- #include
- #include
- #include
- #include
- #include
- #include
- #include
- #include
- #include
- #include
- struct cdev *cdev;
- char kbuf[128]={0};
- unsigned int major=0;
- unsigned int minor=0;
- dev_t devno;
- module_param(major,uint,0664);//方便在命令行传递major的值
- struct class*cls;
- struct device *dev;
- unsigned int condition=0;
- //定义一个等待队列头
- wait_queue_head_t wq_head;
- // 封装操作方法
- int mycdev_open(struct inode *inode, struct file *file)
- {
- printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
- return 0;
- }
- ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
- {
- unsigned long ret;
- if (size > sizeof(kbuf)) // 用户空间期待读取的大小内核满足不了,那就给内核支持的最大大小
- size = sizeof(kbuf);
- if(file->f_flags&O_NONBLOCK)//非阻塞IO
- {}
- else{
- //wait_event_interruptible(wq_head,condition);
- }
- ret = copy_to_user(ubuf, kbuf, size);
- if (ret)
- {
- printk("copy_to_user err\n");
- return -EIO;
- }
- condition=0;
- return 0;
- }
- ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
- {
- unsigned long ret;
- if (size > sizeof(kbuf)) // 用户空间期待读取的大小内核满足不了,那就给内核支持的最大大小
- size = sizeof(kbuf);
- ret = copy_from_user(kbuf, ubuf, size);
-
- if (ret)
- {
- printk("copy_from_user err\n");
- return -EIO;
- }
- condition=1;
- wake_up_interruptible(&wq_head);
-
- return 0;
- }
- int mycdev_close(struct inode *inode, struct file *file)
- {
- printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
- return 0;
- }
- //封装POLL方法
- __poll_t mycdev_poll(struct file *file,struct poll_table_struct *wait)
- {
- __poll_t mask=0;
- //向上提交等待队列头
- poll_wait(file,&wq_head,wait);
- //根据事件是否发生给一个合适的返回值
- if(condition)
- {
- mask=POLLIN;
- }
- return mask;
- }
- struct file_operations fops = {
- .open = mycdev_open,
- .read = mycdev_read,
- .write = mycdev_write,
- .poll = mycdev_poll,
- .release = mycdev_close,
- };
-
- static int __init mycdev_init(void)
- {
- init_waitqueue_head(&wq_head);
- int ret;
- //为字符设备驱动对象申请空间
- cdev=cdev_alloc();
- if(cdev==NULL)
- {
- printk("字符设备驱动对象申请空间失败\n");
- ret=-EFAULT;
- goto out1;
- }
- printk("申请对象空间成功\n");
- //初始化字符设备驱动对象
- cdev_init(cdev,&fops);
- //申请设备号
- if(major>0)//静态指定设备号
- {
- ret=register_chrdev_region(MKDEV(major,minor),3,"myled");
- if(ret)
- {
- printk("静态申请设备号失败\n");
- goto out2;
- }
- }
- else if(major==0)//动态申请设备号
- {
- ret=alloc_chrdev_region(&devno,minor,3,"myled");
- if(ret)
- {
- printk("动态申请设备号失败\n");
- goto out2;
- }
- major=MAJOR(devno);//获取主设备号
- minor=MINOR(devno);//获取次设备号
-
- }
- printk("申请设备号成功\n");
- //注册字符设备驱动对象
- ret=cdev_add(cdev,MKDEV(major,minor),3);
- if(ret)
- {
- printk("注册字符设备驱动对象失败\n");
- goto out3;
- }
- printk("注册字符设备驱动对象成功\n");
- //向上提交目录信息
- cls=class_create(THIS_MODULE,"myled");
- if(IS_ERR(cls))
- {
- printk("向上提交目录失败\n");
- ret=-PTR_ERR(cls);
- goto out4;
- }
- printk("向上提交目录成功\n");
- //向上提交设备节点信息
- int i;
- for(i=0;i<3;i++)
- {
- dev=device_create(cls,NULL,MKDEV(major,i),NULL,"myled%d",i);
- if(IS_ERR(dev))
- {
- printk("向上提交设备节点信息失败\n");
- ret=-PTR_ERR(dev);
- goto out5;
- }
- }
- printk("向上提交设备信息成功\n");
- return 0;
- out5:
- //释放前一次提交成功的设备信息
- for(--i;i>=0;i--)
- {
- device_destroy(cls,MKDEV(major,i));
- }
- class_destroy(cls);//释放目录
- out4:
- cdev_del(cdev);
- out3:
- unregister_chrdev_region(MKDEV(major,minor),3);
- out2:
- kfree(cdev);
- out1:
- return ret;
- }
-
- static void __exit mycdev_exit(void)
- { //取消地址映射
-
- //注销字符设备驱动
- //释放节点信息
- int i;
- for(i=0;i<3;i++)
- {
- device_destroy(cls,MKDEV(major,i));
- }
- //销毁目录
- class_destroy(cls);
- //注销驱动对象
- cdev_del(cdev);
- //释放设备号
- unregister_chrdev_region(MKDEV(major,minor),3);
- //释放对象空间
- kfree(cdev);
- }
- module_init(mycdev_init);
- module_exit(mycdev_exit);
- MODULE_LICENSE("GPL");
- #include
- #include
- #include
- #include
- #include
- #include
- #include
- #include
- #include
-
-
- int main(int argc, char const *argv[])
- {
-
- char buf[128] = {0};
- int fd1,fd2;
- fd1 = open("/dev/input/mouse0", O_RDWR);
- if (fd1 < 0)
- {
- printf("打开鼠标设备文件失败\n");
- exit(-1);
- }
- fd2 = open("/dev/myled0",O_RDWR);
- if(fd2 < 0)
- {
- printf("打开设备文件失败\n");
- }
- //定义事件集合
- fd_set readfds;
- while (1)
- {
- //清空事件集合
- FD_ZERO(&readfds);
- //将要监听的文件描述符添加到刻度集合
- FD_SET(fd1,&readfds);
- FD_SET(fd2,&readfds);
- //等待事件就绪
- printf("%s\n",buf);
- int ret = select(fd2+1,&readfds,NULL,NULL,NULL);
- if(ret<0)
- {
- printf("select err\n");
- exit(-1);
- }
- //判断事件是否发生
- //没发生事件会清除刻度集合,只需要判断文件描述符是否在集合中即可
- if(FD_ISSET(fd1,&readfds))
- {
- read(fd1,buf,sizeof(buf));
- printf("鼠标事件发生%s\n",buf);
- }
- if(FD_ISSET(fd2,&readfds))
- {
- read(fd2,buf,sizeof(buf));
- printf("自定义设备发生%s\n",buf);
- }
- }
-
-
- close(fd1);
- close(fd2);
-
- return 0;
- }
- #include
- #include
- #include
- #include
- #include
- #include
- #include
- #include
-
-
- int main(int argc, char const *argv[])
- {
-
- char buf[128] = {"hello world"};
- int fd = open("/dev/myled0", O_RDWR);
- if (fd < 0)
- {
- printf("打开设备文件失败\n");
- exit(-1);
- }
- write(fd,buf,sizeof(buf));
-
- close(fd);
-
- return 0;
- }