* [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
@ 2015-06-11 16:00 KOBAYASHI Yoshitake
2015-06-12 8:11 ` Paul Bolle
` (2 more replies)
0 siblings, 3 replies; 14+ messages in thread
From: KOBAYASHI Yoshitake @ 2015-06-11 16:00 UTC (permalink / raw)
To: dwmw2, computersforpeace, linux-mtd; +Cc: linux-kernel, KOBAYASHI Yoshitake
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@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
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
2015-06-11 16:00 [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND) KOBAYASHI Yoshitake
@ 2015-06-12 8:11 ` Paul Bolle
2015-06-12 9:49 ` Richard Weinberger
2015-07-24 17:42 ` [PATCH REPOST v3] mtd: nand " KOBAYASHI Yoshitake
2 siblings, 0 replies; 14+ messages in thread
From: Paul Bolle @ 2015-06-12 8:11 UTC (permalink / raw)
To: KOBAYASHI Yoshitake; +Cc: dwmw2, computersforpeace, linux-mtd, linux-kernel
On Fri, 2015-06-12 at 01:00 +0900, KOBAYASHI Yoshitake wrote:
> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
> index 5897d8d..050f0e9 100644
> +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
Why do you default to 'y'?
> + help
> + This enables support for Toshiba BENAND.
> + Toshiba BENAND is a SLC NAND solution that automatically
> + generates ECC inside NAND chip.
> +
> --- /dev/null
> +++ b/drivers/mtd/nand/nand_benand.c
> +EXPORT_SYMBOL(nand_benand_status_chk);
I didn't spot any users of nand_benand_status_chk() outside of this
file. Why is this export needed?
Thanks,
Paul Bolle
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
@ 2015-06-12 8:11 ` Paul Bolle
0 siblings, 0 replies; 14+ messages in thread
From: Paul Bolle @ 2015-06-12 8:11 UTC (permalink / raw)
To: KOBAYASHI Yoshitake; +Cc: linux-mtd, computersforpeace, dwmw2, linux-kernel
On Fri, 2015-06-12 at 01:00 +0900, KOBAYASHI Yoshitake wrote:
> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
> index 5897d8d..050f0e9 100644
> +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
Why do you default to 'y'?
> + help
> + This enables support for Toshiba BENAND.
> + Toshiba BENAND is a SLC NAND solution that automatically
> + generates ECC inside NAND chip.
> +
> --- /dev/null
> +++ b/drivers/mtd/nand/nand_benand.c
> +EXPORT_SYMBOL(nand_benand_status_chk);
I didn't spot any users of nand_benand_status_chk() outside of this
file. Why is this export needed?
Thanks,
Paul Bolle
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
2015-06-11 16:00 [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND) KOBAYASHI Yoshitake
@ 2015-06-12 9:49 ` Richard Weinberger
2015-06-12 9:49 ` Richard Weinberger
2015-07-24 17:42 ` [PATCH REPOST v3] mtd: nand " KOBAYASHI Yoshitake
2 siblings, 0 replies; 14+ messages in thread
From: Richard Weinberger @ 2015-06-12 9:49 UTC (permalink / raw)
To: KOBAYASHI Yoshitake
Cc: David Woodhouse, Brian Norris, linux-mtd@lists.infradead.org,
LKML
On Thu, Jun 11, 2015 at 6:00 PM, KOBAYASHI Yoshitake
<yoshitake.kobayashi@toshiba.co.jp> wrote:
> 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
Yep.
> +void nand_benand_init(struct mtd_info *mtd)
> +{
> + struct nand_chip *chip = mtd->priv;
> +
> + pr_info("%s\n", __func__);
Please kill all these prints. Use ftrace to trace function calls.
> + chip->ecc.size = mtd->writesize;
> + chip->ecc.strength = 1;
BENAND can correct only one bit?
This would explain why you consider it as fast. ;-)
> +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;
In your case this might be okay, as you set strength to 1.
Otherweise you'd have to report the real number of bitflips.
