Add qemu 2.4.0
[kvmfornfv.git] / qemu / roms / u-boot / drivers / mtd / nand / nand_base.c
diff --git a/qemu/roms/u-boot/drivers/mtd/nand/nand_base.c b/qemu/roms/u-boot/drivers/mtd/nand/nand_base.c
new file mode 100644 (file)
index 0000000..1ce55fd
--- /dev/null
@@ -0,0 +1,3438 @@
+/*
+ *  drivers/mtd/nand.c
+ *
+ *  Overview:
+ *   This is the generic MTD driver for NAND flash devices. It should be
+ *   capable of working with almost all NAND chips currently available.
+ *   Basic support for AG-AND chips is provided.
+ *
+ *     Additional technical information is available on
+ *     http://www.linux-mtd.infradead.org/doc/nand.html
+ *
+ *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
+ *               2002-2006 Thomas Gleixner (tglx@linutronix.de)
+ *
+ *  Credits:
+ *     David Woodhouse for adding multichip support
+ *
+ *     Aleph One Ltd. and Toby Churchill Ltd. for supporting the
+ *     rework for 2K page size chips
+ *
+ *  TODO:
+ *     Enable cached programming for 2k page size chips
+ *     Check, if mtd->ecctype should be set to MTD_ECC_HW
+ *     if we have HW ECC support.
+ *     The AG-AND chips have nice features for speed improvement,
+ *     which are not supported yet. Read / program 4 pages in one go.
+ *     BBT table is not serialized, has to be fixed
+ *
+ * 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.
+ *
+ */
+
+#include <common.h>
+
+#define ENOTSUPP       524     /* Operation is not supported */
+
+#include <malloc.h>
+#include <watchdog.h>
+#include <linux/err.h>
+#include <linux/compat.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/nand_bch.h>
+
+#ifdef CONFIG_MTD_PARTITIONS
+#include <linux/mtd/partitions.h>
+#endif
+
+#include <asm/io.h>
+#include <asm/errno.h>
+
+/*
+ * CONFIG_SYS_NAND_RESET_CNT is used as a timeout mechanism when resetting
+ * a flash.  NAND flash is initialized prior to interrupts so standard timers
+ * can't be used.  CONFIG_SYS_NAND_RESET_CNT should be set to a value
+ * which is greater than (max NAND reset time / NAND status read time).
+ * A conservative default of 200000 (500 us / 25 ns) is used as a default.
+ */
+#ifndef CONFIG_SYS_NAND_RESET_CNT
+#define CONFIG_SYS_NAND_RESET_CNT 200000
+#endif
+
+/* Define default oob placement schemes for large and small page devices */
+static struct nand_ecclayout nand_oob_8 = {
+       .eccbytes = 3,
+       .eccpos = {0, 1, 2},
+       .oobfree = {
+               {.offset = 3,
+                .length = 2},
+               {.offset = 6,
+                .length = 2} }
+};
+
+static struct nand_ecclayout nand_oob_16 = {
+       .eccbytes = 6,
+       .eccpos = {0, 1, 2, 3, 6, 7},
+       .oobfree = {
+               {.offset = 8,
+                . length = 8} }
+};
+
+static struct nand_ecclayout nand_oob_64 = {
+       .eccbytes = 24,
+       .eccpos = {
+                  40, 41, 42, 43, 44, 45, 46, 47,
+                  48, 49, 50, 51, 52, 53, 54, 55,
+                  56, 57, 58, 59, 60, 61, 62, 63},
+       .oobfree = {
+               {.offset = 2,
+                .length = 38} }
+};
+
+static struct nand_ecclayout nand_oob_128 = {
+       .eccbytes = 48,
+       .eccpos = {
+                  80, 81, 82, 83, 84, 85, 86, 87,
+                  88, 89, 90, 91, 92, 93, 94, 95,
+                  96, 97, 98, 99, 100, 101, 102, 103,
+                  104, 105, 106, 107, 108, 109, 110, 111,
+                  112, 113, 114, 115, 116, 117, 118, 119,
+                  120, 121, 122, 123, 124, 125, 126, 127},
+       .oobfree = {
+               {.offset = 2,
+                .length = 78} }
+};
+
+static int nand_get_device(struct nand_chip *chip, struct mtd_info *mtd,
+                          int new_state);
+
+static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
+                            struct mtd_oob_ops *ops);
+
+static int nand_wait(struct mtd_info *mtd, struct nand_chip *this);
+
+static int check_offs_len(struct mtd_info *mtd,
+                                       loff_t ofs, uint64_t len)
+{
+       struct nand_chip *chip = mtd->priv;
+       int ret = 0;
+
+       /* Start address must align on block boundary */
+       if (ofs & ((1 << chip->phys_erase_shift) - 1)) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Unaligned address\n", __func__);
+               ret = -EINVAL;
+       }
+
+       /* Length must align on block boundary */
+       if (len & ((1 << chip->phys_erase_shift) - 1)) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Length not block aligned\n",
+                                       __func__);
+               ret = -EINVAL;
+       }
+
+       return ret;
+}
+
+/**
+ * nand_release_device - [GENERIC] release chip
+ * @mtd: MTD device structure
+ *
+ * Deselect, release chip lock and wake up anyone waiting on the device.
+ */
+static void nand_release_device(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+
+       /* De-select the NAND device */
+       chip->select_chip(mtd, -1);
+}
+
+/**
+ * nand_read_byte - [DEFAULT] read one byte from the chip
+ * @mtd: MTD device structure
+ *
+ * Default read function for 8bit buswidth.
+ */
+uint8_t nand_read_byte(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       return readb(chip->IO_ADDR_R);
+}
+
+/**
+ * nand_read_byte16 - [DEFAULT] read one byte endianess aware from the chip
+ * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
+ * @mtd: MTD device structure
+ *
+ * Default read function for 16bit buswidth with endianness conversion.
+ *
+ */
+static uint8_t nand_read_byte16(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       return (uint8_t) cpu_to_le16(readw(chip->IO_ADDR_R));
+}
+
+/**
+ * nand_read_word - [DEFAULT] read one word from the chip
+ * @mtd: MTD device structure
+ *
+ * Default read function for 16bit buswidth without endianness conversion.
+ */
+static u16 nand_read_word(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       return readw(chip->IO_ADDR_R);
+}
+
+/**
+ * nand_select_chip - [DEFAULT] control CE line
+ * @mtd: MTD device structure
+ * @chipnr: chipnumber to select, -1 for deselect
+ *
+ * Default select function for 1 chip devices.
+ */
+static void nand_select_chip(struct mtd_info *mtd, int chipnr)
+{
+       struct nand_chip *chip = mtd->priv;
+
+       switch (chipnr) {
+       case -1:
+               chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
+               break;
+       case 0:
+               break;
+
+       default:
+               BUG();
+       }
+}
+
+/**
+ * nand_write_buf - [DEFAULT] write buffer to chip
+ * @mtd: MTD device structure
+ * @buf: data buffer
+ * @len: number of bytes to write
+ *
+ * Default write function for 8bit buswidth.
+ */
+void nand_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+       int i;
+       struct nand_chip *chip = mtd->priv;
+
+       for (i = 0; i < len; i++)
+               writeb(buf[i], chip->IO_ADDR_W);
+}
+
+/**
+ * nand_read_buf - [DEFAULT] read chip data into buffer
+ * @mtd: MTD device structure
+ * @buf: buffer to store date
+ * @len: number of bytes to read
+ *
+ * Default read function for 8bit buswidth.
+ */
+void nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+       int i;
+       struct nand_chip *chip = mtd->priv;
+
+       for (i = 0; i < len; i++)
+               buf[i] = readb(chip->IO_ADDR_R);
+}
+
+/**
+ * nand_verify_buf - [DEFAULT] Verify chip data against buffer
+ * @mtd: MTD device structure
+ * @buf: buffer containing the data to compare
+ * @len: number of bytes to compare
+ *
+ * Default verify function for 8bit buswidth.
+ */
+static int nand_verify_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+       int i;
+       struct nand_chip *chip = mtd->priv;
+
+       for (i = 0; i < len; i++)
+               if (buf[i] != readb(chip->IO_ADDR_R))
+                       return -EFAULT;
+       return 0;
+}
+
+/**
+ * nand_write_buf16 - [DEFAULT] write buffer to chip
+ * @mtd: MTD device structure
+ * @buf: data buffer
+ * @len: number of bytes to write
+ *
+ * Default write function for 16bit buswidth.
+ */
+void nand_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+       int i;
+       struct nand_chip *chip = mtd->priv;
+       u16 *p = (u16 *) buf;
+       len >>= 1;
+
+       for (i = 0; i < len; i++)
+               writew(p[i], chip->IO_ADDR_W);
+
+}
+
+/**
+ * nand_read_buf16 - [DEFAULT] read chip data into buffer
+ * @mtd: MTD device structure
+ * @buf: buffer to store date
+ * @len: number of bytes to read
+ *
+ * Default read function for 16bit buswidth.
+ */
+void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+       int i;
+       struct nand_chip *chip = mtd->priv;
+       u16 *p = (u16 *) buf;
+       len >>= 1;
+
+       for (i = 0; i < len; i++)
+               p[i] = readw(chip->IO_ADDR_R);
+}
+
+/**
+ * nand_verify_buf16 - [DEFAULT] Verify chip data against buffer
+ * @mtd: MTD device structure
+ * @buf: buffer containing the data to compare
+ * @len: number of bytes to compare
+ *
+ * Default verify function for 16bit buswidth.
+ */
+static int nand_verify_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+       int i;
+       struct nand_chip *chip = mtd->priv;
+       u16 *p = (u16 *) buf;
+       len >>= 1;
+
+       for (i = 0; i < len; i++)
+               if (p[i] != readw(chip->IO_ADDR_R))
+                       return -EFAULT;
+
+       return 0;
+}
+
+/**
+ * nand_block_bad - [DEFAULT] Read bad block marker from the chip
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
+ * @getchip: 0, if the chip is already selected
+ *
+ * Check, if the block is bad.
+ */
+static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
+{
+       int page, chipnr, res = 0, i = 0;
+       struct nand_chip *chip = mtd->priv;
+       u16 bad;
+
+       if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
+               ofs += mtd->erasesize - mtd->writesize;
+
+       page = (int)(ofs >> chip->page_shift) & chip->pagemask;
+
+       if (getchip) {
+               chipnr = (int)(ofs >> chip->chip_shift);
+
+               nand_get_device(chip, mtd, FL_READING);
+
+               /* Select the NAND device */
+               chip->select_chip(mtd, chipnr);
+       }
+
+       do {
+               if (chip->options & NAND_BUSWIDTH_16) {
+                       chip->cmdfunc(mtd, NAND_CMD_READOOB,
+                                       chip->badblockpos & 0xFE, page);
+                       bad = cpu_to_le16(chip->read_word(mtd));
+                       if (chip->badblockpos & 0x1)
+                               bad >>= 8;
+                       else
+                               bad &= 0xFF;
+               } else {
+                       chip->cmdfunc(mtd, NAND_CMD_READOOB, chip->badblockpos,
+                                       page);
+                       bad = chip->read_byte(mtd);
+               }
+
+               if (likely(chip->badblockbits == 8))
+                       res = bad != 0xFF;
+               else
+                       res = hweight8(bad) < chip->badblockbits;
+               ofs += mtd->writesize;
+               page = (int)(ofs >> chip->page_shift) & chip->pagemask;
+               i++;
+       } while (!res && i < 2 && (chip->bbt_options & NAND_BBT_SCAN2NDPAGE));
+
+       if (getchip)
+               nand_release_device(mtd);
+
+       return res;
+}
+
+/**
+ * nand_default_block_markbad - [DEFAULT] mark a block bad
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
+ *
+ * This is the default implementation, which can be overridden by a hardware
+ * specific driver. We try operations in the following order, according to our
+ * bbt_options (NAND_BBT_NO_OOB_BBM and NAND_BBT_USE_FLASH):
+ *  (1) erase the affected block, to allow OOB marker to be written cleanly
+ *  (2) update in-memory BBT
+ *  (3) write bad block marker to OOB area of affected block
+ *  (4) update flash-based BBT
+ * Note that we retain the first error encountered in (3) or (4), finish the
+ * procedures, and dump the error in the end.
+*/
+static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+       struct nand_chip *chip = mtd->priv;
+       uint8_t buf[2] = { 0, 0 };
+       int block, res, ret = 0, i = 0;
+       int write_oob = !(chip->bbt_options & NAND_BBT_NO_OOB_BBM);
+
+       if (write_oob) {
+               struct erase_info einfo;
+
+               /* Attempt erase before marking OOB */
+               memset(&einfo, 0, sizeof(einfo));
+               einfo.mtd = mtd;
+               einfo.addr = ofs;
+               einfo.len = 1 << chip->phys_erase_shift;
+               nand_erase_nand(mtd, &einfo, 0);
+       }
+
+       /* Get block number */
+       block = (int)(ofs >> chip->bbt_erase_shift);
+       /* Mark block bad in memory-based BBT */
+       if (chip->bbt)
+               chip->bbt[block >> 2] |= 0x01 << ((block & 0x03) << 1);
+
+       /* Write bad block marker to OOB */
+       if (write_oob) {
+               struct mtd_oob_ops ops;
+               loff_t wr_ofs = ofs;
+
+               nand_get_device(chip, mtd, FL_WRITING);
+
+               ops.datbuf = NULL;
+               ops.oobbuf = buf;
+               ops.ooboffs = chip->badblockpos;
+               if (chip->options & NAND_BUSWIDTH_16) {
+                       ops.ooboffs &= ~0x01;
+                       ops.len = ops.ooblen = 2;
+               } else {
+                       ops.len = ops.ooblen = 1;
+               }
+               ops.mode = MTD_OPS_PLACE_OOB;
+
+               /* Write to first/last page(s) if necessary */
+               if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
+                       wr_ofs += mtd->erasesize - mtd->writesize;
+               do {
+                       res = nand_do_write_oob(mtd, wr_ofs, &ops);
+                       if (!ret)
+                               ret = res;
+
+                       i++;
+                       wr_ofs += mtd->writesize;
+               } while ((chip->bbt_options & NAND_BBT_SCAN2NDPAGE) && i < 2);
+
+               nand_release_device(mtd);
+       }
+
+       /* Update flash-based bad block table */
+       if (chip->bbt_options & NAND_BBT_USE_FLASH) {
+               res = nand_update_bbt(mtd, ofs);
+               if (!ret)
+                       ret = res;
+       }
+
+       if (!ret)
+               mtd->ecc_stats.badblocks++;
+
+       return ret;
+}
+
+/**
+ * nand_check_wp - [GENERIC] check if the chip is write protected
+ * @mtd: MTD device structure
+ *
+ * Check, if the device is write protected. The function expects, that the
+ * device is already selected.
