linux虚拟鼠标驱动

用linux的input架构

先产生一个input设备并注册，再用platform_device的/sys当做程序入口

最后用一个用户程序利用随机数产生相对坐标，写入入口

驱动：

#include <linux/module.h>
#include <linux/platform_device.h>

#include <linux/input.h>




struct platform_device *vms_dev;

struct input_dev *vms_input_dev;

static ssize_t write_vms(struct device *dev,struct device_attribute *attr,
    const char *buffer,size_t count)
{
    int x,y;
    sscanf(buffer,"%d%d",&x,&y);

    input_report_rel(vms_input_dev,REL_X,x);
    input_report_rel(vms_input_dev,REL_Y,y);
    input_sync(vms_input_dev);

    return count;
}

DEVICE_ATTR(coordinates,0644,NULL,write_vms);

static struct attribute *vms_attrs[] = {
    &dev_attr_coordinates.attr,
    NULL,
};

static struct attribute_group vms_attr_group = {
    .attrs = vms_attrs,
};

static int __init vms_init(void)
{

    vms_input_dev = input_allocate_device();
    set_bit(EV_REL,vms_input_dev->evbit);
    set_bit(REL_X,vms_input_dev->relbit);
    set_bit(REL_Y,vms_input_dev->relbit);

    input_register_device(vms_input_dev);

    printk("input_register_device ok\n");

//use cdev or platform as hardware ISR input
    vms_dev = platform_device_register_simple("vms",-1,NULL,0);

    sysfs_create_group(&vms_dev->dev.kobj,&vms_attr_group);


    return 0;
}

static void __exit vms_exit(void)
{
    input_unregister_device(vms_input_dev);

    printk("input_unregister_device ok\n");

    sysfs_remove_group(&vms_dev->dev.kobj,&vms_attr_group);

    platform_device_unregister(vms_dev);
}


module_init(vms_init);
module_exit(vms_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("archer");

用户虚拟坐标程序：

#include <stdio.h>
#include <string.h>
#include <fcntl.h>




int main(int argc,char *argv[])
{
    int sim_fd;

    int x,y;
    char buffer[10];

    sim_fd = open("/sys/devices/platform/vms/coordinates",O_RDWR);
    if(sim_fd < 0) {
        printf("open fail\n");
        return -1;
    }

    while(1) {
        x = random()%20;
        y = random()%20;

        if(x % 2)
            x = -x;
        if(y % 2)
            y = -y;

    sprintf(buffer,"%d %d %d",x,y,0);

    write(sim_fd,buffer,strlen(buffer));
    fsync(sim_fd);

    sleep(1);
    }

    close(sim_fd);
}

最后用一个  helper工具读取evdev事件包就可以了

gpm -m /dev/input/eventX -t evdev