NAND_ECC_H__ */