Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 934 insertions, 0 deletions

diff --git a/drivers/mtd/chips/jedec.c b/drivers/mtd/chips/jedec.c
new file mode 100644
index 0000000..62d235a
--- /dev/null
+++ b/drivers/mtd/chips/jedec.c
@@ -0,0 +1,934 @@
+
+/* JEDEC Flash Interface.
+ * This is an older type of interface for self programming flash. It is 
+ * commonly use in older AMD chips and is obsolete compared with CFI.
+ * It is called JEDEC because the JEDEC association distributes the ID codes
+ * for the chips.
+ *
+ * See the AMD flash databook for information on how to operate the interface.
+ *
+ * This code does not support anything wider than 8 bit flash chips, I am
+ * not going to guess how to send commands to them, plus I expect they will
+ * all speak CFI..
+ *
+ * $Id: jedec.c,v 1.22 2005/01/05 18:05:11 dwmw2 Exp $
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/mtd/jedec.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/compatmac.h>
+
+static struct mtd_info *jedec_probe(struct map_info *);
+static int jedec_probe8(struct map_info *map,unsigned long base,
+		  struct jedec_private *priv);
+static int jedec_probe16(struct map_info *map,unsigned long base,
+		  struct jedec_private *priv);
+static int jedec_probe32(struct map_info *map,unsigned long base,
+		  struct jedec_private *priv);
+static void jedec_flash_chip_scan(struct jedec_private *priv,unsigned long start,
+			    unsigned long len);
+static int flash_erase(struct mtd_info *mtd, struct erase_info *instr);
+static int flash_write(struct mtd_info *mtd, loff_t start, size_t len,
+		       size_t *retlen, const u_char *buf);
+
+static unsigned long my_bank_size;
+
+/* Listing of parts and sizes. We need this table to learn the sector
+   size of the chip and the total length */
+static const struct JEDECTable JEDEC_table[] = {
+	{
+		.jedec		= 0x013D,
+		.name		= "AMD Am29F017D",
+		.size		= 2*1024*1024,
+		.sectorsize	= 64*1024,
+		.capabilities	= MTD_CAP_NORFLASH
+	},
+	{
+		.jedec		= 0x01AD,
+		.name		= "AMD Am29F016",
+		.size		= 2*1024*1024,
+		.sectorsize	= 64*1024,
+		.capabilities	= MTD_CAP_NORFLASH
+	},
+	{
+		.jedec		= 0x01D5,
+		.name		= "AMD Am29F080",
+		.size		= 1*1024*1024,
+		.sectorsize	= 64*1024,
+		.capabilities	= MTD_CAP_NORFLASH
+	},
+	{
+		.jedec		= 0x01A4,
+		.name		= "AMD Am29F040",
+		.size		= 512*1024,
+		.sectorsize	= 64*1024,
+		.capabilities	= MTD_CAP_NORFLASH
+	},
+	{
+		.jedec		= 0x20E3,
+		.name		= "AMD Am29W040B",
+		.size		= 512*1024,
+		.sectorsize	= 64*1024,
+		.capabilities	= MTD_CAP_NORFLASH
+	},
+	{
+		.jedec		= 0xC2AD,
+		.name		= "Macronix MX29F016",
+		.size		= 2*1024*1024,
+		.sectorsize	= 64*1024,
+		.capabilities	= MTD_CAP_NORFLASH
+	},
+	{ .jedec = 0x0 }
+};
+
+static const struct JEDECTable *jedec_idtoinf(__u8 mfr,__u8 id);
+static void jedec_sync(struct mtd_info *mtd) {};
+static int jedec_read(struct mtd_info *mtd, loff_t from, size_t len, 
+		      size_t *retlen, u_char *buf);
+static int jedec_read_banked(struct mtd_info *mtd, loff_t from, size_t len, 
+			     size_t *retlen, u_char *buf);
+
+static struct mtd_info *jedec_probe(struct map_info *map);
+
+
+
+static struct mtd_chip_driver jedec_chipdrv = {
+	.probe	= jedec_probe,
+	.name	= "jedec",
+	.module	= THIS_MODULE
+};
+
+/* Probe entry point */
+
+static struct mtd_info *jedec_probe(struct map_info *map)
+{
+   struct mtd_info *MTD;
+   struct jedec_private *priv;
+   unsigned long Base;
+   unsigned long SectorSize;
+   unsigned count;
+   unsigned I,Uniq;
+   char Part[200];
+   memset(&priv,0,sizeof(priv));
+
+   MTD = kmalloc(sizeof(struct mtd_info) + sizeof(struct jedec_private), GFP_KERNEL);
+   if (!MTD)
+	   return NULL;
+
+   memset(MTD, 0, sizeof(struct mtd_info) + sizeof(struct jedec_private));
+   priv = (struct jedec_private *)&MTD[1];
+   
+   my_bank_size = map->size;
+
+   if (map->size/my_bank_size > MAX_JEDEC_CHIPS)
+   {
+      printk("mtd: Increase MAX_JEDEC_CHIPS, too many banks.\n");
+      kfree(MTD);
+      return NULL;
+   }
+   
+   for (Base = 0; Base < map->size; Base += my_bank_size)
+   {
+      // Perhaps zero could designate all tests?
