[MTD] [NAND] nand_base.c: reset chip first

Some chips require a RESET after power-up (e.g. Micron MT29FxGxxxxx).
The first command sent is NAND_CMD_READID.
Issue a NAND_CMD_RESET in nand_scan_ident before reading the device id.
Tested with an MT29F4G08AAC.

Signed-off-by: Karl Beldan <karl.beldan@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index d303db39c48d..0a9c9cd33f96 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2318,6 +2318,12 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
         /* Select the device */
         chip->select_chip(mtd, 0);
 
+        /*
+         * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
+         * after power-up
+         */
+        chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+
         /* Send the command for reading device ID */
         chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 
@@ -2488,6 +2494,8 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips)
         /* Check for a chip array */
         for (i = 1; i < maxchips; i++) {
                 chip->select_chip(mtd, i);
+                /* See comment in nand_get_flash_type for reset */
+                chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
                 /* Send the command for reading device ID */
                 chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
                 /* Read manufacturer and device IDs */