ioctl接口（二）

beep.c

#include<linux/init.h>
#include<linux/module.h>
#include<linux/miscdevice.h>
#include<linux/fs.h>
#include<linux/uaccess.h>
#include<linux/io.h>

#include <linux/ioctl.h>
#include<linux/gpio.h>
#include<linux/of_gpio.h>

#define CMD_TEST0 _IO('L',0)
#define CMD_TEST1 _IO('L',1)

#define CMD_TEST2 _IOW('L',2,int)
#define CMD_TEST3 _IOW('L',3,int)
#define CMD_TEST4 _IOR('L',4,int)
struct device_node *test_device_node;
int ret;
int beep_gpio=0;


int misc_open(struct inode *inode,struct file *file)
{
	printk("hello misc_open\n");
	return 0;
}
int misc_release(struct inode *inode,struct file *file)
{
	printk("hello misc_release bye bye\n");
	return 0;
}
ssize_t misc_read(struct file *file,char __user *ubuf,size_t size,loff_t *loff_t)
{
	char kbuf[64]="heheh";
	if(copy_to_user(ubuf,kbuf,strlen(kbuf))!=0)
	{
		printk("copy_to_user error\n");
		return -1;
	}	
	
	return 0;
}
ssize_t misc_write(struct file *file,char __user *ubuf,size_t size,loff_t *loff_t)
{
	char kbuf[64]={0};
	if(copy_from_user(kbuf,ubuf,size)!=0)
	{
		printk("copy_from_user error\n");
		return -1;
	}	
	printk("kbuf is %s\n",kbuf);
	
	return 0;
}
long misc_ioctl(struct file *file,unsigned int cmd,unsigned long value)
{
	int val;
	
	switch(cmd)
	{
		case CMD_TEST0:
			gpio_set_value(beep_gpio,1);
			printk("LED ON!!\n");
			
			break;
		case CMD_TEST1:
			gpio_set_value(beep_gpio,0);
			printk("LED OFF!!\n");
			
			break;
		case CMD_TEST4:
			val=12;
			if(copy_to_user((int *)value,&val,sizeof(val))!=0)
			{
				printk("copy_from_user error\n");
				return -1;
			}	
			break;
	}
	return 0;
}



struct file_operations misc_fops=
{
	.owner=THIS_MODULE,
	.open = misc_open,
	.release = misc_release,
	.read = misc_read,
	.write = misc_write,
	.unlocked_ioctl = misc_ioctl
};
struct miscdevice misc_dev=
{
	.minor=MISC_DYNAMIC_MINOR,
	.name="hello_misc",
	.fops=&misc_fops
};





static int misc_init(void)
{
	int ret;
	ret=misc_register(&misc_dev);
	if(ret<0)
	{
		printk("misc registe is error\n");
		return -1;
	}
		
	printk("msic registe is succeed\n");
	printk("beep_probe\n");
	test_device_node=of_find_node_by_path("/test");
	if(test_device_node==NULL)
	{
		printk("of_find_node_by_path is error\n");
		return -1;
	}
	
	beep_gpio=of_get_named_gpio(test_device_node,"beep-gpio",0);
	if(beep_gpio<0){
		printk("of_get_named_gpio is error\n");
		return -1;
	}
	printk("beep_gpio is %d\n",beep_gpio);
	ret=gpio_request(beep_gpio,"beep");
	if(ret<0){
		printk("gpio_request is error\n");
		return -1;
	}
	gpio_direction_output(beep_gpio,0);

	
	
	return 0;
}
static void misc_exit(void)
{
	misc_deregister(&misc_dev);
	
	printk("misc byb byb\n");
}
module_init(misc_init);
module_exit(misc_exit);
MODULE_LICENSE("GPL");

ioctl.c

#include<stdio.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>
#include<sys/ioctl.h>


#define CMD_TEST0 _IO('L',0)
#define CMD_TEST1 _IO('L',1)

#define CMD_TEST2 _IOW('L',2,int)
#define CMD_TEST3 _IOW('L',3,int)

#define CMD_TEST4 _IOR('L',4,int)

int main(int argc,char *argv[])
{
	int fd;
	int value;
	
	fd=open("/dev/hello_misc",O_RDWR);
	if(fd<0)
	{
		perror("open error\n");
		return fd;
	}
	while(1)
	{
		ioctl(fd,CMD_TEST0);
		
		sleep(2);
		ioctl(fd,CMD_TEST1);
		
		sleep(2);
	}
	return 0;
}

执行效果图：