Rewrite of NAND code based on what is in 2.6.12 Linux kernel
Patch by Ladislav Michl, 29 Jun 2005
diff --git a/drivers/nand/nand_bbt.c b/drivers/nand/nand_bbt.c
new file mode 100644
index 0000000..6f7e05b
--- /dev/null
+++ b/drivers/nand/nand_bbt.c
@@ -0,0 +1,1056 @@
+/*
+ * drivers/mtd/nand_bbt.c
+ *
+ * Overview:
+ * Bad block table support for the NAND driver
+ *
+ * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
+ *
+ * $Id: nand_bbt.c,v 1.28 2004/11/13 10:19:09 gleixner Exp $
+ *
+ * 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.
+ *
+ * Description:
+ *
+ * When nand_scan_bbt is called, then it tries to find the bad block table
+ * depending on the options in the bbt descriptor(s). If a bbt is found
+ * then the contents are read and the memory based bbt is created. If a
+ * mirrored bbt is selected then the mirror is searched too and the
+ * versions are compared. If the mirror has a greater version number
+ * than the mirror bbt is used to build the memory based bbt.
+ * If the tables are not versioned, then we "or" the bad block information.
+ * If one of the bbt's is out of date or does not exist it is (re)created.
+ * If no bbt exists at all then the device is scanned for factory marked
+ * good / bad blocks and the bad block tables are created.
+ *
+ * For manufacturer created bbts like the one found on M-SYS DOC devices
+ * the bbt is searched and read but never created
+ *
+ * The autogenerated bad block table is located in the last good blocks
+ * of the device. The table is mirrored, so it can be updated eventually.
+ * The table is marked in the oob area with an ident pattern and a version
+ * number which indicates which of both tables is more up to date.
+ *
+ * The table uses 2 bits per block
+ * 11b: block is good
+ * 00b: block is factory marked bad
+ * 01b, 10b: block is marked bad due to wear
+ *
+ * The memory bad block table uses the following scheme:
+ * 00b: block is good
+ * 01b: block is marked bad due to wear
+ * 10b: block is reserved (to protect the bbt area)
+ * 11b: block is factory marked bad
+ *
+ * Multichip devices like DOC store the bad block info per floor.
+ *
+ * Following assumptions are made:
+ * - bbts start at a page boundary, if autolocated on a block boundary
+ * - the space neccecary for a bbt in FLASH does not exceed a block boundary
+ *
+ */
+
+#include <common.h>
+
+#if (CONFIG_COMMANDS & CFG_CMD_NAND)
+
+#include <malloc.h>
+#include <linux/mtd/compat.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+
+#include <asm/errno.h>
+
+/**
+ * check_pattern - [GENERIC] check if a pattern is in the buffer
+ * @buf: the buffer to search
+ * @len: the length of buffer to search
+ * @paglen: the pagelength
+ * @td: search pattern descriptor
+ *
+ * Check for a pattern at the given place. Used to search bad block
+ * tables and good / bad block identifiers.
+ * If the SCAN_EMPTY option is set then check, if all bytes except the
+ * pattern area contain 0xff
+ *
+*/
+static int check_pattern (uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
+{
+ int i, end;
+ uint8_t *p = buf;
+
+ end = paglen + td->offs;
+ if (td->options & NAND_BBT_SCANEMPTY) {
+ for (i = 0; i < end; i++) {
+ if (p[i] != 0xff)
+ return -1;
+ }
+ }
+ p += end;
+
+ /* Compare the pattern */
+ for (i = 0; i < td->len; i++) {
+ if (p[i] != td->pattern[i])
+ return -1;
+ }
+
+ p += td->len;
+ end += td->len;
+ if (td->options & NAND_BBT_SCANEMPTY) {
+ for (i = end; i < len; i++) {
+ if (*p++ != 0xff)
+ return -1;
+ }
+ }
+ return 0;
+}
+
+/**
+ * read_bbt - [GENERIC] Read the bad block table starting from page
+ * @mtd: MTD device structure
+ * @buf: temporary buffer
+ * @page: the starting page
+ * @num: the number of bbt descriptors to read
+ * @bits: number of bits per block
+ * @offs: offset in the memory table
+ * @reserved_block_code: Pattern to identify reserved blocks
+ *
+ * Read the bad block table starting from page.
