From 93edbad69b0491d794c2ec86bcc65c69eac676e3 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <maximlevitsky@gmail.com>
Date: Mon, 22 Feb 2010 20:39:40 +0200
Subject: [PATCH] mtd: Workaround wrong write protect status on some xD cards
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---
drivers/mtd/nand/nand_base.c | 8 +++++++-
include/linux/mtd/nand.h | 6 ++++++
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 1c4823696be27..b9dc65c7253ca 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -434,6 +434,11 @@ static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
static int nand_check_wp(struct mtd_info *mtd)
{
struct nand_chip *chip = mtd->priv;
+
+ /* broken xD cards report WP despite being writable */
+ if (chip->options & NAND_BROKEN_XD)
+ return 0;
+
/* Check the WP bit */
chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
return (chip->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1;
@@ -3175,7 +3180,8 @@ int nand_scan_tail(struct mtd_info *mtd)
/* Fill in remaining MTD driver data */
mtd->type = MTD_NANDFLASH;
- mtd->flags = MTD_CAP_NANDFLASH;
+ mtd->flags = (chip->options & NAND_ROM) ? MTD_CAP_ROM :
+ MTD_CAP_NANDFLASH;
mtd->erase = nand_erase;
mtd->point = NULL;
mtd->unpoint = NULL;
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index d152bdf9161fb..8bdacb885f904 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -182,6 +182,12 @@ typedef enum {
/* Chip does not allow subpage writes */
#define NAND_NO_SUBPAGE_WRITE 0x00000200
+/* Device is one of 'new' xD cards that expose fake nand command set */
+#define NAND_BROKEN_XD 0x00000400
+
+/* Device behaves just like nand, but is readonly */
+#define NAND_ROM 0x00000800
+
/* Options valid for Samsung large page devices */
#define NAND_SAMSUNG_LP_OPTIONS \
(NAND_NO_PADDING | NAND_CACHEPRG | NAND_COPYBACK)
--
GitLab