--
Thanks,
//richard
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
@ 2015-06-12 9:49 ` Richard Weinberger
0 siblings, 0 replies; 14+ messages in thread
From: Richard Weinberger @ 2015-06-12 9:49 UTC (permalink / raw)
To: KOBAYASHI Yoshitake
Cc: linux-mtd@lists.infradead.org, Brian Norris, David Woodhouse,
LKML
On Thu, Jun 11, 2015 at 6:00 PM, KOBAYASHI Yoshitake
<yoshitake.kobayashi@toshiba.co.jp> wrote:
> 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
Yep.
> +void nand_benand_init(struct mtd_info *mtd)
> +{
> + struct nand_chip *chip = mtd->priv;
> +
> + pr_info("%s\n", __func__);
Please kill all these prints. Use ftrace to trace function calls.
> + chip->ecc.size = mtd->writesize;
> + chip->ecc.strength = 1;
BENAND can correct only one bit?
This would explain why you consider it as fast. ;-)
> +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;
In your case this might be okay, as you set strength to 1.
Otherweise you'd have to report the real number of bitflips.
--
Thanks,
//richard
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
2015-06-12 9:49 ` Richard Weinberger
@ 2015-06-16 13:33 ` KOBAYASHI Yoshitake
-1 siblings, 0 replies; 14+ messages in thread
From: KOBAYASHI Yoshitake @ 2015-06-16 13:33 UTC (permalink / raw)
To: Richard Weinberger
Cc: David Woodhouse, Brian Norris, linux-mtd@lists.infradead.org,
LKML
On 2015/06/12 18:49, Richard Weinberger wrote:
> On Thu, Jun 11, 2015 at 6:00 PM, KOBAYASHI Yoshitake
> <yoshitake.kobayashi@toshiba.co.jp> wrote:
>> 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
>
> Yep.
>
>> +void nand_benand_init(struct mtd_info *mtd)
>> +{
>> + struct nand_chip *chip = mtd->priv;
>> +
>> + pr_info("%s\n", __func__);
>
> Please kill all these prints. Use ftrace to trace function calls.
Okay, I will delete these prints in next patch.
>> + chip->ecc.size = mtd->writesize;
>> + chip->ecc.strength = 1;
>
> BENAND can correct only one bit?
> This would explain why you consider it as fast. ;-)
BENAND is able to correct up to 8bit. By issuing Status command 70h for read operation, BENAND
can report three types of ECC operation status (Pass / Fail(uncorrectable) / Recommended to rewrite).
Judgement for Recommended to rewrite is based on internal logic of 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;
>
> In your case this might be okay, as you set strength to 1.
> Otherweise you'd have to report the real number of bitflips.
I also thought it is okay in this case.
BENAND return corrected data to Host NAND Controller till uncorrectable status.
The current patch uses this Read Status command 70h to abstract BENAND Multi
bit ECC and Need to Rewrite judgement so BENAND would look like 1bit ECC device.
-- Yoshi
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
@ 2015-06-16 13:33 ` KOBAYASHI Yoshitake
0 siblings, 0 replies; 14+ messages in thread
From: KOBAYASHI Yoshitake @ 2015-06-16 13:33 UTC (permalink / raw)
To: Richard Weinberger
Cc: linux-mtd@lists.infradead.org, Brian Norris, David Woodhouse,
LKML
On 2015/06/12 18:49, Richard Weinberger wrote:
> On Thu, Jun 11, 2015 at 6:00 PM, KOBAYASHI Yoshitake
> <yoshitake.kobayashi@toshiba.co.jp> wrote:
>> 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
>
> Yep.
>
>> +void nand_benand_init(struct mtd_info *mtd)
>> +{
>> + struct nand_chip *chip = mtd->priv;
>> +
>> + pr_info("%s\n", __func__);
>
> Please kill all these prints. Use ftrace to trace function calls.
Okay, I will delete these prints in next patch.
>> + chip->ecc.size = mtd->writesize;
>> + chip->ecc.strength = 1;
>
> BENAND can correct only one bit?