+ *
+ */
+static int read_bbt (struct mtd_info *mtd, uint8_t *buf, int page, int num,
+ int bits, int offs, int reserved_block_code)
+{
+ int res, i, j, act = 0;
+ struct nand_chip *this = mtd->priv;
+ size_t retlen, len, totlen;
+ loff_t from;
+ uint8_t msk = (uint8_t) ((1 << bits) - 1);
+
+ totlen = (num * bits) >> 3;
+ from = ((loff_t)page) << this->page_shift;
+
+ while (totlen) {
+ len = min (totlen, (size_t) (1 << this->bbt_erase_shift));
+ res = mtd->read_ecc (mtd, from, len, &retlen, buf, NULL, this->autooob);
+ if (res < 0) {
+ if (retlen != len) {
+ printk (KERN_INFO "nand_bbt: Error reading bad block table\n");
+ return res;
+ }
+ printk (KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
+ }
+
+ /* Analyse data */
+ for (i = 0; i < len; i++) {
+ uint8_t dat = buf[i];
+ for (j = 0; j < 8; j += bits, act += 2) {
+ uint8_t tmp = (dat >> j) & msk;
+ if (tmp == msk)
+ continue;
+ if (reserved_block_code &&
+ (tmp == reserved_block_code)) {
+ printk (KERN_DEBUG "nand_read_bbt: Reserved block at 0x%08x\n",
+ ((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
+ this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
+ continue;
+ }
+ /* Leave it for now, if its matured we can move this
+ * message to MTD_DEBUG_LEVEL0 */
+ printk (KERN_DEBUG "nand_read_bbt: Bad block at 0x%08x\n",
+ ((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
+ /* Factory marked bad or worn out ? */
+ if (tmp == 0)
+ this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
+ else
+ this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
+ }
+ }
+ totlen -= len;
+ from += len;
+ }
+ return 0;
+}
+
+/**
+ * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
+ * @mtd: MTD device structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ * @chip: read the table for a specific chip, -1 read all chips.
+ * Applies only if NAND_BBT_PERCHIP option is set
+ *
+ * Read the bad block table for all chips starting at a given page
+ * We assume that the bbt bits are in consecutive order.
+*/
+static int read_abs_bbt (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
+{
+ struct nand_chip *this = mtd->priv;
+ int res = 0, i;
+ int bits;
+
+ bits = td->options & NAND_BBT_NRBITS_MSK;
+ if (td->options & NAND_BBT_PERCHIP) {
+ int offs = 0;
+ for (i = 0; i < this->numchips; i++) {
+ if (chip == -1 || chip == i)
+ res = read_bbt (mtd, buf, td->pages[i], this->chipsize >> this->bbt_erase_shift, bits, offs, td->reserved_block_code);
+ if (res)
+ return res;
+ offs += this->chipsize >> (this->bbt_erase_shift + 2);
+ }
+ } else {
+ res = read_bbt (mtd, buf, td->pages[0], mtd->size >> this->bbt_erase_shift, bits, 0, td->reserved_block_code);
+ if (res)
+ return res;
+ }
+ return 0;
+}
+
+/**
+ * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
+ * @mtd: MTD device structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ * @md: descriptor for the bad block table mirror
+ *
+ * Read the bad block table(s) for all chips starting at a given page
+ * We assume that the bbt bits are in consecutive order.
+ *
+*/
+static int read_abs_bbts (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td,
+ struct nand_bbt_descr *md)
+{
+ struct nand_chip *this = mtd->priv;
+
+ /* Read the primary version, if available */
+ if (td->options & NAND_BBT_VERSION) {
+ nand_read_raw (mtd, buf, td->pages[0] << this->page_shift, mtd->oobblock, mtd->oobsize);
+ td->version[0] = buf[mtd->oobblock + td->veroffs];
+ printk (KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", td->pages[0], td->version[0]);
+ }
+
+ /* Read the mirror version, if available */
+ if (md && (md->options & NAND_BBT_VERSION)) {
+ nand_read_raw (mtd, buf, md->pages[0] << this->page_shift, mtd->oobblock, mtd->oobsize);
+ md->version[0] = buf[mtd->oobblock + md->veroffs];
+ printk (KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", md->pages[0], md->version[0]);
+ }
+
+ return 1;
+}
+
+/**
+ * create_bbt - [GENERIC] Create a bad block table by scanning the device
+ * @mtd: MTD device structure
+ * @buf: temporary buffer
+ * @bd: descriptor for the good/bad block search pattern
+ * @chip: create the table for a specific chip, -1 read all chips.
