[PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
KOBAYASHI Yoshitake
yoshitake.kobayashi at toshiba.co.jp
Thu Jun 11 09:00:02 PDT 2015
This patch enables support for Toshiba BENAND.
BENAND is a SLC NAND solution that automatically generates ECC inside
NAND chip.
Some of the comments in the following discussion may need to be considerd.
https://lkml.org/lkml/2015/3/25/310
Signed-off-by: KOBAYASHI Yoshitake <yoshitake.kobayashi at toshiba.co.jp>
---
drivers/mtd/nand/Kconfig | 13 ++++
drivers/mtd/nand/Makefile | 1 +
drivers/mtd/nand/nand_base.c | 32 +++++++++-
drivers/mtd/nand/nand_benand.c | 137 +++++++++++++++++++++++++++++++++++++++
include/linux/mtd/nand.h | 3 +
include/linux/mtd/nand_benand.h | 55 ++++++++++++++++
6 files changed, 239 insertions(+), 2 deletions(-)
create mode 100644 drivers/mtd/nand/nand_benand.c
create mode 100644 include/linux/mtd/nand_benand.h
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 5897d8d..050f0e9 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -22,6 +22,19 @@ menuconfig MTD_NAND
if MTD_NAND
+config MTD_NAND_BENAND
+ tristate
+ depends on MTD_NAND_BENAND_ENABLE
+ default MTD_NAND
+
+config MTD_NAND_BENAND_ENABLE
+ bool "Support for Toshiba BENAND (Built-in ECC NAND)"
+ default y
+ help
+ This enables support for Toshiba BENAND.
+ Toshiba BENAND is a SLC NAND solution that automatically
+ generates ECC inside NAND chip.
+
config MTD_NAND_BCH
tristate
select BCH
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 582bbd05..7f58bc1 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -3,6 +3,7 @@
#
obj-$(CONFIG_MTD_NAND) += nand.o
+obj-$(CONFIG_MTD_NAND_BENAND) += nand_benand.o
obj-$(CONFIG_MTD_NAND_ECC) += nand_ecc.o
obj-$(CONFIG_MTD_NAND_BCH) += nand_bch.o
obj-$(CONFIG_MTD_NAND_IDS) += nand_ids.o
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index c2e1232..98a8932 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -43,6 +43,7 @@
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/nand_bch.h>
+#include <linux/mtd/nand_benand.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/leds.h>
@@ -3526,8 +3527,17 @@ static void nand_decode_ext_id(struct mtd_info *mtd, struct nand_chip *chip,
if (id_len >= 6 && id_data[0] == NAND_MFR_TOSHIBA &&
nand_is_slc(chip) &&
(id_data[5] & 0x7) == 0x6 /* 24nm */ &&
- !(id_data[4] & 0x80) /* !BENAND */) {
- mtd->oobsize = 32 * mtd->writesize >> 9;
+ (id_data[4] & 0x80) /* BENAND */) {
+ pr_info("24nm BENAND\n");
+
+ if (IS_ENABLED(CONFIG_MTD_NAND_BENAND)) {
+ chip->ecc.mode = NAND_ECC_BENAND;
+ pr_info("Selected BENAND Driver\n");
+ }
+
+ } else {
+ pr_info("24nm SLC NAND\n");
+ mtd->oobsize = 32 * mtd->writesize >> 9; /* !BENAND */
}
}
@@ -4075,6 +4085,24 @@ int nand_scan_tail(struct mtd_info *mtd)
}
break;
+ case NAND_ECC_BENAND:
+ if (!mtd_nand_has_benand()) {
+ pr_warn("CONFIG_MTD_NAND_BENAND not enabled\n");
+ BUG();
+ }
+ ecc->calculate = NULL;
+ ecc->correct = NULL;
+ ecc->read_page = nand_read_page_benand;
+ ecc->read_subpage = nand_read_subpage_benand;
+ ecc->write_page = nand_write_page_raw;
+ ecc->read_page_raw = nand_read_page_raw;
+ ecc->write_page_raw = nand_write_page_raw;
+ ecc->read_oob = nand_read_oob_std;
+ ecc->write_oob = nand_write_oob_std;
+
+ nand_benand_init(mtd);
+ break;
+
case NAND_ECC_NONE:
pr_warn("NAND_ECC_NONE selected by board driver. This is not recommended!\n");
ecc->read_page = nand_read_page_raw;
diff --git a/drivers/mtd/nand/nand_benand.c b/drivers/mtd/nand/nand_benand.c
new file mode 100644
index 0000000..56385b0
--- /dev/null
+++ b/drivers/mtd/nand/nand_benand.c
@@ -0,0 +1,137 @@
+/*
+ * drivers/mtd/nand_benand.c
+ *
+ * (C) Copyright Toshiba Corporation
+ * Semiconductor and Storage Products Company 2015
+ *
+ * This program supports BENAND.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_benand.h>
+
+static struct nand_ecclayout benand_oob_64 = {
+ .eccbytes = 0,
+ .eccpos = {},
+ .oobfree = {
+ {.offset = 2, .length = 62}
+ }
+};
+
+static struct nand_ecclayout benand_oob_128 = {
+ .eccbytes = 0,
+ .eccpos = {},
+ .oobfree = {
+ {.offset = 2, .length = 126}
+ }
+};
+
+void nand_benand_init(struct mtd_info *mtd)
+{
+ struct nand_chip *chip = mtd->priv;
+
+ pr_info("%s\n", __func__);
+
+ chip->ecc.size = mtd->writesize;
+ chip->ecc.strength = 1;
+ chip->options |= NAND_SUBPAGE_READ;
+
+ switch (mtd->oobsize) {
