Linux驱动开发：USB驱动之usb_skel分析.doc

Linux驱动开发：USB驱动之usb_skel分析 在学习了这么些天的驱动之后，个人觉得驱动就是个架构的问题，只要把架构弄清楚了 然后往里面添砖加瓦就可以了，所以似乎看起来不是太困难，但也许是是我经验不足吧，这只能算是个人浅见了 这两天在学习USB驱动开发，奇怪的是老师居然不讲USB的代码，让人不理解，后来在网上找资料才发现原来内核已经给我们准备了一个usb_skel的代码向我们介绍几本的USB驱动的架构，于是自己分析了一下代码，画了一个我认为的代码架构(比较难看)，写了一些注释 相关阅读： Linux驱动开发：网络设备之虚拟网卡?/Linux/2012-03/56415.htm Linux驱动开发：Nand Flash时序图分析?/Linux/2012-03/56414.htm Linux驱动开发：网络设备之DM9000驱动架构分析?/Linux/2012-03/56416.htm 废话不多说啦，直接上图上代码，请高手们批评指正！ /* ?* USB Skeleton driver - 2.2 ?* ?* Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@) ?* ?* This program is free software; you can redistribute it and/or ?* modify it under the terms of the GNU General Public License as ?* published by the Free Software Foundation, version 2. ?* ?* This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c ?* but has been rewritten to be easier to read and use. ?* ?*/ #include linux/kernel.h #include linux/errno.h #include linux/init.h #include linux/slab.h #include linux/module.h #include linux/kref.h #include asm/uaccess.h #include linux/usb.h #include linux/mutex.h /* Define these values to match your devices */ #define USB_SKEL_VENDOR_ID 0xfff0????????? //厂商ID #define USB_SKEL_PRODUCT_ID 0xfff0????? //产品ID /* table of devices that work with this driver */ //驱动支持的USB设备列表 static struct usb_device_id skel_table [] = { ??????? { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, ??????? { }, /* Terminating entry */ }; MODULE_DEVICE_TABLE(usb, skel_table); ? /* to prevent a race between open and disconnect */ static DEFINE_MUTEX(skel_open_lock); /* Get a minor range for your devices from the usb maintainer */ #define USB_SKEL_MINOR_BASE 192????? //USB主设备号 /* our private defines. if this grows any larger, use your own .h file */ #define MAX_TRANSFER (PAGE_SIZE - 512) /* MAX_TRANSFER is chosen so that the VM is not stressed by allocations PAGE_SIZE and the number of packets in a page is an integer 512 is the largest possible packet on EHCI */ #define WRITES_IN_FLIGHT 8 /* arbitrarily chosen */ //8、u