+ * Applies only if NAND_BBT_PERCHIP option is set
+ *
+ * Create a bad block table by scanning the device
+ * for the given good/bad block identify pattern
+ */
+static void create_bbt (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd, int chip)
+{
+ struct nand_chip *this = mtd->priv;
+ int i, j, numblocks, len, scanlen;
+ int startblock;
+ loff_t from;
+ size_t readlen, ooblen;
+
+ printk (KERN_INFO "Scanning device for bad blocks\n");
+
+ if (bd->options & NAND_BBT_SCANALLPAGES)
+ len = 1 << (this->bbt_erase_shift - this->page_shift);
+ else {
+ if (bd->options & NAND_BBT_SCAN2NDPAGE)
+ len = 2;
+ else
+ len = 1;
+ }
+ scanlen = mtd->oobblock + mtd->oobsize;
+ readlen = len * mtd->oobblock;
+ ooblen = len * mtd->oobsize;
+
+ if (chip == -1) {
+ /* Note that numblocks is 2 * (real numblocks) here, see i+=2 below as it
+ * makes shifting and masking less painful */
+ numblocks = mtd->size >> (this->bbt_erase_shift - 1);
+ startblock = 0;
+ from = 0;
+ } else {
+ if (chip >= this->numchips) {
+ printk (KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
+ chip + 1, this->numchips);
+ return;
+ }
+ numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
+ startblock = chip * numblocks;
+ numblocks += startblock;
+ from = startblock << (this->bbt_erase_shift - 1);
+ }
+
+ for (i = startblock; i < numblocks;) {
+ nand_read_raw (mtd, buf, from, readlen, ooblen);
+ for (j = 0; j < len; j++) {
+ if (check_pattern (&buf[j * scanlen], scanlen, mtd->oobblock, bd)) {
+ this->bbt[i >> 3] |= 0x03 << (i & 0x6);
+ printk (KERN_WARNING "Bad eraseblock %d at 0x%08x\n",
+ i >> 1, (unsigned int) from);
+ break;
+ }
+ }
+ i += 2;
+ from += (1 << this->bbt_erase_shift);
+ }
+}
+
+/**
+ * search_bbt - [GENERIC] scan the device for a specific bad block table
+ * @mtd: MTD device structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ *
+ * Read the bad block table by searching for a given ident pattern.
+ * Search is preformed either from the beginning up or from the end of
+ * the device downwards. The search starts always at the start of a
+ * block.
+ * If the option NAND_BBT_PERCHIP is given, each chip is searched
+ * for a bbt, which contains the bad block information of this chip.
+ * This is neccecary to provide support for certain DOC devices.
+ *
+ * The bbt ident pattern resides in the oob area of the first page
+ * in a block.
+ */
+static int search_bbt (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
+{
+ struct nand_chip *this = mtd->priv;
+ int i, chips;
+ int bits, startblock, block, dir;
+ int scanlen = mtd->oobblock + mtd->oobsize;
+ int bbtblocks;
+
+ /* Search direction top -> down ? */
+ if (td->options & NAND_BBT_LASTBLOCK) {
+ startblock = (mtd->size >> this->bbt_erase_shift) -1;
+ dir = -1;
+ } else {
+ startblock = 0;
+ dir = 1;
+ }
+
+ /* Do we have a bbt per chip ? */
+ if (td->options & NAND_BBT_PERCHIP) {
+ chips = this->numchips;
+ bbtblocks = this->chipsize >> this->bbt_erase_shift;
+ startblock &= bbtblocks - 1;
+ } else {
+ chips = 1;
+ bbtblocks = mtd->size >> this->bbt_erase_shift;
+ }
+
+ /* Number of bits for each erase block in the bbt */
+ bits = td->options & NAND_BBT_NRBITS_MSK;
+
+ for (i = 0; i < chips; i++) {
+ /* Reset version information */
+ td->version[i] = 0;
+ td->pages[i] = -1;
+ /* Scan the maximum number of blocks */
+ for (block = 0; block < td->maxblocks; block++) {
+ int actblock = startblock + dir * block;
+ /* Read first page */
+ nand_read_raw (mtd, buf, actblock << this->bbt_erase_shift, mtd->oobblock, mtd->oobsize);
+ if (!check_pattern(buf, scanlen, mtd->oobblock, td)) {
+ td->pages[i] = actblock << (this->bbt_erase_shift - this->page_shift);
+ if (td->options & NAND_BBT_VERSION) {
+ td->version[i] = buf[mtd->oobblock + td->veroffs];
+ }
+ break;
+ }
+ }
+ startblock += this->chipsize >> this->bbt_erase_shift;
+ }
+ /* Check, if we found a bbt for each requested chip */
+ for (i = 0; i < chips; i++) {
