[MTD] dataflash OTP support

Now that we can tell when we have one of the newer DataFlash chips,
optionally expose the 128 bytes of OTP memory they provide.  Tested
on at45db642 revision B and D chips.

Switch mtdchar over to a generic HAVE_MTD_OTP flag instead of adding
another #ifdef for each type of chip whose driver has OTP support.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 14f11f8b9e5f..a90d50c2c3e5 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -172,6 +172,11 @@ config MTD_CHAR
           memory chips, and also use ioctl() to obtain information about
           the device, or to erase parts of it.
 
+config HAVE_MTD_OTP
+        bool
+        help
+          Enable access to OTP regions using MTD_CHAR.
+
 config MTD_BLKDEVS
         tristate "Common interface to block layer for MTD 'translation layers'"
         depends on BLOCK