/*模块卸载函数*/
static void memdev_exit(void)
{
cdev_del(&cdev); /*注销设备*/
kfree(mem_devp); /*释放设备结构体内存*/
unregister_chrdev_region(MKDEV(mem_major, 0), 2); /*释放设备号*/
}
MODULE_AUTHOR("David Xie");
MODULE_LICENSE("GPL");
module_init(memdev_init);
module_exit(memdev_exit);
scull.c
-----------------------------------------------------------------
1 obj-m +=scull.o
2 all:
3 make -C /lib/modules/$(shell uname -r)/build M=$(shell pwd) modules
4 clean:
5 make -C /lib/modules/$(shell uname -r)/build M=$(shell pwd) clean
-----------------------------------------------------------------
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <linux/i2c.h>
#include <linux/fcntl.h>
int main()
{
int fd;
char buf[]="this is a test!";
char buf_read[4096];
if((fd=open("/dev/scull",O_RDWR))==-1)
printf("open scull WRONG！\n");
else
printf("open scull SUCCESS!\n");
printf("buf is %s\n",buf);
write(fd,buf,sizeof(buf));
lseek(fd,0,SEEK_SET);
read(fd,buf_read,sizeof(buf));
printf("buf_read is %s\n",buf_read);
return 0;
}