modules.c
#include <linux/init.h>
#include <linux/module.h>
#include<linux/fs.h>
#include<linux/uaccess.h>
#include<linux/io.h>
#include<linux/device.h>
#include<linux/poll.h>
#include<linux/of.h>
#include<linux/of_gpio.h>
int major;
struct device_node *node;
int gpiono;
int gpiono2;
int gpiono3;
char kbuf[128]={0};
int mycdev_open(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *off)
{
int ret;
//判断kbuf的大小,如果<size,把size的数值修改为kbuf的大小
if(size>sizeof(kbuf))
size=sizeof(kbuf);
ret=copy_to_user(ubuf,kbuf,size);
if(ret)
{
printk("copy_to_user filed\n");
return -EIO;//拷贝失败返回错误码
}
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
ssize_t mycdev_writ