+      if (map->buswidth == 0)
+	 map->buswidth = 1;
+      
+      if (map->buswidth == 1){
+	 if (jedec_probe8(map,Base,priv) == 0) {
+		 printk("did recognize jedec chip\n");
+		 kfree(MTD);
+	         return NULL;
+	 }
+      }
+      if (map->buswidth == 2)
+	 jedec_probe16(map,Base,priv);
+      if (map->buswidth == 4)
+	 jedec_probe32(map,Base,priv);
+   }
+   
+   // Get the biggest sector size
+   SectorSize = 0;
+   for (I = 0; priv->chips[I].jedec != 0 && I < MAX_JEDEC_CHIPS; I++)
+   {
+	   //	   printk("priv->chips[%d].jedec is %x\n",I,priv->chips[I].jedec);
+	   //	   printk("priv->chips[%d].sectorsize is %lx\n",I,priv->chips[I].sectorsize);
+      if (priv->chips[I].sectorsize > SectorSize)
+	 SectorSize = priv->chips[I].sectorsize;
+   }
+   
+   // Quickly ensure that the other sector sizes are factors of the largest
+   for (I = 0; priv->chips[I].jedec != 0 && I < MAX_JEDEC_CHIPS; I++)
+   {
+      if ((SectorSize/priv->chips[I].sectorsize)*priv->chips[I].sectorsize != SectorSize)
+      {
+	 printk("mtd: Failed. Device has incompatible mixed sector sizes\n");
+	 kfree(MTD);
+	 return NULL;
+      }      
+   }
+   
+   /* Generate a part name that includes the number of different chips and
+      other configuration information */
+   count = 1;
+   strlcpy(Part,map->name,sizeof(Part)-10);
+   strcat(Part," ");
+   Uniq = 0;
+   for (I = 0; priv->chips[I].jedec != 0 && I < MAX_JEDEC_CHIPS; I++)
+   {
+      const struct JEDECTable *JEDEC;
+      
+      if (priv->chips[I+1].jedec == priv->chips[I].jedec)
+      {
+	 count++;
+	 continue;
+      }
+      
+      // Locate the chip in the jedec table
+      JEDEC = jedec_idtoinf(priv->chips[I].jedec >> 8,priv->chips[I].jedec);
+      if (JEDEC == 0)
+      {
+	 printk("mtd: Internal Error, JEDEC not set\n");
+	 kfree(MTD);
+	 return NULL;
+      }
+      
+      if (Uniq != 0)
+	 strcat(Part,",");
+      Uniq++;
+      
+      if (count != 1)
+	 sprintf(Part+strlen(Part),"%x*[%s]",count,JEDEC->name);
+      else
+	 sprintf(Part+strlen(Part),"%s",JEDEC->name);
+      if (strlen(Part) > sizeof(Part)*2/3)
+	 break;
+      count = 1;
+   }   
+
+   /* Determine if the chips are organized in a linear fashion, or if there
+      are empty banks. Note, the last bank does not count here, only the
+      first banks are important. Holes on non-bank boundaries can not exist
+      due to the way the detection algorithm works. */
+   if (priv->size < my_bank_size)
+      my_bank_size = priv->size;
+   priv->is_banked = 0;
+   //printk("priv->size is %x, my_bank_size is %x\n",priv->size,my_bank_size);
+   //printk("priv->bank_fill[0] is %x\n",priv->bank_fill[0]);
+   if (!priv->size) {
+	   printk("priv->size is zero\n");
+	   kfree(MTD);
+	   return NULL;
+   }
+   if (priv->size/my_bank_size) {
+	   if (priv->size/my_bank_size == 1) {
+		   priv->size = my_bank_size;
+	   }
+	   else {
+		   for (I = 0; I != priv->size/my_bank_size - 1; I++)
+		   {
+		      if (priv->bank_fill[I] != my_bank_size)
+			 priv->is_banked = 1;
+		      
+		      /* This even could be eliminated, but new de-optimized read/write
+			 functions have to be written */
+		      printk("priv->bank_fill[%d] is %lx, priv->bank_fill[0] is %lx\n",I,priv->bank_fill[I],priv->bank_fill[0]);
+		      if (priv->bank_fill[I] != priv->bank_fill[0])
+		      {
+			 printk("mtd: Failed. Cannot handle unsymmetric banking\n");
+			 kfree(MTD);
+			 return NULL;
+		      }      
+		   }
+	   }
