...
static struct pm_ops my_pm = {
    prepare:  my_prepare,
    complete: my_complete,
    suspend:  my_suspend,
    resume:   my_resume,
    freeze:   my_freeze,
    thaw:     my_thaw,
    poweroff: my_poweroff,
    restore:  my_restore,
};
...
static int __init my_module_init(void)
{
    printk("my_module_init\n");
    if ((major = register_chrdev(0, "testdev", &fops))) {
        test_class = class_create(THIS_MODULE, "testclass");
        if (IS_ERR(test_class)) {
            printk("no udev support\n");
            unregister_chrdev(major, "testdev");
            return -EIO;
        }
        test_class->pm = &my_pm;
        device_create(test_class, NULL, MKDEV(major, 0), NULL, "lulu");
        return 0;
    }
    printk("loading failed\n");
    return -EIO;
}