+ */
+static int nand_check_wp(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+
+       /* Broken xD cards report WP despite being writable */
+       if (chip->options & NAND_BROKEN_XD)
+               return 0;
+
+       /* Check the WP bit */
+       chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+       return (chip->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1;
+}
+
+/**
+ * nand_block_checkbad - [GENERIC] Check if a block is marked bad
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
+ * @getchip: 0, if the chip is already selected
+ * @allowbbt: 1, if its allowed to access the bbt area
+ *
+ * Check, if the block is bad. Either by reading the bad block table or
+ * calling of the scan function.
+ */
+static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
+                              int allowbbt)
+{
+       struct nand_chip *chip = mtd->priv;
+
+       if (!(chip->options & NAND_BBT_SCANNED)) {
+               chip->options |= NAND_BBT_SCANNED;
+               chip->scan_bbt(mtd);
+       }
+
+       if (!chip->bbt)
+               return chip->block_bad(mtd, ofs, getchip);
+
+       /* Return info from the table */
+       return nand_isbad_bbt(mtd, ofs, allowbbt);
+}
+
+/* Wait for the ready pin, after a command. The timeout is caught later. */
+void nand_wait_ready(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       u32 timeo = (CONFIG_SYS_HZ * 20) / 1000;
+       u32 time_start;
+
+       time_start = get_timer(0);
+
+       /* Wait until command is processed or timeout occurs */
+       while (get_timer(time_start) < timeo) {
+               if (chip->dev_ready)
+                       if (chip->dev_ready(mtd))
+                               break;
+       }
+}
+
+/**
+ * nand_command - [DEFAULT] Send command to NAND device
+ * @mtd: MTD device structure
+ * @command: the command to be sent
+ * @column: the column address for this command, -1 if none
+ * @page_addr: the page address for this command, -1 if none
+ *
+ * Send command to NAND device. This function is used for small page devices
+ * (256/512 Bytes per page).
+ */
+static void nand_command(struct mtd_info *mtd, unsigned int command,
+                        int column, int page_addr)
+{
+       register struct nand_chip *chip = mtd->priv;
+       int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
+       uint32_t rst_sts_cnt = CONFIG_SYS_NAND_RESET_CNT;
+
+       /* Write out the command to the device */
+       if (command == NAND_CMD_SEQIN) {
+               int readcmd;
+
+               if (column >= mtd->writesize) {
+                       /* OOB area */
+                       column -= mtd->writesize;
+                       readcmd = NAND_CMD_READOOB;
+               } else if (column < 256) {
+                       /* First 256 bytes --> READ0 */
+                       readcmd = NAND_CMD_READ0;
+               } else {
+                       column -= 256;
+                       readcmd = NAND_CMD_READ1;
+               }
+               chip->cmd_ctrl(mtd, readcmd, ctrl);
+               ctrl &= ~NAND_CTRL_CHANGE;
+       }
+       chip->cmd_ctrl(mtd, command, ctrl);
+
+       /* Address cycle, when necessary */
+       ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
+       /* Serially input address */
+       if (column != -1) {
+               /* Adjust columns for 16 bit buswidth */
+               if (chip->options & NAND_BUSWIDTH_16)
+                       column >>= 1;
+               chip->cmd_ctrl(mtd, column, ctrl);
+               ctrl &= ~NAND_CTRL_CHANGE;
+       }
+       if (page_addr != -1) {
+               chip->cmd_ctrl(mtd, page_addr, ctrl);
+               ctrl &= ~NAND_CTRL_CHANGE;
+               chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
+               /* One more address cycle for devices > 32MiB */
+               if (chip->chipsize > (32 << 20))
+                       chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
+       }
+       chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
+
+       /*
+        * Program and erase have their own busy handlers status and sequential
+        * in needs no delay
+        */
+       switch (command) {
+
+       case NAND_CMD_PAGEPROG:
+       case NAND_CMD_ERASE1:
+       case NAND_CMD_ERASE2:
+       case NAND_CMD_SEQIN:
+       case NAND_CMD_STATUS:
+               return;
+
+       case NAND_CMD_RESET:
+               if (chip->dev_ready)
+                       break;
+               udelay(chip->chip_delay);
+               chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
+                              NAND_CTRL_CLE | NAND_CTRL_CHANGE);
+               chip->cmd_ctrl(mtd,
+                              NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
+               while (!(chip->read_byte(mtd) & NAND_STATUS_READY) &&
+                       (rst_sts_cnt--));
+               return;
+
+               /* This applies to read commands */
+       default:
+               /*
+                * If we don't have access to the busy pin, we apply the given
+                * command delay
+                */
+               if (!chip->dev_ready) {
+                       udelay(chip->chip_delay);
+                       return;
+               }
+       }
+       /*
+        * Apply this short delay always to ensure that we do wait tWB in
+        * any case on any machine.
+        */
+       ndelay(100);
+
+       nand_wait_ready(mtd);
+}
+
+/**
+ * nand_command_lp - [DEFAULT] Send command to NAND large page device
+ * @mtd: MTD device structure
+ * @command: the command to be sent
+ * @column: the column address for this command, -1 if none
+ * @page_addr: the page address for this command, -1 if none
+ *
+ * Send command to NAND device. This is the version for the new large page
+ * devices. We don't have the separate regions as we have in the small page
+ * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
+ */
+static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
+                           int column, int page_addr)
+{
+       register struct nand_chip *chip = mtd->priv;
+       uint32_t rst_sts_cnt = CONFIG_SYS_NAND_RESET_CNT;
+
+       /* Emulate NAND_CMD_READOOB */
+       if (command == NAND_CMD_READOOB) {
+               column += mtd->writesize;
+               command = NAND_CMD_READ0;
+       }
+
+       /* Command latch cycle */
+       chip->cmd_ctrl(mtd, command & 0xff,
+                      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+
+       if (column != -1 || page_addr != -1) {
+               int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
+
+               /* Serially input address */
+               if (column != -1) {
+                       /* Adjust columns for 16 bit buswidth */
+                       if (chip->options & NAND_BUSWIDTH_16)
+                               column >>= 1;
+                       chip->cmd_ctrl(mtd, column, ctrl);
+                       ctrl &= ~NAND_CTRL_CHANGE;
+                       chip->cmd_ctrl(mtd, column >> 8, ctrl);
+               }
+               if (page_addr != -1) {
+                       chip->cmd_ctrl(mtd, page_addr, ctrl);
+                       chip->cmd_ctrl(mtd, page_addr >> 8,
+                                      NAND_NCE | NAND_ALE);
+                       /* One more address cycle for devices > 128MiB */
+                       if (chip->chipsize > (128 << 20))
+                               chip->cmd_ctrl(mtd, page_addr >> 16,
+                                              NAND_NCE | NAND_ALE);
+               }
+       }
+       chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
+
+       /*
+        * Program and erase have their own busy handlers status, sequential
+        * in, and deplete1 need no delay.
+        */
+       switch (command) {
+
+       case NAND_CMD_CACHEDPROG:
+       case NAND_CMD_PAGEPROG:
+       case NAND_CMD_ERASE1:
+       case NAND_CMD_ERASE2:
+       case NAND_CMD_SEQIN:
+       case NAND_CMD_RNDIN:
+       case NAND_CMD_STATUS:
+       case NAND_CMD_DEPLETE1:
+               return;
+
+       case NAND_CMD_STATUS_ERROR:
+       case NAND_CMD_STATUS_ERROR0:
+       case NAND_CMD_STATUS_ERROR1:
+       case NAND_CMD_STATUS_ERROR2:
+       case NAND_CMD_STATUS_ERROR3:
+               /* Read error status commands require only a short delay */
+               udelay(chip->chip_delay);
+               return;
+
+       case NAND_CMD_RESET:
+               if (chip->dev_ready)
+                       break;
+               udelay(chip->chip_delay);
+               chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
+                              NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+               chip->cmd_ctrl(mtd, NAND_CMD_NONE,
+                              NAND_NCE | NAND_CTRL_CHANGE);
+               while (!(chip->read_byte(mtd) & NAND_STATUS_READY) &&
+                       (rst_sts_cnt--));
+               return;
+
+       case NAND_CMD_RNDOUT:
+               /* No ready / busy check necessary */
+               chip->cmd_ctrl(mtd, NAND_CMD_RNDOUTSTART,
+                              NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+               chip->cmd_ctrl(mtd, NAND_CMD_NONE,
+                              NAND_NCE | NAND_CTRL_CHANGE);
+               return;
+
+       case NAND_CMD_READ0:
+               chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
+                              NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+               chip->cmd_ctrl(mtd, NAND_CMD_NONE,
+                              NAND_NCE | NAND_CTRL_CHANGE);
+
+               /* This applies to read commands */
+       default:
+               /*
+                * If we don't have access to the busy pin, we apply the given
+                * command delay.
+                */
+               if (!chip->dev_ready) {
+                       udelay(chip->chip_delay);
+                       return;
+               }
+       }
+
+       /*
+        * Apply this short delay always to ensure that we do wait tWB in
+        * any case on any machine.
+        */
+       ndelay(100);
+
+       nand_wait_ready(mtd);
+}
+
+/**
+ * nand_get_device - [GENERIC] Get chip for selected access
+ * @chip: the nand chip descriptor
+ * @mtd: MTD device structure
+ * @new_state: the state which is requested
+ *
+ * Get the device and lock it for exclusive access
+ */
+static int
+nand_get_device(struct nand_chip *chip, struct mtd_info *mtd, int new_state)
+{
+       chip->state = new_state;
+       return 0;
+}
+
+/**
+ * nand_wait - [DEFAULT] wait until the command is done
+ * @mtd: MTD device structure
+ * @chip: NAND chip structure
+ *
+ * Wait for command done. This applies to erase and program only. Erase can
+ * take up to 400ms and program up to 20ms according to general NAND and
+ * SmartMedia specs.
+ */
+static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
+{
+       unsigned long   timeo;
+       int state = chip->state;
+       u32 time_start;
+
+       if (state == FL_ERASING)
+               timeo = (CONFIG_SYS_HZ * 400) / 1000;
+       else
+               timeo = (CONFIG_SYS_HZ * 20) / 1000;
+
+       if ((state == FL_ERASING) && (chip->options & NAND_IS_AND))
+               chip->cmdfunc(mtd, NAND_CMD_STATUS_MULTI, -1, -1);
+       else
+               chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+
+       time_start = get_timer(0);
+
+       while (1) {
+               if (get_timer(time_start) > timeo) {
+                       printf("Timeout!");
+                       return 0x01;
+               }
+
+               if (chip->dev_ready) {
+                       if (chip->dev_ready(mtd))
+                               break;
+               } else {
+                       if (chip->read_byte(mtd) & NAND_STATUS_READY)
+                               break;
+               }
+       }
+#ifdef PPCHAMELON_NAND_TIMER_HACK
+       time_start = get_timer(0);
+       while (get_timer(time_start) < 10)
+               ;
+#endif /*  PPCHAMELON_NAND_TIMER_HACK */
+
+       return (int)chip->read_byte(mtd);
+}
+
+/**
+ * nand_read_page_raw - [INTERN] read raw page data without ecc
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * Not for syndrome calculating ECC controllers, which use a special oob layout.
+ */
+static int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+                             uint8_t *buf, int oob_required, int page)
+{
+       chip->read_buf(mtd, buf, mtd->writesize);
+       if (oob_required)
+               chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+       return 0;
+}
+
+/**
+ * nand_read_page_raw_syndrome - [INTERN] read raw page data without ecc
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * We need a special oob layout and handling even when OOB isn't used.
