From f77814dd5728edaf1239d19755d2aa0d8c33d861 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 8 Feb 2005 17:11:19 +0000 Subject: [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 Signed-off-by: Thomas Gleixner --- drivers/mtd/chips/Kconfig | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) (limited to 'drivers/mtd/chips/Kconfig') diff --git a/drivers/mtd/chips/Kconfig b/drivers/mtd/chips/Kconfig index d682dbc8157..f4eda1e40d5 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 @@ 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 -- cgit v1.2.2