参考原文：http://www.tldp.org/HOWTO/text/Module-HOWTO


15.7. Miscellaneous Device Driver

15.7.1. misc: device driver for "miscellaneous" character devices

A whole bunch of device types that don't appear in large enough numbers on a
system to deserve major numbers of their own share Major Number 10 and are
collectively called "miscellaneous" character devices. This module provides
the common interface to serve that major number, but there are individual
drivers for the specific device types. Those drivers register themselves with
this driver.

Example:
+---------------------------------------------------------------------------+
|modprobe misc                                                              |
+---------------------------------------------------------------------------+

There are no module parameters.
-----------------------------------------------------------------------------

简单翻译就是一些用的不是很多的器件没必要每个都占用一个主设备号，这样容易导致主设备号不够用，所以讲这些“其它”设备都统一用一个主设备号10，提供了统一的驱动接口，但是每个器件拥有独立的驱动程序。