mtd: vf610_nfc: add 32-error correction option for HW ECC

Add option to choose between current 24-error correction and 32-error
correction through Kconfig. 32-error correction allow to use NAND
chips which require up to 8-bit error correction per 512 byte (when
using 2K pages).

Signed-off-by: Stefan Agner <stefan@agner.ch>

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 0a9e96f..3024357 100644 (file)
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -41,6 +41,21 @@ config NAND_VF610_NFC
          The driver supports a maximum 2k page size. The driver
          currently does not support hardware ECC.
 
+choice
+       prompt "Hardware ECC strength"
+       depends on NAND_VF610_NFC
+       default SYS_NAND_VF610_NFC_45_ECC_BYTES
+       help
+         Select the ECC strength used in the hardware BCH ECC block.
+
+config SYS_NAND_VF610_NFC_45_ECC_BYTES
+       bool "24-error correction (45 ECC bytes)"
+
+config SYS_NAND_VF610_NFC_60_ECC_BYTES
+       bool "32-error correction (60 ECC bytes)"
+
+endchoice
+
 comment "Generic NAND options"
 
 # Enhance depends when converting drivers to Kconfig which use this config

diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index 05cbdf3..2c02ff5 100644 (file)
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -71,6 +71,7 @@
 /* NFC ECC mode define */
 #define ECC_BYPASS                     0
 #define ECC_45_BYTE                    6
+#define ECC_60_BYTE                    7
 
 /*** Register Mask and bit definitions */
 
@@ -155,7 +156,10 @@ struct vf610_nfc {
 #define mtd_to_nfc(_mtd) \
        (struct vf610_nfc *)((struct nand_chip *)_mtd->priv)->priv
 
-static struct nand_ecclayout vf610_nfc_ecc45 = {
+#if defined(CONFIG_SYS_NAND_VF610_NFC_45_ECC_BYTES)
+#define ECC_HW_MODE ECC_45_BYTE
+
+static struct nand_ecclayout vf610_nfc_ecc = {
        .eccbytes = 45,
        .eccpos = {19, 20, 21, 22, 23,
                   24, 25, 26, 27, 28, 29, 30, 31,
@@ -167,6 +171,24 @@ static struct nand_ecclayout vf610_nfc_ecc45 = {
                {.offset = 8,
                 .length = 11} }
 };
+#elif defined(CONFIG_SYS_NAND_VF610_NFC_60_ECC_BYTES)
+#define ECC_HW_MODE ECC_60_BYTE
+
+static struct nand_ecclayout vf610_nfc_ecc = {
+       .eccbytes = 60,
+       .eccpos = { 4,  5,  6,  7,  8,  9, 10, 11,
+                  12, 13, 14, 15, 16, 17, 18, 19,
+                  20, 21, 22, 23, 24, 25, 26, 27,
+                  28, 29, 30, 31, 32, 33, 34, 35,
+                  36, 37, 38, 39, 40, 41, 42, 43,
+                  44, 45, 46, 47, 48, 49, 50, 51,
+                  52, 53, 54, 55, 56, 57, 58, 59,
+                  60, 61, 62, 63 },
+       .oobfree = {
+               {.offset = 2,
+                .length = 2} }
+};
+#endif
 
 static inline u32 vf610_nfc_read(struct mtd_info *mtd, uint reg)
 {
@@ -340,7 +362,7 @@ static void vf610_nfc_command(struct mtd_info *mtd, unsigned command,
                vf610_nfc_transfer_size(nfc->regs, page_sz);
                vf610_nfc_send_commands(nfc->regs, NAND_CMD_SEQIN,
                                        command, PROGRAM_PAGE_CMD_CODE);
-               vf610_nfc_ecc_mode(mtd, ECC_45_BYTE);
+               vf610_nfc_ecc_mode(mtd, ECC_HW_MODE);
                break;
 
        case NAND_CMD_RESET:
@@ -365,7 +387,7 @@ static void vf610_nfc_command(struct mtd_info *mtd, unsigned command,
                vf610_nfc_send_commands(nfc->regs, NAND_CMD_READ0,
                                        NAND_CMD_READSTART, READ_PAGE_CMD_CODE);
                vf610_nfc_addr_cycle(mtd, column, page);
-               vf610_nfc_ecc_mode(mtd, ECC_45_BYTE);
+               vf610_nfc_ecc_mode(mtd, ECC_HW_MODE);
                break;
 
        case NAND_CMD_ERASE1:
@@ -645,7 +667,9 @@ static int vf610_nfc_nand_init(int devnum, void __iomem *addr)
                        goto error;
                }
 
-               chip->ecc.layout = &vf610_nfc_ecc45;
+               /* Current HW ECC layouts only use 64 bytes of OOB */
+               if (mtd->oobsize > 64)
+                       mtd->oobsize = 64;
 
                /* propagate ecc.layout to mtd_info */
                mtd->ecclayout = chip->ecc.layout;
@@ -653,9 +677,15 @@ static int vf610_nfc_nand_init(int devnum, void __iomem *addr)
                chip->ecc.write_page = vf610_nfc_write_page;
                chip->ecc.mode = NAND_ECC_HW;
 
-               chip->ecc.bytes = 45;
                chip->ecc.size = PAGE_2K;
+               chip->ecc.layout = &vf610_nfc_ecc;
+#if defined(CONFIG_SYS_NAND_VF610_NFC_45_ECC_BYTES)
                chip->ecc.strength = 24;
+               chip->ecc.bytes = 45;
+#elif defined(CONFIG_SYS_NAND_VF610_NFC_60_ECC_BYTES)
+               chip->ecc.strength = 32;
+               chip->ecc.bytes = 60;
+#endif
 
                /* Enable ECC_STATUS */
                vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_ECC_SRAM_REQ_BIT);