[MTD] NAND: Fix breakage all over the place
authorThomas Gleixner <tglx@cruncher.tec.linutronix.de>
Tue, 20 Jun 2006 18:05:05 +0000 (20:05 +0200)
committerDavid Woodhouse <dwmw2@infradead.org>
Tue, 20 Jun 2006 19:31:24 +0000 (20:31 +0100)
Following problems are addressed:

- wrong status caused early break out of nand_wait()
- removed the bogus status check in nand_wait() which
  is a relict of the abandoned support for interrupted
  erase.
- status check moved to the correct place in read_oob
- oob support for syndrom based ecc with strange layouts
- use given offset in the AUTOOOB based oob operations

Partially based on a patch from Vitaly Vool <vwool@ru.mvista.com>
Thanks to Savin Zlobec <savin@epico.si> for tracking down the
status problem.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
drivers/mtd/mtdchar.c
drivers/mtd/nand/diskonchip.c
drivers/mtd/nand/nand_base.c
include/linux/mtd/nand.h

index 5dd0b8d72c8b67b3fd6a8183eb60f9321cce3226..aa18d45b264bb2d3aef9c71792401ac1d7ccece5 100644 (file)
@@ -504,12 +504,12 @@ static int mtd_ioctl(struct inode *inode, struct file *file,
                        return ret;
 
                ops.len = buf.length;
-               ops.ooblen = mtd->oobsize;
+               ops.ooblen = buf.length;
                ops.ooboffs = buf.start & (mtd->oobsize - 1);
                ops.datbuf = NULL;
                ops.mode = MTD_OOB_PLACE;
 
-               if (ops.ooboffs && ops.len > (ops.ooblen - ops.ooboffs))
+               if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs))
                        return -EINVAL;
 
                ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
@@ -553,12 +553,12 @@ static int mtd_ioctl(struct inode *inode, struct file *file,
                        return ret;
 
                ops.len = buf.length;
-               ops.ooblen = mtd->oobsize;
+               ops.ooblen = buf.length;
                ops.ooboffs = buf.start & (mtd->oobsize - 1);
                ops.datbuf = NULL;
                ops.mode = MTD_OOB_PLACE;
 
-               if (ops.ooboffs && ops.len > (ops.ooblen - ops.ooboffs))
+               if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs))
                        return -EINVAL;
 
                ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
index 463e12ced1b3869a5392974d4183f9386e15b01e..6107f532855b8d4dbb901ff83c721e76a0b59af2 100644 (file)
@@ -464,7 +464,7 @@ static void __init doc2000_count_chips(struct mtd_info *mtd)
        printk(KERN_DEBUG "Detected %d chips per floor.\n", i);
 }
 
-static int doc200x_wait(struct mtd_info *mtd, struct nand_chip *this, int state)
+static int doc200x_wait(struct mtd_info *mtd, struct nand_chip *this)
 {
        struct doc_priv *doc = this->priv;
 
index e74678e928cf500b741d9331b1b006c18f837717..27083ed0a017a6af2da8d41ad48d466e7b98a86d 100644 (file)
@@ -501,7 +501,6 @@ static void nand_command(struct mtd_info *mtd, unsigned int command,
        case NAND_CMD_ERASE2:
        case NAND_CMD_SEQIN:
        case NAND_CMD_STATUS:
-               chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE);
                return;
 
        case NAND_CMD_RESET:
@@ -595,6 +594,7 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
        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;
@@ -621,6 +621,14 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
                while (!(chip->read_byte(mtd) & NAND_STATUS_READY)) ;
                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);
@@ -689,18 +697,17 @@ nand_get_device(struct nand_chip *chip, struct mtd_info *mtd, int new_state)
  * nand_wait - [DEFAULT]  wait until the command is done
  * @mtd:       MTD device structure
  * @this:      NAND chip structure
- * @state:     state to select the max. timeout value
  *
  * 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, int state)
+static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
 {
 