+   }
+   if (priv->is_banked == 1)
+      strcat(Part,", banked");
+
+   //   printk("Part: '%s'\n",Part);
+   
+   memset(MTD,0,sizeof(*MTD));
+  // strlcpy(MTD->name,Part,sizeof(MTD->name));
+   MTD->name = map->name;
+   MTD->type = MTD_NORFLASH;
+   MTD->flags = MTD_CAP_NORFLASH;
+   MTD->erasesize = SectorSize*(map->buswidth);
+   //   printk("MTD->erasesize is %x\n",(unsigned int)MTD->erasesize);
+   MTD->size = priv->size;
+   //   printk("MTD->size is %x\n",(unsigned int)MTD->size);
+   //MTD->module = THIS_MODULE; // ? Maybe this should be the low level module?
+   MTD->erase = flash_erase;
+   if (priv->is_banked == 1)
+      MTD->read = jedec_read_banked;
+   else
+      MTD->read = jedec_read;
+   MTD->write = flash_write;
+   MTD->sync = jedec_sync;
+   MTD->priv = map;
+   map->fldrv_priv = priv;
+   map->fldrv = &jedec_chipdrv;
+   __module_get(THIS_MODULE);
+   return MTD;
+}
+
+/* Helper for the JEDEC function, JEDEC numbers all have odd parity */
+static int checkparity(u_char C)
+{
+   u_char parity = 0;
+   while (C != 0)
+   {
+      parity ^= C & 1;
+      C >>= 1;
+   }
+
+   return parity == 1;
+}
+
+
+/* Take an array of JEDEC numbers that represent interleved flash chips
+   and process them. Check to make sure they are good JEDEC numbers, look
+   them up and then add them to the chip list */   
+static int handle_jedecs(struct map_info *map,__u8 *Mfg,__u8 *Id,unsigned Count,
+		  unsigned long base,struct jedec_private *priv)
+{
+   unsigned I,J;
+   unsigned long Size;
+   unsigned long SectorSize;
+   const struct JEDECTable *JEDEC;
+
+   // Test #2 JEDEC numbers exhibit odd parity
+   for (I = 0; I != Count; I++)
+   {
+      if (checkparity(Mfg[I]) == 0 || checkparity(Id[I]) == 0)
+	 return 0;
+   }
+   
+   // Finally, just make sure all the chip sizes are the same
+   JEDEC = jedec_idtoinf(Mfg[0],Id[0]);
+   
+   if (JEDEC == 0)
+   {
+      printk("mtd: Found JEDEC flash chip, but do not have a table entry for %x:%x\n",Mfg[0],Mfg[1]);
+      return 0;
+   }
+   
+   Size = JEDEC->size;
+   SectorSize = JEDEC->sectorsize;
+   for (I = 0; I != Count; I++)
+   {
+      JEDEC = jedec_idtoinf(Mfg[0],Id[0]);
+      if (JEDEC == 0)
+      {
+	 printk("mtd: Found JEDEC flash chip, but do not have a table entry for %x:%x\n",Mfg[0],Mfg[1]);
+	 return 0;
+      }
+
+      if (Size != JEDEC->size || SectorSize != JEDEC->sectorsize)
+      {
+	 printk("mtd: Failed. Interleved flash does not have matching characteristics\n");
+	 return 0;
+      }      
+   }
+
+   // Load the Chips
+   for (I = 0; I != MAX_JEDEC_CHIPS; I++)
+   {
+      if (priv->chips[I].jedec == 0)
+	 break;
+   }
+
+   if (I + Count > MAX_JEDEC_CHIPS)
+   {
+      printk("mtd: Device has too many chips. Increase MAX_JEDEC_CHIPS\n");
+      return 0;
+   }      
+   
+   // Add them to the table
+   for (J = 0; J != Count; J++)
+   {
+      unsigned long Bank;
+	 
+      JEDEC = jedec_idtoinf(Mfg[J],Id[J]);
+      priv->chips[I].jedec = (Mfg[J] << 8) | Id[J];
+      priv->chips[I].size = JEDEC->size;
+      priv->chips[I].sectorsize = JEDEC->sectorsize;
+      priv->chips[I].base = base + J;
+      priv->chips[I].datashift = J*8;
+      priv->chips[I].capabilities = JEDEC->capabilities;
+      priv->chips[I].offset = priv->size + J;
+
+      // log2 n :|
+      priv->chips[I].addrshift = 0;
+      for (Bank = Count; Bank != 1; Bank >>= 1, priv->chips[I].addrshift++);
+      
+      // Determine how filled this bank is.
