mtd: nand: spansion S30MLxxxP support

Some Spansion chips have a method for determining eraseblock size that
is incompatible with similar ID chips of other sizes. This implements
some heuristic detection of these differences.

This patch checks for a 5-byte ID with trailing zeros as well as a
512-byte page size to ensure that chips are not misdetected as the
S30MLxxxP ORNAND series.

[Tweaked by Artem a bit]

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, 13 insertions, 0 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 0fd22cce0ecc..b0f091aca097 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2900,6 +2900,19 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
                 mtd->writesize = type->pagesize;
                 mtd->oobsize = mtd->writesize / 32;
                 busw = type->options & NAND_BUSWIDTH_16;
+
+                /*
+                 * Check for Spansion/AMD ID + repeating 5th, 6th byte since
+                 * some Spansion chips have erasesize that conflicts with size
+                 * listed in nand_ids table
+                 * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)
+                 */
+                if (*maf_id == NAND_MFR_AMD && id_data[4] != 0x00 &&
+                                id_data[5] == 0x00 && id_data[6] == 0x00 &&
+                                id_data[7] == 0x00 && mtd->writesize == 512) {
+                        mtd->erasesize = 128 * 1024;
+                        mtd->erasesize <<= ((id_data[3] & 0x03) << 1);
+                }
         }
 
         /* Try to identify manufacturer */