+ */
+static int nand_read_page_raw_syndrome(struct mtd_info *mtd,
+                                      struct nand_chip *chip, uint8_t *buf,
+                                      int oob_required, int page)
+{
+       int eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       uint8_t *oob = chip->oob_poi;
+       int steps, size;
+
+       for (steps = chip->ecc.steps; steps > 0; steps--) {
+               chip->read_buf(mtd, buf, eccsize);
+               buf += eccsize;
+
+               if (chip->ecc.prepad) {
+                       chip->read_buf(mtd, oob, chip->ecc.prepad);
+                       oob += chip->ecc.prepad;
+               }
+
+               chip->read_buf(mtd, oob, eccbytes);
+               oob += eccbytes;
+
+               if (chip->ecc.postpad) {
+                       chip->read_buf(mtd, oob, chip->ecc.postpad);
+                       oob += chip->ecc.postpad;
+               }
+       }
+
+       size = mtd->oobsize - (oob - chip->oob_poi);
+       if (size)
+               chip->read_buf(mtd, oob, size);
+
+       return 0;
+}
+
+/**
+ * nand_read_page_swecc - [REPLACEABLE] software ECC based page read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ */
+static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
+                               uint8_t *buf, int oob_required, int page)
+{
+       int i, eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       int eccsteps = chip->ecc.steps;
+       uint8_t *p = buf;
+       uint8_t *ecc_calc = chip->buffers->ecccalc;
+       uint8_t *ecc_code = chip->buffers->ecccode;
+       uint32_t *eccpos = chip->ecc.layout->eccpos;
+
+       chip->ecc.read_page_raw(mtd, chip, buf, 1, page);
+
+       for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
+               chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+       for (i = 0; i < chip->ecc.total; i++)
+               ecc_code[i] = chip->oob_poi[eccpos[i]];
+
+       eccsteps = chip->ecc.steps;
+       p = buf;
+
+       for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+               int stat;
+
+               stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
+               if (stat < 0)
+                       mtd->ecc_stats.failed++;
+               else
+                       mtd->ecc_stats.corrected += stat;
+       }
+       return 0;
+}
+
+/**
+ * nand_read_subpage - [REPLACEABLE] software ECC based sub-page read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @data_offs: offset of requested data within the page
+ * @readlen: data length
+ * @bufpoi: buffer to store read data
+ */
+static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
+                       uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi)
+{
+       int start_step, end_step, num_steps;
+       uint32_t *eccpos = chip->ecc.layout->eccpos;
+       uint8_t *p;
+       int data_col_addr, i, gaps = 0;
+       int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
+       int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
+       int index = 0;
+
+       /* Column address within the page aligned to ECC size (256bytes) */
+       start_step = data_offs / chip->ecc.size;
+       end_step = (data_offs + readlen - 1) / chip->ecc.size;
+       num_steps = end_step - start_step + 1;
+
+       /* Data size aligned to ECC ecc.size */
+       datafrag_len = num_steps * chip->ecc.size;
+       eccfrag_len = num_steps * chip->ecc.bytes;
+
+       data_col_addr = start_step * chip->ecc.size;
+       /* If we read not a page aligned data */
+       if (data_col_addr != 0)
+               chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_col_addr, -1);
+
+       p = bufpoi + data_col_addr;
+       chip->read_buf(mtd, p, datafrag_len);
+
+       /* Calculate ECC */
+       for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size)
+               chip->ecc.calculate(mtd, p, &chip->buffers->ecccalc[i]);
+
+       /*
+        * The performance is faster if we position offsets according to
+        * ecc.pos. Let's make sure that there are no gaps in ECC positions.
+        */
+       for (i = 0; i < eccfrag_len - 1; i++) {
+               if (eccpos[i + start_step * chip->ecc.bytes] + 1 !=
+                       eccpos[i + start_step * chip->ecc.bytes + 1]) {
+                       gaps = 1;
+                       break;
+               }
+       }
+       if (gaps) {
+               chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
+               chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+       } else {
+               /*
+                * Send the command to read the particular ECC bytes take care
+                * about buswidth alignment in read_buf.
+                */
+               index = start_step * chip->ecc.bytes;
+
+               aligned_pos = eccpos[index] & ~(busw - 1);
+               aligned_len = eccfrag_len;
+               if (eccpos[index] & (busw - 1))
+                       aligned_len++;
+               if (eccpos[index + (num_steps * chip->ecc.bytes)] & (busw - 1))
+                       aligned_len++;
+
+               chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
+                                       mtd->writesize + aligned_pos, -1);
+               chip->read_buf(mtd, &chip->oob_poi[aligned_pos], aligned_len);
+       }
+
+       for (i = 0; i < eccfrag_len; i++)
+               chip->buffers->ecccode[i] = chip->oob_poi[eccpos[i + index]];
+
+       p = bufpoi + data_col_addr;
+       for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size) {
+               int stat;
+
+               stat = chip->ecc.correct(mtd, p,
+                       &chip->buffers->ecccode[i], &chip->buffers->ecccalc[i]);
+               if (stat < 0)
+                       mtd->ecc_stats.failed++;
+               else
+                       mtd->ecc_stats.corrected += stat;
+       }
+       return 0;
+}
+
+/**
+ * nand_read_page_hwecc - [REPLACEABLE] hardware ECC based page read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * Not for syndrome calculating ECC controllers which need a special oob layout.
+ */
+static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
+                               uint8_t *buf, int oob_required, int page)
+{
+       int i, eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       int eccsteps = chip->ecc.steps;
+       uint8_t *p = buf;
+       uint8_t *ecc_calc = chip->buffers->ecccalc;
+       uint8_t *ecc_code = chip->buffers->ecccode;
+       uint32_t *eccpos = chip->ecc.layout->eccpos;
+
+       for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+               chip->ecc.hwctl(mtd, NAND_ECC_READ);
+               chip->read_buf(mtd, p, eccsize);
+               chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+       }
+       chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+       for (i = 0; i < chip->ecc.total; i++)
+               ecc_code[i] = chip->oob_poi[eccpos[i]];
+
+       eccsteps = chip->ecc.steps;
+       p = buf;
+
+       for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+               int stat;
+
+               stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
+               if (stat < 0)
+                       mtd->ecc_stats.failed++;
+               else
+                       mtd->ecc_stats.corrected += stat;
+       }
+       return 0;
+}
+
+/**
+ * nand_read_page_hwecc_oob_first - [REPLACEABLE] hw ecc, read oob first
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * Hardware ECC for large page chips, require OOB to be read first. For this
+ * ECC mode, the write_page method is re-used from ECC_HW. These methods
+ * read/write ECC from the OOB area, unlike the ECC_HW_SYNDROME support with
+ * multiple ECC steps, follows the "infix ECC" scheme and reads/writes ECC from
+ * the data area, by overwriting the NAND manufacturer bad block markings.
+ */
+static int nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
+       struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
+{
+       int i, eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       int eccsteps = chip->ecc.steps;
+       uint8_t *p = buf;
+       uint8_t *ecc_code = chip->buffers->ecccode;
+       uint32_t *eccpos = chip->ecc.layout->eccpos;
+       uint8_t *ecc_calc = chip->buffers->ecccalc;
+
+       /* Read the OOB area first */
+       chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
+       chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+       chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+       for (i = 0; i < chip->ecc.total; i++)
+               ecc_code[i] = chip->oob_poi[eccpos[i]];
+
+       for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+               int stat;
+
+               chip->ecc.hwctl(mtd, NAND_ECC_READ);
+               chip->read_buf(mtd, p, eccsize);
+               chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+               stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
+               if (stat < 0)
+                       mtd->ecc_stats.failed++;
+               else
+                       mtd->ecc_stats.corrected += stat;
+       }
+       return 0;
+}
+
+/**
+ * nand_read_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page read
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * The hw generator calculates the error syndrome automatically. Therefore we
+ * need a special oob layout and handling.
+ */
+static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+                                  uint8_t *buf, int oob_required, int page)
+{
+       int i, eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       int eccsteps = chip->ecc.steps;
+       uint8_t *p = buf;
+       uint8_t *oob = chip->oob_poi;
+
+       for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+               int stat;
+
+               chip->ecc.hwctl(mtd, NAND_ECC_READ);
+               chip->read_buf(mtd, p, eccsize);
+
+               if (chip->ecc.prepad) {
+                       chip->read_buf(mtd, oob, chip->ecc.prepad);
+                       oob += chip->ecc.prepad;
+               }
+
+               chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
+               chip->read_buf(mtd, oob, eccbytes);
+               stat = chip->ecc.correct(mtd, p, oob, NULL);
+
+               if (stat < 0)
+                       mtd->ecc_stats.failed++;
+               else
+                       mtd->ecc_stats.corrected += stat;
+
+               oob += eccbytes;
+
+               if (chip->ecc.postpad) {
+                       chip->read_buf(mtd, oob, chip->ecc.postpad);
+                       oob += chip->ecc.postpad;
+               }
+       }
+
+       /* Calculate remaining oob bytes */
+       i = mtd->oobsize - (oob - chip->oob_poi);
+       if (i)
+               chip->read_buf(mtd, oob, i);
+
+       return 0;
+}
+
+/**
+ * nand_transfer_oob - [INTERN] Transfer oob to client buffer
+ * @chip: nand chip structure
+ * @oob: oob destination address
+ * @ops: oob ops structure
+ * @len: size of oob to transfer
+ */
+static uint8_t *nand_transfer_oob(struct nand_chip *chip, uint8_t *oob,
+                                 struct mtd_oob_ops *ops, size_t len)
+{
+       switch (ops->mode) {
+
+       case MTD_OPS_PLACE_OOB:
+       case MTD_OPS_RAW:
+               memcpy(oob, chip->oob_poi + ops->ooboffs, len);
+               return oob + len;
+
+       case MTD_OPS_AUTO_OOB: {
+               struct nand_oobfree *free = chip->ecc.layout->oobfree;
+               uint32_t boffs = 0, roffs = ops->ooboffs;
+               size_t bytes = 0;
+
+               for (; free->length && len; free++, len -= bytes) {
+                       /* Read request not from offset 0? */
+                       if (unlikely(roffs)) {
+                               if (roffs >= free->length) {
+                                       roffs -= free->length;
+                                       continue;
+                               }
+                               boffs = free->offset + roffs;
+                               bytes = min_t(size_t, len,
+                                             (free->length - roffs));
+                               roffs = 0;
+                       } else {
+                               bytes = min_t(size_t, len, free->length);
+                               boffs = free->offset;
+                       }
+                       memcpy(oob, chip->oob_poi + boffs, bytes);
+                       oob += bytes;
+               }
+               return oob;
+       }
+       default:
+               BUG();
+       }
+       return NULL;
+}
+
+/**
+ * nand_do_read_ops - [INTERN] Read data with ECC
+ * @mtd: MTD device structure
+ * @from: offset to read from
+ * @ops: oob ops structure
+ *
+ * Internal function. Called with chip held.
+ */
+static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
+                           struct mtd_oob_ops *ops)
+{
+       int chipnr, page, realpage, col, bytes, aligned, oob_required;
+       struct nand_chip *chip = mtd->priv;
+       struct mtd_ecc_stats stats;
+       int ret = 0;
+       uint32_t readlen = ops->len;
+       uint32_t oobreadlen = ops->ooblen;
+       uint32_t max_oobsize = ops->mode == MTD_OPS_AUTO_OOB ?
+               mtd->oobavail : mtd->oobsize;
+
+       uint8_t *bufpoi, *oob, *buf;
+       unsigned int max_bitflips = 0;
+
+       stats = mtd->ecc_stats;
+
+       chipnr = (int)(from >> chip->chip_shift);
+       chip->select_chip(mtd, chipnr);
+
+       realpage = (int)(from >> chip->page_shift);
+       page = realpage & chip->pagemask;
+
+       col = (int)(from & (mtd->writesize - 1));
+
+       buf = ops->datbuf;
+       oob = ops->oobbuf;
+       oob_required = oob ? 1 : 0;
+
+       while (1) {
+               WATCHDOG_RESET();
+
+               bytes = min(mtd->writesize - col, readlen);
+               aligned = (bytes == mtd->writesize);
+
+               /* Is the current page in the buffer? */
+               if (realpage != chip->pagebuf || oob) {
+                       bufpoi = aligned ? buf : chip->buffers->databuf;
+
+                       chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
+
+                       /*
+                        * Now read the page into the buffer.  Absent an error,
+                        * the read methods return max bitflips per ecc step.
+                        */
+                       if (unlikely(ops->mode == MTD_OPS_RAW))
+                               ret = chip->ecc.read_page_raw(mtd, chip, bufpoi,
+                                                             oob_required,
+                                                             page);
+                       else if (!aligned && NAND_HAS_SUBPAGE_READ(chip) &&
+                           !oob)
+                               ret = chip->ecc.read_subpage(mtd, chip,
+                                                       col, bytes, bufpoi);
+                       else
+                               ret = chip->ecc.read_page(mtd, chip, bufpoi,
+                                                         oob_required, page);
+                       if (ret < 0) {
+                               if (!aligned)
+                                       /* Invalidate page cache */
+                                       chip->pagebuf = -1;
+                               break;
+                       }
+
+                       max_bitflips = max_t(unsigned int, max_bitflips, ret);
+
+                       /* Transfer not aligned data */
+                       if (!aligned) {
+                               if (!NAND_HAS_SUBPAGE_READ(chip) && !oob &&
+                                   !(mtd->ecc_stats.failed - stats.failed) &&
+                                   (ops->mode != MTD_OPS_RAW)) {
+                                       chip->pagebuf = realpage;
+                                       chip->pagebuf_bitflips = ret;
+                               } else {
+                                       /* Invalidate page cache */
+                                       chip->pagebuf = -1;
+                               }
+                               memcpy(buf, chip->buffers->databuf + col, bytes);
+                       }
+
+                       buf += bytes;
+
+                       if (unlikely(oob)) {
+                               int toread = min(oobreadlen, max_oobsize);
+
+                               if (toread) {
+                                       oob = nand_transfer_oob(chip,
+                                               oob, ops, toread);
+                                       oobreadlen -= toread;
+                               }
+                       }
+               } else {
+                       memcpy(buf, chip->buffers->databuf + col, bytes);
+                       buf += bytes;
+                       max_bitflips = max_t(unsigned int, max_bitflips,
+                                            chip->pagebuf_bitflips);
+               }
+
+               readlen -= bytes;
+
+               if (!readlen)
+                       break;
+
+               /* For subsequent reads align to page boundary */
+               col = 0;
+               /* Increment page address */
+               realpage++;
+
+               page = realpage & chip->pagemask;
+               /* Check, if we cross a chip boundary */
+               if (!page) {
+                       chipnr++;
+                       chip->select_chip(mtd, -1);
+                       chip->select_chip(mtd, chipnr);
+               }
+       }
+
+       ops->retlen = ops->len - (size_t) readlen;
+       if (oob)
+               ops->oobretlen = ops->ooblen - oobreadlen;
+
+       if (ret)
+               return ret;
+
+       if (mtd->ecc_stats.failed - stats.failed)
+               return -EBADMSG;
+
+       return max_bitflips;
+}
+
+/**
+ * nand_read - [MTD Interface] MTD compatibility function for nand_do_read_ecc
+ * @mtd: MTD device structure
+ * @from: offset to read from
+ * @len: number of bytes to read
+ * @retlen: pointer to variable to store the number of read bytes
+ * @buf: the databuffer to put data
+ *
+ * Get hold of the chip and call nand_do_read.