+      Bank = base & (~(my_bank_size-1));
+      if (priv->bank_fill[Bank/my_bank_size] < base + 
+	  (JEDEC->size << priv->chips[I].addrshift) - Bank)
+	 priv->bank_fill[Bank/my_bank_size] =  base + (JEDEC->size << priv->chips[I].addrshift) - Bank;
+      I++;
+   }
+
+   priv->size += priv->chips[I-1].size*Count;
+	 
+   return priv->chips[I-1].size;
+}
+
+/* Lookup the chip information from the JEDEC ID table. */
+static const struct JEDECTable *jedec_idtoinf(__u8 mfr,__u8 id)
+{
+   __u16 Id = (mfr << 8) | id;
+   unsigned long I = 0;
+   for (I = 0; JEDEC_table[I].jedec != 0; I++)
+      if (JEDEC_table[I].jedec == Id)
+	 return JEDEC_table + I;
+   return NULL;
+}
+
+// Look for flash using an 8 bit bus interface
+static int jedec_probe8(struct map_info *map,unsigned long base,
+		  struct jedec_private *priv)
+{ 
+   #define flread(x) map_read8(map,base+x)
+   #define flwrite(v,x) map_write8(map,v,base+x)
+
+   const unsigned long AutoSel1 = 0xAA;
+   const unsigned long AutoSel2 = 0x55;
+   const unsigned long AutoSel3 = 0x90;
+   const unsigned long Reset = 0xF0;
+   __u32 OldVal;
+   __u8 Mfg[1];
+   __u8 Id[1];
+   unsigned I;
+   unsigned long Size;
+
+   // Wait for any write/erase operation to settle
+   OldVal = flread(base);
+   for (I = 0; OldVal != flread(base) && I < 10000; I++)
+      OldVal = flread(base);
+   
+   // Reset the chip
+   flwrite(Reset,0x555); 
+   
+   // Send the sequence
+   flwrite(AutoSel1,0x555);
+   flwrite(AutoSel2,0x2AA);
+   flwrite(AutoSel3,0x555);
+   
+   //  Get the JEDEC numbers
+   Mfg[0] = flread(0);
+   Id[0] = flread(1);
+   //   printk("Mfg is %x, Id is %x\n",Mfg[0],Id[0]);
+      
+   Size = handle_jedecs(map,Mfg,Id,1,base,priv);
+   //   printk("handle_jedecs Size is %x\n",(unsigned int)Size);
+   if (Size == 0)
+   {
+      flwrite(Reset,0x555);
+      return 0;
+   }
+   
+
+   // Reset.