+ if (td->pages[i] == -1)
+ printk (KERN_WARNING "Bad block table not found for chip %d\n", i);
+ else
+ printk (KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i], td->version[i]);
+ }
+ return 0;
+}
+
+/**
+ * search_read_bbts - [GENERIC] scan the device for bad block table(s)
+ * @mtd: MTD device structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ * @md: descriptor for the bad block table mirror
+ *
+ * Search and read the bad block table(s)
+*/
+static int search_read_bbts (struct mtd_info *mtd, uint8_t *buf,
+ struct nand_bbt_descr *td, struct nand_bbt_descr *md)
+{
+ /* Search the primary table */
+ search_bbt (mtd, buf, td);
+
+ /* Search the mirror table */
+ if (md)
+ search_bbt (mtd, buf, md);
+
+ /* Force result check */
+ return 1;
+}
+
+
+/**
+ * write_bbt - [GENERIC] (Re)write the bad block table
+ *
+ * @mtd: MTD device structure
+ * @buf: temporary buffer
+ * @td: descriptor for the bad block table
+ * @md: descriptor for the bad block table mirror
+ * @chipsel: selector for a specific chip, -1 for all
+ *
+ * (Re)write the bad block table
+ *
+*/
+static int write_bbt (struct mtd_info *mtd, uint8_t *buf,
+ struct nand_bbt_descr *td, struct nand_bbt_descr *md, int chipsel)
+{
+ struct nand_chip *this = mtd->priv;
+ struct nand_oobinfo oobinfo;
+ struct erase_info einfo;
+ int i, j, res, chip = 0;
+ int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
+ int nrchips, bbtoffs, pageoffs;
+ uint8_t msk[4];
+ uint8_t rcode = td->reserved_block_code;
+ size_t retlen, len = 0;
+ loff_t to;
+
+ if (!rcode)
+ rcode = 0xff;
+ /* Write bad block table per chip rather than per device ? */
+ if (td->options & NAND_BBT_PERCHIP) {
+ numblocks = (int) (this->chipsize >> this->bbt_erase_shift);
+ /* Full device write or specific chip ? */
+ if (chipsel == -1) {
+ nrchips = this->numchips;
+ } else {
+ nrchips = chipsel + 1;
+ chip = chipsel;
+ }
+ } else {
+ numblocks = (int) (mtd->size >> this->bbt_erase_shift);
+ nrchips = 1;
+ }
+
+ /* Loop through the chips */
+ for (; chip < nrchips; chip++) {
+
+ /* There was already a version of the table, reuse the page
+ * This applies for absolute placement too, as we have the
+ * page nr. in td->pages.
+ */
+ if (td->pages[chip] != -1) {
+ page = td->pages[chip];
+ goto write;
+ }
+
+ /* Automatic placement of the bad block table */
+ /* Search direction top -> down ? */
+ if (td->options & NAND_BBT_LASTBLOCK) {
+ startblock = numblocks * (chip + 1) - 1;
+ dir = -1;
+ } else {
+ startblock = chip * numblocks;
+ dir = 1;
+ }
+
+ for (i = 0; i < td->maxblocks; i++) {
+ int block = startblock + dir * i;
+ /* Check, if the block is bad */
+ switch ((this->bbt[block >> 2] >> (2 * (block & 0x03))) & 0x03) {
+ case 0x01:
+ case 0x03:
+ continue;
+ }
+ page = block << (this->bbt_erase_shift - this->page_shift);
+ /* Check, if the block is used by the mirror table */
+ if (!md || md->pages[chip] != page)
+ goto write;
+ }
+ printk (KERN_ERR "No space left to write bad block table\n");
+ return -ENOSPC;
+write:
+
+ /* Set up shift count and masks for the flash table */
+ bits = td->options & NAND_BBT_NRBITS_MSK;
+ switch (bits) {
+ case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01; msk[2] = ~rcode; msk[3] = 0x01; break;
+ case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01; msk[2] = ~rcode; msk[3] = 0x03; break;
+ case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C; msk[2] = ~rcode; msk[3] = 0x0f; break;
+ case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F; msk[2] = ~rcode; msk[3] = 0xff; break;
+ default: return -EINVAL;
+ }
+
+ bbtoffs = chip * (numblocks >> 2);
+
+ to = ((loff_t) page) << this->page_shift;
+
+ memcpy (&oobinfo, this->autooob, sizeof(oobinfo));
+ oobinfo.useecc = MTD_NANDECC_PLACEONLY;
+
+ /* Must we save the block contents ? */
+ if (td->options & NAND_BBT_SAVECONTENT) {
+ /* Make it block aligned */
+ to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
