mtd: spi-nor: add TB (Top/Bottom) protect support

Some flash support a bit in the status register that inverts protection
so that it applies to the bottom of the flash, not the top. This yields
additions to the protection range table, as noted in the comments.

Because this feature is not universal to all flash that support
lock/unlock, control it via a new flag.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 62356d50815b..3c36113a88e1 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -85,6 +85,7 @@
 #define SR_BP0                  BIT(2)  /* Block protect 0 */
 #define SR_BP1                  BIT(3)  /* Block protect 1 */
 #define SR_BP2                  BIT(4)  /* Block protect 2 */
+#define SR_TB                   BIT(5)  /* Top/Bottom protect */
 #define SR_SRWD                 BIT(7)  /* SR write protect */
 
 #define SR_QUAD_EN_MX           BIT(6)  /* Macronix Quad I/O */
@@ -116,6 +117,7 @@ enum spi_nor_ops {
 
 enum spi_nor_option_flags {
         SNOR_F_USE_FSR          = BIT(0),
+        SNOR_F_HAS_SR_TB        = BIT(1),
 };
 
 /**