* Several improvements to the new NAND subsystem:

  - JFFS2 related commands implemented in mtd-utils style
  - Support for bad blocks
  - Bad block testing commands
  - NAND lock commands
  Please take a look at doc/README.nand for more details
  Patch by Guido Classen, 10 Oct 2006

1 files changed, 869 insertions, 0 deletions

diff --git a/drivers/nand/nand_util.c b/drivers/nand/nand_util.c
new file mode 100644
index 000000000..5a8e58a74
--- /dev/null
+++ b/drivers/nand/nand_util.c
@@ -0,0 +1,869 @@
+/*
+ * drivers/nand/nand_util.c
+ *
+ * Copyright (C) 2006 by Weiss-Electronic GmbH.
+ * All rights reserved.
+ *
+ * @author:	Guido Classen <clagix@gmail.com>
+ * @descr:	NAND Flash support
+ * @references: borrowed heavily from Linux mtd-utils code:
+ *		flash_eraseall.c by Arcom Control System Ltd
+ *		nandwrite.c by Steven J. Hill (sjhill@realitydiluted.com)
+ *			       and Thomas Gleixner (tglx@linutronix.de)
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+
+#if (CONFIG_COMMANDS & CFG_CMD_NAND) && !defined(CFG_NAND_LEGACY)
+
+#include <command.h>
+#include <watchdog.h>
+#include <malloc.h>
+
+#include <nand.h>
+#include <jffs2/jffs2.h>
+
+typedef struct erase_info erase_info_t;
+typedef struct mtd_info	  mtd_info_t;
+
+/* support only for native endian JFFS2 */
+#define cpu_to_je16(x) (x)
+#define cpu_to_je32(x) (x)
+
+/*****************************************************************************/
+static int nand_block_bad_scrub(struct mtd_info *mtd, loff_t ofs, int getchip)
+{
+	return 0;
+}
+
+/**
+ * nand_erase_opts: - erase NAND flash with support for various options
+ *		      (jffs2 formating)
+ *
+ * @param meminfo	NAND device to erase
+ * @param opts		options,  @see struct nand_erase_options
+ * @return		0 in case of success
+ *
+ * This code is ported from flash_eraseall.c from Linux mtd utils by
+ * Arcom Control System Ltd.
+ */
+int nand_erase_opts(nand_info_t *meminfo, const nand_erase_options_t *opts)
+{
+	struct jffs2_unknown_node cleanmarker;
+	int clmpos = 0;
+	int clmlen = 8;
+	erase_info_t erase;
+	ulong erase_length;
+	int isNAND;
+	int bbtest = 1;
+	int result;
+	int percent_complete = -1;
+	int (*nand_block_bad_old)(struct mtd_info *, loff_t, int) = NULL;
+	const char *mtd_device = meminfo->name;
+
+	memset(&erase, 0, sizeof(erase));
+
+	erase.mtd = meminfo;
+	erase.len  = meminfo->erasesize;
+	if (opts->offset == 0 && opts->length == 0) {
+		/* erase complete chip */
+		erase.addr = 0;
+		erase_length = meminfo->size;
+	} else {
+		/* erase specified region */
+		erase.addr = opts->offset;
+		erase_length = opts->length;
+	}
+
+	isNAND = meminfo->type == MTD_NANDFLASH ? 1 : 0;
+
+	if (opts->jffs2) {
+		cleanmarker.magic = cpu_to_je16 (JFFS2_MAGIC_BITMASK);
+		cleanmarker.nodetype = cpu_to_je16 (JFFS2_NODETYPE_CLEANMARKER);
+		if (isNAND) {
+			struct nand_oobinfo *oobinfo = &meminfo->oobinfo;
+
+			/* check for autoplacement */
+			if (oobinfo->useecc == MTD_NANDECC_AUTOPLACE) {
+				/* get the position of the free bytes */
+				if (!oobinfo->oobfree[0][1]) {
+					printf(" Eeep. Autoplacement selected "
+					       "and no empty space in oob\n");
+					return -1;
+				}
+				clmpos = oobinfo->oobfree[0][0];
+				clmlen = oobinfo->oobfree[0][1];
+				if (clmlen > 8)
+					clmlen = 8;
+			} else {
+				/* legacy mode */
+				switch (meminfo->oobsize) {
+				case 8:
+					clmpos = 6;
+					clmlen = 2;
+					break;
+				case 16:
+					clmpos = 8;
+					clmlen = 8;
+					break;
+				case 64:
+					clmpos = 16;
+					clmlen = 8;
+					break;
+				}
+			}
+
+			cleanmarker.totlen = cpu_to_je32(8);
+		} else {
+			cleanmarker.totlen =
+				cpu_to_je32(sizeof(struct jffs2_unknown_node));
+		}
+		cleanmarker.hdr_crc =  cpu_to_je32(
+			crc32_no_comp(0, (unsigned char *) &cleanmarker,
+				      sizeof(struct jffs2_unknown_node) - 4));
+	}
+
+	/* scrub option allows to erase badblock. To prevent internal
+	 * check from erase() method, set block check method to dummy
+	 * and disable bad block table while erasing.
