[PATCH] NAND: fix reading/writing OOB for syndrome
Vitaly Wool
vwool at ru.mvista.com
Wed Jun 7 06:39:25 EDT 2006
Folks,
being unable to read/write OOB for the NAND flash with 'syndrome' controller (standard read/write oob functions presume OOB is contiguous which is wrong in this case), I took a clumsy attempt to implement this functionality. :)
Signed-off-by: Vitaly Wool <vwool at ru.mvista.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 77406fc..fbfd9fb 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1083,6 +1083,116 @@ static int nand_read(struct mtd_info *mt
return ret;
}
+
+/**
+ * nand_read_oob_raw - [REPLACABLE] the most common OOB data read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @offs: offset to start writing from
+ * @length: length of the OOB data to read
+ * @page: page number to read
+ */
+static void nand_read_oob_raw(struct mtd_info *mtd, struct nand_chip *chip, uint8_t *buf, int offs, int length, int page)
+{
+ chip->read_buf(mtd, buf, length);
+}
+static void (*nand_read_oob_swecc)(struct mtd_info *mtd, struct nand_chip *chip, uint8_t *buf, int offs, int length, int page) = &nand_read_oob_raw;
+static void (*nand_read_oob_hwecc)(struct mtd_info *mtd, struct nand_chip *chip, uint8_t *buf, int offs, int length, int page) = &nand_read_oob_raw;
+
+/**
+ * nand_read_oob_syndrome - [REPLACABLE] OOB data read function for HW ECC
+ * with syndromes
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @offs: offset to start reading from
+ * @length: length of the OOB data to read
+ * @page: page number to read
+ */
+static void nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip, uint8_t *buf, int offs, int length, int page)
+{
+ int portion = mtd->oobsize / chip->ecc.steps;
+ uint8_t *bufpoi = buf;
+ int i;
+
+ /*
+ * We presume here that the chip driver is capable of
+ * emulating NAND_CMD_READOOB properly
+ */
+ for (i = 0 ; i < chip->ecc.steps ; i++) {
+ if (offs) {
+ while (portion < offs) {
+ offs -= portion;
+ i++;
+ }
+ }
+ chip->read_buf(mtd, bufpoi, portion - offs);
+ bufpoi += portion - offs;
+ offs = 0;
+ chip->cmdfunc(mtd, NAND_CMD_READOOB, (i + 1) * portion, page);
+ }
+}
+
+/**
+ * nand_write_oob_raw - [REPLACABLE] the most common OOB data write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer where to write data from
+ * @offs: offset to start writing from
+ * @length: length of the OOB data to write
+ * @page: page number to write
+ */
+static void nand_write_oob_raw(struct mtd_info *mtd, struct nand_chip *chip, const uint8_t *buf, int offs, int length, int page)
+{
+ chip->write_buf(mtd, buf, length);
+}
+static void (*nand_write_oob_swecc)(struct mtd_info *mtd, struct nand_chip *chip, const uint8_t *buf, int offs, int length, int page) = nand_write_oob_raw;
+static void (*nand_write_oob_hwecc)(struct mtd_info *mtd, struct nand_chip *chip, const uint8_t *buf, int offs, int length, int page) = nand_write_oob_raw;
+
+/**
+ * nand_write_oob_syndrome - [REPLACABLE] OOB data write function for HW ECC
+ * with syndrome
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer where to write data from
+ * @offs: offset to start writing from
+ * @length: length of the OOB data to write
+ * @page: page number to write
+ */
+static void nand_write_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip, const uint8_t *buf, int offs, int length, int page)
+{
+ int portion = mtd->oobsize / chip->ecc.steps;
+ int eccsize = chip->ecc.size;
+ const uint8_t *bufpoi = buf;
+ int i, len;
+
+ for (i = 0 ; i < chip->ecc.steps ; i++) {
+ if (offs < portion) {
