[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 <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: David Woodhouse <[email protected]>
kyagi · Sep 22, 2006 · 187ef15 · 187ef15
1 parent e478bec
commit 187ef15
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diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -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[] = {

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
@@ -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))
+					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 */

diff --git a/include/mtd/mtd-abi.h b/include/mtd/mtd-abi.h
@@ -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