+	 */
+	if (opts->scrub) {
+		struct nand_chip *priv_nand = meminfo->priv;
+
+		nand_block_bad_old = priv_nand->block_bad;
+		priv_nand->block_bad = nand_block_bad_scrub;
+		/* we don't need the bad block table anymore...
+		 * after scrub, there are no bad blocks left!
+		 */
+		if (priv_nand->bbt) {
+			kfree(priv_nand->bbt);
+		}
+		priv_nand->bbt = NULL;
+	}
+
+	for (;
+	     erase.addr < opts->offset + erase_length;
+	     erase.addr += meminfo->erasesize) {
+
+		WATCHDOG_RESET ();
+
+		if (!opts->scrub && bbtest) {
+			int ret = meminfo->block_isbad(meminfo, erase.addr);
+			if (ret > 0) {
+				if (!opts->quiet)
+					printf("\rSkipping bad block at  "
+                                               "0x%08x                   "
+                                               "                         \n",
+                                               erase.addr);
+				continue;
+
+			} else if (ret < 0) {
+				printf("\n%s: MTD get bad block failed: %d\n",
+				       mtd_device,
+				       ret);
+				return -1;
+			}
+		}
+
+		result = meminfo->erase(meminfo, &erase);
+		if (result != 0) {
+			printf("\n%s: MTD Erase failure: %d\n",
+			       mtd_device, result);
+			continue;
+		}
+
+		/* format for JFFS2 ? */
+		if (opts->jffs2) {
+
+			/* write cleanmarker */
+			if (isNAND) {
+				size_t written;
+				result = meminfo->write_oob(meminfo,
+							    erase.addr + clmpos,
+							    clmlen,
+							    &written,
+							    (unsigned char *)
+							    &cleanmarker);
+				if (result != 0) {
+					printf("\n%s: MTD writeoob failure: %d\n",
+					       mtd_device, result);
+					continue;
+				}
+			} else {
+				printf("\n%s: this erase routine only supports"
+				       " NAND devices!\n",
+				       mtd_device);
+			}
+		}
+
+		if (!opts->quiet) {
+			int percent = (int)
+				((unsigned long long)
+				 (erase.addr+meminfo->erasesize-opts->offset)
+				 * 100 / erase_length);
+
+			/* output progress message only at whole percent
+			 * steps to reduce the number of messages printed
+			 * on (slow) serial consoles
+			 */
+			if (percent != percent_complete) {
+				percent_complete = percent;
+
+				printf("\rErasing at 0x%x -- %3d%% complete.",
+				       erase.addr, percent);
+
+				if (opts->jffs2 && result == 0)
+					printf(" Cleanmarker written at 0x%x.",
+					       erase.addr);
+			}
+		}
+	}
+	if (!opts->quiet)
+		printf("\n");
+
+	if (nand_block_bad_old) {
+		struct nand_chip *priv_nand = meminfo->priv;
+
+		priv_nand->block_bad = nand_block_bad_old;
+		priv_nand->scan_bbt(meminfo);
+	}
+
+	return 0;
+}
+
+#define MAX_PAGE_SIZE	2048
+#define MAX_OOB_SIZE	64
+
+/*
+ * buffer array used for writing data
+ */
+static unsigned char data_buf[MAX_PAGE_SIZE];
+static unsigned char oob_buf[MAX_OOB_SIZE];
+
+/* OOB layouts to pass into the kernel as default */
+static struct nand_oobinfo none_oobinfo = {
+	.useecc = MTD_NANDECC_OFF,
+};
+
+static struct nand_oobinfo jffs2_oobinfo = {
+	.useecc = MTD_NANDECC_PLACE,
+	.eccbytes = 6,
+	.eccpos = { 0, 1, 2, 3, 6, 7 }
+};
+
+static struct nand_oobinfo yaffs_oobinfo = {
+	.useecc = MTD_NANDECC_PLACE,
+	.eccbytes = 6,
+	.eccpos = { 8, 9, 10, 13, 14, 15}
+};
+
+static struct nand_oobinfo autoplace_oobinfo = {
