lart.c

基于linux-2.6.28的mtd驱动

   /* was the erase successfull? */
   if ((status & STATUS_ERASE_ERR))
	 {
		printk (KERN_WARNING "%s: erase error at address 0x%.8x.\n",module_name,offset);
		return (0);
	 }

   return (1);
}

static int flash_erase (struct mtd_info *mtd,struct erase_info *instr)
{
   __u32 addr,len;
   int i,first;

#ifdef LART_DEBUG
   printk (KERN_DEBUG "%s(addr = 0x%.8x, len = %d)\n", __func__, instr->addr, instr->len);
#endif

   /* sanity checks */
   if (instr->addr + instr->len > mtd->size) return (-EINVAL);

   /*
	* check that both start and end of the requested erase are
	* aligned with the erasesize at the appropriate addresses.
	*
	* skip all erase regions which are ended before the start of
	* the requested erase. Actually, to save on the calculations,
	* we skip to the first erase region which starts after the
	* start of the requested erase, and then go back one.
	*/
   for (i = 0; i < mtd->numeraseregions && instr->addr >= mtd->eraseregions[i].offset; i++) ;
   i--;

   /*
	* ok, now i is pointing at the erase region in which this
	* erase request starts. Check the start of the requested
	* erase range is aligned with the erase size which is in
	* effect here.
	*/
   if (instr->addr & (mtd->eraseregions[i].erasesize - 1)) return (-EINVAL);

   /* Remember the erase region we start on */
   first = i;

   /*
	* next, check that the end of the requested erase is aligned
	* with the erase region at that address.
	*
	* as before, drop back one to point at the region in which
	* the address actually falls
	*/
   for (; i < mtd->numeraseregions && instr->addr + instr->len >= mtd->eraseregions[i].offset; i++) ;
   i--;

   /* is the end aligned on a block boundary? */
   if ((instr->addr + instr->len) & (mtd->eraseregions[i].erasesize - 1)) return (-EINVAL);

   addr = instr->addr;
   len = instr->len;

   i = first;

   /* now erase those blocks */
   while (len)
	 {
		if (!erase_block (addr))
		  {
			 instr->state = MTD_ERASE_FAILED;
			 return (-EIO);
		  }

		addr += mtd->eraseregions[i].erasesize;
		len -= mtd->eraseregions[i].erasesize;

		if (addr == mtd->eraseregions[i].offset + (mtd->eraseregions[i].erasesize * mtd->eraseregions[i].numblocks)) i++;
	 }

   instr->state = MTD_ERASE_DONE;
   mtd_erase_callback(instr);

   return (0);
}

static int flash_read (struct mtd_info *mtd,loff_t from,size_t len,size_t *retlen,u_char *buf)
{
#ifdef LART_DEBUG
   printk (KERN_DEBUG "%s(from = 0x%.8x, len = %d)\n", __func__, (__u32)from, len);
#endif

   /* sanity checks */
   if (!len) return (0);
   if (from + len > mtd->size) return (-EINVAL);

   /* we always read len bytes */
   *retlen = len;

   /* first, we read bytes until we reach a dword boundary */
   if (from & (BUSWIDTH - 1))
	 {
		int gap = BUSWIDTH - (from & (BUSWIDTH - 1));

		while (len && gap--) *buf++ = read8 (from++), len--;
	 }

   /* now we read dwords until we reach a non-dword boundary */
   while (len >= BUSWIDTH)
	 {
		*((__u32 *) buf) = read32 (from);

		buf += BUSWIDTH;
		from += BUSWIDTH;
		len -= BUSWIDTH;
	 }

   /* top up the last unaligned bytes */
   if (len & (BUSWIDTH - 1))
	 while (len--) *buf++ = read8 (from++);

   return (0);
}

/*
 * Write one dword ``x'' to flash memory at offset ``offset''. ``offset''
 * must be 32 bits, i.e. it must be on a dword boundary.
 *
 * Returns 1 if successful, 0 otherwise.
 */
static inline int write_dword (__u32 offset,__u32 x)
{
   __u32 status;

