[MTD] Support for protection register support on Intel FLASH chips
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.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/mtd/chips/Kconfig b/drivers/mtd/chips/Kconfig
index d682dbc..f4eda1e 100644
--- 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 @@
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