[MTD] Support for protection register support on Intel FLASH chips

[mv-sheeva.git] / drivers / mtd / chips / Kconfig

diff --git a/drivers/mtd/chips/Kconfig b/drivers/mtd/chips/Kconfig
index d682dbc8157e4030a641a245b305ea7d112593e2..f4eda1e40d519edb3e423246d9b8f03ba6e1d81a 100644 (file)
--- a/drivers/mtd/chips/Kconfig
+++ b/drivers/mtd/chips/Kconfig
@@ -1,5 +1,5 @@
 # drivers/mtd/chips/Kconfig
-# $Id: Kconfig,v 1.13 2004/12/01 15:49:10 nico Exp $
+# $Id: Kconfig,v 1.14 2005/02/08 17:11:15 nico Exp $
 
 menu "RAM/ROM/Flash chip drivers"
        depends on MTD!=n
@@ -155,6 +155,31 @@ config MTD_CFI_I8
          If your flash chips are interleaved in eights - i.e. you have eight
          flash chips addressed by each bus cycle, then say 'Y'.
 
+config MTD_OTP
+       bool "Protection Registers aka one-time programmable (OTP) bits"
+       depends on MTD_CFI_ADV_OPTIONS
+       default n
+       help
+         This enables support for reading, writing and locking so called
+         "Protection Registers" present on some flash chips.
+         A subset of them are pre-programmed at the factory with a
+         unique set of values. The rest is user-programmable.
+
+         The user-programmable Protection Registers contain one-time
+         programmable (OTP) bits; when programmed, register bits cannot be
+         erased. Each Protection Register can be accessed multiple times to
+         program individual bits, as long as the register remains unlocked.
+
+         Each Protection Register has an associated Lock Register bit. When a
+         Lock Register bit is programmed, the associated Protection Register
+         can only be read; it can no longer be programmed. Additionally,
+         because the Lock Register bits themselves are OTP, when programmed,
+         Lock Register bits cannot be erased. Therefore, when a Protection
+         Register is locked, it cannot be unlocked.
+
+         This feature should therefore be used with extreme care. Any mistake
+         in the programming of OTP bits will waste them.
+
 config MTD_CFI_INTELEXT
        tristate "Support for Intel/Sharp flash chips"
        depends on MTD_GEN_PROBE