+   flwrite(Reset,0x555);
+   
+   return 1;
+   
+   #undef flread
+   #undef flwrite
+}
+
+// Look for flash using a 16 bit bus interface (ie 2 8-bit chips)
+static int jedec_probe16(struct map_info *map,unsigned long base,
+		  struct jedec_private *priv)
+{
+   return 0;
+}
+
+// Look for flash using a 32 bit bus interface (ie 4 8-bit chips)
+static int jedec_probe32(struct map_info *map,unsigned long base,
+		  struct jedec_private *priv)
+{
+   #define flread(x) map_read32(map,base+((x)<<2))
+   #define flwrite(v,x) map_write32(map,v,base+((x)<<2))
+
+   const unsigned long AutoSel1 = 0xAAAAAAAA;
+   const unsigned long AutoSel2 = 0x55555555;
+   const unsigned long AutoSel3 = 0x90909090;
+   const unsigned long Reset = 0xF0F0F0F0;
+   __u32 OldVal;
+   __u8 Mfg[4];
+   __u8 Id[4];
+   unsigned I;
+   unsigned long Size;
+
+   // Wait for any write/erase operation to settle
+   OldVal = flread(base);
+   for (I = 0; OldVal != flread(base) && I < 10000; I++)
+      OldVal = flread(base);
+   
+   // Reset the chip
+   flwrite(Reset,0x555); 
+   
+   // Send the sequence
+   flwrite(AutoSel1,0x555);
+   flwrite(AutoSel2,0x2AA);
+   flwrite(AutoSel3,0x555);
+   
+   // Test #1, JEDEC numbers are readable from 0x??00/0x??01
+   if (flread(0) != flread(0x100) || 
+       flread(1) != flread(0x101))
+   {
+      flwrite(Reset,0x555);
+      return 0;
+   }
+
+   // Split up the JEDEC numbers
+   OldVal = flread(0);
+   for (I = 0; I != 4; I++)
+      Mfg[I] = (OldVal >> (I*8));
+   OldVal = flread(1);
+   for (I = 0; I != 4; I++)
+      Id[I] = (OldVal >> (I*8));
+      
+   Size = handle_jedecs(map,Mfg,Id,4,base,priv);
+   if (Size == 0)
+   {
+      flwrite(Reset,0x555);
+      return 0;
+   }
+   
+   /* Check if there is address wrap around within a single bank, if this
+      returns JEDEC numbers then we assume that it is wrap around. Notice
+      we call this routine with the JEDEC return still enabled, if two or
+      more flashes have a truncated address space the probe test will still
+      work */
+   if (base + (Size<<2)+0x555 < map->size &&
+       base + (Size<<2)+0x555 < (base & (~(my_bank_size-1))) + my_bank_size)
+   {
+      if (flread(base+Size) != flread(base+Size + 0x100) ||
+	  flread(base+Size + 1) != flread(base+Size + 0x101))
+      {
+	 jedec_probe32(map,base+Size,priv);
+      }
+   }
+
+   // Reset.
+   flwrite(0xF0F0F0F0,0x555);
+   
+   return 1;
+   
+   #undef flread
+   #undef flwrite
+}
+
+/* Linear read. */
+static int jedec_read(struct mtd_info *mtd, loff_t from, size_t len, 
+		      size_t *retlen, u_char *buf)
+{
+   struct map_info *map = mtd->priv;
+   
+   map_copy_from(map, buf, from, len);
+   *retlen = len;
+   return 0;   
+}
+
+/* Banked read. Take special care to jump past the holes in the bank
+   mapping. This version assumes symetry in the holes.. */
+static int jedec_read_banked(struct mtd_info *mtd, loff_t from, size_t len, 
+			     size_t *retlen, u_char *buf)
+{
+   struct map_info *map = mtd->priv;
+   struct jedec_private *priv = map->fldrv_priv;
+
+   *retlen = 0;
+   while (len > 0)
+   {
+      // Determine what bank and offset into that bank the first byte is
+      unsigned long bank = from & (~(priv->bank_fill[0]-1));
+      unsigned long offset = from & (priv->bank_fill[0]-1);
+      unsigned long get = len;
+      if (priv->bank_fill[0] - offset < len)
+	 get = priv->bank_fill[0] - offset;
+
+      bank /= priv->bank_fill[0];      
+      map_copy_from(map,buf + *retlen,bank*my_bank_size + offset,get);
+      
+      len -= get;
+      *retlen += get;
+      from += get;
+   }   
+   return 0;   
+}
+
+/* Pass the flags value that the flash return before it re-entered read 
+   mode. */
+static void jedec_flash_failed(unsigned char code)
+{
+   /* Bit 5 being high indicates that there was an internal device
+      failure, erasure time limits exceeded or something */
+   if ((code & (1 << 5)) != 0)
+   {
+      printk("mtd: Internal Flash failure\n");
+      return;
+   }
+   printk("mtd: Programming didn't take\n");
+}
+
+/* This uses the erasure function described in the AMD Flash Handbook, 
+   it will work for flashes with a fixed sector size only. Flashes with
+   a selection of sector sizes (ie the AMD Am29F800B) will need a different
+   routine. This routine tries to parallize erasing multiple chips/sectors 
+   where possible */
+static int flash_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+   // Does IO to the currently selected chip
+   #define flread(x) map_read8(map,chip->base+((x)<<chip->addrshift))
+   #define flwrite(v,x) map_write8(map,v,chip->base+((x)<<chip->addrshift))
+   
+   unsigned long Time = 0;
+   unsigned long NoTime = 0;
+   unsigned long start = instr->addr, len = instr->len;
+   unsigned int I;
+   struct map_info *map = mtd->priv;
+   struct jedec_private *priv = map->fldrv_priv;
+
+   // Verify the arguments..