+ len = 1 << this->bbt_erase_shift;
+ res = mtd->read_ecc (mtd, to, len, &retlen, buf, &buf[len], &oobinfo);
+ if (res < 0) {
+ if (retlen != len) {
+ printk (KERN_INFO "nand_bbt: Error reading block for writing the bad block table\n");
+ return res;
+ }
+ printk (KERN_WARNING "nand_bbt: ECC error while reading block for writing bad block table\n");
+ }
+ /* Calc the byte offset in the buffer */
+ pageoffs = page - (int)(to >> this->page_shift);
+ offs = pageoffs << this->page_shift;
+ /* Preset the bbt area with 0xff */
+ memset (&buf[offs], 0xff, (size_t)(numblocks >> sft));
+ /* Preset the bbt's oob area with 0xff */
+ memset (&buf[len + pageoffs * mtd->oobsize], 0xff,
+ ((len >> this->page_shift) - pageoffs) * mtd->oobsize);
+ if (td->options & NAND_BBT_VERSION) {
+ buf[len + (pageoffs * mtd->oobsize) + td->veroffs] = td->version[chip];
+ }
+ } else {
+ /* Calc length */
+ len = (size_t) (numblocks >> sft);
+ /* Make it page aligned ! */
+ len = (len + (mtd->oobblock-1)) & ~(mtd->oobblock-1);
+ /* Preset the buffer with 0xff */
+ memset (buf, 0xff, len + (len >> this->page_shift) * mtd->oobsize);
+ offs = 0;
+ /* Pattern is located in oob area of first page */
+ memcpy (&buf[len + td->offs], td->pattern, td->len);
+ if (td->options & NAND_BBT_VERSION) {
+ buf[len + td->veroffs] = td->version[chip];
+ }
+ }
+
+ /* walk through the memory table */
+ for (i = 0; i < numblocks; ) {
+ uint8_t dat;
+ dat = this->bbt[bbtoffs + (i >> 2)];
+ for (j = 0; j < 4; j++ , i++) {
+ int sftcnt = (i << (3 - sft)) & sftmsk;
+ /* Do not store the reserved bbt blocks ! */
+ buf[offs + (i >> sft)] &= ~(msk[dat & 0x03] << sftcnt);
+ dat >>= 2;
+ }
+ }
+
+ memset (&einfo, 0, sizeof (einfo));
+ einfo.mtd = mtd;
+ einfo.addr = (unsigned long) to;
+ einfo.len = 1 << this->bbt_erase_shift;
+ res = nand_erase_nand (mtd, &einfo, 1);
+ if (res < 0) {
+ printk (KERN_WARNING "nand_bbt: Error during block erase: %d\n", res);
+ return res;
+ }
+
+ res = mtd->write_ecc (mtd, to, len, &retlen, buf, &buf[len], &oobinfo);
+ if (res < 0) {
+ printk (KERN_WARNING "nand_bbt: Error while writing bad block table %d\n", res);
+ return res;
+ }
+ printk (KERN_DEBUG "Bad block table written to 0x%08x, version 0x%02X\n",
+ (unsigned int) to, td->version[chip]);
+
+ /* Mark it as used */
+ td->pages[chip] = page;
+ }
+ return 0;
+}
+
+/**
+ * nand_memory_bbt - [GENERIC] create a memory based bad block table
+ * @mtd: MTD device structure
+ * @bd: descriptor for the good/bad block search pattern
+ *
+ * The function creates a memory based bbt by scanning the device
+ * for manufacturer / software marked good / bad blocks
+*/
+static int nand_memory_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd)
+{
+ struct nand_chip *this = mtd->priv;
+
+ /* Ensure that we only scan for the pattern and nothing else */
+ bd->options = 0;
+ create_bbt (mtd, this->data_buf, bd, -1);
+ return 0;
+}
+
+/**
+ * check_create - [GENERIC] create and write bbt(s) if neccecary
+ * @mtd: MTD device structure
+ * @buf: temporary buffer
+ * @bd: descriptor for the good/bad block search pattern
+ *
+ * The function checks the results of the previous call to read_bbt
+ * and creates / updates the bbt(s) if neccecary
+ * Creation is neccecary if no bbt was found for the chip/device
+ * Update is neccecary if one of the tables is missing or the
+ * version nr. of one table is less than the other
+*/
+static int check_create (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
+{
+ int i, chips, writeops, chipsel, res;
+ struct nand_chip *this = mtd->priv;
+ struct nand_bbt_descr *td = this->bbt_td;
+ struct nand_bbt_descr *md = this->bbt_md;
+ struct nand_bbt_descr *rd, *rd2;
+
+ /* Do we have a bbt per chip ? */
+ if (td->options & NAND_BBT_PERCHIP)
+ chips = this->numchips;
+ else
+ chips = 1;
+
+ for (i = 0; i < chips; i++) {
+ writeops = 0;
+ rd = NULL;
+ rd2 = NULL;
+ /* Per chip or per device ? */
+ chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