+	.useecc = MTD_NANDECC_AUTOPLACE
+};
+
+/**
+ * nand_write_opts: - write image to NAND flash with support for various options
+ *
+ * @param meminfo	NAND device to erase
+ * @param opts		write options (@see nand_write_options)
+ * @return		0 in case of success
+ *
+ * This code is ported from nandwrite.c from Linux mtd utils by
+ * Steven J. Hill and Thomas Gleixner.
+ */
+int nand_write_opts(nand_info_t *meminfo, const nand_write_options_t *opts)
+{
+	int imglen = 0;
+	int pagelen;
+	int baderaseblock;
+	int blockstart = -1;
+	loff_t offs;
+	int readlen;
+	int oobinfochanged = 0;
+	int percent_complete = -1;
+	struct nand_oobinfo old_oobinfo;
+	ulong mtdoffset = opts->offset;
+	ulong erasesize_blockalign;
+	u_char *buffer = opts->buffer;
+	size_t written;
+	int result;
+
+	if (opts->pad && opts->writeoob) {
+		printf("Can't pad when oob data is present.\n");
+		return -1;
+	}
+
+	/* set erasesize to specified number of blocks - to match
+	 * jffs2 (virtual) block size */
+	if (opts->blockalign == 0) {
+		erasesize_blockalign = meminfo->erasesize;
+	} else {
+		erasesize_blockalign = meminfo->erasesize * opts->blockalign;
+	}
+
+	/* make sure device page sizes are valid */
+	if (!(meminfo->oobsize == 16 && meminfo->oobblock == 512)
+	    && !(meminfo->oobsize == 8 && meminfo->oobblock == 256)
+	    && !(meminfo->oobsize == 64 && meminfo->oobblock == 2048)) {
+		printf("Unknown flash (not normal NAND)\n");
+		return -1;
+	}
+
+	/* read the current oob info */
+	memcpy(&old_oobinfo, &meminfo->oobinfo, sizeof(old_oobinfo));
+
+	/* write without ecc? */
+	if (opts->noecc) {
+		memcpy(&meminfo->oobinfo, &none_oobinfo,
+		       sizeof(meminfo->oobinfo));
+		oobinfochanged = 1;
+	}
+
+	/* autoplace ECC? */
+	if (opts->autoplace && (old_oobinfo.useecc != MTD_NANDECC_AUTOPLACE)) {
+
+		memcpy(&meminfo->oobinfo, &autoplace_oobinfo,
+		       sizeof(meminfo->oobinfo));
+		oobinfochanged = 1;
+	}
+
+	/* force OOB layout for jffs2 or yaffs? */
+	if (opts->forcejffs2 || opts->forceyaffs) {
+		struct nand_oobinfo *oobsel =
+			opts->forcejffs2 ? &jffs2_oobinfo : &yaffs_oobinfo;
+
+		if (meminfo->oobsize == 8) {
+			if (opts->forceyaffs) {
+				printf("YAFSS cannot operate on "
+				       "256 Byte page size\n");
+				goto restoreoob;
+			}
+			/* Adjust number of ecc bytes */
+			jffs2_oobinfo.eccbytes = 3;
+		}
+
+		memcpy(&meminfo->oobinfo, oobsel, sizeof(meminfo->oobinfo));
+	}
+
+	/* get image length */
+	imglen = opts->length;
+	pagelen = meminfo->oobblock
+		+ ((opts->writeoob != 0) ? meminfo->oobsize : 0);
+
+	/* check, if file is pagealigned */
+	if ((!opts->pad) && ((imglen % pagelen) != 0)) {
+		printf("Input block length is not page aligned\n");
+		goto restoreoob;
+	}
+
+	/* check, if length fits into device */
+	if (((imglen / pagelen) * meminfo->oobblock)
+	     > (meminfo->size - opts->offset)) {
+		printf("Image %d bytes, NAND page %d bytes, "
+		       "OOB area %u bytes, device size %u bytes\n",
+		       imglen, pagelen, meminfo->oobblock, meminfo->size);
+		printf("Input block does not fit into device\n");
+		goto restoreoob;
+	}
+
+	if (!opts->quiet)
+		printf("\n");
+
+	/* get data from input and write to the device */