        unsigned long timeo = jiffies;
-       int status;
+       int status, state = chip->state;
 
        if (state == FL_ERASING)
                timeo += (HZ * 400) / 1000;
@@ -719,10 +726,6 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip, int state)
                chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
 
        while (time_before(jiffies, timeo)) {
-               /* Check, if we were interrupted */
-               if (chip->state != state)
-                       return 0;
-
                if (chip->dev_ready) {
                        if (chip->dev_ready(mtd))
                                break;
@@ -909,12 +912,25 @@ static uint8_t *nand_transfer_oob(struct nand_chip *chip, uint8_t *oob,
 
        case MTD_OOB_AUTO: {
                struct nand_oobfree *free = chip->ecc.layout->oobfree;
-               size_t bytes;
+               uint32_t boffs = 0, roffs = ops->ooboffs;
+               size_t bytes = 0;
 
                for(; free->length && len; free++, len -= bytes) {
-                       bytes = min_t(size_t, len, free->length);
-
-                       memcpy(oob, chip->oob_poi + free->offset, 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;
@@ -1083,6 +1099,145 @@ static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
        return ret;
 }
 
+/**
+ * nand_read_oob_std - [REPLACABLE] the most common OOB data read function
+ * @mtd:       mtd info structure
+ * @chip:      nand chip info structure
+ * @page:      page number to read
+ * @sndcmd:    flag whether to issue read command or not
+ */
+static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
+                            int page, int sndcmd)
+{
+       if (sndcmd) {
+               chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
+               sndcmd = 0;
+       }
+       chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+       return sndcmd;
+}
+
+/**
+ * nand_read_oob_syndrome - [REPLACABLE] OOB data read function for HW ECC
+ *                         with syndromes
+ * @mtd:       mtd info structure
+ * @chip:      nand chip info structure
+ * @page:      page number to read
+ * @sndcmd:    flag whether to issue read command or not
+ */
+static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+                                 int page, int sndcmd)
+{
+       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 1;
+}
+
+/**
+ * nand_write_oob_std - [REPLACABLE] 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_write_oob_syndrome - [REPLACABLE] 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 + chunk;
+
+       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
@@ -1094,11 +1249,11 @@ static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
 static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
                            struct mtd_oob_ops *ops)
 {
-       int col, page, realpage, chipnr, sndcmd = 1;
+       int page, realpage, chipnr, sndcmd = 1;
        struct nand_chip *chip = mtd->priv;
        int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
-       int direct, bytes, readlen = ops->len;
-       uint8_t *bufpoi, *buf = ops->oobbuf;
+       int readlen = ops->len;
+       uint8_t *buf = ops->oobbuf;
 
        DEBUG(MTD_DEBUG_LEVEL3, "nand_read_oob: from = 0x%08Lx, len = %i\n",
              (unsigned long long)from, readlen);
@@ -1110,29 +1265,11 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
        realpage = (int)(from >> chip->page_shift);
        page = realpage & chip->pagemask;
 
-       if (ops->mode != MTD_OOB_AUTO) {
-               col = ops->ooboffs;
-               direct = 1;
-       } else {
-               col = 0;
-               direct = 0;
-       }
+       chip->oob_poi = chip->buffers.oobrbuf;
 
        while(1) {
-               bytes = direct ? ops->ooblen : mtd->oobsize;
-               bufpoi = direct ? buf : chip->buffers.oobrbuf;
-
-               if (likely(sndcmd)) {
-                       chip->cmdfunc(mtd, NAND_CMD_READOOB, col, page);
-                       sndcmd = 0;
-               }
-
-               chip->read_buf(mtd, bufpoi, bytes);
-
-               if (unlikely(!direct))
-                       buf = nand_transfer_oob(chip, buf, ops);
-               else
-                       buf += ops->ooblen;
+               sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd);
+               buf = nand_transfer_oob(chip, buf, ops);
 
