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标题: 读写SPI FLASH--驱动部分（6） [打印本页]

作者: yuyang911220 时间: 2015-2-27 09:08 标题: 读写SPI FLASH--驱动部分（6）

/* fill pre opcode */
addr = base + SPI_PREOP;
val = readw((void *)(spi_char.mem_virt+SPI_PREOP));
SPI_DBG("before init, SPI_PREOOP=%08x/n", val);
val = SPI_WR_ENABLE | (SPI_WSR_ENABLE << 8);
writew(val, (void *)addr);
val = readw((void *)(spi_char.mem_virt+SPI_PREOP));
SPI_DBG("after init, SPI_PREOP=%08x/n", val);

/* disable Atomic Cycle Sequence */
val = readw((void *)(spi_char.mem_virt+SPI_CTRL));
val &= ~SPI_CTRL_ACS;
val &= ~SPI_CTRL_SPOP;
writew(val, (void*)(spi_char.mem_virt+SPI_CTRL));
}

loff_t spi_lseek(struct file *filp, loff_t off, int whence)
{
loff_t newpos;

switch (whence)
{
      case 0: /* SEEK_SET */
         newpos = off;
         break;

      case 1: /* SEEK_CUR */
         newpos = spi_char.fp + off;
         break;

      case 2: /* SEEK_END */
         newpos = spi_char.fp + off;
         break;

      default: /* cant't happen */
         return (-EINVAL);
         break;
   }

   if(newpos < 0 || newpos >= SPI_FLASH_SIZE)
   {
      return (-EINVAL);
   }

   spi_char.fp = newpos;
   return (newpos);
}

// Linux file operations
struct file_operations file_ops =
{
.owner =    THIS_MODULE,
.read =    spi_read,
.write =    spi_write,
.llseek = spi_lseek,
   .open =       spi_open,
   .release = spi_release,
   .ioctl = spi_ioctl,
};

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