设备模型之外，对于驱动程序的开发者来说，有三样东西是不可缺少的：第一是协议或标准的spec，也就是规范，比如usb协议规范；第二是硬件的datasheet，即你的驱动要支持的硬件的手册；第三就是内核里类似驱动的源代码，比如你要写触摸屏驱动的话，就可以参考内核里已经有的一些触摸屏驱动-Device model, the developer of the driver, there are three things are essential: The first is the protocol or standard spec, which is the norm, such as usb protocol specification　second is a hardware datasheet, ie your drive to support the hardware manuals　third is similar to the kernel driver source code, for example, you want to write touch screen driver, then it can refer to the kernel already have some of the touch screen driver