mtd: expose ecc_strength through sysfs

ecc_strength element of struct mtd_info is exposed as a read-only variable in
sysfs.

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd
index 4d55a18..43d1818 100644
--- a/Documentation/ABI/testing/sysfs-class-mtd
+++ b/Documentation/ABI/testing/sysfs-class-mtd
@@ -123,3 +123,15 @@
 		half page, or a quarter page).
 
 		In the case of ECC NOR, it is the ECC block size.
+
+What:		/sys/class/mtd/mtdX/ecc_strength
+Date:		April 2012
+KernelVersion:	3.4
+Contact:	linux-mtd@lists.infradead.org
+Description:
+		Maximum number of bit errors that the device is capable of
+		correcting within each region covering an ecc step.  This will
+		always be a non-negative integer.  Note that some devices will
+		have multiple ecc steps within each writesize region.
+
+		In the case of devices lacking any ECC capability, it is 0.