17
在这什么都在失去理智飞涨的历史时刻，我会尽力的保持头脑的清醒，不会忘记自己要聊的
是关于什么，所以，首先要去 drivers/usb 目录下走一走看一看。
atm class core gadget host image misc mon serial storage Kconfig
Makefile README usb-skeleton.c
ls命令的结果就是上面的 10个目录和 4个文件。usb-skeleton.c是一个简单的 usb driver
的框架，感兴趣的可以去看看，目前来说，它还吸引不了我的眼球。那么首先应该关注什么？
如果迎面走来一个 ppmm，你会首先看脸、脚还是其它？当然答案依据每个人的癖好会有
所不同。不过这里的问题应该只有一个答案，那就是 Kconfig、Makefile、README。
README 里有关于这个目录下内容的一般性描述，它不是关键，只是帮助你了解。再说了，
面对读我吧读我吧这么热情奔放的呼唤，善良的我们是不可能无动于衷的，所以先来看看里
面都有些什么内容。
23 Here is a list of what each subdirectory here is, and what is contained in
24 them.
25
26 core/ - This is for the core USB host code, including the
27 usbfs files and the hub class driver ("khubd").
28
29 host/ - This is for USB host controller drivers. This
30 includes UHCI, OHCI, EHCI, and others that might
31 be used with more specialized "embedded" systems.
32
33 gadget/ - This is for USB peripheral controller drivers and
34 the various gadget drivers which talk to them.
35
36
37 Individual USB driver directories. A new driver should be added to the
38 first subdirectory in the list below that it fits into.
39
40 image/ - This is for still image drivers, like scanners or
41 digital cameras.
42 input/ - This is for any driver that uses the input subsystem,
43 like keyboard, mice, touchscreens, tablets, etc.
44 media/ - This is for multimedia drivers, like video cameras,
45 radios, and any other drivers that talk to the v4l
46 subsystem.
47 net/ - This is for network drivers.
48 serial/ - This is for USB to serial drivers.
49 storage/ - This is for USB mass-storage drivers.
50 class/ - This is for all USB device drivers that do not fit
51 into any of the above categories, and work for a range