+   if (start + len > mtd->size ||
+       (start % mtd->erasesize) != 0 ||
+       (len % mtd->erasesize) != 0 ||
+       (len/mtd->erasesize) == 0)
+      return -EINVAL;
+   
+   jedec_flash_chip_scan(priv,start,len);
+
+   // Start the erase sequence on each chip
+   for (I = 0; priv->chips[I].jedec != 0 && I < MAX_JEDEC_CHIPS; I++)
+   {
+      unsigned long off;
+      struct jedec_flash_chip *chip = priv->chips + I;
+      
+      if (chip->length == 0)
+	 continue;
+      
+      if (chip->start + chip->length > chip->size)
+      {
+	 printk("DIE\n");
+	 return -EIO;
+      }     
+      
+      flwrite(0xF0,chip->start + 0x555);
+      flwrite(0xAA,chip->start + 0x555);
+      flwrite(0x55,chip->start + 0x2AA);
+      flwrite(0x80,chip->start + 0x555);
+      flwrite(0xAA,chip->start + 0x555);
+      flwrite(0x55,chip->start + 0x2AA);
+
+      /* Once we start selecting the erase sectors the delay between each 
+         command must not exceed 50us or it will immediately start erasing 
+         and ignore the other sectors */
+      for (off = 0; off < len; off += chip->sectorsize)
+      {
+	 // Check to make sure we didn't timeout
+	 flwrite(0x30,chip->start + off);
+	 if (off == 0)
+	    continue;
+	 if ((flread(chip->start + off) & (1 << 3)) != 0)
+	 {
+	    printk("mtd: Ack! We timed out the erase timer!\n");
+	    return -EIO;
+	 }       	 
+      }
+   }   
+
+   /* We could split this into a timer routine and return early, performing
+      background erasure.. Maybe later if the need warrents */
+
+   /* Poll the flash for erasure completion, specs say this can take as long
+      as 480 seconds to do all the sectors (for a 2 meg flash). 
+      Erasure time is dependent on chip age, temp and wear.. */
+   
+   /* This being a generic routine assumes a 32 bit bus. It does read32s
+      and bundles interleved chips into the same grouping. This will work 
+      for all bus widths */
+   Time = 0;
+   NoTime = 0;
+   for (I = 0; priv->chips[I].jedec != 0 && I < MAX_JEDEC_CHIPS; I++)
+   {
+      struct jedec_flash_chip *chip = priv->chips + I;
+      unsigned long off = 0;
+      unsigned todo[4] = {0,0,0,0};
+      unsigned todo_left = 0;
+      unsigned J;
+      
+      if (chip->length == 0)
+	 continue;
+
+      /* Find all chips in this data line, realistically this is all 
+         or nothing up to the interleve count */
+      for (J = 0; priv->chips[J].jedec != 0 && J < MAX_JEDEC_CHIPS; J++)
+      {
+	 if ((priv->chips[J].base & (~((1<<chip->addrshift)-1))) == 
+	     (chip->base & (~((1<<chip->addrshift)-1))))
+	 {
+	    todo_left++;
+	    todo[priv->chips[J].base & ((1<<chip->addrshift)-1)] = 1;
+	 }	 
+      }
+
+      /*      printk("todo: %x %x %x %x\n",(short)todo[0],(short)todo[1],
+	      (short)todo[2],(short)todo[3]);
+      */
+      while (1)
+      {
+	 __u32 Last[4];
+	 unsigned long Count = 0;
+	 
+	 /* During erase bit 7 is held low and bit 6 toggles, we watch this,
+	    should it stop toggling or go high then the erase is completed,
+  	    or this is not really flash ;> */
+	 switch (map->buswidth) {
+	 case 1:
+	    Last[0] = map_read8(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    Last[1] = map_read8(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    Last[2] = map_read8(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    break;
+	 case 2:
+	    Last[0] = map_read16(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    Last[1] = map_read16(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    Last[2] = map_read16(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    break;
