mtd: rawnand: Support bad block markers in first, second or last page

Currently supported bad block marker positions within the block are:
* in first page only
* in last page only
* in first or second page

Some ESMT NANDs are known to have been shipped by the manufacturer
with bad block markers in the first or last page, instead of the
first or second page.

Also the datasheets for Cypress/Spansion/AMD NANDs claim that the
first, second *and* last page needs to be checked.

Therefore we make it possible to set NAND_BBM_FIRSTPAGE,
NAND_BBM_SECONDPAGE and NAND_BBM_LASTPAGE independently in any
combination.

To simplify the code, the logic to evaluate the flags is moved to a
a new function nand_bbm_get_next_page().

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

1 files changed, 43 insertions, 20 deletions

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 6e2d728d2fd9..2cf71060d6f8 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -283,6 +283,31 @@ static void nand_release_device(struct nand_chip *chip)
 }
 
 /**
+ * nand_bbm_get_next_page - Get the next page for bad block markers
+ * @chip: NAND chip object
+ * @page: First page to start checking for bad block marker usage
+ *
+ * Returns an integer that corresponds to the page offset within a block, for
+ * a page that is used to store bad block markers. If no more pages are
+ * available, -EINVAL is returned.
+ */
+int nand_bbm_get_next_page(struct nand_chip *chip, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int last_page = ((mtd->erasesize - mtd->writesize) >>
+			 chip->page_shift) & chip->pagemask;
+
+	if (page == 0 && chip->options & NAND_BBM_FIRSTPAGE)
+		return 0;
+	else if (page <= 1 && chip->options & NAND_BBM_SECONDPAGE)
+		return 1;
+	else if (page <= last_page && chip->options & NAND_BBM_LASTPAGE)
+		return last_page;
+
+	return -EINVAL;
+}
+
+/**
  * nand_block_bad - [DEFAULT] Read bad block marker from the chip
  * @chip: NAND chip object
  * @ofs: offset from device start
@@ -291,19 +316,15 @@ static void nand_release_device(struct nand_chip *chip)
  */
 static int nand_block_bad(struct nand_chip *chip, loff_t ofs)
 {
-	struct mtd_info *mtd = nand_to_mtd(chip);
-	int page, page_end, res;
+	int first_page, page_offset;
+	int res;
 	u8 bad;
 
-	if (chip->options & NAND_BBM_LASTPAGE)
-		ofs += mtd->erasesize - mtd->writesize;
+	first_page = (int)(ofs >> chip->page_shift) & chip->pagemask;
+	page_offset = nand_bbm_get_next_page(chip, 0);
 
-	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
-	page_end = page + (((chip->options & NAND_BBM_FIRSTPAGE) &&
-			    (chip->options & NAND_BBM_SECONDPAGE)) ? 2 : 1);
-
-	for (; page < page_end; page++) {
-		res = chip->ecc.read_oob(chip, page);
+	while (page_offset >= 0) {
+		res = chip->ecc.read_oob(chip, first_page + page_offset);
 		if (res < 0)
 			return res;
 
@@ -315,6 +336,8 @@ static int nand_block_bad(struct nand_chip *chip, loff_t ofs)
 			res = hweight8(bad) < chip->badblockbits;
 		if (res)
 			return res;
+
+		page_offset = nand_bbm_get_next_page(chip, page_offset + 1);
 	}
 
 	return 0;
@@ -494,7 +517,7 @@ static int nand_default_block_markbad(struct nand_chip *chip, loff_t ofs)
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	struct mtd_oob_ops ops;
 	uint8_t buf[2] = { 0, 0 };
-	int ret = 0, res, i = 0;
+	int ret = 0, res, page_offset;
 
 	memset(&ops, 0, sizeof(ops));
 	ops.oobbuf = buf;
@@ -507,18 +530,18 @@ static int nand_default_block_markbad(struct nand_chip *chip, loff_t ofs)
 	}
 	ops.mode = MTD_OPS_PLACE_OOB;
 
-	/* Write to first/last page(s) if necessary */
-	if (chip->options & NAND_BBM_LASTPAGE)
-		ofs += mtd->erasesize - mtd->writesize;
-	do {
-		res = nand_do_write_oob(chip, ofs, &ops);
+	page_offset = nand_bbm_get_next_page(chip, 0);
+
+	while (page_offset >= 0) {
+		res = nand_do_write_oob(chip,
+					ofs + (page_offset * mtd->writesize),
+					&ops);
+
 		if (!ret)
 			ret = res;
 
-		i++;
-		ofs += mtd->writesize;
-	} while ((chip->options & NAND_BBM_FIRSTPAGE) &&
-		 (chip->options & NAND_BBM_SECONDPAGE) && i < 2);
+		page_offset = nand_bbm_get_next_page(chip, page_offset + 1);
+	}
 
 	return ret;
 }