通过libusb读取鼠标数据

#include <iostream>
#include <stdio.h>
#include <libusb-1.0/libusb.h>
using namespace std;
 
int main(int arc, char **argv)
{
    libusb_device **devs;	//pointer to pointer of device, used to retrieve a list of devices
    libusb_context *ctx = NULL; //a libusb session
    int r;				//for return values
    ssize_t cnt;		//holding number of devices in list
    r = libusb_init(&ctx);	//initialize a library session
    if(r < 0) {
    	cout<<"Init Error "<<r<<endl; //there was an error
    	return 1;
    }
    
    libusb_set_debug(ctx, 3); //set verbosity level to 3, as suggested in the documentation
    cnt = libusb_get_device_list(ctx, &devs); //get the list of devices
    if(cnt < 0) {
    	cout<<"Get Device Error"<<endl; //there was an error
    }
    
    libusb_device_handle *dev_handle;	//a device handle
    /*dev_handle = libusb_open_device_with_vid_pid(ctx, 0x0cf3, 0xe005); //open mouse*/
    /*dev_handle = libusb_open_device_with_vid_pid(ctx, 0x0483, 0x5710); //open mouse*/
    dev_handle = libusb_open_device_with_vid_pid(ctx, 0x413c, 0x301a); //open mouse
    if(dev_handle == NULL)
    {
        cout<<"Cannot open device"<<endl;
        	libusb_free_device_list(devs, 1); //free the list, unref the devices in it
        	libusb_exit(ctx);	//close the session
        	return 0;
    } else {
        cout<<"Device Opened"<<endl;
        libusb_free_device_list(devs, 1);	//free the list, unref the devices in it
        if(libusb_kernel_driver_active(dev_handle, 0) == 1) { //find out if kernel driver is attached
    	    cout<<"Kernel Driver Active"<<endl;

    	if(libusb_detach_kernel_driver(dev_handle, 0) == 0) //detach it
    	    cout<<"Kernel Driver Detached!"<<endl;
        }
	r = libusb_claim_interface(dev_handle, 0);	//claim interface 0 (the first) of device (mine had jsut 1)
	if(r < 0) {
	    cout<<"Cannot Claim Interface"<<endl;
	    return 1;
	}
	cout<<"Claimed Interface"<<endl;
	int size;
	unsigned char datain[1024]="\0";
	for(int i=0;i<10;i++)
	{
	    int rr = libusb_interrupt_transfer(dev_handle,
	    		0x81,
	    		datain,
	    		0x0004,
	    		&size,
	    		1000);
	    std::cout<<"libusb_interrupt_transfer rr: "<<rr<<endl;
	    cout<<"size: "<<size<<endl;
	    printf("data: ");
	    for(int j=0; j<size; j++)
	    	  printf("%02x ", (unsigned char)(datain[j]));
	    printf("\n");
	}
	
	r = libusb_release_interface(dev_handle, 0); //release the claimed interface
	if(r!=0) {
	    cout<<"Cannot Release Interface"<<endl;
	    return 1;
	}
	cout<<"Released Interface"<<endl;
	
	libusb_attach_kernel_driver(dev_handle, 0);
	libusb_close(dev_handle);
	libusb_exit(ctx); //close the session
	return 0;
    }
}

实际上打开的是设备"/dev/bus/usb/001/007",并在其上进行了fops的调用，可见标准字符设备节点的调用可以再/dev/目录下的任何目录级的设备文件下调用。

结束！