> This would explain why you consider it as fast. ;-)
BENAND is able to correct up to 8bit. By issuing Status command 70h for read operation, BENAND
can report three types of ECC operation status (Pass / Fail(uncorrectable) / Recommended to rewrite).
Judgement for Recommended to rewrite is based on internal logic of 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;
>
> In your case this might be okay, as you set strength to 1.
> Otherweise you'd have to report the real number of bitflips.
I also thought it is okay in this case.
BENAND return corrected data to Host NAND Controller till uncorrectable status.
The current patch uses this Read Status command 70h to abstract BENAND Multi
bit ECC and Need to Rewrite judgement so BENAND would look like 1bit ECC device.
-- Yoshi
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
2015-06-12 8:11 ` Paul Bolle
@ 2015-06-16 13:37 ` KOBAYASHI Yoshitake
-1 siblings, 0 replies; 14+ messages in thread
From: KOBAYASHI Yoshitake @ 2015-06-16 13:37 UTC (permalink / raw)
To: Paul Bolle; +Cc: dwmw2, computersforpeace, linux-mtd, linux-kernel
On 2015/06/12 17:11, Paul Bolle wrote:
> On Fri, 2015-06-12 at 01:00 +0900, KOBAYASHI Yoshitake wrote:
>> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
>> index 5897d8d..050f0e9 100644
>
>> +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
>
> Why do you default to 'y'?
Setting the config to 'y' will not affect the SLCNAND operation.
I thought it is common to use BENAND and other vendor SLCNAND together
in the same model with same software build.
>> --- /dev/null
>> +++ b/drivers/mtd/nand/nand_benand.c
>
>> +EXPORT_SYMBOL(nand_benand_status_chk);
>
> I didn't spot any users of nand_benand_status_chk() outside of this
> file. Why is this export needed?
I agree with you. Thanks for checking.
I will delete this in next patch.
-- Yoshi
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
@ 2015-06-16 13:37 ` KOBAYASHI Yoshitake
0 siblings, 0 replies; 14+ messages in thread
From: KOBAYASHI Yoshitake @ 2015-06-16 13:37 UTC (permalink / raw)
To: Paul Bolle; +Cc: linux-mtd, computersforpeace, dwmw2, linux-kernel
On 2015/06/12 17:11, Paul Bolle wrote:
> On Fri, 2015-06-12 at 01:00 +0900, KOBAYASHI Yoshitake wrote:
>> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
>> index 5897d8d..050f0e9 100644
>
>> +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
>
> Why do you default to 'y'?
Setting the config to 'y' will not affect the SLCNAND operation.
I thought it is common to use BENAND and other vendor SLCNAND together
in the same model with same software build.
>> --- /dev/null
>> +++ b/drivers/mtd/nand/nand_benand.c
>
>> +EXPORT_SYMBOL(nand_benand_status_chk);
>
> I didn't spot any users of nand_benand_status_chk() outside of this
> file. Why is this export needed?
I agree with you. Thanks for checking.
I will delete this in next patch.
-- Yoshi
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
2015-06-16 13:33 ` KOBAYASHI Yoshitake
@ 2015-06-16 13:53 ` Richard Weinberger
-1 siblings, 0 replies; 14+ messages in thread
From: Richard Weinberger @ 2015-06-16 13:53 UTC (permalink / raw)
To: KOBAYASHI Yoshitake
Cc: David Woodhouse, Brian Norris, linux-mtd@lists.infradead.org,
LKML
Am 16.06.2015 um 15:33 schrieb KOBAYASHI Yoshitake:
>>> + /* correctable */
>>> + else if (status & NAND_STATUS_RECOM_REWRT) {
>>> + pr_info("BENAND : Recommended to rewrite!\n");
>>> + bitflips = chip->ecc.strength;
>>
>> In your case this might be okay, as you set strength to 1.
>> Otherweise you'd have to report the real number of bitflips.
>
> I also thought it is okay in this case.
> BENAND return corrected data to Host NAND Controller till uncorrectable status.