+ */
+static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
+                    size_t *retlen, uint8_t *buf)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct mtd_oob_ops ops;
+       int ret;
+
+       nand_get_device(chip, mtd, FL_READING);
+       ops.len = len;
+       ops.datbuf = buf;
+       ops.oobbuf = NULL;
+       ops.mode = MTD_OPS_PLACE_OOB;
+       ret = nand_do_read_ops(mtd, from, &ops);
+       *retlen = ops.retlen;
+       nand_release_device(mtd);
+       return ret;
+}
+
+/**
+ * nand_read_oob_std - [REPLACEABLE] the most common OOB data read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @page: page number to read
+ */
+static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
+                            int page)
+{
+       chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
+       chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+       return 0;
+}
+
+/**
+ * nand_read_oob_syndrome - [REPLACEABLE] OOB data read function for HW ECC
+ *                         with syndromes
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @page: page number to read
+ */
+static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+                                 int page)
+{
+       uint8_t *buf = chip->oob_poi;
+       int length = mtd->oobsize;
+       int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
+       int eccsize = chip->ecc.size;
+       uint8_t *bufpoi = buf;
+       int i, toread, sndrnd = 0, pos;
+
+       chip->cmdfunc(mtd, NAND_CMD_READ0, chip->ecc.size, page);
+       for (i = 0; i < chip->ecc.steps; i++) {
+               if (sndrnd) {
+                       pos = eccsize + i * (eccsize + chunk);
+                       if (mtd->writesize > 512)
+                               chip->cmdfunc(mtd, NAND_CMD_RNDOUT, pos, -1);
+                       else
+                               chip->cmdfunc(mtd, NAND_CMD_READ0, pos, page);
+               } else
+                       sndrnd = 1;
+               toread = min_t(int, length, chunk);
+               chip->read_buf(mtd, bufpoi, toread);
+               bufpoi += toread;
+               length -= toread;
+       }
+       if (length > 0)
+               chip->read_buf(mtd, bufpoi, length);
+
+       return 0;
+}
+
+/**
+ * nand_write_oob_std - [REPLACEABLE] the most common OOB data write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @page: page number to write
+ */
+static int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
+                             int page)
+{
+       int status = 0;
+       const uint8_t *buf = chip->oob_poi;
+       int length = mtd->oobsize;
+
+       chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
+       chip->write_buf(mtd, buf, length);
+       /* Send command to program the OOB data */
+       chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+
+       status = chip->waitfunc(mtd, chip);
+
+       return status & NAND_STATUS_FAIL ? -EIO : 0;
+}
+
+/**
+ * nand_write_oob_syndrome - [REPLACEABLE] OOB data write function for HW ECC
+ *                          with syndrome - only for large page flash
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @page: page number to write
+ */
+static int nand_write_oob_syndrome(struct mtd_info *mtd,
+                                  struct nand_chip *chip, int page)
+{
+       int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
+       int eccsize = chip->ecc.size, length = mtd->oobsize;
+       int i, len, pos, status = 0, sndcmd = 0, steps = chip->ecc.steps;
+       const uint8_t *bufpoi = chip->oob_poi;
+
+       /*
+        * data-ecc-data-ecc ... ecc-oob
+        * or
+        * data-pad-ecc-pad-data-pad .... ecc-pad-oob
+        */
+       if (!chip->ecc.prepad && !chip->ecc.postpad) {
+               pos = steps * (eccsize + chunk);
+               steps = 0;
+       } else
+               pos = eccsize;
+
+       chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
+       for (i = 0; i < steps; i++) {
+               if (sndcmd) {
+                       if (mtd->writesize <= 512) {
+                               uint32_t fill = 0xFFFFFFFF;
+
+                               len = eccsize;
+                               while (len > 0) {
+                                       int num = min_t(int, len, 4);
+                                       chip->write_buf(mtd, (uint8_t *)&fill,
+                                                       num);
+                                       len -= num;
+                               }
+                       } else {
+                               pos = eccsize + i * (eccsize + chunk);
+                               chip->cmdfunc(mtd, NAND_CMD_RNDIN, pos, -1);
+                       }
+               } else
+                       sndcmd = 1;
+               len = min_t(int, length, chunk);
+               chip->write_buf(mtd, bufpoi, len);
+               bufpoi += len;
+               length -= len;
+       }
+       if (length > 0)
+               chip->write_buf(mtd, bufpoi, length);
+
+       chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+       status = chip->waitfunc(mtd, chip);
+
+       return status & NAND_STATUS_FAIL ? -EIO : 0;
+}
+
+/**
+ * nand_do_read_oob - [INTERN] NAND read out-of-band
+ * @mtd: MTD device structure
+ * @from: offset to read from
+ * @ops: oob operations description structure
+ *
+ * NAND read out-of-band data from the spare area.
+ */
+static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
+                           struct mtd_oob_ops *ops)
+{
+       int page, realpage, chipnr;
+       struct nand_chip *chip = mtd->priv;
+       struct mtd_ecc_stats stats;
+       int readlen = ops->ooblen;
+       int len;
+       uint8_t *buf = ops->oobbuf;
+       int ret = 0;
+
+       MTDDEBUG(MTD_DEBUG_LEVEL3, "%s: from = 0x%08Lx, len = %i\n",
+                       __func__, (unsigned long long)from, readlen);
+
+       stats = mtd->ecc_stats;
+
+       if (ops->mode == MTD_OPS_AUTO_OOB)
+               len = chip->ecc.layout->oobavail;
+       else
+               len = mtd->oobsize;
+
+       if (unlikely(ops->ooboffs >= len)) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Attempt to start read "
+                                       "outside oob\n", __func__);
+               return -EINVAL;
+       }
+
+       /* Do not allow reads past end of device */
+       if (unlikely(from >= mtd->size ||
+                    ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) -
+                                       (from >> chip->page_shift)) * len)) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Attempt read beyond end "
+                                       "of device\n", __func__);
+               return -EINVAL;
+       }
+
+       chipnr = (int)(from >> chip->chip_shift);
+       chip->select_chip(mtd, chipnr);
+
+       /* Shift to get page */
+       realpage = (int)(from >> chip->page_shift);
+       page = realpage & chip->pagemask;
+
+       while (1) {
+               WATCHDOG_RESET();
+               if (ops->mode == MTD_OPS_RAW)
+                       ret = chip->ecc.read_oob_raw(mtd, chip, page);
+               else
+                       ret = chip->ecc.read_oob(mtd, chip, page);
+
+               if (ret < 0)
+                       break;
+
+               len = min(len, readlen);
+               buf = nand_transfer_oob(chip, buf, ops, len);
+
+               readlen -= len;
+               if (!readlen)
+                       break;
+
+               /* Increment page address */
+               realpage++;
+
+               page = realpage & chip->pagemask;
+               /* Check, if we cross a chip boundary */
+               if (!page) {
+                       chipnr++;
+                       chip->select_chip(mtd, -1);
+                       chip->select_chip(mtd, chipnr);
+               }
+       }
+
+       ops->oobretlen = ops->ooblen - readlen;
+
+       if (ret < 0)
+               return ret;
+
+       if (mtd->ecc_stats.failed - stats.failed)
+               return -EBADMSG;
+
+       return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
+}
+
+/**
+ * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
+ * @mtd: MTD device structure
+ * @from: offset to read from
+ * @ops: oob operation description structure
+ *
+ * NAND read data and/or out-of-band data.
+ */
+static int nand_read_oob(struct mtd_info *mtd, loff_t from,
+                        struct mtd_oob_ops *ops)
+{
+       struct nand_chip *chip = mtd->priv;
+       int ret = -ENOTSUPP;
+
+       ops->retlen = 0;
+
+       /* Do not allow reads past end of device */
+       if (ops->datbuf && (from + ops->len) > mtd->size) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Attempt read "
+                               "beyond end of device\n", __func__);
+               return -EINVAL;
+       }
+
+       nand_get_device(chip, mtd, FL_READING);
+
+       switch (ops->mode) {
+       case MTD_OPS_PLACE_OOB:
+       case MTD_OPS_AUTO_OOB:
+       case MTD_OPS_RAW:
+               break;
+
+       default:
+               goto out;
+       }
+
+       if (!ops->datbuf)
+               ret = nand_do_read_oob(mtd, from, ops);
+       else
+               ret = nand_do_read_ops(mtd, from, ops);
+
+out:
+       nand_release_device(mtd);
+       return ret;
+}
+
+
+/**
+ * nand_write_page_raw - [INTERN] raw page write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ *
+ * Not for syndrome calculating ECC controllers, which use a special oob layout.
+ */
+static int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+                               const uint8_t *buf, int oob_required)
+{
+       chip->write_buf(mtd, buf, mtd->writesize);
+       if (oob_required)
+               chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+       return 0;
+}
+
+/**
+ * nand_write_page_raw_syndrome - [INTERN] raw page write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ *
+ * We need a special oob layout and handling even when ECC isn't checked.
+ */
+static int nand_write_page_raw_syndrome(struct mtd_info *mtd,
+                                       struct nand_chip *chip,
+                                       const uint8_t *buf, int oob_required)
+{
+       int eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       uint8_t *oob = chip->oob_poi;
+       int steps, size;
+
+       for (steps = chip->ecc.steps; steps > 0; steps--) {
+               chip->write_buf(mtd, buf, eccsize);
+               buf += eccsize;
+
+               if (chip->ecc.prepad) {
+                       chip->write_buf(mtd, oob, chip->ecc.prepad);
+                       oob += chip->ecc.prepad;
+               }
+
+               chip->read_buf(mtd, oob, eccbytes);
+               oob += eccbytes;
+
+               if (chip->ecc.postpad) {
+                       chip->write_buf(mtd, oob, chip->ecc.postpad);
+                       oob += chip->ecc.postpad;
+               }
+       }
+
+       size = mtd->oobsize - (oob - chip->oob_poi);
+       if (size)
+               chip->write_buf(mtd, oob, size);
+
+       return 0;
+}
+/**
+ * nand_write_page_swecc - [REPLACEABLE] software ECC based page write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ */
+static int nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
+                                 const uint8_t *buf, int oob_required)
+{
+       int i, eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       int eccsteps = chip->ecc.steps;
+       uint8_t *ecc_calc = chip->buffers->ecccalc;
+       const uint8_t *p = buf;
+       uint32_t *eccpos = chip->ecc.layout->eccpos;
+
+       /* Software ECC calculation */
+       for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
+               chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+       for (i = 0; i < chip->ecc.total; i++)
+               chip->oob_poi[eccpos[i]] = ecc_calc[i];
+
+       return chip->ecc.write_page_raw(mtd, chip, buf, 1);
+}
+
+/**
+ * nand_write_page_hwecc - [REPLACEABLE] hardware ECC based page write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ */
+static int nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
+                                 const uint8_t *buf, int oob_required)
+{
+       int i, eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       int eccsteps = chip->ecc.steps;
+       uint8_t *ecc_calc = chip->buffers->ecccalc;
+       const uint8_t *p = buf;
+       uint32_t *eccpos = chip->ecc.layout->eccpos;
+
+       for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+               chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
+               chip->write_buf(mtd, p, eccsize);
+               chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+       }
+
+       for (i = 0; i < chip->ecc.total; i++)
+               chip->oob_poi[eccpos[i]] = ecc_calc[i];
+
+       chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+       return 0;
+}
+
+/**
+ * nand_write_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page write
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ *
+ * The hw generator calculates the error syndrome automatically. Therefore we
+ * need a special oob layout and handling.
+ */
+static int nand_write_page_syndrome(struct mtd_info *mtd,
+                                   struct nand_chip *chip,
+                                   const uint8_t *buf, int oob_required)
+{
+       int i, eccsize = chip->ecc.size;
+       int eccbytes = chip->ecc.bytes;
+       int eccsteps = chip->ecc.steps;
+       const uint8_t *p = buf;
+       uint8_t *oob = chip->oob_poi;
+
+       for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+
+               chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
+               chip->write_buf(mtd, p, eccsize);
+
+               if (chip->ecc.prepad) {
+                       chip->write_buf(mtd, oob, chip->ecc.prepad);
+                       oob += chip->ecc.prepad;
+               }
+
+               chip->ecc.calculate(mtd, p, oob);
+               chip->write_buf(mtd, oob, eccbytes);
+               oob += eccbytes;
+
+               if (chip->ecc.postpad) {
+                       chip->write_buf(mtd, oob, chip->ecc.postpad);
+                       oob += chip->ecc.postpad;
+               }
+       }
+
+       /* Calculate remaining oob bytes */
+       i = mtd->oobsize - (oob - chip->oob_poi);
+       if (i)
+               chip->write_buf(mtd, oob, i);
+
+       return 0;
+}
+
+/**
+ * nand_write_page - [REPLACEABLE] write one page
+ * @mtd: MTD device structure
+ * @chip: NAND chip descriptor
+ * @buf: the data to write
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ * @cached: cached programming
+ * @raw: use _raw version of write_page
+ */
+static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+                          const uint8_t *buf, int oob_required, int page,
+                          int cached, int raw)
+{
+       int status;
+
+       chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
+
+       if (unlikely(raw))
+               status = chip->ecc.write_page_raw(mtd, chip, buf, oob_required);
+       else
+               status = chip->ecc.write_page(mtd, chip, buf, oob_required);
+
+       if (status < 0)
+               return status;
+
+       /*
+        * Cached progamming disabled for now. Not sure if it's worth the
+        * trouble. The speed gain is not very impressive. (2.3->2.6Mib/s).