                readlen -= ops->ooblen;
                if (!readlen)
@@ -1365,7 +1502,7 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
        if (!cached || !(chip->options & NAND_CACHEPRG)) {
 
                chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
-               status = chip->waitfunc(mtd, chip, FL_WRITING);
+               status = chip->waitfunc(mtd, chip);
                /*
                 * See if operation failed and additional status checks are
                 * available
@@ -1378,7 +1515,7 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
                        return -EIO;
        } else {
                chip->cmdfunc(mtd, NAND_CMD_CACHEDPROG, -1, -1);
-               status = chip->waitfunc(mtd, chip, FL_WRITING);
+               status = chip->waitfunc(mtd, chip);
        }
 
 #ifdef CONFIG_MTD_NAND_VERIFY_WRITE
@@ -1411,11 +1548,25 @@ static uint8_t *nand_fill_oob(struct nand_chip *chip, uint8_t *oob,
 
        case MTD_OOB_AUTO: {
                struct nand_oobfree *free = chip->ecc.layout->oobfree;
-               size_t bytes;
+               uint32_t boffs = 0, woffs = ops->ooboffs;
+               size_t bytes = 0;
 
                for(; free->length && len; free++, len -= bytes) {
-                       bytes = min_t(size_t, len, free->length);
-                       memcpy(chip->oob_poi + free->offset, oob, 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 + woffs, oob, bytes);
                        oob += bytes;
                }
                return oob;
@@ -1532,7 +1683,7 @@ static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
        if (!len)
                return 0;
 
-       nand_get_device(chip, mtd, FL_READING);
+       nand_get_device(chip, mtd, FL_WRITING);
 
        chip->ops.len = len;
        chip->ops.datbuf = (uint8_t *)buf;
@@ -1592,48 +1743,18 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
        if (page == chip->pagebuf)
                chip->pagebuf = -1;
 
-       if (ops->mode == MTD_OOB_AUTO || NAND_MUST_PAD(chip)) {
-               chip->oob_poi = chip->buffers.oobwbuf;
-               memset(chip->oob_poi, 0xff, mtd->oobsize);
-               nand_fill_oob(chip, ops->oobbuf, ops);
-               chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize,
-                             page & chip->pagemask);
-               chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
-               memset(chip->oob_poi, 0xff, mtd->oobsize);
-       } else {
-               chip->cmdfunc(mtd, NAND_CMD_SEQIN,
-                             mtd->writesize + ops->ooboffs,
-                             page & chip->pagemask);
-               chip->write_buf(mtd, ops->oobbuf, ops->len);
-       }
-
-       /* Send command to program the OOB data */
-       chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+       chip->oob_poi = chip->buffers.oobwbuf;
+       memset(chip->oob_poi, 0xff, mtd->oobsize);
+       nand_fill_oob(chip, ops->oobbuf, ops);
+       status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
+       memset(chip->oob_poi, 0xff, mtd->oobsize);
 
-       status = chip->waitfunc(mtd, chip, FL_WRITING);
+       if (status)
+               return status;
 
-       /* See if device thinks it succeeded */
-       if (status & NAND_STATUS_FAIL) {
-               DEBUG(MTD_DEBUG_LEVEL0, "nand_write_oob: "
-                     "Failed write, page 0x%08x\n", page);
-               return -EIO;
-       }
        ops->retlen = ops->len;
 
-#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
-       if (ops->mode != MTD_OOB_AUTO) {
-               /* Send command to read back the data */
-               chip->cmdfunc(mtd, NAND_CMD_READOOB, ops->ooboffs,
-                             page & chip->pagemask);
-
-               if (chip->verify_buf(mtd, ops->oobbuf, ops->len)) {
-                       DEBUG(MTD_DEBUG_LEVEL0, "nand_write_oob: "
-                             "Failed write verify, page 0x%08x\n", page);
-                       return -EIO;
-               }
-       }
-#endif
-               return 0;
+       return 0;
 }
 
