C++ class_unregister函数代码示例

static void __exit cleanup_basic_device_module(void)
{
    class_unregister(&lfs_sysfs_class);
    // kobject_put(lfs_kobj);
    device_destroy(lfs_class, MKDEV(major_number, 0));
    class_unregister(lfs_class);
    class_destroy(lfs_class);
    unregister_chrdev(major_number, DEVICE_NAME);
    printk(KERN_INFO "LSDDriver: Bye!\n");
}

static int __init fir_init(void)
{
	int ret;
	ret = register_chrdev(0,DEVICE_NAME, &fir_fops);
	if(ret < 0)
	{
		printk("fir: can't get major number\n");
		return ret;
	}

	fir_major = ret;
	fir_class = class_create(THIS_MODULE, "fir_class");
	if(IS_ERR(fir_class))
	{
		printk("fir: failed in creating class\n");
		unregister_chrdev(fir_major, DEVICE_NAME);
		return -1;
	}

	fir_device = device_create(fir_class,NULL,MKDEV(fir_major,0),NULL,DEVICE_NAME);
	if(IS_ERR(fir_device))
	{
		printk("fir: failed in creating device!\n");
		unregister_chrdev(fir_major, DEVICE_NAME);
		class_unregister(fir_class);
		class_destroy(fir_class);
		return -1;
	}
	
	fir_addr = (unsigned long) ioremap(FIR_BASEADDR, sizeof(u32));

	printk("fir installed successfully!\n");
	return 0;
}

int __init watchdog_dev_init(void)
{
	int err;

	watchdog_wq = alloc_workqueue("watchdogd",
				      WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
	if (!watchdog_wq) {
		pr_err("Failed to create watchdog workqueue\n");
		return -ENOMEM;
	}

	err = class_register(&watchdog_class);
	if (err < 0) {
		pr_err("couldn't register class\n");
		goto err_register;
	}

	err = alloc_chrdev_region(&watchdog_devt, 0, MAX_DOGS, "watchdog");
	if (err < 0) {
		pr_err("watchdog: unable to allocate char dev region\n");
		goto err_alloc;
	}

	return 0;

err_alloc:
	class_unregister(&watchdog_class);
err_register:
	destroy_workqueue(watchdog_wq);
	return err;
}

static void __exit dmabufr_exit(void)
{
	dev_t dev = MKDEV(major, 0);

	class_unregister(dmabufr_class);
	unregister_chrdev_region(dev, DMABUFR_NUM_DEVICES);
}

static void uart16550_cleanup(void)
{
        int have_com1 =0;
        int have_com2 = 0;
        cdev_del(firstcdev);
        cdev_del(secondcdev);         

          if(behavior==0x3){
                have_com1=1; have_com2=1;
         }
         else if(behavior==0x2){
                have_com1=0; have_com2=1;
         }
         else if(behavior==0x1){
                have_com1=1; have_com2=0;
         }

        if (have_com1) {
                /* Reset the hardware device for COM1 */
                uart16550_hw_cleanup_device(COM1_BASEPORT);
                /* Remove the sysfs info for /dev/com1 */
                device_destroy(uart16550_class, MKDEV(major, 0));
        }
        if (have_com2) {
                /* Reset the hardware device for COM2 */
                uart16550_hw_cleanup_device(COM2_BASEPORT);
                /* Remove the sysfs info for /dev/com2 */
                device_destroy(uart16550_class, MKDEV(major, 1));
        }
        
        class_unregister(uart16550_class);
        class_destroy(uart16550_class);
}

static void __exit smc_mod_exit(void)
{
	platform_driver_unregister(&smc_driver);
	class_unregister(&smc_class);
	unregister_chrdev(smc_major, SMC_DEV_NAME);
	mutex_destroy(&smc_lock);
}

static void __exit rmidev_exit(void)
{
	pr_debug("%s: exiting.\n", __func__);
	platform_driver_unregister(&rmidev_driver);
	class_unregister(rmidev_device_class);
	class_destroy(rmidev_device_class);
}

static int __init smc_mod_init(void)
{
	int ret = -1;
	
	mutex_init(&smc_lock);
	
	smc_major = register_chrdev(0, SMC_DEV_NAME, &smc_fops);
	if(smc_major<=0) {
		mutex_destroy(&smc_lock);
		pr_error("register chrdev error\n");
		goto error_register_chrdev;
	}
	
	if(class_register(&smc_class)<0) {
		pr_error("register class error\n");
		goto error_class_register;
	}
	
	if(platform_driver_register(&smc_driver)<0) {
		pr_error("register platform driver error\n");
		goto error_platform_drv_register;
	}
	
	return 0;
error_platform_drv_register:
	class_unregister(&smc_class);
error_class_register:
	unregister_chrdev(smc_major, SMC_DEV_NAME);
error_register_chrdev:
	mutex_destroy(&smc_lock);
	return ret;
}

static int macvtap_init(void)
{
	int err;

	err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap");

	if (err)
		goto out1;

	err = class_register(&macvtap_class);
	if (err)
		goto out2;

	err = register_netdevice_notifier(&macvtap_notifier_block);
	if (err)
		goto out3;

	err = macvlan_link_register(&macvtap_link_ops);
	if (err)
		goto out4;

	return 0;

out4:
	unregister_netdevice_notifier(&macvtap_notifier_block);
out3:
	class_unregister(&macvtap_class);
out2:
	tap_destroy_cdev(macvtap_major, &macvtap_cdev);
out1:
	return err;
}

static int __init motor_init(void)
{
	int err;

	printk(KERN_INFO DRV_DESC ", version " DRV_VERSION "\n");

