mtd: nand: refactor BB marker detection

Some level of support for various scanning locations was already built in,
but this required clean-up. First, BB marker location cannot be determined
_only_ by the page size. Instead, I implemented some heuristic detection
based on data sheets from various manufacturers (all found in
nand_base.c:nand_get_flash_type()).

Second, once these options were identified, they were not handled properly
by nand_bbt.c:nand_default_bbt(). I updated the static nand_bbt_desc structs
to reflect the need for more combinations of detection. The memory allocation
here probably needs to be done dynamically in the very near future (see next
patches).

Signed-off-by: Brian Norris <norris@broadcom.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 20 insertions, 4 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index e6cf9aefef13..bd697909db53 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2920,9 +2920,14 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
                 chip->chip_shift = ffs((unsigned)(chip->chipsize >> 32)) + 32 - 1;
 
         /* Set the bad block position */
-        chip->badblockpos = mtd->writesize > 512 ?
-                NAND_LARGE_BADBLOCK_POS : NAND_SMALL_BADBLOCK_POS;
-        chip->badblockbits = 8;
+        if (!(busw & NAND_BUSWIDTH_16) && (*maf_id == NAND_MFR_STMICRO ||
+                                (*maf_id == NAND_MFR_SAMSUNG &&
+                                 mtd->writesize == 512) ||
+                                *maf_id == NAND_MFR_AMD))
+                chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
+        else
+                chip->badblockpos = NAND_LARGE_BADBLOCK_POS;
+
 
         /* Get chip options, preserve non chip based options */
         chip->options &= ~NAND_CHIPOPTIONS_MSK;
@@ -2941,12 +2946,23 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 
         /*
          * Bad block marker is stored in the last page of each block
-         * on Samsung and Hynix MLC devices
+         * on Samsung and Hynix MLC devices; stored in first two pages
+         * of each block on Micron devices with 2KiB pages and on
+         * SLC Samsung, Hynix, and AMD/Spansion. All others scan only
+         * the first page.
          */
         if ((chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
                         (*maf_id == NAND_MFR_SAMSUNG ||
                          *maf_id == NAND_MFR_HYNIX))
                 chip->options |= NAND_BBT_SCANLASTPAGE;
+        else if ((!(chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
+                                (*maf_id == NAND_MFR_SAMSUNG ||
+                                 *maf_id == NAND_MFR_HYNIX ||
+                                 *maf_id == NAND_MFR_AMD)) ||
+                        (mtd->writesize == 2048 &&
+                         *maf_id == NAND_MFR_MICRON))
+                chip->options |= NAND_BBT_SCAN2NDPAGE;
+
 
         /* Check for AND chips with 4 page planes */
         if (chip->options & NAND_4PAGE_ARRAY)