> The current patch uses this Read Status command 70h to abstract BENAND Multi
> bit ECC and Need to Rewrite judgement so BENAND would look like 1bit ECC device.
The layers above MTD need to know how many bits got repaired.
It seems like BENAND suffers from the same shortcomings than On-Die-ECC. ;-\
Please see my patches how to deal with that. Maybe you can find a better solution.
Thanks,
//richard
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
@ 2015-06-16 13:53 ` Richard Weinberger
0 siblings, 0 replies; 14+ messages in thread
From: Richard Weinberger @ 2015-06-16 13:53 UTC (permalink / raw)
To: KOBAYASHI Yoshitake
Cc: linux-mtd@lists.infradead.org, Brian Norris, David Woodhouse,
LKML
Am 16.06.2015 um 15:33 schrieb KOBAYASHI Yoshitake:
>>> + /* correctable */
>>> + else if (status & NAND_STATUS_RECOM_REWRT) {
>>> + pr_info("BENAND : Recommended to rewrite!\n");
>>> + bitflips = chip->ecc.strength;
>>
>> In your case this might be okay, as you set strength to 1.
>> Otherweise you'd have to report the real number of bitflips.
>
> I also thought it is okay in this case.
> BENAND return corrected data to Host NAND Controller till uncorrectable status.
> The current patch uses this Read Status command 70h to abstract BENAND Multi
> bit ECC and Need to Rewrite judgement so BENAND would look like 1bit ECC device.
The layers above MTD need to know how many bits got repaired.
It seems like BENAND suffers from the same shortcomings than On-Die-ECC. ;-\
Please see my patches how to deal with that. Maybe you can find a better solution.
Thanks,
//richard
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
2015-06-16 13:53 ` Richard Weinberger
@ 2015-06-19 14:46 ` KOBAYASHI Yoshitake
-1 siblings, 0 replies; 14+ messages in thread
From: KOBAYASHI Yoshitake @ 2015-06-19 14:46 UTC (permalink / raw)
To: Richard Weinberger
Cc: David Woodhouse, Brian Norris, linux-mtd@lists.infradead.org,
LKML
> Please see my patches how to deal with that. Maybe you can find a better solution.
Thank you for your suggestion. I considered to use your submitted patch on BENAND
driver, but I believe reading twice the same page approach will affect read performance.
Additionally, BENAND does not support Disable ECC. So, I cannot use same approach.
I consider other solutions.
BENAND Read Status CMD (70h) can report Rewrite Recommend. BENAND also has extended
ECC Status CMD (7Ah). This can report number of bit error / sector data.
If I can use an extended ECC Status CMD (7Ah) in BENAND driver (nand_benand.c),
I suggest to implement it as the follows:
+++ b/drivers/mtd/nand/nand_benand.c
.....
+/* ECC Status Read Command */
+#define NAND_CMD_ECC_STATUS 0x7A
.....
+ chip->ecc.strength = 8;
.....
+ /* correctable */
+ else if (status & NAND_STATUS_RECOM_REWRT) {
+ if (chip->cmd_ctrl &&
+ IS_ENABLED(CONFIG_MTD_NAND_BENAND_ECC_STATUS)) {
+
+ /* Check Read ECC Status */
+ chip->cmd_ctrl(mtd, NAND_CMD_ECC_STATUS,
+ NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+ ecc_status = chip->read_byte(mtd);
+ bitflips = ecc_status & 0xff;
+ mtd->ecc_stats.corrected += bitflips;
If above implementation cannot be acceptable, I would like to use "mtd->bitflip_threshold"
to inform number of bitflip, as the follows:
+ } else {
+ /*
+ * If can't use chip->cmd_ctrl,
+ * we can't get real number of bitflips.
+ * So, we set bitflips mtd->bitflip_threshold.