+ /* Mirrored table avilable ? */
+ if (md) {
+ if (td->pages[i] == -1 && md->pages[i] == -1) {
+ writeops = 0x03;
+ goto create;
+ }
+
+ if (td->pages[i] == -1) {
+ rd = md;
+ td->version[i] = md->version[i];
+ writeops = 1;
+ goto writecheck;
+ }
+
+ if (md->pages[i] == -1) {
+ rd = td;
+ md->version[i] = td->version[i];
+ writeops = 2;
+ goto writecheck;
+ }
+
+ if (td->version[i] == md->version[i]) {
+ rd = td;
+ if (!(td->options & NAND_BBT_VERSION))
+ rd2 = md;
+ goto writecheck;
+ }
+
+ if (((int8_t) (td->version[i] - md->version[i])) > 0) {
+ rd = td;
+ md->version[i] = td->version[i];
+ writeops = 2;
+ } else {
+ rd = md;
+ td->version[i] = md->version[i];
+ writeops = 1;
+ }
+
+ goto writecheck;
+
+ } else {
+ if (td->pages[i] == -1) {
+ writeops = 0x01;
+ goto create;
+ }
+ rd = td;
+ goto writecheck;
+ }
+create:
+ /* Create the bad block table by scanning the device ? */
+ if (!(td->options & NAND_BBT_CREATE))
+ continue;
+
+ /* Create the table in memory by scanning the chip(s) */
+ create_bbt (mtd, buf, bd, chipsel);
+
+ td->version[i] = 1;
+ if (md)
+ md->version[i] = 1;
+writecheck:
+ /* read back first ? */
+ if (rd)
+ read_abs_bbt (mtd, buf, rd, chipsel);
+ /* If they weren't versioned, read both. */
+ if (rd2)
+ read_abs_bbt (mtd, buf, rd2, chipsel);
+
+ /* Write the bad block table to the device ? */
+ if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
+ res = write_bbt (mtd, buf, td, md, chipsel);
+ if (res < 0)
+ return res;
+ }
+
+ /* Write the mirror bad block table to the device ? */
+ if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
+ res = write_bbt (mtd, buf, md, td, chipsel);
+ if (res < 0)
+ return res;
+ }
+ }
+ return 0;
+}
+
+/**
+ * mark_bbt_regions - [GENERIC] mark the bad block table regions
+ * @mtd: MTD device structure
+ * @td: bad block table descriptor
+ *
+ * The bad block table regions are marked as "bad" to prevent
+ * accidental erasures / writes. The regions are identified by
+ * the mark 0x02.
+*/
+static void mark_bbt_region (struct mtd_info *mtd, struct nand_bbt_descr *td)
+{
+ struct nand_chip *this = mtd->priv;
+ int i, j, chips, block, nrblocks, update;
+ uint8_t oldval, newval;
+
+ /* Do we have a bbt per chip ? */
+ if (td->options & NAND_BBT_PERCHIP) {
+ chips = this->numchips;
+ nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
+ } else {
+ chips = 1;
+ nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
+ }
+
+ for (i = 0; i < chips; i++) {
+ if ((td->options & NAND_BBT_ABSPAGE) ||
+ !(td->options & NAND_BBT_WRITE)) {
+ if (td->pages[i] == -1) continue;
+ block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
+ block <<= 1;
+ oldval = this->bbt[(block >> 3)];
+ newval = oldval | (0x2 << (block & 0x06));
+ this->bbt[(block >> 3)] = newval;
+ if ((oldval != newval) && td->reserved_block_code)
+ nand_update_bbt(mtd, block << (this->bbt_erase_shift - 1));
+ continue;
+ }
+ update = 0;
+ if (td->options & NAND_BBT_LASTBLOCK)
+ block = ((i + 1) * nrblocks) - td->maxblocks;
+ else
+ block = i * nrblocks;
+ block <<= 1;
+ for (j = 0; j < td->maxblocks; j++) {
+ oldval = this->bbt[(block >> 3)];
+ newval = oldval | (0x2 << (block & 0x06));
+ this->bbt[(block >> 3)] = newval;
+ if (oldval != newval) update = 1;
+ block += 2;
+ }
+ /* If we want reserved blocks to be recorded to flash, and some
+ new ones have been marked, then we need to update the stored
+ bbts. This should only happen once. */
+ if (update && td->reserved_block_code)
+ nand_update_bbt(mtd, (block - 2) << (this->bbt_erase_shift - 1));
+ }
+}
+
+/**
+ * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
+ * @mtd: MTD device structure
+ * @bd: descriptor for the good/bad block search pattern
+ *
+ * The function checks, if a bad block table(s) is/are already
+ * available. If not it scans the device for manufacturer
+ * marked good / bad blocks and writes the bad block table(s) to
+ * the selected place.
