文字駆動サンプルプログラム【駆動:例6-3.call_dev.c】【適用:例6-4.call_app】

文字駆動call_dev.c
 

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/fcntl.h>

#define CALL_DEV_NAME "calldev"
#define CALL_DEV_MAJOR  240


int call_open(struct inode *inode, struct file *filp)
{	
	int num = MINOR(inode->i_rdev);

	printk("call open->minor : %d 
", num);

	return 0;
}

loff_t call_llseek(struct file *filp, loff_t off, int whence)
{
	printk("call llseek->off: %08x, whence:%08x 
", off, whence);
	return 0x23;
}

ssize_t call_read(struct file *filp, char *buf, size_t count, loff_t *fops)
{
	printk("call read->buf:%08x, count:%08x 
",buf, count);
	return 0x33;
}

ssize_t call_write(struct file *filp, const char *buf,size_t count, loff_t *f_ops)
{
	printk("call write->buf:%08x, count:%08x 
",buf, count);
	return 0x43;
}

int call_ioctl(struct file *filp,unsigned int cmd, unsigned long arg)
{
	printk("call ioctl->cmd: %08x, arg:%08x 
",cmd,arg);
	return 0x53;
}

int call_release(struct inode *inode,struct file *filp)
{
	printk("call release 
");
	return 0;
}

struct file_operations call_fops =
{
	.owner	= THIS_MODULE,
	.llseek	= call_llseek,
	.read	= call_read,
	.write	= call_write,
	.unlocked_ioctl = call_ioctl,
	.open 	= call_open,
	.release	= call_release,
};


int call_init(void)
{
	int result;

	printk("call call_init 
");

	result = register_chrdev(CALL_DEV_MAJOR, CALL_DEV_NAME,&call_fops);

	if(result <0)
		return result;

	return 0;
}

void call_exit(void)
{
	printk("call call_exit 
");
	unregister_chrdev(CALL_DEV_MAJOR, CALL_DEV_NAME);
}

module_init(call_init);
module_exit(call_exit);

MODULE_LICENSE("Dual BSD/GPL");

テスト用アプリケーションcall_app.c:
 

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

#define DEVICE_FILENAME "/dev/calldev"

int main()
{
	int dev;
	char buff[128];
	int ret;

	printf("1) device file open 
");
	dev = open(DEVICE_FILENAME, O_RDWR|O_NDELAY);

	if(dev >= 0)
	{
		printf("2) seek function call 
");

		ret = lseek(dev, 0x20, SEEK_SET);
		printf("ret = %08X 
", ret);
	}

	printf("3) read function call 
");
	ret = read(dev, 0x30, 0x31);
	printf("ret = %08X 
", ret);


	printf("4) write function call 
");
	ret = write(dev, 0x40, 0x41);
	printf("ret = 0x08X 
",ret);


	printf("5) ioctl function call 
");
	ret = ioctl(dev, 0x51, 0x52);
	printf("ret = %08X
" , ret);

	printf("6) device file close 
");
	ret = close(dev);
	printf("ret = %08X 
", ret);

	return 0;
}

実行結果:
root@xiangpingli:/home/linux/study/6.4# insmod call_dev.ko root@xiangpingli:/home/linux/study/6.4# mknod/dev/calldev c 240 32 root@xiangpingli:/home/linux/study/6.4# ./call_app 1) device file open 2) seek function call ret = 00000023 3) read function call ret = 00000033 4) write function call ret = 00000043 5) ioctl function call ret = 00000053 6) device file close ret = 00000000 root@xiangpingli:/home/linux/study/6.4# dmesg [ 2309.523091] call call_init [ 2329.501102] call open->minor : 32 [ 2329.501113] call llseek->off: 00000020, whence:00000000 [ 2329.501151] call read->buf:00000030, count:00000031 [ 2329.501158] call write->buf:00000040, count:00000041 [ 2329.501170] call ioctl->cmd: 00000051, arg:00000052 [ 2329.501178] call release root@xiangpingli:/home/linux/study/6.4#