[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>

drivers/mtd/chips/Kconfig

 # 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

drivers/mtd/mtdpart.c

@@ -5,7 +5,7 @@
  *
  * This code is GPL
  *
- * $Id: mtdpart.c,v 1.51 2004/11/16 18:28:59 dwmw2 Exp $
+ * $Id: mtdpart.c,v 1.53 2005/02/08 17:11:13 nico Exp $
  *
  * 	02-21-2002	Thomas Gleixner <gleixner@autronix.de>
  *			added support for read_oob, write_oob
@@ -116,6 +116,13 @@ static int part_read_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t le
 					len, retlen, buf);
 }
 
+static int part_get_user_prot_info (struct mtd_info *mtd,
+				    struct otp_info *buf, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->get_user_prot_info (part->master, buf, len);
+}
+
 static int part_read_fact_prot_reg (struct mtd_info *mtd, loff_t from, size_t len, 
 			size_t *retlen, u_char *buf)
 {
@@ -124,6 +131,13 @@ static int part_read_fact_prot_reg (struct mtd_info *mtd, loff_t from, size_t le
 					len, retlen, buf);
 }
 
+static int part_get_fact_prot_info (struct mtd_info *mtd,
+				    struct otp_info *buf, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->get_fact_prot_info (part->master, buf, len);
+}
+
 static int part_write (struct mtd_info *mtd, loff_t to, size_t len,
 			size_t *retlen, const u_char *buf)
 {
@@ -182,6 +196,12 @@ static int part_write_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t l
 					len, retlen, buf);
 }
 
+static int part_lock_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len) 
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->lock_user_prot_reg (part->master, from, len);
+}
+
 static int part_writev (struct mtd_info *mtd,  const struct kvec *vecs,
 			 unsigned long count, loff_t to, size_t *retlen)
 {
@@ -409,6 +429,12 @@ int add_mtd_partitions(struct mtd_info *master,
 			slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
 		if(master->write_user_prot_reg)
 			slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
+		if(master->lock_user_prot_reg)
+			slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
+		if(master->get_user_prot_info)
+			slave->mtd.get_user_prot_info = part_get_user_prot_info;
+		if(master->get_fact_prot_info)
+			slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
 		if (master->sync)
 			slave->mtd.sync = part_sync;
 		if (!i && master->suspend && master->resume) {

include/linux/mtd/cfi.h

 
 /* Common Flash Interface structures 
  * See http://support.intel.com/design/flash/technote/index.htm
- * $Id: cfi.h,v 1.51 2005/02/05 02:06:16 nico Exp $
+ * $Id: cfi.h,v 1.52 2005/02/08 17:11:15 nico Exp $
  */
 
 #ifndef __MTD_CFI_H__
@@ -252,7 +252,7 @@ static inline uint32_t cfi_build_cmd_addr(uint32_t cmd_ofs, int interleave, int
  * It looks too long to be inline, but in the common case it should almost all
  * get optimised away. 
  */
-static inline map_word cfi_build_cmd(u_char cmd, struct map_info *map, struct cfi_private *cfi)
+static inline map_word cfi_build_cmd(u_long cmd, struct map_info *map, struct cfi_private *cfi)
 {
 	map_word val = { {0} };
 	int wordwidth, words_per_bus, chip_mode, chips_per_word;

include/linux/mtd/flashchip.h

@@ -6,7 +6,7 @@
  *
  * (C) 2000 Red Hat. GPLd.
  *
- * $Id: flashchip.h,v 1.15 2004/11/05 22:41:06 nico Exp $
+ * $Id: flashchip.h,v 1.16 2005/02/08 17:11:15 nico Exp $
  *
  */
 
@@ -29,6 +29,7 @@ typedef enum {
 	FL_ERASE_SUSPENDED,
 	FL_WRITING,
 	FL_WRITING_TO_BUFFER,
+	FL_OTP_WRITE,
 	FL_WRITE_SUSPENDING,
 	FL_WRITE_SUSPENDED,
 	FL_PM_SUSPENDED,

include/linux/mtd/map.h

 
 /* Overhauled routines for dealing with different mmap regions of flash */
-/* $Id: map.h,v 1.46 2005/01/05 17:09:44 dwmw2 Exp $ */
+/* $Id: map.h,v 1.47 2005/02/08 17:11:15 nico Exp $ */
 
 #ifndef __LINUX_MTD_MAP_H__
 #define __LINUX_MTD_MAP_H__
@@ -263,6 +263,17 @@ static inline map_word map_word_and(struct map_info *map, map_word val1, map_wor
 	return r;
 }
 
+static inline map_word map_word_clr(struct map_info *map, map_word val1, map_word val2)
+{
+	map_word r;
+	int i;
+
+	for (i=0; i<map_words(map); i++) {
+		r.x[i] = val1.x[i] & ~val2.x[i];
+	}
+	return r;
+}
+
 static inline map_word map_word_or(struct map_info *map, map_word val1, map_word val2)
 {
 	map_word r;
@@ -273,6 +284,7 @@ static inline map_word map_word_or(struct map_info *map, map_word val1, map_word
 	}
 	return r;
 }
+
 #define map_word_andequal(m, a, b, z) map_word_equal(m, z, map_word_and(m, a, b))
 
 static inline int map_word_bitsset(struct map_info *map, map_word val1, map_word val2)
@@ -338,6 +350,7 @@ static inline map_word map_word_ff(struct map_info *map)
 	}
 	return r;
 }
+
 static inline map_word inline_map_read(struct map_info *map, unsigned long ofs)
 {
 	map_word r;

include/linux/mtd/mtd.h

 /* 
- * $Id: mtd.h,v 1.56 2004/08/09 18:46:04 dmarlin Exp $
+ * $Id: mtd.h,v 1.57 2005/02/08 17:11:15 nico Exp $
  *
  * Copyright (C) 1999-2003 David Woodhouse <dwmw2@infradead.org> et al.
  *
@@ -113,12 +113,12 @@ struct mtd_info {
 	 * flash devices. The user data is one time programmable but the
 	 * factory data is read only. 
 	 */
-	int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
-
+	int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 	int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
-
-	/* This function is not yet implemented */
+	int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
+	int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 	int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
+	int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
 
 	/* kvec-based read/write methods. We need these especially for NAND flash,
 	   with its limited number of write cycles per erase.

include/mtd/mtd-abi.h

 /*
- * $Id: mtd-abi.h,v 1.7 2004/11/23 15:37:32 gleixner Exp $
+ * $Id: mtd-abi.h,v 1.8 2005/02/08 17:11:16 nico Exp $
  *
  * Portions of MTD ABI definition which are shared by kernel and user space 
  */
@@ -80,6 +80,12 @@ struct region_info_user {
 	uint32_t regionindex;
 };
 
+struct otp_info {
+	uint32_t start;
+	uint32_t length;
+	uint32_t locked;
+};
+
 #define MEMGETINFO              _IOR('M', 1, struct mtd_info_user)
 #define MEMERASE                _IOW('M', 2, struct erase_info_user)
 #define MEMWRITEOOB             _IOWR('M', 3, struct mtd_oob_buf)