+	while (imglen && (mtdoffset < meminfo->size)) {
+
+		WATCHDOG_RESET ();
+
+		/*
+		 * new eraseblock, check for bad block(s). Stay in the
+		 * loop to be sure if the offset changes because of
+		 * a bad block, that the next block that will be
+		 * written to is also checked. Thus avoiding errors if
+		 * the block(s) after the skipped block(s) is also bad
+		 * (number of blocks depending on the blockalign
+		 */
+		while (blockstart != (mtdoffset & (~erasesize_blockalign+1))) {
+			blockstart = mtdoffset & (~erasesize_blockalign+1);
+			offs = blockstart;
+			baderaseblock = 0;
+
+			/* check all the blocks in an erase block for
+			 * bad blocks */
+			do {
+				int ret = meminfo->block_isbad(meminfo, offs);
+
+				if (ret < 0) {
+					printf("Bad block check failed\n");
+					goto restoreoob;
+				}
+				if (ret == 1) {
+					baderaseblock = 1;
+					if (!opts->quiet)
+						printf("\rBad block at 0x%lx "
+						       "in erase block from "
+						       "0x%x will be skipped\n",
+						       (long) offs,
+						       blockstart);
+				}
+
+				if (baderaseblock) {
+					mtdoffset = blockstart
+						+ erasesize_blockalign;
+				}
+				offs +=	 erasesize_blockalign
+					/ opts->blockalign;
+			} while (offs < blockstart + erasesize_blockalign);
+		}
+
+		readlen = meminfo->oobblock;
+		if (opts->pad && (imglen < readlen)) {
+			readlen = imglen;
+			memset(data_buf + readlen, 0xff,
+			       meminfo->oobblock - readlen);
+		}
+
+		/* read page data from input memory buffer */
+		memcpy(data_buf, buffer, readlen);
+		buffer += readlen;
+
+		if (opts->writeoob) {
+			/* read OOB data from input memory block, exit
+			 * on failure */
+			memcpy(oob_buf, buffer, meminfo->oobsize);
+			buffer += meminfo->oobsize;
+
+			/* write OOB data first, as ecc will be placed
+			 * in there*/
+			result = meminfo->write_oob(meminfo,
+						    mtdoffset,
+						    meminfo->oobsize,
+						    &written,
+						    (unsigned char *)
+						    &oob_buf);
+
+			if (result != 0) {
+				printf("\nMTD writeoob failure: %d\n",
+				       result);
+				goto restoreoob;
+			}
+			imglen -= meminfo->oobsize;
+		}
+
+		/* write out the page data */
+		result = meminfo->write(meminfo,
+					mtdoffset,
+					meminfo->oobblock,
+					&written,
+					(unsigned char *) &data_buf);
+
+		if (result != 0) {
+			printf("writing NAND page at offset 0x%lx failed\n",
+			       mtdoffset);
+			goto restoreoob;
+		}
+		imglen -= readlen;
+
+		if (!opts->quiet) {
+			int percent = (int)
+				((unsigned long long)
+				 (opts->length-imglen) * 100
+				 / opts->length);
+			/* output progress message only at whole percent
+			 * steps to reduce the number of messages printed
+			 * on (slow) serial consoles
+			 */
+			if (percent != percent_complete) {
+				printf("\rWriting data at 0x%x "
+				       "-- %3d%% complete.",
+				       mtdoffset, percent);
+				percent_complete = percent;
+			}
+		}
+
+		mtdoffset += meminfo->oobblock;
+	}
+
+	if (!opts->quiet)
+		printf("\n");
+
+restoreoob:
+	if (oobinfochanged) {
+		memcpy(&meminfo->oobinfo, &old_oobinfo,
+		       sizeof(meminfo->oobinfo));
+	}
+
+	if (imglen > 0) {
+		printf("Data did not fit into device, due to bad blocks\n");