+        */
+       cached = 0;
+
+       if (!cached || !(chip->options & NAND_CACHEPRG)) {
+
+               chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+               status = chip->waitfunc(mtd, chip);
+               /*
+                * See if operation failed and additional status checks are
+                * available.
+                */
+               if ((status & NAND_STATUS_FAIL) && (chip->errstat))
+                       status = chip->errstat(mtd, chip, FL_WRITING, status,
+                                              page);
+
+               if (status & NAND_STATUS_FAIL)
+                       return -EIO;
+       } else {
+               chip->cmdfunc(mtd, NAND_CMD_CACHEDPROG, -1, -1);
+               status = chip->waitfunc(mtd, chip);
+       }
+
+#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
+       /* Send command to read back the data */
+       chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+       if (chip->verify_buf(mtd, buf, mtd->writesize))
+               return -EIO;
+
+       /* Make sure the next page prog is preceded by a status read */
+       chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+#endif
+       return 0;
+}
+
+/**
+ * nand_fill_oob - [INTERN] Transfer client buffer to oob
+ * @mtd: MTD device structure
+ * @oob: oob data buffer
+ * @len: oob data write length
+ * @ops: oob ops structure
+ */
+static uint8_t *nand_fill_oob(struct mtd_info *mtd, uint8_t *oob, size_t len,
+                             struct mtd_oob_ops *ops)
+{
+       struct nand_chip *chip = mtd->priv;
+
+       /*
+        * Initialise to all 0xFF, to avoid the possibility of left over OOB
+        * data from a previous OOB read.
+        */
+       memset(chip->oob_poi, 0xff, mtd->oobsize);
+
+       switch (ops->mode) {
+
+       case MTD_OPS_PLACE_OOB:
+       case MTD_OPS_RAW:
+               memcpy(chip->oob_poi + ops->ooboffs, oob, len);
+               return oob + len;
+
+       case MTD_OPS_AUTO_OOB: {
+               struct nand_oobfree *free = chip->ecc.layout->oobfree;
+               uint32_t boffs = 0, woffs = ops->ooboffs;
+               size_t bytes = 0;
+
+               for (; free->length && len; free++, len -= bytes) {
+                       /* Write request not from offset 0? */
+                       if (unlikely(woffs)) {
+                               if (woffs >= free->length) {
+                                       woffs -= free->length;
+                                       continue;
+                               }
+                               boffs = free->offset + woffs;
+                               bytes = min_t(size_t, len,
+                                             (free->length - woffs));
+                               woffs = 0;
+                       } else {
+                               bytes = min_t(size_t, len, free->length);
+                               boffs = free->offset;
+                       }
+                       memcpy(chip->oob_poi + boffs, oob, bytes);
+                       oob += bytes;
+               }
+               return oob;
+       }
+       default:
+               BUG();
+       }
+       return NULL;
+}
+
+#define NOTALIGNED(x)  ((x & (chip->subpagesize - 1)) != 0)
+
+/**
+ * nand_do_write_ops - [INTERN] NAND write with ECC
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @ops: oob operations description structure
+ *
+ * NAND write with ECC.
+ */
+static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
+                            struct mtd_oob_ops *ops)
+{
+       int chipnr, realpage, page, blockmask, column;
+       struct nand_chip *chip = mtd->priv;
+       uint32_t writelen = ops->len;
+
+       uint32_t oobwritelen = ops->ooblen;
+       uint32_t oobmaxlen = ops->mode == MTD_OPS_AUTO_OOB ?
+                               mtd->oobavail : mtd->oobsize;
+
+       uint8_t *oob = ops->oobbuf;
+       uint8_t *buf = ops->datbuf;
+       int ret, subpage;
+       int oob_required = oob ? 1 : 0;
+
+       ops->retlen = 0;
+       if (!writelen)
+               return 0;
+
+       column = to & (mtd->writesize - 1);
+       subpage = column || (writelen & (mtd->writesize - 1));
+
+       if (subpage && oob)
+               return -EINVAL;
+
+       chipnr = (int)(to >> chip->chip_shift);
+       chip->select_chip(mtd, chipnr);
+
+       /* Check, if it is write protected */
+       if (nand_check_wp(mtd)) {
+               printk (KERN_NOTICE "nand_do_write_ops: Device is write protected\n");
+               return -EIO;
+       }
+
+       realpage = (int)(to >> chip->page_shift);
+       page = realpage & chip->pagemask;
+       blockmask = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
+
+       /* Invalidate the page cache, when we write to the cached page */
+       if (to <= (chip->pagebuf << chip->page_shift) &&
+           (chip->pagebuf << chip->page_shift) < (to + ops->len))
+               chip->pagebuf = -1;
+
+       /* Don't allow multipage oob writes with offset */
+       if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen))
+               return -EINVAL;
+
+       while (1) {
+               WATCHDOG_RESET();
+
+               int bytes = mtd->writesize;
+               int cached = writelen > bytes && page != blockmask;
+               uint8_t *wbuf = buf;
+
+               /* Partial page write? */
+               if (unlikely(column || writelen < mtd->writesize)) {
+                       cached = 0;
+                       bytes = min_t(int, bytes - column, (int) writelen);
+                       chip->pagebuf = -1;
+                       memset(chip->buffers->databuf, 0xff, mtd->writesize);
+                       memcpy(&chip->buffers->databuf[column], buf, bytes);
+                       wbuf = chip->buffers->databuf;
+               }
+
+               if (unlikely(oob)) {
+                       size_t len = min(oobwritelen, oobmaxlen);
+                       oob = nand_fill_oob(mtd, oob, len, ops);
+                       oobwritelen -= len;
+               } else {
+                       /* We still need to erase leftover OOB data */
+                       memset(chip->oob_poi, 0xff, mtd->oobsize);
+               }
+
+               ret = chip->write_page(mtd, chip, wbuf, oob_required, page,
+                                      cached, (ops->mode == MTD_OPS_RAW));
+               if (ret)
+                       break;
+
+               writelen -= bytes;
+               if (!writelen)
+                       break;
+
+               column = 0;
+               buf += bytes;
+               realpage++;
+
+               page = realpage & chip->pagemask;
+               /* Check, if we cross a chip boundary */
+               if (!page) {
+                       chipnr++;
+                       chip->select_chip(mtd, -1);
+                       chip->select_chip(mtd, chipnr);
+               }
+       }
+
+       ops->retlen = ops->len - writelen;
+       if (unlikely(oob))
+               ops->oobretlen = ops->ooblen;
+       return ret;
+}
+
+/**
+ * nand_write - [MTD Interface] NAND write with ECC
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @len: number of bytes to write
+ * @retlen: pointer to variable to store the number of written bytes
+ * @buf: the data to write
+ *
+ * NAND write with ECC.
+ */
+static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
+                         size_t *retlen, const uint8_t *buf)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct mtd_oob_ops ops;
+       int ret;
+
+       nand_get_device(chip, mtd, FL_WRITING);
+       ops.len = len;
+       ops.datbuf = (uint8_t *)buf;
+       ops.oobbuf = NULL;
+       ops.mode = MTD_OPS_PLACE_OOB;
+       ret = nand_do_write_ops(mtd, to, &ops);
+       *retlen = ops.retlen;
+       nand_release_device(mtd);
+       return ret;
+}
+
+/**
+ * nand_do_write_oob - [MTD Interface] NAND write out-of-band
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @ops: oob operation description structure
+ *
+ * NAND write out-of-band.
+ */
+static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
+                            struct mtd_oob_ops *ops)
+{
+       int chipnr, page, status, len;
+       struct nand_chip *chip = mtd->priv;
+
+       MTDDEBUG(MTD_DEBUG_LEVEL3, "%s: to = 0x%08x, len = %i\n",
+                        __func__, (unsigned int)to, (int)ops->ooblen);
+
+       if (ops->mode == MTD_OPS_AUTO_OOB)
+               len = chip->ecc.layout->oobavail;
+       else
+               len = mtd->oobsize;
+
+       /* Do not allow write past end of page */
+       if ((ops->ooboffs + ops->ooblen) > len) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Attempt to write "
+                               "past end of page\n", __func__);
+               return -EINVAL;
+       }
+
+       if (unlikely(ops->ooboffs >= len)) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Attempt to start "
+                               "write outside oob\n", __func__);
+               return -EINVAL;
+       }
+
+       /* Do not allow write past end of device */
+       if (unlikely(to >= mtd->size ||
+                    ops->ooboffs + ops->ooblen >
+                       ((mtd->size >> chip->page_shift) -
+                        (to >> chip->page_shift)) * len)) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Attempt write beyond "
+                               "end of device\n", __func__);
+               return -EINVAL;
+       }
+
+       chipnr = (int)(to >> chip->chip_shift);
+       chip->select_chip(mtd, chipnr);
+
+       /* Shift to get page */
+       page = (int)(to >> chip->page_shift);
+
+       /*
+        * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
+        * of my DiskOnChip 2000 test units) will clear the whole data page too
+        * if we don't do this. I have no clue why, but I seem to have 'fixed'
+        * it in the doc2000 driver in August 1999.  dwmw2.
+        */
+       chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+
+       /* Check, if it is write protected */
+       if (nand_check_wp(mtd))
+               return -EROFS;
+
+       /* Invalidate the page cache, if we write to the cached page */
+       if (page == chip->pagebuf)
+               chip->pagebuf = -1;
+
+       nand_fill_oob(mtd, ops->oobbuf, ops->ooblen, ops);
+
+       if (ops->mode == MTD_OPS_RAW)
+               status = chip->ecc.write_oob_raw(mtd, chip, page & chip->pagemask);
+       else
+               status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
+
+       if (status)
+               return status;
+
+       ops->oobretlen = ops->ooblen;
+
+       return 0;
+}
+
+/**
+ * nand_write_oob - [MTD Interface] NAND write data and/or out-of-band
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @ops: oob operation description structure
+ */
+static int nand_write_oob(struct mtd_info *mtd, loff_t to,
+                         struct mtd_oob_ops *ops)
+{
+       struct nand_chip *chip = mtd->priv;
+       int ret = -ENOTSUPP;
+
+       ops->retlen = 0;
+
+       /* Do not allow writes past end of device */
+       if (ops->datbuf && (to + ops->len) > mtd->size) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Attempt write beyond "
+                               "end of device\n", __func__);
+               return -EINVAL;
+       }
+
+       nand_get_device(chip, mtd, FL_WRITING);
+
+       switch (ops->mode) {
+       case MTD_OPS_PLACE_OOB:
+       case MTD_OPS_AUTO_OOB:
+       case MTD_OPS_RAW:
+               break;
+
+       default:
+               goto out;
+       }
+
+       if (!ops->datbuf)
+               ret = nand_do_write_oob(mtd, to, ops);
+       else
+               ret = nand_do_write_ops(mtd, to, ops);
+
+out:
+       nand_release_device(mtd);
+       return ret;
+}
+
+/**
+ * single_erase_cmd - [GENERIC] NAND standard block erase command function
+ * @mtd: MTD device structure
+ * @page: the page address of the block which will be erased
+ *
+ * Standard erase command for NAND chips.
+ */
+static void single_erase_cmd(struct mtd_info *mtd, int page)
+{
+       struct nand_chip *chip = mtd->priv;
+       /* Send commands to erase a block */
+       chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
+       chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
+}
+
+/**
+ * multi_erase_cmd - [GENERIC] AND specific block erase command function
+ * @mtd: MTD device structure
+ * @page: the page address of the block which will be erased
+ *
+ * AND multi block erase command function. Erase 4 consecutive blocks.
+ */
+static void multi_erase_cmd(struct mtd_info *mtd, int page)
+{
+       struct nand_chip *chip = mtd->priv;
+       /* Send commands to erase a block */
+       chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
+       chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
+       chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
+       chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
+       chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
+}
+
+/**
+ * nand_erase - [MTD Interface] erase block(s)
+ * @mtd: MTD device structure
+ * @instr: erase instruction
+ *
+ * Erase one ore more blocks.
+ */
+static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+       return nand_erase_nand(mtd, instr, 0);
+}
+
+#define BBT_PAGE_MASK  0xffffff3f
+/**
+ * nand_erase_nand - [INTERN] erase block(s)
+ * @mtd: MTD device structure
+ * @instr: erase instruction
+ * @allowbbt: allow erasing the bbt area
+ *
+ * Erase one ore more blocks.
