dev目录下有我创建的设备文件，/proc/devices里能看见。sys/class中也看得见我创建的类，驱动加载成功，make驱动时没有错误。我的驱动和源码如下：

复制代码 #include <linux/module.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/miscdevice.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/cdev.h> #include <asm/irq.h> #include <mach/gpio.h> #include <plat/regs-gpio.h> #include <plat/gpio-cfg.h> #include <mach/hardware.h> #include <linux/io.h> #include <asm/uaccess.h> MODULE_LICENSE("Dual BSD/GPL"); MODULE_DESCRIPTION("OK6410_V 0.1"); dev_t devno; static struct cdev cdev_first; static struct class *firstdrv_class; volatile unsigned long *gpmcon = NULL; volatile unsigned long *gpmdat = NULL; static int first_drv_open(struct inode *inode, struct file *file) {     /* 配置gpm1-4引脚为输出*/     *gpmcon &= 0xffff0000;     *gpmcon |= 0x00001111;      return 0;      } static ssize_t first_drv_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) {     int val;     int r;     //printk("first_drv_write\n");     r=copy_from_user(&val, buf, count); //    copy_to_user();     if (val == 1)     {         // 点灯         *gpmdat &= 0xfffffff0;     }     else     {         // 灭灯         *gpmdat |= 0xf;     }          return 0; } static struct file_operations first_drv_fops ={     .owner  =   THIS_MODULE,    /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */     .open   =   first_drv_open,         .write  =   first_drv_write,       }; static int __init first_drv_init(void) {          int result;          gpmcon = (volatile unsigned long *)ioremap(0x7f008820, 16);     gpmdat = gpmcon + 1;          printk(KERN_NOTICE "MODULE IS INITING\n");              result=alloc_chrdev_region(&devno,0,1,"myled");     if(result<0)     printk(KERN_NOTICE "region wrong!");     cdev_init(&cdev_first,&first_drv_fops);     cdev_first.owner=THIS_MODULE;     cdev_first.ops=&first_drv_fops;     cdev_add(&cdev_first,devno,1);               firstdrv_class = class_create(THIS_MODULE, "mydrv");  //sys/class     device_create(firstdrv_class, NULL, devno, NULL, "myled"); /* /dev/xyz */     return 0; } static void __exit first_drv_exit(void) {          cdev_del(&cdev_first);     unregister_chrdev_region(devno,1);          device_destroy(firstdrv_class,devno);     class_destroy(firstdrv_class);          iounmap(gpmcon);     printk(KERN_NOTICE "my driver exit\n"); } module_init(first_drv_init); module_exit(first_drv_exit);

测试程序：

复制代码 #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <stdio.h> /* firstdrvtest on   * firstdrvtest off   */ int main(int argc, char **argv) {     int fd;     int val = 1;     char *filename="/dev/myled";     fd = open("filename", O_RDWR);     if (fd < 0)     {         printf("can't open!\n");     }     if (argc != 2)     {         printf("Usage :\n");         printf("%s <on|off>\n", argv[0]);         return 0;     }     if (strcmp(argv[1], "on") == 0)     {         val  = 1;     }     else     {         val = 0;     }          write(fd, &val, 4);     return 0; }

请高手解答，非常感谢对新手的帮助。

下面这一行错了
fd = open("filename", O_RDWR);

请问我应该怎么改啊？谢谢你的回答了。
我改成fd = open("/dev/myled", O_RDWR);
或fd = open(filename, O_RDWR);
错误都一样啊。

1) 加载你的驱动后, 请检查一下 /dev/myled 这个文件是否存在, 不存在的话肯定有问题
2) 你也使用 strerror 这个函数获得open失败时具体的错误原因