[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: Håvard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 168d3ba..c4d26de 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -57,6 +57,16 @@
 			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))
+					printk(KERN_WARNING
+					       "%s: unlock failed, "
+					       "writes may not work\n",
+					       mtd->name);
+			}
+
 			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 */