[MTD] NAND: add subpage write support
Linux-MTD Mailing List
linux-mtd at lists.infradead.org
Wed Nov 29 11:59:02 EST 2006
Gitweb: http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=29072b96078ffde36f03d51e6b5d0cff1ba8c7df
Commit: 29072b96078ffde36f03d51e6b5d0cff1ba8c7df
Parent: f6a7ecb18dabd88bd9f28e7bece564cabe8ffe82
Author: Thomas Gleixner <tglx at linutronix.de>
AuthorDate: Thu Sep 28 15:38:36 2006 +0200
Committer: Artem Bityutskiy <dedekind at infradead.org>
CommitDate: Wed Nov 29 17:03:52 2006 +0200
[MTD] NAND: add subpage write support
Many SLC NANDs support up to 4 writes at one NAND page. Add support
of this feature.
Signed-off-by: Artem Bityutskiy <dedekind at infradead.org>
---
drivers/mtd/mtdconcat.c | 1 +
drivers/mtd/mtdpart.c | 1 +
drivers/mtd/nand/nand_base.c | 53 +++++++++++++++++++++++++++++++++++-------
include/linux/mtd/mtd.h | 2 ++
include/linux/mtd/nand.h | 9 +++++++
5 files changed, 57 insertions(+), 9 deletions(-)
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index ec51483..0690268 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -772,6 +772,7 @@ struct mtd_info *mtd_concat_create(struc
concat->mtd.ecc_stats.badblocks +=
subdev[i]->ecc_stats.badblocks;
if (concat->mtd.writesize != subdev[i]->writesize ||
+ concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
concat->mtd.oobsize != subdev[i]->oobsize ||
concat->mtd.ecctype != subdev[i]->ecctype ||
concat->mtd.eccsize != subdev[i]->eccsize ||
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 89692f8..bafd2fb 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -340,6 +340,7 @@ int add_mtd_partitions(struct mtd_info *
slave->mtd.oobsize = master->oobsize;
slave->mtd.ecctype = master->ecctype;
slave->mtd.eccsize = master->eccsize;
+ slave->mtd.subpage_sft = master->subpage_sft;
slave->mtd.name = parts[i].name;
slave->mtd.bank_size = master->bank_size;
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 5dcb2e0..eed3271 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1590,7 +1590,7 @@ static uint8_t *nand_fill_oob(struct nan
return NULL;
}
-#define NOTALIGNED(x) (x & (mtd->writesize-1)) != 0
+#define NOTALIGNED(x) (x & (chip->subpagesize - 1)) != 0
/**
* nand_do_write_ops - [Internal] NAND write with ECC
@@ -1603,15 +1603,16 @@ #define NOTALIGNED(x) (x & (mtd->writesi
static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
struct mtd_oob_ops *ops)
{
- int chipnr, realpage, page, blockmask;
+ int chipnr, realpage, page, blockmask, column;
struct nand_chip *chip = mtd->priv;
uint32_t writelen = ops->len;
uint8_t *oob = ops->oobbuf;
uint8_t *buf = ops->datbuf;
- int bytes = mtd->writesize;
- int ret;
+ int ret, subpage;
ops->retlen = 0;
+ if (!writelen)
+ return 0;
/* reject writes, which are not page aligned */
if (NOTALIGNED(to) || NOTALIGNED(ops->len)) {
@@ -1620,8 +1621,11 @@ static int nand_do_write_ops(struct mtd_
return -EINVAL;
}
- if (!writelen)
- return 0;
+ column = to & (mtd->writesize - 1);
+ subpage = column || (writelen & (mtd->writesize - 1));
+
+ if (subpage && oob)
+ return -EINVAL;
chipnr = (int)(to >> chip->chip_shift);
chip->select_chip(mtd, chipnr);
@@ -1644,12 +1648,24 @@ static int nand_do_write_ops(struct mtd_
memset(chip->oob_poi, 0xff, mtd->oobsize);
while(1) {
+ int bytes = mtd->writesize;
int cached = writelen > bytes && page != blockmask;
+ uint8_t *wbuf = buf;
+