+ */
+ bitflips = mtd->bitflip_threshold;
+ mtd->ecc_stats.corrected += bitflips;
+ }
+ }
+
+ return bitflips;
+}
-- Yoshi
On 2015/06/16 22:53, Richard Weinberger wrote:
> Am 16.06.2015 um 15:33 schrieb KOBAYASHI Yoshitake:
>>>> + /* correctable */
>>>> + else if (status & NAND_STATUS_RECOM_REWRT) {
>>>> + pr_info("BENAND : Recommended to rewrite!\n");
>>>> + bitflips = chip->ecc.strength;
>>>
>>> In your case this might be okay, as you set strength to 1.
>>> Otherweise you'd have to report the real number of bitflips.
>>
>> I also thought it is okay in this case.
>> BENAND return corrected data to Host NAND Controller till uncorrectable status.
>> The current patch uses this Read Status command 70h to abstract BENAND Multi
>> bit ECC and Need to Rewrite judgement so BENAND would look like 1bit ECC device.
>
> The layers above MTD need to know how many bits got repaired.
> It seems like BENAND suffers from the same shortcomings than On-Die-ECC. ;-\
> Please see my patches how to deal with that. Maybe you can find a better solution.
>
> Thanks,
> //richard
>
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Please read the FAQ at http://www.tux.org/lkml/
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND)
@ 2015-06-19 14:46 ` KOBAYASHI Yoshitake
0 siblings, 0 replies; 14+ messages in thread
From: KOBAYASHI Yoshitake @ 2015-06-19 14:46 UTC (permalink / raw)
To: Richard Weinberger
Cc: linux-mtd@lists.infradead.org, Brian Norris, David Woodhouse,
LKML
> Please see my patches how to deal with that. Maybe you can find a better solution.
Thank you for your suggestion. I considered to use your submitted patch on BENAND
driver, but I believe reading twice the same page approach will affect read performance.
Additionally, BENAND does not support Disable ECC. So, I cannot use same approach.
I consider other solutions.
BENAND Read Status CMD (70h) can report Rewrite Recommend. BENAND also has extended
ECC Status CMD (7Ah). This can report number of bit error / sector data.
If I can use an extended ECC Status CMD (7Ah) in BENAND driver (nand_benand.c),
I suggest to implement it as the follows:
+++ b/drivers/mtd/nand/nand_benand.c
.....
+/* ECC Status Read Command */
+#define NAND_CMD_ECC_STATUS 0x7A
.....
+ chip->ecc.strength = 8;
.....
+ /* correctable */
+ else if (status & NAND_STATUS_RECOM_REWRT) {
+ if (chip->cmd_ctrl &&
+ IS_ENABLED(CONFIG_MTD_NAND_BENAND_ECC_STATUS)) {
+
+ /* Check Read ECC Status */
+ chip->cmd_ctrl(mtd, NAND_CMD_ECC_STATUS,
+ NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+ ecc_status = chip->read_byte(mtd);
+ bitflips = ecc_status & 0xff;
+ mtd->ecc_stats.corrected += bitflips;
If above implementation cannot be acceptable, I would like to use "mtd->bitflip_threshold"
to inform number of bitflip, as the follows:
+ } else {
+ /*
+ * If can't use chip->cmd_ctrl,
+ * we can't get real number of bitflips.
+ * So, we set bitflips mtd->bitflip_threshold.
+ */
+ bitflips = mtd->bitflip_threshold;
+ mtd->ecc_stats.corrected += bitflips;
+ }
+ }
+
+ return bitflips;
+}
-- Yoshi
On 2015/06/16 22:53, Richard Weinberger wrote:
> Am 16.06.2015 um 15:33 schrieb KOBAYASHI Yoshitake:
>>>> + /* correctable */
>>>> + else if (status & NAND_STATUS_RECOM_REWRT) {
>>>> + pr_info("BENAND : Recommended to rewrite!\n");
>>>> + bitflips = chip->ecc.strength;
>>>
>>> In your case this might be okay, as you set strength to 1.
>>> Otherweise you'd have to report the real number of bitflips.
>>
>> I also thought it is okay in this case.
>> BENAND return corrected data to Host NAND Controller till uncorrectable status.
>> The current patch uses this Read Status command 70h to abstract BENAND Multi
>> bit ECC and Need to Rewrite judgement so BENAND would look like 1bit ECC device.