+	 case 3:
+	    Last[0] = map_read32(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    Last[1] = map_read32(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    Last[2] = map_read32(map,(chip->base >> chip->addrshift) + chip->start + off);
+	    break;
+	 }
+	 Count = 3;
+	 while (todo_left != 0)
+	 {
+	    for (J = 0; J != 4; J++)
+	    {
+	       __u8 Byte1 = (Last[(Count-1)%4] >> (J*8)) & 0xFF;
+	       __u8 Byte2 = (Last[(Count-2)%4] >> (J*8)) & 0xFF;
+	       __u8 Byte3 = (Last[(Count-3)%4] >> (J*8)) & 0xFF;
+	       if (todo[J] == 0)
+		  continue;
+	       
+	       if ((Byte1 & (1 << 7)) == 0 && Byte1 != Byte2)
+	       {
+//		  printk("Check %x %x %x\n",(short)J,(short)Byte1,(short)Byte2);
+		  continue;
+	       }
+	       
+	       if (Byte1 == Byte2)
+	       {
+		  jedec_flash_failed(Byte3);
+		  return -EIO;
+	       }
+	       
+	       todo[J] = 0;
+	       todo_left--;
+	    }
+	    
+/*	    if (NoTime == 0)
+	       Time += HZ/10 - schedule_timeout(HZ/10);*/
+	    NoTime = 0;
+
+	    switch (map->buswidth) {
+	    case 1:
+	       Last[Count % 4] = map_read8(map,(chip->base >> chip->addrshift) + chip->start + off);
+	      break;
+	    case 2:
+	       Last[Count % 4] = map_read16(map,(chip->base >> chip->addrshift) + chip->start + off);
+	      break;
+	    case 4:
+	       Last[Count % 4] = map_read32(map,(chip->base >> chip->addrshift) + chip->start + off);
+	      break;
+	    }
+	    Count++;
+	    
+/*	    // Count time, max of 15s per sector (according to AMD)
+	    if (Time > 15*len/mtd->erasesize*HZ)
+	    {
+	       printk("mtd: Flash Erase Timed out\n");
+	       return -EIO;
+	    }	    */
+	 }
+	 	 
+	 // Skip to the next chip if we used chip erase
+	 if (chip->length == chip->size)
+	    off = chip->size;
+	 else
+	    off += chip->sectorsize;
+	 
+	 if (off >= chip->length)
+	    break;
+	 NoTime = 1;
+      }
+      
+      for (J = 0; priv->chips[J].jedec != 0 && J < MAX_JEDEC_CHIPS; J++)
+      {
+	 if ((priv->chips[J].base & (~((1<<chip->addrshift)-1))) ==
+	     (chip->base & (~((1<<chip->addrshift)-1))))
+	    priv->chips[J].length = 0;
+      }      
+   }
+       	    
+   //printk("done\n");
+   instr->state = MTD_ERASE_DONE;
+   mtd_erase_callback(instr);
+   return 0;
+   
+   #undef flread
+   #undef flwrite
+}
+
+/* This is the simple flash writing function. It writes to every byte, in
+   sequence. It takes care of how to properly address the flash if
+   the flash is interleved. It can only be used if all the chips in the 
+   array are identical!*/
+static int flash_write(struct mtd_info *mtd, loff_t start, size_t len,
+		       size_t *retlen, const u_char *buf)
+{
+   /* Does IO to the currently selected chip. It takes the bank addressing
+      base (which is divisible by the chip size) adds the necessary lower bits
+      of addrshift (interleave index) and then adds the control register index. */
+   #define flread(x) map_read8(map,base+(off&((1<<chip->addrshift)-1))+((x)<<chip->addrshift))
+   #define flwrite(v,x) map_write8(map,v,base+(off&((1<<chip->addrshift)-1))+((x)<<chip->addrshift))
+   
+   struct map_info *map = mtd->priv;
+   struct jedec_private *priv = map->fldrv_priv;
+   unsigned long base;
+   unsigned long off;
+   size_t save_len = len;
+   
+   if (start + len > mtd->size)
+      return -EIO;
+   
+   //printk("Here");
+   
+   //printk("flash_write: start is %x, len is %x\n",start,(unsigned long)len);
+   while (len != 0)
+   {
+      struct jedec_flash_chip *chip = priv->chips;
+      unsigned long bank;
+      unsigned long boffset;
+	 
+      // Compute the base of the flash.