+ */
+int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
+                   int allowbbt)
+{
+       int page, status, pages_per_block, ret, chipnr;
+       struct nand_chip *chip = mtd->priv;
+       loff_t rewrite_bbt[CONFIG_SYS_NAND_MAX_CHIPS] = {0};
+       unsigned int bbt_masked_page = 0xffffffff;
+       loff_t len;
+
+       MTDDEBUG(MTD_DEBUG_LEVEL3, "%s: start = 0x%012llx, len = %llu\n",
+                               __func__, (unsigned long long)instr->addr,
+                               (unsigned long long)instr->len);
+
+       if (check_offs_len(mtd, instr->addr, instr->len))
+               return -EINVAL;
+
+       /* Grab the lock and see if the device is available */
+       nand_get_device(chip, mtd, FL_ERASING);
+
+       /* Shift to get first page */
+       page = (int)(instr->addr >> chip->page_shift);
+       chipnr = (int)(instr->addr >> chip->chip_shift);
+
+       /* Calculate pages in each block */
+       pages_per_block = 1 << (chip->phys_erase_shift - chip->page_shift);
+
+       /* Select the NAND device */
+       chip->select_chip(mtd, chipnr);
+
+       /* Check, if it is write protected */
+       if (nand_check_wp(mtd)) {
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Device is write protected!!!\n",
+                                       __func__);
+               instr->state = MTD_ERASE_FAILED;
+               goto erase_exit;
+       }
+
+       /*
+        * If BBT requires refresh, set the BBT page mask to see if the BBT
+        * should be rewritten. Otherwise the mask is set to 0xffffffff which
+        * can not be matched. This is also done when the bbt is actually
+        * erased to avoid recursive updates.
+        */
+       if (chip->options & BBT_AUTO_REFRESH && !allowbbt)
+               bbt_masked_page = chip->bbt_td->pages[chipnr] & BBT_PAGE_MASK;
+
+       /* Loop through the pages */
+       len = instr->len;
+
+       instr->state = MTD_ERASING;
+
+       while (len) {
+               WATCHDOG_RESET();
+               /* Check if we have a bad block, we do not erase bad blocks! */
+               if (!instr->scrub && nand_block_checkbad(mtd, ((loff_t) page) <<
+                                       chip->page_shift, 0, allowbbt)) {
+                       pr_warn("%s: attempt to erase a bad block at page 0x%08x\n",
+                                  __func__, page);
+                       instr->state = MTD_ERASE_FAILED;
+                       goto erase_exit;
+               }
+
+               /*
+                * Invalidate the page cache, if we erase the block which
+                * contains the current cached page.
+                */
+               if (page <= chip->pagebuf && chip->pagebuf <
+                   (page + pages_per_block))
+                       chip->pagebuf = -1;
+
+               chip->erase_cmd(mtd, page & chip->pagemask);
+
+               status = chip->waitfunc(mtd, chip);
+
+               /*
+                * See if operation failed and additional status checks are
+                * available
+                */
+               if ((status & NAND_STATUS_FAIL) && (chip->errstat))
+                       status = chip->errstat(mtd, chip, FL_ERASING,
+                                              status, page);
+
+               /* See if block erase succeeded */
+               if (status & NAND_STATUS_FAIL) {
+                       MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: Failed erase, "
+                                       "page 0x%08x\n", __func__, page);
+                       instr->state = MTD_ERASE_FAILED;
+                       instr->fail_addr =
+                               ((loff_t)page << chip->page_shift);
+                       goto erase_exit;
+               }
+
+               /*
+                * If BBT requires refresh, set the BBT rewrite flag to the
+                * page being erased.
+                */
+               if (bbt_masked_page != 0xffffffff &&
+                   (page & BBT_PAGE_MASK) == bbt_masked_page)
+                       rewrite_bbt[chipnr] =
+                               ((loff_t)page << chip->page_shift);
+
+               /* Increment page address and decrement length */
+               len -= (1 << chip->phys_erase_shift);
+               page += pages_per_block;
+
+               /* Check, if we cross a chip boundary */
+               if (len && !(page & chip->pagemask)) {
+                       chipnr++;
+                       chip->select_chip(mtd, -1);
+                       chip->select_chip(mtd, chipnr);
+
+                       /*
+                        * If BBT requires refresh and BBT-PERCHIP, set the BBT
+                        * page mask to see if this BBT should be rewritten.
+                        */
+                       if (bbt_masked_page != 0xffffffff &&
+                           (chip->bbt_td->options & NAND_BBT_PERCHIP))
+                               bbt_masked_page = chip->bbt_td->pages[chipnr] &
+                                       BBT_PAGE_MASK;
+               }
+       }
+       instr->state = MTD_ERASE_DONE;
+
+erase_exit:
+
+       ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
+
+       /* Deselect and wake up anyone waiting on the device */
+       nand_release_device(mtd);
+
+       /* Do call back function */
+       if (!ret)
+               mtd_erase_callback(instr);
+
+       /*
+        * If BBT requires refresh and erase was successful, rewrite any
+        * selected bad block tables.
+        */
+       if (bbt_masked_page == 0xffffffff || ret)
+               return ret;
+
+       for (chipnr = 0; chipnr < chip->numchips; chipnr++) {
+               if (!rewrite_bbt[chipnr])
+                       continue;
+               /* Update the BBT for chip */
+               MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: nand_update_bbt "
+                       "(%d:0x%0llx 0x%0x)\n", __func__, chipnr,
+                       rewrite_bbt[chipnr], chip->bbt_td->pages[chipnr]);
+               nand_update_bbt(mtd, rewrite_bbt[chipnr]);
+       }
+
+       /* Return more or less happy */
+       return ret;
+}
+
+/**
+ * nand_sync - [MTD Interface] sync
+ * @mtd: MTD device structure
+ *
+ * Sync is actually a wait for chip ready function.
+ */
+static void nand_sync(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+
+       MTDDEBUG(MTD_DEBUG_LEVEL3, "%s: called\n", __func__);
+
+       /* Grab the lock and see if the device is available */
+       nand_get_device(chip, mtd, FL_SYNCING);
+       /* Release it and go back */
+       nand_release_device(mtd);
+}
+
+/**
+ * nand_block_isbad - [MTD Interface] Check if block at offset is bad
+ * @mtd: MTD device structure
+ * @offs: offset relative to mtd start
+ */
+static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
+{
+       return nand_block_checkbad(mtd, offs, 1, 0);
+}
+
+/**
+ * nand_block_markbad - [MTD Interface] Mark block at the given offset as bad
+ * @mtd: MTD device structure
+ * @ofs: offset relative to mtd start
+ */
+static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+       struct nand_chip *chip = mtd->priv;
+       int ret;
+
+       ret = nand_block_isbad(mtd, ofs);
+       if (ret) {
+               /* If it was bad already, return success and do nothing */
+               if (ret > 0)
+                       return 0;
+               return ret;
+       }
+
+       return chip->block_markbad(mtd, ofs);
+}
+
+ /**
+ * nand_onfi_set_features- [REPLACEABLE] set features for ONFI nand
+ * @mtd: MTD device structure
+ * @chip: nand chip info structure
+ * @addr: feature address.
+ * @subfeature_param: the subfeature parameters, a four bytes array.
+ */
+static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip,
+                       int addr, uint8_t *subfeature_param)
+{
+       int status;
+
+       if (!chip->onfi_version)
+               return -EINVAL;
+
+       chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES, addr, -1);
+       chip->write_buf(mtd, subfeature_param, ONFI_SUBFEATURE_PARAM_LEN);
+       status = chip->waitfunc(mtd, chip);
+       if (status & NAND_STATUS_FAIL)
+               return -EIO;
+       return 0;
+}
+
+/**
+ * nand_onfi_get_features- [REPLACEABLE] get features for ONFI nand
+ * @mtd: MTD device structure
+ * @chip: nand chip info structure
+ * @addr: feature address.
+ * @subfeature_param: the subfeature parameters, a four bytes array.
+ */
+static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip,
+                       int addr, uint8_t *subfeature_param)
+{
+       if (!chip->onfi_version)
+               return -EINVAL;
+
+       /* clear the sub feature parameters */
+       memset(subfeature_param, 0, ONFI_SUBFEATURE_PARAM_LEN);
+
+       chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, addr, -1);
+       chip->read_buf(mtd, subfeature_param, ONFI_SUBFEATURE_PARAM_LEN);
+       return 0;
+}
+
+/* Set default functions */
+static void nand_set_defaults(struct nand_chip *chip, int busw)
+{
+       /* check for proper chip_delay setup, set 20us if not */
+       if (!chip->chip_delay)
+               chip->chip_delay = 20;
+
+       /* check, if a user supplied command function given */
+       if (chip->cmdfunc == NULL)
+               chip->cmdfunc = nand_command;
+
+       /* check, if a user supplied wait function given */
+       if (chip->waitfunc == NULL)
+               chip->waitfunc = nand_wait;
+
+       if (!chip->select_chip)
+               chip->select_chip = nand_select_chip;
+       if (!chip->read_byte)
+               chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
+       if (!chip->read_word)
+               chip->read_word = nand_read_word;
+       if (!chip->block_bad)
+               chip->block_bad = nand_block_bad;
+       if (!chip->block_markbad)
+               chip->block_markbad = nand_default_block_markbad;
+       if (!chip->write_buf)
+               chip->write_buf = busw ? nand_write_buf16 : nand_write_buf;
+       if (!chip->read_buf)
+               chip->read_buf = busw ? nand_read_buf16 : nand_read_buf;
+       if (!chip->verify_buf)
+               chip->verify_buf = busw ? nand_verify_buf16 : nand_verify_buf;
+       if (!chip->scan_bbt)
+               chip->scan_bbt = nand_default_bbt;
+       if (!chip->controller)
+               chip->controller = &chip->hwcontrol;
+}
+
+#ifdef CONFIG_SYS_NAND_ONFI_DETECTION
+/* Sanitize ONFI strings so we can safely print them */
+static void sanitize_string(char *s, size_t len)
+{
+       ssize_t i;
+
+       /* Null terminate */
+       s[len - 1] = 0;
+
+       /* Remove non printable chars */
+       for (i = 0; i < len - 1; i++) {
+               if (s[i] < ' ' || s[i] > 127)
+                       s[i] = '?';
+       }
+
+       /* Remove trailing spaces */
+       strim(s);
+}
+
+static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
+{
+       int i;
+       while (len--) {
+               crc ^= *p++ << 8;
+               for (i = 0; i < 8; i++)
+                       crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
+       }
+
+       return crc;
+}
+
+/*
+ * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
+ */
+static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
+                                       int *busw)
+{
+       struct nand_onfi_params *p = &chip->onfi_params;
+       int i;
+       int val;
+
+       /* Try ONFI for unknown chip or LP */
+       chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
+       if (chip->read_byte(mtd) != 'O' || chip->read_byte(mtd) != 'N' ||
+               chip->read_byte(mtd) != 'F' || chip->read_byte(mtd) != 'I')
+               return 0;
+
+       chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
+       for (i = 0; i < 3; i++) {
+               chip->read_buf(mtd, (uint8_t *)p, sizeof(*p));
+               if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
+                               le16_to_cpu(p->crc)) {
+                       pr_info("ONFI param page %d valid\n", i);
+                       break;
+               }
+       }
+
+       if (i == 3)
+               return 0;
+
+       /* Check version */
+       val = le16_to_cpu(p->revision);
+       if (val & (1 << 5))
+               chip->onfi_version = 23;
+       else if (val & (1 << 4))
+               chip->onfi_version = 22;
+       else if (val & (1 << 3))
+               chip->onfi_version = 21;
+       else if (val & (1 << 2))
+               chip->onfi_version = 20;
+       else if (val & (1 << 1))
+               chip->onfi_version = 10;
+       else
+               chip->onfi_version = 0;
+
+       if (!chip->onfi_version) {
+               pr_info("%s: unsupported ONFI version: %d\n", __func__, val);
+               return 0;
+       }
+
+       sanitize_string(p->manufacturer, sizeof(p->manufacturer));
+       sanitize_string(p->model, sizeof(p->model));
+       if (!mtd->name)
+               mtd->name = p->model;
+       mtd->writesize = le32_to_cpu(p->byte_per_page);
+       mtd->erasesize = le32_to_cpu(p->pages_per_block) * mtd->writesize;
+       mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
+       chip->chipsize = le32_to_cpu(p->blocks_per_lun);
+       chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
+       *busw = 0;
+       if (le16_to_cpu(p->features) & 1)
+               *busw = NAND_BUSWIDTH_16;
+
+       pr_info("ONFI flash detected\n");
+       return 1;
+}
+#else
+static inline int nand_flash_detect_onfi(struct mtd_info *mtd,
+                                       struct nand_chip *chip,
+                                       int *busw)
+{
+       return 0;
+}
+#endif
+
+/*
+ * nand_id_has_period - Check if an ID string has a given wraparound period
+ * @id_data: the ID string
+ * @arrlen: the length of the @id_data array
+ * @period: the period of repitition
+ *
+ * Check if an ID string is repeated within a given sequence of bytes at
+ * specific repetition interval period (e.g., {0x20,0x01,0x7F,0x20} has a
+ * period of 2). This is a helper function for nand_id_len(). Returns non-zero
+ * if the repetition has a period of @period; otherwise, returns zero.
+ */
+static int nand_id_has_period(u8 *id_data, int arrlen, int period)
+{
+       int i, j;
+       for (i = 0; i < period; i++)
+               for (j = i + period; j < arrlen; j += period)
+                       if (id_data[i] != id_data[j])
+                               return 0;
+       return 1;
+}
+
+/*
+ * nand_id_len - Get the length of an ID string returned by CMD_READID
+ * @id_data: the ID string
+ * @arrlen: the length of the @id_data array
+
+ * Returns the length of the ID string, according to known wraparound/trailing
+ * zero patterns. If no pattern exists, returns the length of the array.
+ */
+static int nand_id_len(u8 *id_data, int arrlen)
+{
+       int last_nonzero, period;
+
+       /* Find last non-zero byte */
+       for (last_nonzero = arrlen - 1; last_nonzero >= 0; last_nonzero--)
+               if (id_data[last_nonzero])
+                       break;
+
+       /* All zeros */
+       if (last_nonzero < 0)
+               return 0;
+
+       /* Calculate wraparound period */
+       for (period = 1; period < arrlen; period++)
+               if (nand_id_has_period(id_data, arrlen, period))
+                       break;
+
+       /* There's a repeated pattern */
+       if (period < arrlen)
+               return period;
+
+       /* There are trailing zeros */
+       if (last_nonzero < arrlen - 1)
+               return last_nonzero + 1;
+
+       /* No pattern detected */
+       return arrlen;
+}
+
+/*
+ * Many new NAND share similar device ID codes, which represent the size of the
+ * chip. The rest of the parameters must be decoded according to generic or
+ * manufacturer-specific "extended ID" decoding patterns.
