GPIO핀을 JNI를 통해 ioctl로 컨트롤하려고 합니다

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/gpio.h>
 
static ssize_t d3_gpio_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
return 0;
}
 
static ssize_t d3_gpio_write(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
return 0;
}
 
 
static long d3_gpio_ioctl (struct file *file, unsigned int cmd, unsigned long arg)
{
	int val = -1;
	printk("[] d3_gpio_ioctl cmd(%d) arg(%d) \n", cmd, arg);
	switch(cmd)
	{
		case 1: //read
			val = gpio_get_value(D3_GPIO4);
			printk("[] ioctl read... GPIO4 is %d \n",val);
			return val;
 
		case 2: //write
			if(arg == 1)
			{
				gpio_set_value(D3_GPIO4, 1); //High
				printk("[] ioctl write... GPIO4 Set to HIGH.");
			}
			else if(arg == 0)
			{
				gpio_set_value(D3_GPIO4, 0); //Low
				printk("[] ioctl write... GPIO4 Set to LOW. ");
			}
			break;
 
		default:
			printk("[] ioctl unknown command...\n");
			break;
	}
	return 0;
}
 
static int d3_gpio_open(struct inode *inode, struct file *file)
{
	return 0;
}
static int d3_gpio_release(struct inode *inode, struct file *file)
{
	return 0;
}
 
static const struct file_operations d3_gpio_fops = {
	.owner = THIS_MODULE,
	.read = d3_gpio_read,
	.write = d3_gpio_write,
	.unlocked_ioctl = d3_gpio_ioctl,
	.open = d3_gpio_open,
	.release = d3_gpio_release,
};
 
static struct miscdevice d3_gpio_dev = {
	.minor		= MISC_DYNAMIC_MINOR,
	.name		= "d3gpio",
	.fops		= &d3_gpio_fops,
};
 
static int __init d3_gpio_init(void)
{
     printk("[] d3_gpio_init\n");
	return misc_register(&d3_gpio_dev);
}
 
static void __exit d3_gpio_exit(void)
{
	misc_deregister(&d3_gpio_dev);
}
 
module_init(d3_gpio_init);
module_exit(d3_gpio_exit);
 
MODULE_DESCRIPTION("D3 GPIO driver");
MODULE_LICENSE("GPL");

#include "jni.h"
#include "nativeClass.h"
#include <stdio.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <android/log.h>
 
JNIEXPORT void JNICALL Java_com_example_android_navigationdrawerexample_nativeClass_init(JNIEnv *env, jobject obj)
{
	int dev = 0;
	int ret = 0;
 
    dev = open("/dev/d3gpio", O_RDWR);
    if(dev < 0)
    	 LOGE("gpio open fail : %d \n", dev);
 
    ret = ioctl(dev, 0x2, 0x1);
    LOGE("ioctl result : %d \n", ret);
 
    close(dev);
    return;
}