	/*register the class */
	motor_class = class_create(THIS_MODULE, "motor_class");
	if(IS_ERR(motor_class)){
		goto err;
	}

	err = motor_add_one(0, mot0);
	if (err) goto err;

	err = motor_add_one(1, mot1);
	if (err) goto err;

	err = motor_add_one(2, mot2);
	if (err) goto err;

	err = motor_add_one(3, mot3);
	if (err) goto err;

	return 0;

err:
	class_unregister(motor_class);
	return -1;
}

/** @brief The LKM cleanup function
 *  Similar to the initialization function, it is static. The __exit macro notifies that if this
 *  code is used for a built-in driver (not a LKM) that this function is not required.
 */
static void __exit sysmon_exit(void)
{
    data_packet_list_node *dp = NULL;
    unsigned long flags;

    device_destroy(SYSMONClass, MKDEV(majorNumber, 0));     // remove the device
    class_unregister(SYSMONClass);                          // unregister the device class
    class_destroy(SYSMONClass);                             // remove the device class
    unregister_chrdev(majorNumber, DEVICE_NAME);             // unregister the major number

    dp = getNodeFromActiveList();
    
    spin_lock_irqsave(&dp_list_lock, flags);

    while(dp != NULL)
    {
        kfree(dp);
        dp = getNodeFromActiveList();
    }

    dp = getNodeFromStorageList(false);

    while(dp != NULL)
    {
        kfree(dp);
        dp = getNodeFromStorageList(false);
    }
  
    spin_unlock_irqrestore(&dp_list_lock, flags);
  
    printk(KERN_INFO "SYSMON: Goodbye from the LKM!\n");
}

static int __init ultrasonic_init(void) 
{
	int ret;
	ret = register_chrdev(0,DEVICE_NAME, &ultrasonic_fops);
	if(ret < 0)
	{
		printk("ultrasonic: can't get major number\n");
		return ret;
	}
	ultrasonic_major = ret;
	ultrasonic_class = class_create(THIS_MODULE, "ultrasonic_class");
	if(IS_ERR(ultrasonic_class))
	{
		printk("ultrasonic: failed in creating class\n");
		unregister_chrdev(ultrasonic_major, DEVICE_NAME);
		return -1;
	}
	ultrasonic_device = device_create(ultrasonic_class,\
									  NULL, \
									  MKDEV(ultrasonic_major, 0), \
									  NULL,\
									  DEVICE_NAME);
	if(IS_ERR(ultrasonic_device))
	{
		printk("ultrasonic: failed in creating device!\n");
		unregister_chrdev(ultrasonic_major, DEVICE_NAME);
		class_unregister(ultrasonic_class);
		class_destroy(ultrasonic_class);
		return -1;
	}
	base_addr = (unsigned long) ioremap(ULTRASONIC_PHY_ADDR, sizeof(u32));
	printk("Ultrasonic initail successfully\n");
	return 0;
}

static void __exit ebbchar_exit(void){
	device_destroy(ebbcharClass, MKDEV(majorNumber, 0));
	class_unregister(ebbcharClass);
	class_destroy(ebbcharClass);
	unregister_chrdev(majorNumber, DEVICE_NAME);
	printk(KERN_INFO "EBBChar: Goodbye from the LKM!\n");
}

/***********************************************************************
*
* module  section    (init&exit)
*
************************************************************************/
static int  
init_ge2d_device(void)
{
	int  ret=0;
	
	strcpy(ge2d_device.name,"ge2d");
	ret=register_chrdev(0,ge2d_device.name,&ge2d_fops);
	if(ret <=0) 
	{
		amlog_level(LOG_LEVEL_HIGH,"register ge2d device error\r\n");
		return  ret ;
	}
	ge2d_device.major=ret;
	ge2d_device.dbg_enable=0;
	amlog_level(LOG_LEVEL_LOW,"ge2d_dev major:%d\r\n",ret);
	ret = class_register(&ge2d_class);
	if(ret<0 )
	{
		amlog_level(LOG_LEVEL_HIGH,"error create ge2d class\r\n");
		return ret;
	}
	ge2d_device.cla=&ge2d_class ;
	ge2d_device.dev=device_create(ge2d_device.cla,NULL,MKDEV(ge2d_device.major,0),NULL,ge2d_device.name);
	if (IS_ERR(ge2d_device.dev)) {
		amlog_level(LOG_LEVEL_HIGH,"create ge2d device error\n");
		class_unregister(ge2d_device.cla);
		return -1 ;
	}
	return ge2d_setup();
	
}

static void macvtap_exit(void)
{
	rtnl_link_unregister(&macvtap_link_ops);
	unregister_netdevice_notifier(&macvtap_notifier_block);
	class_unregister(&macvtap_class);
	tap_destroy_cdev(macvtap_major, &macvtap_cdev);
}