+ */
+static void nand_decode_ext_id(struct mtd_info *mtd, struct nand_chip *chip,
+                               u8 id_data[8], int *busw)
+{
+       int extid, id_len;
+       /* The 3rd id byte holds MLC / multichip data */
+       chip->cellinfo = id_data[2];
+       /* The 4th id byte is the important one */
+       extid = id_data[3];
+
+       id_len = nand_id_len(id_data, 8);
+
+       /*
+        * Field definitions are in the following datasheets:
+        * Old style (4,5 byte ID): Samsung K9GAG08U0M (p.32)
+        * New Samsung (6 byte ID): Samsung K9GAG08U0F (p.44)
+        * Hynix MLC   (6 byte ID): Hynix H27UBG8T2B (p.22)
+        *
+        * Check for ID length, non-zero 6th byte, cell type, and Hynix/Samsung
+        * ID to decide what to do.
+        */
+       if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG &&
+                       (chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
+                       id_data[5] != 0x00) {
+               /* Calc pagesize */
+               mtd->writesize = 2048 << (extid & 0x03);
+               extid >>= 2;
+               /* Calc oobsize */
+               switch (((extid >> 2) & 0x04) | (extid & 0x03)) {
+               case 1:
+                       mtd->oobsize = 128;
+                       break;
+               case 2:
+                       mtd->oobsize = 218;
+                       break;
+               case 3:
+                       mtd->oobsize = 400;
+                       break;
+               case 4:
+                       mtd->oobsize = 436;
+                       break;
+               case 5:
+                       mtd->oobsize = 512;
+                       break;
+               case 6:
+               default: /* Other cases are "reserved" (unknown) */
+                       mtd->oobsize = 640;
+                       break;
+               }
+               extid >>= 2;
+               /* Calc blocksize */
+               mtd->erasesize = (128 * 1024) <<
+                       (((extid >> 1) & 0x04) | (extid & 0x03));
+               *busw = 0;
+       } else if (id_len == 6 && id_data[0] == NAND_MFR_HYNIX &&
+                       (chip->cellinfo & NAND_CI_CELLTYPE_MSK)) {
+               unsigned int tmp;
+
+               /* Calc pagesize */
+               mtd->writesize = 2048 << (extid & 0x03);
+               extid >>= 2;
+               /* Calc oobsize */
+               switch (((extid >> 2) & 0x04) | (extid & 0x03)) {
+               case 0:
+                       mtd->oobsize = 128;
+                       break;
+               case 1:
+                       mtd->oobsize = 224;
+                       break;
+               case 2:
+                       mtd->oobsize = 448;
+                       break;
+               case 3:
+                       mtd->oobsize = 64;
+                       break;
+               case 4:
+                       mtd->oobsize = 32;
+                       break;
+               case 5:
+                       mtd->oobsize = 16;
+                       break;
+               default:
+                       mtd->oobsize = 640;
+                       break;
+               }
+               extid >>= 2;
+               /* Calc blocksize */
+               tmp = ((extid >> 1) & 0x04) | (extid & 0x03);
+               if (tmp < 0x03)
+                       mtd->erasesize = (128 * 1024) << tmp;
+               else if (tmp == 0x03)
+                       mtd->erasesize = 768 * 1024;
+               else
+                       mtd->erasesize = (64 * 1024) << tmp;
+               *busw = 0;
+       } else {
+               /* Calc pagesize */
+               mtd->writesize = 1024 << (extid & 0x03);
+               extid >>= 2;
+               /* Calc oobsize */
+               mtd->oobsize = (8 << (extid & 0x01)) *
+                       (mtd->writesize >> 9);
+               extid >>= 2;
+               /* Calc blocksize. Blocksize is multiples of 64KiB */
+               mtd->erasesize = (64 * 1024) << (extid & 0x03);
+               extid >>= 2;
+               /* Get buswidth information */
+               *busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
+       }
+}
+
+ /*
+ * Old devices have chip data hardcoded in the device ID table. nand_decode_id
+ * decodes a matching ID table entry and assigns the MTD size parameters for
+ * the chip.
+ */
+static void nand_decode_id(struct mtd_info *mtd, struct nand_chip *chip,
+                               const struct nand_flash_dev *type, u8 id_data[8],
+                               int *busw)
+{
+       int maf_id = id_data[0];
+
+       mtd->erasesize = type->erasesize;
+       mtd->writesize = type->pagesize;
+       mtd->oobsize = mtd->writesize / 32;
+       *busw = type->options & NAND_BUSWIDTH_16;
+
+       /*
+        * Check for Spansion/AMD ID + repeating 5th, 6th byte since
+        * some Spansion chips have erasesize that conflicts with size
+        * listed in nand_ids table.
+        * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)
+        */
+       if (maf_id == NAND_MFR_AMD && id_data[4] != 0x00 && id_data[5] == 0x00
+                       && id_data[6] == 0x00 && id_data[7] == 0x00
+                       && mtd->writesize == 512) {
+               mtd->erasesize = 128 * 1024;
+               mtd->erasesize <<= ((id_data[3] & 0x03) << 1);
+       }
+}
+
+ /*
+ * Set the bad block marker/indicator (BBM/BBI) patterns according to some
+ * heuristic patterns using various detected parameters (e.g., manufacturer,
+ * page size, cell-type information).
+ */
+static void nand_decode_bbm_options(struct mtd_info *mtd,
+                                   struct nand_chip *chip, u8 id_data[8])
+{
+       int maf_id = id_data[0];
+
+       /* Set the bad block position */
+       if (mtd->writesize > 512 || (chip->options & NAND_BUSWIDTH_16))
+               chip->badblockpos = NAND_LARGE_BADBLOCK_POS;
+       else
+               chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
+
+       /*
+        * Bad block marker is stored in the last page of each block on Samsung
+        * and Hynix MLC devices; stored in first two pages of each block on
+        * Micron devices with 2KiB pages and on SLC Samsung, Hynix, Toshiba,
+        * AMD/Spansion, and Macronix.  All others scan only the first page.
+        */
+       if ((chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
+                       (maf_id == NAND_MFR_SAMSUNG ||
+                        maf_id == NAND_MFR_HYNIX))
+               chip->bbt_options |= NAND_BBT_SCANLASTPAGE;
+       else if ((!(chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
+                               (maf_id == NAND_MFR_SAMSUNG ||
+                                maf_id == NAND_MFR_HYNIX ||
+                                maf_id == NAND_MFR_TOSHIBA ||
+                                maf_id == NAND_MFR_AMD ||
+                                maf_id == NAND_MFR_MACRONIX)) ||
+                       (mtd->writesize == 2048 &&
+                        maf_id == NAND_MFR_MICRON))
+               chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
+}
+
+/*
+ * Get the flash and manufacturer id and lookup if the type is supported.
+ */
+static const struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
+                                                 struct nand_chip *chip,
+                                                 int busw,
+                                                 int *maf_id, int *dev_id,
+                                                 const struct nand_flash_dev *type)
+{
+       const char *name;
+       int i, maf_idx;
+       u8 id_data[8];
+
+       /* Select the device */
+       chip->select_chip(mtd, 0);
+
+       /*
+        * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
+        * after power-up.
+        */
+       chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+
+       /* Send the command for reading device ID */
+       chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+
+       /* Read manufacturer and device IDs */
+       *maf_id = chip->read_byte(mtd);
+       *dev_id = chip->read_byte(mtd);
+
+       /*
+        * Try again to make sure, as some systems the bus-hold or other
+        * interface concerns can cause random data which looks like a
+        * possibly credible NAND flash to appear. If the two results do
+        * not match, ignore the device completely.
+        */
+
+       chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+
+       /* Read entire ID string */
+       for (i = 0; i < 8; i++)
+               id_data[i] = chip->read_byte(mtd);
+
+       if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
+               pr_info("%s: second ID read did not match "
+                       "%02x,%02x against %02x,%02x\n", __func__,
+                       *maf_id, *dev_id, id_data[0], id_data[1]);
+               return ERR_PTR(-ENODEV);
+       }
+
+       if (!type)
+               type = nand_flash_ids;
+
+       for (; type->name != NULL; type++)
+               if (*dev_id == type->id)
+                       break;
+
+       chip->onfi_version = 0;
+       if (!type->name || !type->pagesize) {
+               /* Check is chip is ONFI compliant */
+               if (nand_flash_detect_onfi(mtd, chip, &busw))
+                       goto ident_done;
+       }
+
+       if (!type->name)
+               return ERR_PTR(-ENODEV);
+
+       if (!mtd->name)
+               mtd->name = type->name;
+
+       chip->chipsize = (uint64_t)type->chipsize << 20;
+
+       if (!type->pagesize && chip->init_size) {
+               /* Set the pagesize, oobsize, erasesize by the driver */
+               busw = chip->init_size(mtd, chip, id_data);
+       } else if (!type->pagesize) {
+               /* Decode parameters from extended ID */
+               nand_decode_ext_id(mtd, chip, id_data, &busw);
+       } else {
+               nand_decode_id(mtd, chip, type, id_data, &busw);
+       }
+       /* Get chip options, preserve non chip based options */
+       chip->options |= type->options;
+
+       /*
+        * Check if chip is not a Samsung device. Do not clear the
+        * options for chips which do not have an extended id.
+        */
+       if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
+               chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
+ident_done:
+
+       /* Try to identify manufacturer */
+       for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {
+               if (nand_manuf_ids[maf_idx].id == *maf_id)
+                       break;
+       }
+
+       /*
+        * Check, if buswidth is correct. Hardware drivers should set
+        * chip correct!
+        */
+       if (busw != (chip->options & NAND_BUSWIDTH_16)) {
+               pr_info("NAND device: Manufacturer ID:"
+                       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id,
+                       *dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
+               pr_warn("NAND bus width %d instead %d bit\n",
+                          (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
+                          busw ? 16 : 8);
+               return ERR_PTR(-EINVAL);
+       }
+
+       nand_decode_bbm_options(mtd, chip, id_data);
+
+       /* Calculate the address shift from the page size */
+       chip->page_shift = ffs(mtd->writesize) - 1;
+       /* Convert chipsize to number of pages per chip -1 */
+       chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
+
+       chip->bbt_erase_shift = chip->phys_erase_shift =
+               ffs(mtd->erasesize) - 1;
+       if (chip->chipsize & 0xffffffff)
+               chip->chip_shift = ffs((unsigned)chip->chipsize) - 1;
+       else {
+               chip->chip_shift = ffs((unsigned)(chip->chipsize >> 32));
+               chip->chip_shift += 32 - 1;
+       }
+
+       chip->badblockbits = 8;
+
+       /* Check for AND chips with 4 page planes */
+       if (chip->options & NAND_4PAGE_ARRAY)
+               chip->erase_cmd = multi_erase_cmd;
+       else
+               chip->erase_cmd = single_erase_cmd;
+
+       /* Do not replace user supplied command function! */
+       if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
+               chip->cmdfunc = nand_command_lp;
+
+       name = type->name;
+#ifdef CONFIG_SYS_NAND_ONFI_DETECTION
+       if (chip->onfi_version)
+               name = chip->onfi_params.model;
+#endif
+       pr_info("NAND device: Manufacturer ID: 0x%02x, Chip ID: 0x%02x (%s %s),"
+               " page size: %d, OOB size: %d\n",
+               *maf_id, *dev_id, nand_manuf_ids[maf_idx].name,
+               name,
+               mtd->writesize, mtd->oobsize);
+
+       return type;
+}
+
+/**
+ * nand_scan_ident - [NAND Interface] Scan for the NAND device
+ * @mtd: MTD device structure
+ * @maxchips: number of chips to scan for
+ * @table: alternative NAND ID table
+ *
+ * This is the first phase of the normal nand_scan() function. It reads the
+ * flash ID and sets up MTD fields accordingly.
+ *
+ * The mtd->owner field must be set to the module of the caller.
+ */
+int nand_scan_ident(struct mtd_info *mtd, int maxchips,
+                   const struct nand_flash_dev *table)
+{
+       int i, busw, nand_maf_id, nand_dev_id;
+       struct nand_chip *chip = mtd->priv;
+       const struct nand_flash_dev *type;
+
+       /* Get buswidth to select the correct functions */
+       busw = chip->options & NAND_BUSWIDTH_16;
+       /* Set the default functions */
+       nand_set_defaults(chip, busw);
+
+       /* Read the flash type */
+       type = nand_get_flash_type(mtd, chip, busw,
+                               &nand_maf_id, &nand_dev_id, table);
+
+       if (IS_ERR(type)) {
+#ifndef CONFIG_SYS_NAND_QUIET_TEST
+               pr_warn("No NAND device found\n");
+#endif
+               chip->select_chip(mtd, -1);
+               return PTR_ERR(type);
+       }
+
+       /* Check for a chip array */
+       for (i = 1; i < maxchips; i++) {
+               chip->select_chip(mtd, i);
+               /* See comment in nand_get_flash_type for reset */
+               chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+               /* Send the command for reading device ID */
+               chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+               /* Read manufacturer and device IDs */
+               if (nand_maf_id != chip->read_byte(mtd) ||
+                   nand_dev_id != chip->read_byte(mtd))
+                       break;
+       }
+#ifdef DEBUG
+       if (i > 1)
+               pr_info("%d NAND chips detected\n", i);
+#endif
+
+       /* Store the number of chips and calc total size for mtd */
+       chip->numchips = i;
+       mtd->size = i * chip->chipsize;
+
+       return 0;
+}
+
+
+/**
+ * nand_scan_tail - [NAND Interface] Scan for the NAND device
+ * @mtd: MTD device structure
+ *
+ * This is the second phase of the normal nand_scan() function. It fills out
+ * all the uninitialized function pointers with the defaults and scans for a
+ * bad block table if appropriate.
