From 33efde5ecac91ab118ff00b95a181fd6d75f8645 Mon Sep 17 00:00:00 2001
From: Karl Beldan <karl.beldan@gmail.com>
Date: Mon, 15 Sep 2008 16:08:03 +0200
Subject: [PATCH] NAND: Reset chip on power-up
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: Scott Wood <scottwood@freescale.com>
---
drivers/mtd/nand/nand_base.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 4069ab1278..ba05b762ed 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2450,6 +2450,12 @@ 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);
@@ -2620,6 +2626,8 @@ 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 */
--
2.39.5