>
> The layers above MTD need to know how many bits got repaired.
> It seems like BENAND suffers from the same shortcomings than On-Die-ECC. ;-\
> Please see my patches how to deal with that. Maybe you can find a better solution.
>
> Thanks,
> //richard
>
>
>
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH REPOST v3] mtd: nand support for Toshiba BENAND (Built-in ECC NAND)
2015-06-11 16:00 [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND) KOBAYASHI Yoshitake
2015-06-12 8:11 ` Paul Bolle
2015-06-12 9:49 ` Richard Weinberger
@ 2015-07-24 17:42 ` KOBAYASHI Yoshitake
2 siblings, 0 replies; 14+ messages in thread
From: KOBAYASHI Yoshitake @ 2015-07-24 17:42 UTC (permalink / raw)
To: dwmw2, computersforpeace, linux-mtd; +Cc: linux-kernel, KOBAYASHI Yoshitake
This patch enables support for Toshiba BENAND. BENAND is a SLC NAND
solution that automatically generates ECC inside NAND chip.
I considered to use the patch of on-die ECC, but I believe reading twice
the same page approach will affect read performance. Additionally, BENAND
does not support Disable ECC. So, I cannot use same approach.
BENAND Read Status CMD(70h) is able to report Rewrite Recommend. BENAND
also has extended ECC Status CMD(7Ah). This command is able to report the
number of bit error/sector data. When MTD_NAND_BENAND_ENABLE option enabled,
this driver use the extended ECC status CMD(7Ah) to report real number of
bitflips. In case of difficult to use CMD(7Ah), this driver use
"mtd->bitflip_threshold" to assume the number of bitflips.
Changelog[v3]:
1. Change implementation for 8bit on-die ECC of BENAND.
- chip->ecc.strength is changed 1 to 8.
2. When a bit error beyond a threshold occurred in read operation inside
BENAND, use the 0x7A command(BENAND original command) to get actual
number of bitflips.
- Add the config MTD_NAND_BENAND_ECC_STATUS for ECC Status Read Command.
- Use the 0x7A command when config MTD_NAND_BENAND_ECC_STATUS is enable
and chip->cmd_ctrl is implemented.
3. Delete all pr_info().
Changelog[v2]:
Added nand_benand.c and nand_benand.h
Changelog[v1]
The original version.
(I forgot to add nand_benand.c and nand_benand.h)
Signed-off-by: KOBAYASHI Yoshitake <yoshitake.kobayashi@toshiba.co.jp>
---
drivers/mtd/nand/Kconfig | 21 +++++
drivers/mtd/nand/Makefile | 1 +
drivers/mtd/nand/nand_base.c | 30 +++++++-
drivers/mtd/nand/nand_benand.c | 154 +++++++++++++++++++++++++++++++++++++++
include/linux/mtd/nand.h | 1 +
include/linux/mtd/nand_benand.h | 48 ++++++++++++
6 files changed, 253 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 5b2806a..67e13c2 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -22,6 +22,27 @@ 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_BENAND_ECC_STATUS
+ bool "Enable ECC Status Read Command(0x7A)"
+ depends on MTD_NAND_BENAND_ENABLE
+ help
+ This enables support for ECC Status Read Command(0x7A) of BENAND.
+ When this enables, report the real number of bitflips.
+ In other cases, report the assumud number.
