1. cdev_initandcdev_addfunctions perform the character device registration.cdev_addadds the character device to the system. Whencdev_addfunction successfully completes, the device is live and the kernel can inv
sysfs通过class_create和device_create在设备树中创建相应的设备,应用层udev会自动根据设备树的变化生成相应的设备节点。 综上:在2.6内核之前通过函数cdev_init和cdev_add添加字符设备,另外还需要手动创建设备节点;在2.6之后的内核,通过cdev_init和cdev_add添加字符设备,通过class_create和device_create函数往sys文件系统中...
chrdevs是一个指针数组,成员类型为**struct char_device_struct ***,下标与字符设备号有一定的对应关系, **struct char_device_struct **中有成员: unsignedintmajor; structcdev*cdev; major : 是主设备号 cdev : 指向该字符设备号对应的cdev结构体 3、应用层、VFS层 用户如果想操作硬件,必须调用内核中的str...
logI("[flashlight_probe] Unable to create class, err = %d ~", ¦ ¦(int)PTR_ERR(flashlight_class)); goto flashlight_probe_error; } flashlight_device = ¦ device_create(flashlight_class, NULL, flashlight_devno, NULL, FLASHLIGHT_DEVNAME); if (NULL == flashlight_device) { logI("[f...
error = cdev_add(&cdev,devno,1);if(error <0) { printk("cdev_add fail \n"); unregister_chrdev_region(devno,1);returnerror; }return0; }staticvoidhello_exit(void){ printk("hello_exit \n"); cdev_del(cdev); unregister_chrdev_region(devno,1);return; ...
(&cdev,&hello_ops);error = cdev_add(&cdev,devno,1);if(error < 0){printk("cdev_add fail \n");unregister_chrdev_region(devno,1);returnerror;}return0;}staticvoid hello_exit(void){printk("hello_exit \n");cdev_del(cdev);unregister_chrdev_region(devno,1);return;}module_init(hello_...
chrdevs是一个指针数组,成员类型为**struct char_device_struct ***,下标与字符设备号有一定的对应关系, **struct char_device_struct **中有成员: unsignedintmajor; structcdev*cdev; major : 是主设备号 cdev : 指向该字符设备号对应的cdev结构体 ...
chrdevs是一个指针数组,成员类型为**struct char_device_struct ***,下标与字符设备号有一定的对应关系, **struct char_device_struct **中有成员: unsignedintmajor; structcdev*cdev; major : 是主设备号 cdev : 指向该字符设备号对应的cdev结构体 ...
* __register_chrdev() - create and register a cdev occupying a range of minors * @major: major device number or 0 for dynamic allocation * @baseminor: first of the requested range of minor numbers * @count: the number of minor numbers required ...
* __register_chrdev() - create and register a cdev occupying a range of minors * @major: major device number or 0 for dynamic allocation * @baseminor: first of the requested range of minor numbers * @count: the number of minor numbers required ...