#ifdef LART_DEBUG
   printk (KERN_DEBUG "%s(): 0x%.8x <- 0x%.8x\n", __func__, offset, x);
#endif

   /* setup writing */
   write32 (DATA_TO_FLASH (PGM_SETUP),offset);

   /* write the data */
   write32 (x,offset);

   /* wait for the write to finish */
   do
	 {
		write32 (DATA_TO_FLASH (STATUS_READ),offset);
		status = FLASH_TO_DATA (read32 (offset));
	 }
   while ((~status & STATUS_BUSY) != 0);

   /* put the flash back into command mode */
   write32 (DATA_TO_FLASH (READ_ARRAY),offset);

   /* was the write successfull? */
   if ((status & STATUS_PGM_ERR) || read32 (offset) != x)
	 {
		printk (KERN_WARNING "%s: write error at address 0x%.8x.\n",module_name,offset);
		return (0);
	 }

   return (1);
}

static int flash_write (struct mtd_info *mtd,loff_t to,size_t len,size_t *retlen,const u_char *buf)
{
   __u8 tmp[4];
   int i,n;

#ifdef LART_DEBUG
   printk (KERN_DEBUG "%s(to = 0x%.8x, len = %d)\n", __func__, (__u32)to, len);
#endif

   *retlen = 0;

   /* sanity checks */
   if (!len) return (0);
   if (to + len > mtd->size) return (-EINVAL);

   /* first, we write a 0xFF.... padded byte until we reach a dword boundary */
   if (to & (BUSWIDTH - 1))
	 {
		__u32 aligned = to & ~(BUSWIDTH - 1);
		int gap = to - aligned;

		i = n = 0;

		while (gap--) tmp[i++] = 0xFF;
		while (len && i < BUSWIDTH) tmp[i++] = buf[n++], len--;
		while (i < BUSWIDTH) tmp[i++] = 0xFF;

		if (!write_dword (aligned,*((__u32 *) tmp))) return (-EIO);

		to += n;
		buf += n;
		*retlen += n;
	 }

   /* now we write dwords until we reach a non-dword boundary */
   while (len >= BUSWIDTH)
	 {
		if (!write_dword (to,*((__u32 *) buf))) return (-EIO);

		to += BUSWIDTH;
		buf += BUSWIDTH;
		*retlen += BUSWIDTH;
		len -= BUSWIDTH;
	 }

   /* top up the last unaligned bytes, padded with 0xFF.... */
   if (len & (BUSWIDTH - 1))
	 {
		i = n = 0;

		while (len--) tmp[i++] = buf[n++];
		while (i < BUSWIDTH) tmp[i++] = 0xFF;

		if (!write_dword (to,*((__u32 *) tmp))) return (-EIO);

		*retlen += n;
	 }

   return (0);
}

/***************************************************************************************************/

static struct mtd_info mtd;

static struct mtd_erase_region_info erase_regions[] = {
	/* parameter blocks */
	{
		.offset		= 0x00000000,
		.erasesize	= FLASH_BLOCKSIZE_PARAM,
		.numblocks	= FLASH_NUMBLOCKS_16m_PARAM,
	},
	/* main blocks */
	{
		.offset	 = FLASH_BLOCKSIZE_PARAM * FLASH_NUMBLOCKS_16m_PARAM,
		.erasesize	= FLASH_BLOCKSIZE_MAIN,
		.numblocks	= FLASH_NUMBLOCKS_16m_MAIN,
	}
};