+
config MTD_NAND_BCH
tristate
select BCH
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 1f897ec..d019309 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 ceb68ca..1ffdb5c 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -41,6 +41,7 @@
#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>
@@ -3522,8 +3523,13 @@ 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 */) {
+
+ if (IS_ENABLED(CONFIG_MTD_NAND_BENAND))
+ chip->ecc.mode = NAND_ECC_BENAND;
+
+ } else {
+ mtd->oobsize = 32 * mtd->writesize >> 9; /* !BENAND */
}
}
@@ -4111,6 +4117,26 @@ 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;
+ ecc->size = mtd->writesize;
+ ecc->strength = 8;
+
+ 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..43f89ae
--- /dev/null
+++ b/drivers/mtd/nand/nand_benand.c
@@ -0,0 +1,154 @@
+/*
+ * 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>
+
+/* Recommended to rewrite for BENAND */
+#define NAND_STATUS_RECOM_REWRT 0x08
+
+/* ECC Status Read Command */
+#define NAND_CMD_ECC_STATUS 0x7A
+
+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}
+ }
+};
+
+
+static int nand_benand_status_chk(struct mtd_info *mtd, struct nand_chip *chip)
+{
+ unsigned int max_bitflips = 0;
+ u8 status;
+
+ /* Check Read Status */
+ chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+ status = chip->read_byte(mtd);
+
+ /* timeout */
+ if (!(status & NAND_STATUS_READY)) {
+ pr_debug("BENAND : Time Out!\n");
+ return -EIO;
+ }
+
+ /* uncorrectable */
+ else if (status & NAND_STATUS_FAIL)
+ mtd->ecc_stats.failed++;
+
+ /* correctable */
+ else if (status & NAND_STATUS_RECOM_REWRT) {
+ if (chip->cmd_ctrl &&
+ IS_ENABLED(CONFIG_MTD_NAND_BENAND_ECC_STATUS)) {
+
+ int i;
+ u8 ecc_status;
+ unsigned int bitflips;
+
+ /* Check Read ECC Status */
+ chip->cmd_ctrl(mtd, NAND_CMD_ECC_STATUS,
+ NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+ /* Get bitflips info per 512Byte */
+ for (i = 0; i < mtd->writesize >> 9; i++) {
+ ecc_status = chip->read_byte(mtd);
+ bitflips = ecc_status & 0x0f;
+ max_bitflips = max_t(unsigned int,
+ max_bitflips, bitflips);
+ }
+ mtd->ecc_stats.corrected += max_bitflips;
+ } else {
+ /*
+ * If can't use chip->cmd_ctrl,
+ * we can't get real number of bitflips.
+ * So, we set max_bitflips mtd->bitflip_threshold.
+ */
+ max_bitflips = mtd->bitflip_threshold;
+ mtd->ecc_stats.corrected += max_bitflips;
+ }
+ }
+
+ return max_bitflips;
+}
+
+
+void nand_benand_init(struct mtd_info *mtd)
+{
+ struct nand_chip *chip = mtd->priv;
+
+ 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;
+
+ 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;
+
+ 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);
+
+
+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 f25e2bd..ba3c2f1 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -117,6 +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..0aa5aec
--- /dev/null
+++ b/include/linux/mtd/nand_benand.h
@@ -0,0 +1,48 @@
+/*
+ * 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);
+
+#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;
+}
+
+#endif /* CONFIG_MTD_NAND_BENAND_ENABLE */
+#endif
--
1.7.2.5
^ permalink raw reply related [flat|nested] 14+ messages in thread
end of thread, other threads:[~2015-07-24 17:44 UTC | newest]
Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-06-11 16:00 [PATCH v2] mtd: nand: support for Toshiba BENAND (Built-in ECC NAND) KOBAYASHI Yoshitake
2015-06-12 8:11 ` Paul Bolle
2015-06-12 8:11 ` Paul Bolle
2015-06-16 13:37 ` KOBAYASHI Yoshitake
2015-06-16 13:37 ` KOBAYASHI Yoshitake
2015-06-12 9:49 ` Richard Weinberger
2015-06-12 9:49 ` Richard Weinberger
2015-06-16 13:33 ` KOBAYASHI Yoshitake
2015-06-16 13:33 ` KOBAYASHI Yoshitake
2015-06-16 13:53 ` Richard Weinberger
2015-06-16 13:53 ` Richard Weinberger
2015-06-19 14:46 ` KOBAYASHI Yoshitake
2015-06-19 14:46 ` KOBAYASHI Yoshitake
2015-07-24 17:42 ` [PATCH REPOST v3] mtd: nand " KOBAYASHI Yoshitake
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