usb驱动程序设计

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/usb.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/slab.h>

//传输变量 
#define BULKOUT_BUFFER_SIZE 512
char *bulkout_buffer;
//usb设备定义
struct usb_device *udev; 
//保存端点 
__u8 bulk_out_endaddr； 

static struct usb_device_id dnw_id_table[] = {
	//获取USB设备ID 
	{ USB_DEVICE(,) },//通过lsusb获取 
	{}
};

static int dnw_open(struct inode* inode, struct file *file)
{
	//申请拷贝空间 
	bulkout_buffer = kmalloc(BULKOUT_BUFFER_SIZE,GFP_KERNEL);
	return 0;	
}

static int dnw_release(struct inode* inode, struct file *file)
{
	//释放拷贝空间 
	kfree(bulkout_buffer);
	return 0;
}

static ssize_t dnw_write(struct file *file, const char __user *buf, size_t len, loff_t *pos)
{
	size_t to_write;
	size_t total_write = 0;
	size_t act_len;
	while(len>0)
	{
		to_write = min((size_t)len,BULKOUT_BUFFER_SIZE);
		copy_from_user(bulkout_buffer+total_write,buf);
	
		usb_bulk_msg(udev,usb_sndbulkpipe(udev,bulk_out_endaddr),bulkout_buffer,to_write,&act_len,3*HZ);//（2）获取端点信息 
		
		len -= to_write;
		total_write += to_write;
	}
	
	return total_write;
}

static struct file_operations dnw_ops =
{
	.owner =	THIS_MODULE,
	.write =	dnw_write,
	.open =		dnw_open,
	.release =	dnw_release,
};

static struct usb_class_driver dnw_class = {
	.name = "dnw%d";
	.fops = &dnw_ops;
	.minor_base = 100;
};


static int usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
	int i = 0;
	//接口设置描述
	struct usb_host_interface *interface;
	/* 端点描述符 */
	struct usb_endpoint_descriptor *endpoint;
	
	interface = intf->cur_altsetting;
	
//	interface->desc.bNumEndpoints;
	
	/* 获取端点0描述符 */
//	endpoint = &interface->endpoint[0].desc;
	
	for(i=0;i<interface->desc.bNumEndpoints;i++)
	{
		endpoint = &interface->endpoint[i].desc;
		//判断bulk_out端点 
		if(usb_endpoint_is_bulk_out(endpoint))	
		{
			bulk_out_endaddr = endpoint->bEndpointAddress;
			break;
		}
	} 
	
	usb_register_dev(intf,&dnw_class);	
	
	usb_get_dev( interface_to_usbdev(intf) );
} 

static void dnw_disconnect(struct usb_interface *intf)
{
	usb_deregister_dev(intf,&dnw_class);
}

//usb结构体初始化 
static struct usb_driver dnw_driver = {
	.name		= "dnw",   /* 驱动名 */
	.probe		= dnw_probe, /* 捕获函数 */
	.disconnect	= dnw_disconnect, /* 卸载函数 */
	.id_table	= dnw_id_table, /* 设备列表 */
}; 

int dnw_init()
{
	//usb注册 
	usb_register(&dnw_driver);
	return 0;
} 

void dnw_exit()
{
	usb_deregister(&dnw_driver);
}

module_init(dnw_init);
module_exit(dnw_exit);
//支持协议 
MODULE_LICENSE("GPL");