+ */
+int nand_scan_tail(struct mtd_info *mtd)
+{
+       int i;
+       struct nand_chip *chip = mtd->priv;
+
+       /* New bad blocks should be marked in OOB, flash-based BBT, or both */
+       BUG_ON((chip->bbt_options & NAND_BBT_NO_OOB_BBM) &&
+                       !(chip->bbt_options & NAND_BBT_USE_FLASH));
+
+       if (!(chip->options & NAND_OWN_BUFFERS))
+               chip->buffers = memalign(ARCH_DMA_MINALIGN,
+                                        sizeof(*chip->buffers));
+       if (!chip->buffers)
+               return -ENOMEM;
+
+       /* Set the internal oob buffer location, just after the page data */
+       chip->oob_poi = chip->buffers->databuf + mtd->writesize;
+
+       /*
+        * If no default placement scheme is given, select an appropriate one.
+        */
+       if (!chip->ecc.layout && (chip->ecc.mode != NAND_ECC_SOFT_BCH)) {
+               switch (mtd->oobsize) {
+               case 8:
+                       chip->ecc.layout = &nand_oob_8;
+                       break;
+               case 16:
+                       chip->ecc.layout = &nand_oob_16;
+                       break;
+               case 64:
+                       chip->ecc.layout = &nand_oob_64;
+                       break;
+               case 128:
+                       chip->ecc.layout = &nand_oob_128;
+                       break;
+               default:
+                       pr_warn("No oob scheme defined for oobsize %d\n",
+                                  mtd->oobsize);
+               }
+       }
+
+       if (!chip->write_page)
+               chip->write_page = nand_write_page;
+
+       /* set for ONFI nand */
+       if (!chip->onfi_set_features)
+               chip->onfi_set_features = nand_onfi_set_features;
+       if (!chip->onfi_get_features)
+               chip->onfi_get_features = nand_onfi_get_features;
+
+       /*
+        * Check ECC mode, default to software if 3byte/512byte hardware ECC is
+        * selected and we have 256 byte pagesize fallback to software ECC
+        */
+
+       switch (chip->ecc.mode) {
+       case NAND_ECC_HW_OOB_FIRST:
+               /* Similar to NAND_ECC_HW, but a separate read_page handle */
+               if (!chip->ecc.calculate || !chip->ecc.correct ||
+                    !chip->ecc.hwctl) {
+                       pr_warn("No ECC functions supplied; "
+                                  "hardware ECC not possible\n");
+                       BUG();
+               }
+               if (!chip->ecc.read_page)
+                       chip->ecc.read_page = nand_read_page_hwecc_oob_first;
+
+       case NAND_ECC_HW:
+               /* Use standard hwecc read page function? */
+               if (!chip->ecc.read_page)
+                       chip->ecc.read_page = nand_read_page_hwecc;
+               if (!chip->ecc.write_page)
+                       chip->ecc.write_page = nand_write_page_hwecc;
+               if (!chip->ecc.read_page_raw)
+                       chip->ecc.read_page_raw = nand_read_page_raw;
+               if (!chip->ecc.write_page_raw)
+                       chip->ecc.write_page_raw = nand_write_page_raw;
+               if (!chip->ecc.read_oob)
+                       chip->ecc.read_oob = nand_read_oob_std;
+               if (!chip->ecc.write_oob)
+                       chip->ecc.write_oob = nand_write_oob_std;
+
+       case NAND_ECC_HW_SYNDROME:
+               if ((!chip->ecc.calculate || !chip->ecc.correct ||
+                    !chip->ecc.hwctl) &&
+                   (!chip->ecc.read_page ||
+                    chip->ecc.read_page == nand_read_page_hwecc ||
+                    !chip->ecc.write_page ||
+                    chip->ecc.write_page == nand_write_page_hwecc)) {
+                       pr_warn("No ECC functions supplied; "
+                                  "hardware ECC not possible\n");
+                       BUG();
+               }
+               /* Use standard syndrome read/write page function? */
+               if (!chip->ecc.read_page)
+                       chip->ecc.read_page = nand_read_page_syndrome;
+               if (!chip->ecc.write_page)
+                       chip->ecc.write_page = nand_write_page_syndrome;
+               if (!chip->ecc.read_page_raw)
+                       chip->ecc.read_page_raw = nand_read_page_raw_syndrome;
+               if (!chip->ecc.write_page_raw)
+                       chip->ecc.write_page_raw = nand_write_page_raw_syndrome;
+               if (!chip->ecc.read_oob)
+                       chip->ecc.read_oob = nand_read_oob_syndrome;
+               if (!chip->ecc.write_oob)
+                       chip->ecc.write_oob = nand_write_oob_syndrome;
+
+               if (mtd->writesize >= chip->ecc.size) {
+                       if (!chip->ecc.strength) {
+                               pr_warn("Driver must set ecc.strength when using hardware ECC\n");
+                               BUG();
+                       }
+                       break;
+               }
+               pr_warn("%d byte HW ECC not possible on "
+                          "%d byte page size, fallback to SW ECC\n",
+                          chip->ecc.size, mtd->writesize);
+               chip->ecc.mode = NAND_ECC_SOFT;
+
+       case NAND_ECC_SOFT:
+               chip->ecc.calculate = nand_calculate_ecc;
+               chip->ecc.correct = nand_correct_data;
+               chip->ecc.read_page = nand_read_page_swecc;
+               chip->ecc.read_subpage = nand_read_subpage;
+               chip->ecc.write_page = nand_write_page_swecc;
+               chip->ecc.read_page_raw = nand_read_page_raw;
+               chip->ecc.write_page_raw = nand_write_page_raw;
+               chip->ecc.read_oob = nand_read_oob_std;
+               chip->ecc.write_oob = nand_write_oob_std;
+               if (!chip->ecc.size)
+                       chip->ecc.size = 256;
+               chip->ecc.bytes = 3;
+               chip->ecc.strength = 1;
+               break;
+
+       case NAND_ECC_SOFT_BCH:
+               if (!mtd_nand_has_bch()) {
+                       pr_warn("CONFIG_MTD_ECC_BCH not enabled\n");
+                       return -EINVAL;
+               }
+               chip->ecc.calculate = nand_bch_calculate_ecc;
+               chip->ecc.correct = nand_bch_correct_data;
+               chip->ecc.read_page = nand_read_page_swecc;
+               chip->ecc.read_subpage = nand_read_subpage;
+               chip->ecc.write_page = nand_write_page_swecc;
+               chip->ecc.read_page_raw = nand_read_page_raw;
+               chip->ecc.write_page_raw = nand_write_page_raw;
+               chip->ecc.read_oob = nand_read_oob_std;
+               chip->ecc.write_oob = nand_write_oob_std;
+               /*
+                * Board driver should supply ecc.size and ecc.bytes values to
+                * select how many bits are correctable; see nand_bch_init()
+                * for details. Otherwise, default to 4 bits for large page
+                * devices.
+                */
+               if (!chip->ecc.size && (mtd->oobsize >= 64)) {
+                       chip->ecc.size = 512;
+                       chip->ecc.bytes = 7;
+               }
+               chip->ecc.priv = nand_bch_init(mtd,
+                                              chip->ecc.size,
+                                              chip->ecc.bytes,
+                                              &chip->ecc.layout);
+               if (!chip->ecc.priv)
+                       pr_warn("BCH ECC initialization failed!\n");
+               chip->ecc.strength =
+                       chip->ecc.bytes * 8 / fls(8 * chip->ecc.size);
+               break;
+
+       case NAND_ECC_NONE:
+               pr_warn("NAND_ECC_NONE selected by board driver. "
+                       "This is not recommended !!\n");
+               chip->ecc.read_page = nand_read_page_raw;
+               chip->ecc.write_page = nand_write_page_raw;
+               chip->ecc.read_oob = nand_read_oob_std;
+               chip->ecc.read_page_raw = nand_read_page_raw;
+               chip->ecc.write_page_raw = nand_write_page_raw;
+               chip->ecc.write_oob = nand_write_oob_std;
+               chip->ecc.size = mtd->writesize;
+               chip->ecc.bytes = 0;
+               break;
+
+       default:
+               pr_warn("Invalid NAND_ECC_MODE %d\n", chip->ecc.mode);
+               BUG();
+       }
+
+       /* For many systems, the standard OOB write also works for raw */
+       if (!chip->ecc.read_oob_raw)
+               chip->ecc.read_oob_raw = chip->ecc.read_oob;
+       if (!chip->ecc.write_oob_raw)
+               chip->ecc.write_oob_raw = chip->ecc.write_oob;
+
+       /*
+        * The number of bytes available for a client to place data into
+        * the out of band area.
+        */
+       chip->ecc.layout->oobavail = 0;
+       for (i = 0; chip->ecc.layout->oobfree[i].length
+                       && i < ARRAY_SIZE(chip->ecc.layout->oobfree); i++)
+               chip->ecc.layout->oobavail +=
+                       chip->ecc.layout->oobfree[i].length;
+       mtd->oobavail = chip->ecc.layout->oobavail;
+
+       /*
+        * Set the number of read / write steps for one page depending on ECC
+        * mode.
+        */
+       chip->ecc.steps = mtd->writesize / chip->ecc.size;
+       if (chip->ecc.steps * chip->ecc.size != mtd->writesize) {
+               pr_warn("Invalid ECC parameters\n");
+               BUG();
+       }
+       chip->ecc.total = chip->ecc.steps * chip->ecc.bytes;
+
+       /* Allow subpage writes up to ecc.steps. Not possible for MLC flash */
+       if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
+           !(chip->cellinfo & NAND_CI_CELLTYPE_MSK)) {
+               switch (chip->ecc.steps) {
+               case 2:
+                       mtd->subpage_sft = 1;
+                       break;
+               case 4:
+               case 8:
+               case 16:
+                       mtd->subpage_sft = 2;
+                       break;
+               }
+       }
+       chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
+
+       /* Initialize state */
+       chip->state = FL_READY;
+
+       /* De-select the device */
+       chip->select_chip(mtd, -1);
+
+       /* Invalidate the pagebuffer reference */
+       chip->pagebuf = -1;
+
+       /* Large page NAND with SOFT_ECC should support subpage reads */
+       if ((chip->ecc.mode == NAND_ECC_SOFT) && (chip->page_shift > 9))
+               chip->options |= NAND_SUBPAGE_READ;
+
+       /* Fill in remaining MTD driver data */
+       mtd->type = MTD_NANDFLASH;
+       mtd->flags = (chip->options & NAND_ROM) ? MTD_CAP_ROM :
+                                               MTD_CAP_NANDFLASH;
+       mtd->_erase = nand_erase;
+       mtd->_point = NULL;
+       mtd->_unpoint = NULL;
+       mtd->_read = nand_read;
+       mtd->_write = nand_write;
+       mtd->_read_oob = nand_read_oob;
+       mtd->_write_oob = nand_write_oob;
+       mtd->_sync = nand_sync;
+       mtd->_lock = NULL;
+       mtd->_unlock = NULL;
+       mtd->_block_isbad = nand_block_isbad;
+       mtd->_block_markbad = nand_block_markbad;
+
+       /* propagate ecc info to mtd_info */
+       mtd->ecclayout = chip->ecc.layout;
+       mtd->ecc_strength = chip->ecc.strength;
+       /*
+        * Initialize bitflip_threshold to its default prior scan_bbt() call.
+        * scan_bbt() might invoke mtd_read(), thus bitflip_threshold must be
+        * properly set.
+        */
+       if (!mtd->bitflip_threshold)
+               mtd->bitflip_threshold = mtd->ecc_strength;
+
+       /* Check, if we should skip the bad block table scan */
+       if (chip->options & NAND_SKIP_BBTSCAN)
+               chip->options |= NAND_BBT_SCANNED;
+
+       return 0;
+}
+
+/**
+ * nand_scan - [NAND Interface] Scan for the NAND device
+ * @mtd: MTD device structure
+ * @maxchips: number of chips to scan for
+ *
+ * This fills out all the uninitialized function pointers with the defaults.
+ * The flash ID is read and the mtd/chip structures are filled with the
+ * appropriate values. The mtd->owner field must be set to the module of the
+ * caller.
+ */
+int nand_scan(struct mtd_info *mtd, int maxchips)
+{
+       int ret;
+
+       ret = nand_scan_ident(mtd, maxchips, NULL);
+       if (!ret)
+               ret = nand_scan_tail(mtd);
+       return ret;
+}
+
+/**
+ * nand_release - [NAND Interface] Free resources held by the NAND device
+ * @mtd: MTD device structure
+ */
+void nand_release(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+
+       if (chip->ecc.mode == NAND_ECC_SOFT_BCH)
+               nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
+
+#ifdef CONFIG_MTD_PARTITIONS
+       /* Deregister partitions */
+       del_mtd_partitions(mtd);
+#endif
+
+       /* Free bad block table memory */
+       kfree(chip->bbt);
+       if (!(chip->options & NAND_OWN_BUFFERS))
+               kfree(chip->buffers);
+
+       /* Free bad block descriptor memory */
+       if (chip->badblock_pattern && chip->badblock_pattern->options
+                       & NAND_BBT_DYNAMICSTRUCT)
+               kfree(chip->badblock_pattern);
+}