+		return -1;
+	}
+
+	/* return happy */
+	return 0;
+}
+
+/**
+ * nand_read_opts: - read image from NAND flash with support for various options
+ *
+ * @param meminfo	NAND device to erase
+ * @param opts		read options (@see struct nand_read_options)
+ * @return		0 in case of success
+ *
+ */
+int nand_read_opts(nand_info_t *meminfo, const nand_read_options_t *opts)
+{
+	int imglen = opts->length;
+	int pagelen;
+	int baderaseblock;
+	int blockstart = -1;
+	int percent_complete = -1;
+	loff_t offs;
+	size_t readlen;
+	ulong mtdoffset = opts->offset;
+	u_char *buffer = opts->buffer;
+	int result;
+
+	/* make sure device page sizes are valid */
+	if (!(meminfo->oobsize == 16 && meminfo->oobblock == 512)
+	    && !(meminfo->oobsize == 8 && meminfo->oobblock == 256)
+	    && !(meminfo->oobsize == 64 && meminfo->oobblock == 2048)) {
+		printf("Unknown flash (not normal NAND)\n");
+		return -1;
+	}
+
+	pagelen = meminfo->oobblock
+		+ ((opts->readoob != 0) ? meminfo->oobsize : 0);
+
+	/* check, if length is not larger than device */
+	if (((imglen / pagelen) * meminfo->oobblock)
+	     > (meminfo->size - opts->offset)) {
+		printf("Image %d bytes, NAND page %d bytes, "
+		       "OOB area %u bytes, device size %u bytes\n",
+		       imglen, pagelen, meminfo->oobblock, meminfo->size);
+		printf("Input block is larger than device\n");
+		return -1;
+	}
+
+	if (!opts->quiet)
+		printf("\n");
+
+	/* get data from input and write to the device */
+	while (imglen && (mtdoffset < meminfo->size)) {
+
+		WATCHDOG_RESET ();
+
+		/*
+		 * new eraseblock, check for bad block(s). Stay in the
+		 * loop to be sure if the offset changes because of
+		 * a bad block, that the next block that will be
+		 * written to is also checked. Thus avoiding errors if
+		 * the block(s) after the skipped block(s) is also bad
+		 * (number of blocks depending on the blockalign
+		 */
+		while (blockstart != (mtdoffset & (~meminfo->erasesize+1))) {
+			blockstart = mtdoffset & (~meminfo->erasesize+1);
+			offs = blockstart;
+			baderaseblock = 0;
+
+			/* check all the blocks in an erase block for
+			 * bad blocks */
+			do {
+				int ret = meminfo->block_isbad(meminfo, offs);
+
+				if (ret < 0) {
+					printf("Bad block check failed\n");
+					return -1;
+				}
+				if (ret == 1) {
+					baderaseblock = 1;
+					if (!opts->quiet)
+						printf("\rBad block at 0x%lx "
+						       "in erase block from "
+						       "0x%x will be skipped\n",
+						       (long) offs,
+						       blockstart);
+				}
+
+				if (baderaseblock) {
+					mtdoffset = blockstart
+						+ meminfo->erasesize;
+				}
+				offs +=	 meminfo->erasesize;
+
+			} while (offs < blockstart + meminfo->erasesize);
+		}
+
+
+		/* read page data to memory buffer */
+		result = meminfo->read(meminfo,
+				       mtdoffset,
+				       meminfo->oobblock,
+				       &readlen,
+				       (unsigned char *) &data_buf);
+
+		if (result != 0) {
+			printf("reading NAND page at offset 0x%lx failed\n",
+			       mtdoffset);
+			return -1;
+		}
+
+		if (imglen < readlen) {
+			readlen = imglen;
+		}
+
+		memcpy(buffer, data_buf, readlen);
+		buffer += readlen;
+		imglen -= readlen;
+
+		if (opts->readoob) {