+ /* Partial page write ? */
+ if (unlikely(column || writelen < (mtd->writesize - 1))) {
+ cached = 0;
+ bytes = min_t(int, bytes - column, (int) writelen);
+ chip->pagebuf = -1;
+ memset(chip->buffers->databuf, 0xff, mtd->writesize);
+ memcpy(&chip->buffers->databuf[column], buf, bytes);
+ wbuf = chip->buffers->databuf;
+ }
if (unlikely(oob))
oob = nand_fill_oob(chip, oob, ops);
- ret = chip->write_page(mtd, chip, buf, page, cached,
+ ret = chip->write_page(mtd, chip, wbuf, page, cached,
(ops->mode == MTD_OOB_RAW));
if (ret)
break;
@@ -1658,6 +1674,7 @@ static int nand_do_write_ops(struct mtd_
if (!writelen)
break;
+ column = 0;
buf += bytes;
realpage++;
@@ -2201,8 +2218,8 @@ static struct nand_flash_dev *nand_get_f
/* Newer devices have all the information in additional id bytes */
if (!type->pagesize) {
int extid;
- /* The 3rd id byte contains non relevant data ATM */
- extid = chip->read_byte(mtd);
+ /* The 3rd id byte holds MLC / multichip data */
+ chip->cellinfo = chip->read_byte(mtd);
/* The 4th id byte is the important one */
extid = chip->read_byte(mtd);
/* Calc pagesize */
@@ -2482,6 +2499,24 @@ int nand_scan_tail(struct mtd_info *mtd)
}
chip->ecc.total = chip->ecc.steps * chip->ecc.bytes;
+ /*
+ * Allow subpage writes up to ecc.steps. Not possible for MLC
+ * FLASH.
+ */
+ if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
+ !(chip->cellinfo & NAND_CI_CELLTYPE_MSK)) {
+ switch(chip->ecc.steps) {
+ case 2:
+ mtd->subpage_sft = 1;
+ break;
+ case 4:
+ case 8:
+ mtd->subpage_sft = 2;
+ break;
+ }
+ }
+ chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
+
/* Initialize state */
chip->state = FL_READY;
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index e34bbc9..18acb6d 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -200,6 +200,8 @@ #define MTD_PROGREGION_CTRLMODE_INVALID(
/* ECC status information */
struct mtd_ecc_stats ecc_stats;
+ /* Subpage shift (NAND) */
+ int subpage_sft;
void *priv;
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 6fc3e07..1aeedf2 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -166,6 +166,9 @@ #define BBT_AUTO_REFRESH 0x00000080
* for all large page devices, as they do not support
* autoincrement.*/
#define NAND_NO_READRDY 0x00000100
+/* Chip does not allow subpage writes */
+#define NAND_NO_SUBPAGE_WRITE 0x00000200
+
/* Options valid for Samsung large page devices */
#define NAND_SAMSUNG_LP_OPTIONS \
@@ -193,6 +196,9 @@ #define NAND_OWN_BUFFERS 0x00040000
/* Nand scan has allocated controller struct */
#define NAND_CONTROLLER_ALLOC 0x80000000
+/* Cell info constants */
+#define NAND_CI_CHIPNR_MSK 0x03
+#define NAND_CI_CELLTYPE_MSK 0x0C
/*
* nand_state_t - chip states
@@ -341,6 +347,7 @@ struct nand_buffers {
* @chipsize: [INTERN] the size of one chip for multichip arrays
* @pagemask: [INTERN] page number mask = number of (pages / chip) - 1
* @pagebuf: [INTERN] holds the pagenumber which is currently in data_buf
+ * @subpagesize: [INTERN] holds the subpagesize
* @ecclayout: [REPLACEABLE] the default ecc placement scheme
* @bbt: [INTERN] bad block table pointer
* @bbt_td: [REPLACEABLE] bad block table descriptor for flash lookup
@@ -388,6 +395,8 @@ struct nand_chip {
unsigned long chipsize;
int pagemask;
int pagebuf;
+ int subpagesize;
+ uint8_t cellinfo;
int badblockpos;
nand_state_t state;
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