From patchwork Mon Sep 15 12:37:29 2008
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Subject: nand_base.c: reset chip first
From: karl beldan <karl.beldan@gmail.com>
X-Patchwork-Id: 278
Message-Id: <ea2442770809150537p538f5298s9b5b003a1825b09f@mail.gmail.com>
To: linux-mtd@lists.infradead.org
Cc: David.Woodhouse@intel.com
Date: Mon, 15 Sep 2008 14:37:29 +0200

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>


diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index d1129ba..2cfac9b 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);