+ *
+ * The bad block table memory is allocated here. It must be freed
+ * by calling the nand_free_bbt function.
+ *
+*/
+int nand_scan_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd)
+{
+ struct nand_chip *this = mtd->priv;
+ int len, res = 0;
+ uint8_t *buf;
+ struct nand_bbt_descr *td = this->bbt_td;
+ struct nand_bbt_descr *md = this->bbt_md;
+
+ len = mtd->size >> (this->bbt_erase_shift + 2);
+ /* Allocate memory (2bit per block) */
+ this->bbt = kmalloc (len, GFP_KERNEL);
+ if (!this->bbt) {
+ printk (KERN_ERR "nand_scan_bbt: Out of memory\n");
+ return -ENOMEM;
+ }
+ /* Clear the memory bad block table */
+ memset (this->bbt, 0x00, len);
+
+ /* If no primary table decriptor is given, scan the device
+ * to build a memory based bad block table
+ */
+ if (!td)
+ return nand_memory_bbt(mtd, bd);
+
+ /* Allocate a temporary buffer for one eraseblock incl. oob */
+ len = (1 << this->bbt_erase_shift);
+ len += (len >> this->page_shift) * mtd->oobsize;
+ buf = kmalloc (len, GFP_KERNEL);
+ if (!buf) {
+ printk (KERN_ERR "nand_bbt: Out of memory\n");
+ kfree (this->bbt);
+ this->bbt = NULL;
+ return -ENOMEM;
+ }
+
+ /* Is the bbt at a given page ? */
+ if (td->options & NAND_BBT_ABSPAGE) {
+ res = read_abs_bbts (mtd, buf, td, md);
+ } else {
+ /* Search the bad block table using a pattern in oob */
+ res = search_read_bbts (mtd, buf, td, md);
+ }
+
+ if (res)
+ res = check_create (mtd, buf, bd);
+
+ /* Prevent the bbt regions from erasing / writing */
+ mark_bbt_region (mtd, td);
+ if (md)
+ mark_bbt_region (mtd, md);
+
+ kfree (buf);
+ return res;
+}
+
+
+/**
+ * nand_update_bbt - [NAND Interface] update bad block table(s)
+ * @mtd: MTD device structure
+ * @offs: the offset of the newly marked block
+ *
+ * The function updates the bad block table(s)
+*/
+int nand_update_bbt (struct mtd_info *mtd, loff_t offs)
+{
+ struct nand_chip *this = mtd->priv;
+ int len, res = 0, writeops = 0;
+ int chip, chipsel;
+ uint8_t *buf;
+ struct nand_bbt_descr *td = this->bbt_td;
+ struct nand_bbt_descr *md = this->bbt_md;
+
+ if (!this->bbt || !td)
+ return -EINVAL;
+
+ len = mtd->size >> (this->bbt_erase_shift + 2);
+ /* Allocate a temporary buffer for one eraseblock incl. oob */
+ len = (1 << this->bbt_erase_shift);
+ len += (len >> this->page_shift) * mtd->oobsize;
+ buf = kmalloc (len, GFP_KERNEL);
+ if (!buf) {
+ printk (KERN_ERR "nand_update_bbt: Out of memory\n");
+ return -ENOMEM;
+ }
+
+ writeops = md != NULL ? 0x03 : 0x01;
+
+ /* Do we have a bbt per chip ? */
+ if (td->options & NAND_BBT_PERCHIP) {
+ chip = (int) (offs >> this->chip_shift);
+ chipsel = chip;
+ } else {
+ chip = 0;
+ chipsel = -1;
+ }
+
+ td->version[chip]++;
+ if (md)
+ md->version[chip]++;
+
+ /* Write the bad block table to the device ? */
+ if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
+ res = write_bbt (mtd, buf, td, md, chipsel);
+ if (res < 0)
+ goto out;
+ }
+ /* Write the mirror bad block table to the device ? */
+ if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
+ res = write_bbt (mtd, buf, md, td, chipsel);
+ }
+
+out:
+ kfree (buf);
+ return res;
+}
+
+/* Define some generic bad / good block scan pattern which are used
+ * while scanning a device for factory marked good / bad blocks
+ *
+ * The memory based patterns just
+ */
+static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
+
+static struct nand_bbt_descr smallpage_memorybased = {
+ .options = 0,
+ .offs = 5,
+ .len = 1,
+ .pattern = scan_ff_pattern
+};
+
+static struct nand_bbt_descr largepage_memorybased = {
