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-rw-r--r--drivers/mtd/nand/nand_util.c858
1 files changed, 858 insertions, 0 deletions
diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
new file mode 100644
index 0000000000..d57294e624
--- /dev/null
+++ b/drivers/mtd/nand/nand_util.c
@@ -0,0 +1,858 @@
+/*
+ * 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>
+#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;
+ 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;
+}
+