+			result = meminfo->read_oob(meminfo,
+						   mtdoffset,
+						   meminfo->oobsize,
+						   &readlen,
+						   (unsigned char *)
+						   &oob_buf);
+
+			if (result != 0) {
+				printf("\nMTD readoob failure: %d\n",
+				       result);
+				return -1;
+			}
+
+
+			if (imglen < readlen) {
+				readlen = imglen;
+			}
+
+			memcpy(buffer, oob_buf, readlen);
+
+			buffer += readlen;
+			imglen -= readlen;
+		}
+
+		if (!opts->quiet) {
+			int percent = (int)
+				((unsigned long long)
+				 (opts->length-imglen) * 100
+				 / opts->length);
+			/* output progress message only at whole percent
+			 * steps to reduce the number of messages printed
+			 * on (slow) serial consoles
+			 */
+			if (percent != percent_complete) {
+			if (!opts->quiet)
+				printf("\rReading data from 0x%x "
+				       "-- %3d%% complete.",
+				       mtdoffset, percent);
+				percent_complete = percent;
+			}
+		}
+
+		mtdoffset += meminfo->oobblock;
+	}
+
+	if (!opts->quiet)
+		printf("\n");
+
+	if (imglen > 0) {
+		printf("Could not read entire image due to bad blocks\n");
+		return -1;
+	}
+
+	/* return happy */
+	return 0;
+}
+
+/******************************************************************************
+ * Support for locking / unlocking operations of some NAND devices
+ *****************************************************************************/
+
+#define NAND_CMD_LOCK		0x2a
+#define NAND_CMD_LOCK_TIGHT	0x2c
+#define NAND_CMD_UNLOCK1	0x23
+#define NAND_CMD_UNLOCK2	0x24
+#define NAND_CMD_LOCK_STATUS	0x7a
+
+/**
+ * nand_lock: Set all pages of NAND flash chip to the LOCK or LOCK-TIGHT
+ *	      state
+ *
+ * @param meminfo	nand mtd instance
+ * @param tight		bring device in lock tight mode
+ *
+ * @return		0 on success, -1 in case of error
+ *
+ * The lock / lock-tight command only applies to the whole chip. To get some
+ * parts of the chip lock and others unlocked use the following sequence:
+ *
+ * - Lock all pages of the chip using nand_lock(mtd, 0) (or the lockpre pin)
+ * - Call nand_unlock() once for each consecutive area to be unlocked
+ * - If desired: Bring the chip to the lock-tight state using nand_lock(mtd, 1)
+ *
+ *   If the device is in lock-tight state software can't change the
+ *   current active lock/unlock state of all pages. nand_lock() / nand_unlock()
+ *   calls will fail. It is only posible to leave lock-tight state by
+ *   an hardware signal (low pulse on _WP pin) or by power down.
+ */
+int nand_lock(nand_info_t *meminfo, int tight)
+{
+	int ret = 0;
+	int status;
+	struct nand_chip *this = meminfo->priv;
+
+	/* select the NAND device */
+	this->select_chip(meminfo, 0);
+
+	this->cmdfunc(meminfo,
+		      (tight ? NAND_CMD_LOCK_TIGHT : NAND_CMD_LOCK),
+		      -1, -1);
+
+	/* call wait ready function */
+	status = this->waitfunc(meminfo, this, FL_WRITING);
+
+	/* see if device thinks it succeeded */
+	if (status & 0x01) {
+		ret = -1;
+	}
+
+	/* de-select the NAND device */
+	this->select_chip(meminfo, -1);
+	return ret;
+}
+
+/**
+ * nand_get_lock_status: - query current lock state from one page of NAND
+ *			   flash
+ *
+ * @param meminfo	nand mtd instance
+ * @param offset	page address to query (muss be page aligned!)