+ int status;
+ chip->cmdfunc(mtd, NAND_CMD_SEQIN,
+ eccsize + i * (eccsize + portion) + offs, page);
+ len = min_t(int, length, portion - offs);
+ chip->write_buf(mtd, bufpoi, len);
+ bufpoi += len;
+ length -= len;
+ offs = 0;
+
+ if (i < chip->ecc.steps - 1) {
+ chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+ status = chip->waitfunc(mtd, chip, FL_WRITING);
+
+ /* See if device thinks it succeeded */
+ if (status & NAND_STATUS_FAIL)
+ DEBUG(MTD_DEBUG_LEVEL0, "%s: "
+ "Failed write, page 0x%08x\n",
+ __FUNCTION__, page);
+ }
+ } else
+ offs -= portion;
+ }
+}
+
/**
* nand_do_read_oob - [Intern] NAND read out-of-band
* @mtd: MTD device structure
@@ -1127,7 +1237,7 @@ static int nand_do_read_oob(struct mtd_i
sndcmd = 0;
}
- chip->read_buf(mtd, bufpoi, bytes);
+ chip->ecc.read_oob(mtd, chip, bufpoi, col, bytes, page);
if (unlikely(!direct))
buf = nand_transfer_oob(chip, buf, ops);
@@ -1598,13 +1708,13 @@ static int nand_do_write_oob(struct mtd_
nand_fill_oob(chip, ops->oobbuf, ops);
chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize,
page & chip->pagemask);
- chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
+ chip->ecc.write_oob(mtd, chip, chip->oob_poi, 0, mtd->oobsize, page & chip->pagemask);
memset(chip->oob_poi, 0xff, mtd->oobsize);
} else {
chip->cmdfunc(mtd, NAND_CMD_SEQIN,
mtd->writesize + ops->ooboffs,
page & chip->pagemask);
- chip->write_buf(mtd, ops->oobbuf, ops->len);
+ chip->ecc.write_oob(mtd, chip, ops->oobbuf, ops->ooboffs, ops->len, page & chip->pagemask);
}
/* Send command to program the OOB data */
@@ -2265,6 +2375,10 @@ int nand_scan(struct mtd_info *mtd, int
chip->ecc.read_page = nand_read_page_hwecc;
if (!chip->ecc.write_page)
chip->ecc.write_page = nand_write_page_hwecc;
+ if (!chip->ecc.read_oob)
+ chip->ecc.read_oob = nand_read_oob_hwecc;
+ if (!chip->ecc.write_oob)
+ chip->ecc.write_oob = nand_write_oob_hwecc;
case NAND_ECC_HW_SYNDROME:
if (!chip->ecc.calculate || !chip->ecc.correct ||
@@ -2278,6 +2392,10 @@ int nand_scan(struct mtd_info *mtd, int
chip->ecc.read_page = nand_read_page_syndrome;
if (!chip->ecc.write_page)
chip->ecc.write_page = nand_write_page_syndrome;
+ if (!chip->ecc.read_oob)
+ chip->ecc.read_oob = nand_read_oob_syndrome;
+ if (!chip->ecc.write_oob)
+ chip->ecc.write_oob = nand_write_oob_syndrome;
if (mtd->writesize >= chip->ecc.size)
break;
@@ -2291,6 +2409,8 @@ int nand_scan(struct mtd_info *mtd, int
chip->ecc.correct = nand_correct_data;
chip->ecc.read_page = nand_read_page_swecc;
chip->ecc.write_page = nand_write_page_swecc;
+ chip->ecc.read_oob = nand_read_oob_swecc;
+ chip->ecc.write_oob = nand_write_oob_swecc;
chip->ecc.size = 256;
chip->ecc.bytes = 3;
break;
@@ -2300,6 +2420,8 @@ int nand_scan(struct mtd_info *mtd, int
"This is not recommended !!\n");
chip->ecc.read_page = nand_read_page_raw;
chip->ecc.write_page = nand_write_page_raw;
+ chip->ecc.read_oob = nand_read_oob_raw;
+ chip->ecc.write_oob = nand_write_oob_raw;
chip->ecc.size = mtd->writesize;
chip->ecc.bytes = 0;
break;
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index bf2ce68..ef6adfa 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -250,6 +250,19 @@ struct nand_ecc_ctrl {
void (*write_page)(struct mtd_info *mtd,
struct nand_chip *chip,
const uint8_t *buf);
+ void (*read_oob)(struct mtd_info *mtd,
+ struct nand_chip *chip,
+ uint8_t *buf,
+ int offs,
+ int length,
+ int page);
+ void (*write_oob)(struct mtd_info *mtd,
+ struct nand_chip *chip,
+ const uint8_t *buf,
+ int offs,
+ int length,
+ int page);
+
};
/**
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