Commit 187ef152 authored by Håvard Skinnemoen's avatar Håvard Skinnemoen Committed by David Woodhouse

[MTD] Unlock NOR flash automatically where necessary

Introduce the MTD_STUPID_LOCK flag which indicates that the flash chip is
always locked after power-up, so all sectors need to be unlocked before it
is usable.

If this flag is set, and the chip provides an unlock() operation,
mtd_add_device will unlock the whole MTD device if it's writeable.  This
means that non-writeable partitions will stay locked.

Set MTD_STUPID_LOCK in fixup_use_atmel_lock() so that these chips will work
as expected.
Signed-off-by: default avatarHåvard Skinnemoen <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarDavid Woodhouse <>
parent e478bec0
......@@ -212,6 +212,7 @@ static void fixup_use_atmel_lock(struct mtd_info *mtd, void *param)
mtd->lock = cfi_atmel_lock;
mtd->unlock = cfi_atmel_unlock;
mtd->flags |= MTD_STUPID_LOCK;
static struct cfi_fixup cfi_fixup_table[] = {
......@@ -57,6 +57,16 @@ int add_mtd_device(struct mtd_info *mtd)
mtd->index = i;
mtd->usecount = 0;
/* Some chips always power up locked. Unlock them now */
if ((mtd->flags & MTD_WRITEABLE)
&& (mtd->flags & MTD_STUPID_LOCK) && mtd->unlock) {
if (mtd->unlock(mtd, 0, mtd->size))
"%s: unlock failed, "
"writes may not work\n",
DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
/* No need to get a refcount on the module containing
the notifier, since we hold the mtd_table_mutex */
......@@ -34,6 +34,7 @@ struct mtd_oob_buf {
#define MTD_WRITEABLE 0x400 /* Device is writeable */
#define MTD_BIT_WRITEABLE 0x800 /* Single bits can be flipped */
#define MTD_NO_ERASE 0x1000 /* No erase necessary */
#define MTD_STUPID_LOCK 0x2000 /* Always locked after reset */
// Some common devices / combinations of capabilities
#define MTD_CAP_ROM 0
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