Program for Linux USB-devices driver step by step (ONE)

浏览数：18 / 时间：2015年06月20日

Program for Linux USB-devices driver

开始啃硬骨头~ 这里我打算一步步给出USB device driver 的demo，希望有心能能够共同交流学习. 希望认识更多对Linux有兴趣的geek.

目前由于环境和自身能力方面原因还没能做实物的测试，篇章的最后打算给出一个在x86上模拟USB读写的driver，以后能够做实物测试之后再更新this blog

我的联系方式：

[email protected]（由于偶不能登QQ，所以thunder bird的邮件只要电脑开着就一直在线~）

测试环境：

Ubuntu 14.0

kernel: 3.13.0

下面我比较详细的对代码进行了注释，要点都在代码中啦~

这段代码仅仅是个例子，相当于第一个驱动设备hello world一样，力求最简单化概括性的给出USB设备插入，拔出相关的处理过程，后面慢慢的写的更深入的时候，代码也就越来越”复杂“

我整理了USB device driver 代码相关的结构体，做了目录便于查阅

/**************************************************************
code writer 	: EOF
code date	: 2014.08.18
code file	        : ./USB_1/usb_1.c
e-mail		: [email protected]

code purpose:
	This is a demo for how to code for a USB device driver.

	If there is something wrong with my code, please touch 
me by e-mail. Thank you. 	

*************************************************************/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/usb.h>
#include <linux/module.h>
#include <linux/moduleparam.h>

/*
**  	This two Macro used to create a structure -- 
** 'usb_device_id' by 'USB_DEVICE'
*/
#define VENDOR_ID	0x08f7
#define PRODUCT_ID	0x0002

#define DEVICE_NAME	"usb_1"

MODULE_AUTHOR("EOF");
MODULE_LICENSE("Dual BSD/GPL");

/*
**  id_table stored many USB device's 'usb_device_id' structure 
*/
static struct usb_device_id id_table[] = 
{
	{ USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
	{ },
};

/*
**	The 'MODULE_DEVICE_TABLE' Macro marks device in the
** module image so that the module can be loaded on demand if 
** the device is hotplugged.
*/

MODULE_DEVICE_TABLE(usb,id_table);


/*
**	The probe() method is invoked by khubd after device enumeration.
**
**	@interface	:contains information gleaned during the 
**  enumeration process.
**
**	@id		: the entry in the driver's 'usb_device_id' table
**  that matches the values read from the USB-device.
**	
*/
static int usb_probe(struct usb_interface * interface,
		     const struct usb_device_id *id)
{
	dev_info(&interface->dev,"USB device now attached\n");

	return 0;
}

/*
** 	disconnect() method is called when the device is unplugged or
** when the module is unloaded.
*/
static void usb_disconnect(struct usb_interface* interface)
{
	dev_info(&interface->dev,"USB device now disconnect\n");
}

/*
**	Each USB device has a 'usb_driver' data structure.
*/
static struct usb_driver usb_driver = 
{
	.name	=	DEVICE_NAME,
	.probe	=	usb_probe,
	.disconnect =	usb_disconnect,
	.id_table   =	id_table,
};

static int usb_init(void)
{
	return usb_register(&usb_driver);
}

static void usb_exit(void)
{
	usb_deregister(&usb_driver);
}

module_init(usb_init);
module_exit(usb_exit);