[OCLUG-Tech] device driver magic number for ioctl() in linux

["Zhao, Joe" <jozhao [ at ] ciena [ dot ] com>]

Hi,

For a device driver using ioctl() calls in linux, we need to define a
unique magic number system wide.

Can we define the magic number with the value greater than 0xFF? Where
is this magic number used by linux kernel?

Thanks in advance.

Joe