+ *
+ * @return		-1 in case of error
+ *			>0 lock status:
+ *			  bitfield with the following combinations:
+ *			  NAND_LOCK_STATUS_TIGHT: page in tight state
+ *			  NAND_LOCK_STATUS_LOCK:  page locked
+ *			  NAND_LOCK_STATUS_UNLOCK: page unlocked
+ *
+ */
+int nand_get_lock_status(nand_info_t *meminfo, ulong offset)
+{
+	int ret = 0;
+	int chipnr;
+	int page;
+	struct nand_chip *this = meminfo->priv;
+
+	/* select the NAND device */
+	chipnr = (int)(offset >> this->chip_shift);
+	this->select_chip(meminfo, chipnr);
+
+
+	if ((offset & (meminfo->oobblock - 1)) != 0) {
+		printf ("nand_get_lock_status: "
+			"Start address must be beginning of "
+			"nand page!\n");
+		ret = -1;
+		goto out;
+	}
+
+	/* check the Lock Status */
+	page = (int)(offset >> this->page_shift);
+	this->cmdfunc(meminfo, NAND_CMD_LOCK_STATUS, -1, page & this->pagemask);
+
+	ret = this->read_byte(meminfo) & (NAND_LOCK_STATUS_TIGHT
+					  | NAND_LOCK_STATUS_LOCK
+					  | NAND_LOCK_STATUS_UNLOCK);
+
+ out:
+	/* de-select the NAND device */
+	this->select_chip(meminfo, -1);
+	return ret;
+}
+
+/**
+ * nand_unlock: - Unlock area of NAND pages
+ *		  only one consecutive area can be unlocked at one time!
+ *
+ * @param meminfo	nand mtd instance
+ * @param start		start byte address
+ * @param length	number of bytes to unlock (must be a multiple of
+ *			page size nand->oobblock)
+ *
+ * @return		0 on success, -1 in case of error
+ */
+int nand_unlock(nand_info_t *meminfo, ulong start, ulong length)
+{
+	int ret = 0;
+	int chipnr;
+	int status;
+	int page;
+	struct nand_chip *this = meminfo->priv;
+	printf ("nand_unlock: start: %08x, length: %d!\n",
+		(int)start, (int)length);
+
+	/* select the NAND device */
+	chipnr = (int)(start >> this->chip_shift);
+	this->select_chip(meminfo, chipnr);
+
+	/* check the WP bit */
+	this->cmdfunc(meminfo, NAND_CMD_STATUS, -1, -1);
+	if ((this->read_byte(meminfo) & 0x80) == 0) {
+		printf ("nand_unlock: Device is write protected!\n");
+		ret = -1;
+		goto out;
+	}
+
+	if ((start & (meminfo->oobblock - 1)) != 0) {
+		printf ("nand_unlock: Start address must be beginning of "
+			"nand page!\n");
+		ret = -1;
+		goto out;
+	}
+
+	if (length == 0 || (length & (meminfo->oobblock - 1)) != 0) {
+		printf ("nand_unlock: Length must be a multiple of nand page "
+			"size!\n");
+		ret = -1;
+		goto out;
+	}
+
+	/* submit address of first page to unlock */
+	page = (int)(start >> this->page_shift);
+	this->cmdfunc(meminfo, NAND_CMD_UNLOCK1, -1, page & this->pagemask);
+
+	/* submit ADDRESS of LAST page to unlock */
+	page += (int)(length >> this->page_shift) - 1;
+	this->cmdfunc(meminfo, NAND_CMD_UNLOCK2, -1, page & this->pagemask);
+
+	/* call wait ready function */
+	status = this->waitfunc(meminfo, this, FL_WRITING);
+	/* see if device thinks it succeeded */
+	if (status & 0x01) {
+		/* there was an error */
+		ret = -1;
+		goto out;
+	}
+
+ out:
+	/* de-select the NAND device */
+	this->select_chip(meminfo, -1);
+	return ret;
+}
+
+#endif /* (CONFIG_COMMANDS & CFG_CMD_NAND) && !defined(CFG_NAND_LEGACY) */