#ifdef HAVE_PARTITIONS
static struct mtd_partition lart_partitions[] = {
	/* blob */
	{
		.name	= "blob",
		.offset	= BLOB_START,
		.size	= BLOB_LEN,
	},
	/* kernel */
	{
		.name	= "kernel",
		.offset	= KERNEL_START,		/* MTDPART_OFS_APPEND */
		.size	= KERNEL_LEN,
	},
	/* initial ramdisk / file system */
	{
		.name	= "file system",
		.offset	= INITRD_START,		/* MTDPART_OFS_APPEND */
		.size	= INITRD_LEN,		/* MTDPART_SIZ_FULL */
	}
};
#endif

int __init lart_flash_init (void)
{
   int result;
   memset (&mtd,0,sizeof (mtd));
   printk ("MTD driver for LART. Written by Abraham vd Merwe <[e-mail]>\n");
   printk ("%s: Probing for 28F160x3 flash on LART...\n",module_name);
   if (!flash_probe ())
	 {
		printk (KERN_WARNING "%s: Found no LART compatible flash device\n",module_name);
		return (-ENXIO);
	 }
   printk ("%s: This looks like a LART board to me.\n",module_name);
   mtd.name = module_name;
   mtd.type = MTD_NORFLASH;
   mtd.writesize = 1;
   mtd.flags = MTD_CAP_NORFLASH;
   mtd.size = FLASH_BLOCKSIZE_PARAM * FLASH_NUMBLOCKS_16m_PARAM + FLASH_BLOCKSIZE_MAIN * FLASH_NUMBLOCKS_16m_MAIN;
   mtd.erasesize = FLASH_BLOCKSIZE_MAIN;
   mtd.numeraseregions = ARRAY_SIZE(erase_regions);
   mtd.eraseregions = erase_regions;
   mtd.erase = flash_erase;
   mtd.read = flash_read;
   mtd.write = flash_write;
   mtd.owner = THIS_MODULE;

#ifdef LART_DEBUG
   printk (KERN_DEBUG
		   "mtd.name = %s\n"
		   "mtd.size = 0x%.8x (%uM)\n"
		   "mtd.erasesize = 0x%.8x (%uK)\n"
		   "mtd.numeraseregions = %d\n",
		   mtd.name,
		   mtd.size,mtd.size / (1024*1024),
		   mtd.erasesize,mtd.erasesize / 1024,
		   mtd.numeraseregions);

   if (mtd.numeraseregions)
	 for (result = 0; result < mtd.numeraseregions; result++)
	   printk (KERN_DEBUG
			   "\n\n"
			   "mtd.eraseregions[%d].offset = 0x%.8x\n"
			   "mtd.eraseregions[%d].erasesize = 0x%.8x (%uK)\n"
			   "mtd.eraseregions[%d].numblocks = %d\n",
			   result,mtd.eraseregions[result].offset,
			   result,mtd.eraseregions[result].erasesize,mtd.eraseregions[result].erasesize / 1024,
			   result,mtd.eraseregions[result].numblocks);

#ifdef HAVE_PARTITIONS
   printk ("\npartitions = %d\n", ARRAY_SIZE(lart_partitions));

   for (result = 0; result < ARRAY_SIZE(lart_partitions); result++)
	 printk (KERN_DEBUG
			 "\n\n"
			 "lart_partitions[%d].name = %s\n"
			 "lart_partitions[%d].offset = 0x%.8x\n"
			 "lart_partitions[%d].size = 0x%.8x (%uK)\n",
			 result,lart_partitions[result].name,
			 result,lart_partitions[result].offset,
			 result,lart_partitions[result].size,lart_partitions[result].size / 1024);
#endif
#endif

#ifndef HAVE_PARTITIONS
   result = add_mtd_device (&mtd);
#else
   result = add_mtd_partitions (&mtd,lart_partitions, ARRAY_SIZE(lart_partitions));
#endif

   return (result);
}

void __exit lart_flash_exit (void)
{
#ifndef HAVE_PARTITIONS
   del_mtd_device (&mtd);
#else
   del_mtd_partitions (&mtd);
#endif
}

module_init (lart_flash_init);
module_exit (lart_flash_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Abraham vd Merwe <[e-mail]>");
MODULE_DESCRIPTION("MTD driver for Intel 28F160F3 on LART board");