 /**
@@ -1659,7 +1780,7 @@ static int nand_write_oob(struct mtd_info *mtd, loff_t to,
                return -EINVAL;
        }
 
-       nand_get_device(chip, mtd, FL_READING);
+       nand_get_device(chip, mtd, FL_WRITING);
 
        switch(ops->mode) {
        case MTD_OOB_PLACE:
@@ -1833,7 +1954,7 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
 
                chip->erase_cmd(mtd, page & chip->pagemask);
 
-               status = chip->waitfunc(mtd, chip, FL_ERASING);
+               status = chip->waitfunc(mtd, chip);
 
                /*
                 * See if operation failed and additional status checks are
@@ -2265,6 +2386,10 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                        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_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 ||
@@ -2278,6 +2403,10 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                        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_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)
                        break;
@@ -2291,6 +2420,8 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                chip->ecc.correct = nand_correct_data;
                chip->ecc.read_page = nand_read_page_swecc;
                chip->ecc.write_page = nand_write_page_swecc;
+               chip->ecc.read_oob = nand_read_oob_std;
+               chip->ecc.write_oob = nand_write_oob_std;
                chip->ecc.size = 256;
                chip->ecc.bytes = 3;
                break;
@@ -2300,6 +2431,8 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                       "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.write_oob = nand_write_oob_std;
                chip->ecc.size = mtd->writesize;
                chip->ecc.bytes = 0;
                break;
index bf2ce68901f5a83e209d75f88830e0f0c5389c05..a30969eb9afe694d2a2a62c554b8c5f473f41c6a 100644 (file)
@@ -63,18 +63,21 @@ extern void nand_release (struct mtd_info *mtd);
  */
 #define NAND_CMD_READ0         0
 #define NAND_CMD_READ1         1
+#define NAND_CMD_RNDOUT                5
 #define NAND_CMD_PAGEPROG      0x10
 #define NAND_CMD_READOOB       0x50
 #define NAND_CMD_ERASE1                0x60
 #define NAND_CMD_STATUS                0x70
 #define NAND_CMD_STATUS_MULTI  0x71
 #define NAND_CMD_SEQIN         0x80
+#define NAND_CMD_RNDIN         0x85
 #define NAND_CMD_READID                0x90
 #define NAND_CMD_ERASE2                0xd0
 #define NAND_CMD_RESET         0xff
 
 /* Extended commands for large page devices */
 #define NAND_CMD_READSTART     0x30
+#define NAND_CMD_RNDOUTSTART   0xE0
 #define NAND_CMD_CACHEDPROG    0x15
 
 /* Extended commands for AG-AND device */
@@ -250,6 +253,13 @@ struct nand_ecc_ctrl {
        void                    (*write_page)(struct mtd_info *mtd,
                                              struct nand_chip *chip,
                                              const uint8_t *buf);
+       int                     (*read_oob)(struct mtd_info *mtd,
+                                           struct nand_chip *chip,
+                                           int page,
+                                           int sndcmd);
+       int                     (*write_oob)(struct mtd_info *mtd,
+                                            struct nand_chip *chip,
+                                            int page);
 };
 
 /**
@@ -339,7 +349,7 @@ struct nand_chip {
                                    unsigned int ctrl);
        int             (*dev_ready)(struct mtd_info *mtd);
        void            (*cmdfunc)(struct mtd_info *mtd, unsigned command, int column, int page_addr);
-       int             (*waitfunc)(struct mtd_info *mtd, struct nand_chip *this, int state);
+       int             (*waitfunc)(struct mtd_info *mtd, struct nand_chip *this);
        void            (*erase_cmd)(struct mtd_info *mtd, int page);
        int             (*scan_bbt)(struct mtd_info *mtd);
        int             (*errstat)(struct mtd_info *mtd, struct nand_chip *this, int state, int status, int page);