+ .options = 0,
+ .offs = 0,
+ .len = 2,
+ .pattern = scan_ff_pattern
+};
+
+static struct nand_bbt_descr smallpage_flashbased = {
+ .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
+ .offs = 5,
+ .len = 1,
+ .pattern = scan_ff_pattern
+};
+
+static struct nand_bbt_descr largepage_flashbased = {
+ .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
+ .offs = 0,
+ .len = 2,
+ .pattern = scan_ff_pattern
+};
+
+static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
+
+static struct nand_bbt_descr agand_flashbased = {
+ .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
+ .offs = 0x20,
+ .len = 6,
+ .pattern = scan_agand_pattern
+};
+
+/* Generic flash bbt decriptors
+*/
+static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
+static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
+
+static struct nand_bbt_descr bbt_main_descr = {
+ .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+ | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+ .offs = 8,
+ .len = 4,
+ .veroffs = 12,
+ .maxblocks = 4,
+ .pattern = bbt_pattern
+};
+
+static struct nand_bbt_descr bbt_mirror_descr = {
+ .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+ | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+ .offs = 8,
+ .len = 4,
+ .veroffs = 12,
+ .maxblocks = 4,
+ .pattern = mirror_pattern
+};
+
+/**
+ * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
+ * @mtd: MTD device structure
+ *
+ * This function selects the default bad block table
+ * support for the device and calls the nand_scan_bbt function
+ *
+*/
+int nand_default_bbt (struct mtd_info *mtd)
+{
+ struct nand_chip *this = mtd->priv;
+
+ /* Default for AG-AND. We must use a flash based
+ * bad block table as the devices have factory marked
+ * _good_ blocks. Erasing those blocks leads to loss
+ * of the good / bad information, so we _must_ store
+ * this information in a good / bad table during
+ * startup
+ */
+ if (this->options & NAND_IS_AND) {
+ /* Use the default pattern descriptors */
+ if (!this->bbt_td) {
+ this->bbt_td = &bbt_main_descr;
+ this->bbt_md = &bbt_mirror_descr;
+ }
+ this->options |= NAND_USE_FLASH_BBT;
+ return nand_scan_bbt (mtd, &agand_flashbased);
+ }
+
+
+ /* Is a flash based bad block table requested ? */
+ if (this->options & NAND_USE_FLASH_BBT) {
+ /* Use the default pattern descriptors */
+ if (!this->bbt_td) {
+ this->bbt_td = &bbt_main_descr;
+ this->bbt_md = &bbt_mirror_descr;
+ }
+ if (!this->badblock_pattern) {
+ this->badblock_pattern = (mtd->oobblock > 512) ?
+ &largepage_flashbased : &smallpage_flashbased;
+ }
+ } else {
+ this->bbt_td = NULL;
+ this->bbt_md = NULL;
+ if (!this->badblock_pattern) {
+ this->badblock_pattern = (mtd->oobblock > 512) ?
+ &largepage_memorybased : &smallpage_memorybased;
+ }
+ }
+ return nand_scan_bbt (mtd, this->badblock_pattern);
+}
+
+/**
+ * nand_isbad_bbt - [NAND Interface] Check if a block is bad
+ * @mtd: MTD device structure
+ * @offs: offset in the device
+ * @allowbbt: allow access to bad block table region
+ *
+*/
+int nand_isbad_bbt (struct mtd_info *mtd, loff_t offs, int allowbbt)
+{
+ struct nand_chip *this = mtd->priv;
+ int block;
+ uint8_t res;
+
+ /* Get block number * 2 */
+ block = (int) (offs >> (this->bbt_erase_shift - 1));
+ res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
+
+ DEBUG (MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
+ (unsigned int)offs, res, block >> 1);
+
+ switch ((int)res) {
+ case 0x00: return 0;
+ case 0x01: return 1;
+ case 0x02: return allowbbt ? 0 : 1;
+ }
+ return 1;
+}
+
+#endif