mtd: nand: more BB Detection refactoring and dynamic scan options

[pandora-kernel.git] / drivers / mtd / nand / nand_bbt.c

diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index ec1700e..469de17 100644 (file)
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -93,6 +93,28 @@ static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_desc
                        return -1;
        }
 
+       /* Check both positions 1 and 6 for pattern? */
+       if (td->options & NAND_BBT_SCANBYTE1AND6) {
+               if (td->options & NAND_BBT_SCANEMPTY) {
+                       p += td->len;
+                       end += NAND_SMALL_BADBLOCK_POS - td->offs;
+                       /* Check region between positions 1 and 6 */
+                       for (i = 0; i < NAND_SMALL_BADBLOCK_POS - td->offs - td->len;
+                                       i++) {
+                               if (*p++ != 0xff)
+                                       return -1;
+                       }
+               }
+               else {
+                       p += NAND_SMALL_BADBLOCK_POS - td->offs;
+               }
+               /* Compare the pattern */
+               for (i = 0; i < td->len; i++) {
+                       if (p[i] != td->pattern[i])
+                               return -1;
+               }
+       }
+
        if (td->options & NAND_BBT_SCANEMPTY) {
                p += td->len;
                end += td->len;
@@ -124,6 +146,13 @@ static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
                if (p[td->offs + i] != td->pattern[i])
                        return -1;
        }
+       /* Need to check location 1 AND 6? */
+       if (td->options & NAND_BBT_SCANBYTE1AND6) {
+               for (i = 0; i < td->len; i++) {
+                       if (p[NAND_SMALL_BADBLOCK_POS + i] != td->pattern[i])
+                               return -1;
+               }
+       }
        return 0;
 }
 
@@ -397,12 +426,10 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
 
        if (bd->options & NAND_BBT_SCANALLPAGES)
                len = 1 << (this->bbt_erase_shift - this->page_shift);
-       else {
-               if (bd->options & NAND_BBT_SCAN2NDPAGE)
-                       len = 2;
-               else
-                       len = 1;
-       }
+       else if (bd->options & NAND_BBT_SCAN2NDPAGE)
+               len = 2;
+       else
+               len = 1;
 
        if (!(bd->options & NAND_BBT_SCANEMPTY)) {
                /* We need only read few bytes from the OOB area */
@@ -1092,41 +1119,6 @@ int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
  * while scanning a device for factory marked good / bad blocks. */
 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
 
-static struct nand_bbt_descr smallpage_memorybased = {
-       .options = 0,
-       .offs = NAND_SMALL_BADBLOCK_POS,
-       .len = 1,
-       .pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr smallpage_scan2nd_memorybased = {
-       .options = NAND_BBT_SCAN2NDPAGE,
-       .offs = NAND_SMALL_BADBLOCK_POS,
-       .len = 2,
-       .pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr largepage_memorybased = {
-       .options = 0,
-       .offs = NAND_LARGE_BADBLOCK_POS,
-       .len = 1,
-       .pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr largepage_scan2nd_memorybased = {
-       .options = NAND_BBT_SCAN2NDPAGE,
-       .offs = NAND_LARGE_BADBLOCK_POS,
-       .len = 2,
-       .pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr lastpage_memorybased = {
-       .options = NAND_BBT_SCANLASTPAGE,
-       .offs = 0,
-       .len = 1,
-       .pattern = scan_ff_pattern
-};
-
 static struct nand_bbt_descr smallpage_flashbased = {
        .options = NAND_BBT_SCAN2NDPAGE,
        .offs = NAND_SMALL_BADBLOCK_POS,
@@ -1175,6 +1167,43 @@ static struct nand_bbt_descr bbt_mirror_descr = {
        .pattern = mirror_pattern
 };
 
+#define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
+               NAND_BBT_SCANBYTE1AND6)
+/**
+ * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
+ * @this:      NAND chip to create descriptor for
+ *
+ * This function allocates and initializes a nand_bbt_descr for BBM detection
+ * based on the properties of "this". The new descriptor is stored in
+ * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
+ * passed to this function.
+ *
+ * TODO: Handle other flags, replace other static structs
+ *        (e.g. handle NAND_BBT_FLASH for flash-based BBT,
+ *             replace smallpage_flashbased)
+ *
+ */
+static int nand_create_default_bbt_descr(struct nand_chip *this)
+{
+       struct nand_bbt_descr *bd;
+       if (this->badblock_pattern) {
+               printk(KERN_WARNING "BBT descr already allocated; not replacing.\n");
+               return -EINVAL;
+       }
+       bd = kzalloc(sizeof(*bd), GFP_KERNEL);
+       if (!bd) {
+               printk(KERN_ERR "nand_create_default_bbt_descr: Out of memory\n");
+               return -ENOMEM;
+       }
+       bd->options = this->options & BBT_SCAN_OPTIONS;
+       bd->offs = this->badblockpos;
+       bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
+       bd->pattern = scan_ff_pattern;
+       bd->options |= NAND_BBT_DYNAMICSTRUCT;
+       this->badblock_pattern = bd;
+       return 0;
+}
+
 /**
  * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
  * @mtd:       MTD device structure
@@ -1217,20 +1246,8 @@ int nand_default_bbt(struct mtd_info *mtd)
        } else {
                this->bbt_td = NULL;
                this->bbt_md = NULL;
-               if (!this->badblock_pattern) {
-                       if (this->options & NAND_BBT_SCANLASTPAGE)
-                               this->badblock_pattern = &lastpage_memorybased;
-                       else if (this->options & NAND_BBT_SCAN2NDPAGE)
-                               this->badblock_pattern = this->badblockpos ==
-                                       NAND_SMALL_BADBLOCK_POS ?
-                                       &smallpage_scan2nd_memorybased :
-                                       &largepage_scan2nd_memorybased;
-                       else
-                               this->badblock_pattern = this->badblockpos ==
-                                       NAND_SMALL_BADBLOCK_POS ?
-                                       &smallpage_memorybased :
-                                       &largepage_memorybased;
-               }
+               if (!this->badblock_pattern)
+                       nand_create_default_bbt_descr(this);
        }
        return nand_scan_bbt(mtd, this->badblock_pattern);
 }