+      off = ((unsigned long)start) % (chip->size << chip->addrshift);
+      base = start - off;
+
+      // Perform banked addressing translation.
+      bank = base & (~(priv->bank_fill[0]-1));
+      boffset = base & (priv->bank_fill[0]-1);
+      bank = (bank/priv->bank_fill[0])*my_bank_size;
+      base = bank + boffset;
+      
+    //  printk("Flasing %X %X %X\n",base,chip->size,len);
+     // printk("off is %x, compare with %x\n",off,chip->size << chip->addrshift);
+      
+      // Loop over this page
+      for (; off != (chip->size << chip->addrshift) && len != 0; start++, len--, off++,buf++)
+      {
+	 unsigned char oldbyte = map_read8(map,base+off);
+	 unsigned char Last[4];
+	 unsigned long Count = 0;
+
+	 if (oldbyte == *buf) {
+	//	 printk("oldbyte and *buf is %x,len is %x\n",oldbyte,len);
+	    continue;
+	 }
+	 if (((~oldbyte) & *buf) != 0)
+	    printk("mtd: warn: Trying to set a 0 to a 1\n");
+	     
+	 // Write
+	 flwrite(0xAA,0x555);
+	 flwrite(0x55,0x2AA);
+	 flwrite(0xA0,0x555);
+	 map_write8(map,*buf,base + off);
+	 Last[0] = map_read8(map,base + off);
+	 Last[1] = map_read8(map,base + off);
+	 Last[2] = map_read8(map,base + off);
+	 
+	 /* Wait for the flash to finish the operation. We store the last 4
+	    status bytes that have been retrieved so we can determine why
+	    it failed. The toggle bits keep toggling when there is a 
+	    failure */
+	 for (Count = 3; Last[(Count - 1) % 4] != Last[(Count - 2) % 4] &&
+	      Count < 10000; Count++)
+	    Last[Count % 4] = map_read8(map,base + off);
+	 if (Last[(Count - 1) % 4] != *buf)
+	 {
+	    jedec_flash_failed(Last[(Count - 3) % 4]);
+	    return -EIO;
+	 }	 
+      }
+   }
+   *retlen = save_len;
+   return 0;
+}
+
+/* This is used to enhance the speed of the erase routine,
+   when things are being done to multiple chips it is possible to
+   parallize the operations, particularly full memory erases of multi
+   chip memories benifit */
+static void jedec_flash_chip_scan(struct jedec_private *priv,unsigned long start,
+		     unsigned long len)
+{
+   unsigned int I;
+
+   // Zero the records
+   for (I = 0; priv->chips[I].jedec != 0 && I < MAX_JEDEC_CHIPS; I++)
+      priv->chips[I].start = priv->chips[I].length = 0;
+   
+   // Intersect the region with each chip
+   for (I = 0; priv->chips[I].jedec != 0 && I < MAX_JEDEC_CHIPS; I++)
+   {
+      struct jedec_flash_chip *chip = priv->chips + I;
+      unsigned long ByteStart;
+      unsigned long ChipEndByte = chip->offset + (chip->size << chip->addrshift);
+      
+      // End is before this chip or the start is after it
+      if (start+len < chip->offset ||
+	  ChipEndByte - (1 << chip->addrshift) < start)
+	 continue;
+      
+      if (start < chip->offset)
+      {
+	 ByteStart = chip->offset;
+	 chip->start = 0;
+      }      
+      else
+      {
+	 chip->start = (start - chip->offset + (1 << chip->addrshift)-1) >> chip->addrshift;
+	 ByteStart = start;
+      }
+
+      if (start + len >= ChipEndByte)
+	 chip->length = (ChipEndByte - ByteStart) >> chip->addrshift;
+      else
+	 chip->length = (start + len - ByteStart + (1 << chip->addrshift)-1) >> chip->addrshift;
+   }
+}
+
+int __init jedec_init(void)
+{
+	register_mtd_chip_driver(&jedec_chipdrv);
+	return 0;
+}
+
+static void __exit jedec_exit(void)
+{
+	unregister_mtd_chip_driver(&jedec_chipdrv);
+}
+
+module_init(jedec_init);
+module_exit(jedec_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jason Gunthorpe <jgg@deltatee.com> et al.");
+MODULE_DESCRIPTION("Old MTD chip driver for JEDEC-compliant flash chips");