+ case 64:
+ chip->ecc.layout = &benand_oob_64;
+ break;
+ case 128:
+ chip->ecc.layout = &benand_oob_128;
+ break;
+ default:
+ pr_warn("No oob scheme defined for oobsize %d\n",
+ mtd->oobsize);
+ BUG();
+ }
+
+}
+EXPORT_SYMBOL(nand_benand_init);
+
+int nand_read_page_benand(struct mtd_info *mtd, struct nand_chip *chip,
+ uint8_t *buf, int oob_required, int page)
+{
+ unsigned int max_bitflips = 0;
+
+ pr_debug("%s\n", __func__);
+
+ chip->ecc.read_page_raw(mtd, chip, buf, oob_required, page);
+ max_bitflips = nand_benand_status_chk(mtd, chip);
+
+ return max_bitflips;
+}
+EXPORT_SYMBOL(nand_read_page_benand);
+
+
+int nand_read_subpage_benand(struct mtd_info *mtd, struct nand_chip *chip,
+ uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
+ int page)
+{
+ uint8_t *p;
+ unsigned int max_bitflips = 0;
+
+ pr_debug("%s\n", __func__);
+
+ if (data_offs != 0)
+ chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_offs, -1);
+
+
+ p = bufpoi + data_offs;
+ chip->read_buf(mtd, p, readlen);
+
+ max_bitflips = nand_benand_status_chk(mtd, chip);
+
+ return max_bitflips;
+}
+EXPORT_SYMBOL(nand_read_subpage_benand);
+
+
+int nand_benand_status_chk(struct mtd_info *mtd, struct nand_chip *chip)
+{
+ unsigned int bitflips = 0;
+ u8 status;
+
+ pr_debug("%s\n", __func__);
+
+ /* Check Read Status */
+ chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+ status = chip->read_byte(mtd);
+
+ /* timeout */
+ if (!(status & NAND_STATUS_READY)) {
+ pr_info("BENAND : Time Out!\n");
+ return -EIO;
+ }
+
+ /* uncorrectable */
+ else if (status & NAND_STATUS_FAIL) {
+ pr_info("BENAND : Uncorrectable!\n");
+ mtd->ecc_stats.failed++;
+ }
+
+ /* correctable */
+ else if (status & NAND_STATUS_RECOM_REWRT) {
+ pr_info("BENAND : Recommended to rewrite!\n");
+ bitflips = chip->ecc.strength;
+ mtd->ecc_stats.corrected += chip->ecc.strength;
+ }
+
+ return bitflips;
+
+}
+EXPORT_SYMBOL(nand_benand_status_chk);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Toshiba Corporation Semiconductor and Storage Products Company");
+MODULE_DESCRIPTION("BENAND (Built-in ECC NAND) support");
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 3d4ea7e..8f59ad9 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -101,6 +101,8 @@ extern int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
/* Status bits */
#define NAND_STATUS_FAIL 0x01
#define NAND_STATUS_FAIL_N1 0x02
+/* Recommended to rewrite for BENAND */
+#define NAND_STATUS_RECOM_REWRT 0x08
#define NAND_STATUS_TRUE_READY 0x20
#define NAND_STATUS_READY 0x40
#define NAND_STATUS_WP 0x80
@@ -115,6 +117,7 @@ typedef enum {
NAND_ECC_HW_SYNDROME,
NAND_ECC_HW_OOB_FIRST,
NAND_ECC_SOFT_BCH,
+ NAND_ECC_BENAND,
} nand_ecc_modes_t;
/*
diff --git a/include/linux/mtd/nand_benand.h b/include/linux/mtd/nand_benand.h
new file mode 100644
index 0000000..48fcc49
--- /dev/null
+++ b/include/linux/mtd/nand_benand.h
@@ -0,0 +1,55 @@
+/*
+ * linux/include/linux/mtd/nand_benand.h
+ *
+ * (C) Copyright Toshiba Corporation
+ * Semiconductor and Storage Products Company 2015
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __MTD_NAND_BENAND_H__
+#define __MTD_NAND_BENAND_H__
+
+#if defined(CONFIG_MTD_NAND_BENAND_ENABLE)
+
+static inline int mtd_nand_has_benand(void) { return 1; }
+
+void nand_benand_init(struct mtd_info *mtd);
+
+int nand_read_page_benand(struct mtd_info *mtd, struct nand_chip *chip,
+ uint8_t *buf, int oob_required, int page);
+
+int nand_read_subpage_benand(struct mtd_info *mtd, struct nand_chip *chip,
+ uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
+ int page);
+
+int nand_benand_status_chk(struct mtd_info *mtd, struct nand_chip *chipr);
+
+#else /* CONFIG_MTD_NAND_BENAND_ENABLE */
+static inline int mtd_nand_has_benand(void) { return 0; }
+
+void nand_benand_init(struct mtd_info *mtd) {}
+
+int nand_read_page_benand(struct mtd_info *mtd, struct nand_chip *chip,
+ uint8_t *buf, int oob_required, int page)
+{
+ return -1;
+}
+
+int nand_read_subpage_benand(struct mtd_info *mtd, struct nand_chip *chip,
+ uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
+ int page)
+{
+ return -1;
+}
+
+int nand_benand_status_chk(struct mtd_info *mtd, struct nand_chip *chipr)
+{
+ return -1;
+}
+
+#endif /* CONFIG_MTD_NAND_BENAND_ENABLE */
+#endif
--
1.7.2.5
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