国嵌内核驱动进阶班-7-1（Ioctl设备控制)--- 测试代码

#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <asm/io.h>
#include <linux/slab.h>
#include <asm/uaccess.h>

#include "memdev.h"

static int mem_major = MEMDEV_MAJOR;

module_param(mem_major, int, S_IRUGO);

struct mem_dev *mem_devp; /*设备结构体指针*/

struct cdev cdev;

/*文件打开函数*/
int mem_open(struct inode *inode, struct file *filp)
{
struct mem_dev *dev;

/*获取次设备号*/
int num = MINOR(inode->i_rdev);

if (num >= MEMDEV_NR_DEVS)
return -ENODEV;
dev = &mem_devp[num];

/*将设备描述结构指针赋值给文件私有数据指针*/
filp->private_data = dev;

return 0;
}

/*文件释放函数*/
int mem_release(struct inode *inode, struct file *filp)
{
return 0;
}

/*IO操作*/
long memdev_ioctl(struct file *filp,
unsigned int cmd, unsigned long arg)
//long (*compat_ioctl) (struct file *filp, unsigned int cmd,
//                         unsigned long arg)
{
printk("<--- memdev_ioctl is call @@@ --->\n\n");

int err = 0;
int ret = 0;
int ioarg = 0;

/* 检测命令的有效性 */
if (_IOC_TYPE(cmd) != MEMDEV_IOC_MAGIC)
return -EINVAL;
if (_IOC_NR(cmd) > MEMDEV_IOC_MAXNR)
return -EINVAL;

/* 根据命令类型，检测参数空间是否可以访问 */
if (_IOC_DIR(cmd) & _IOC_READ)
err = !access_ok(VERIFY_WRITE, (void *)arg, _IOC_SIZE(cmd));
else if (_IOC_DIR(cmd) & _IOC_WRITE)
err = !access_ok(VERIFY_READ, (void *)arg, _IOC_SIZE(cmd));
if (err)
return -EFAULT;

/* 根据命令，执行相应的操作 */
switch(cmd) {

/* 打印当前设备信息 */
case MEMDEV_IOCPRINT:
printk("<--- CMD MEMDEV_IOCPRINT Done--->\n\n");
break;

/* 获取参数 */
case MEMDEV_IOCGETDATA:
ioarg = 1101;
ret = __put_user(ioarg, (int *)arg);
break;

/* 设置参数 */
case MEMDEV_IOCSETDATA:
ret = __get_user(ioarg, (int *)arg);
printk("<--- In Kernel MEMDEV_IOCSETDATA ioarg = %d --->\n\n",ioarg);
break;

default:
return -EINVAL;
}
return ret;

}

/*文件操作结构体*/
static const struct file_operations mem_fops =
{
.owner = THIS_MODULE,
.open = mem_open,
.release = mem_release,
.unlocked_ioctl = memdev_ioctl,
};

/*设备驱动模块加载函数*/
static int memdev_init(void)
{
int result;
int i;

dev_t devno = MKDEV(mem_major, 0);

/* 静态申请设备号*/
if (mem_major)
result = register_chrdev_region(devno, 2, "memdev");
else  /* 动态分配设备号 */
{
result = alloc_chrdev_region(&devno, 0, 2, "memdev");
mem_major = MAJOR(devno);
}

if (result < 0)
return result;

/*初始化cdev结构*/
cdev_init(&cdev, &mem_fops);
cdev.owner = THIS_MODULE;
cdev.ops = &mem_fops;

/* 注册字符设备 */
cdev_add(&cdev, MKDEV(mem_major, 0), MEMDEV_NR_DEVS);

/* 为设备描述结构分配内存*/
mem_devp = kmalloc(MEMDEV_NR_DEVS * sizeof(struct mem_dev), GFP_KERNEL);
if (!mem_devp)    /*申请失败*/
{
result =  - ENOMEM;
goto fail_malloc;
}
memset(mem_devp, 0, sizeof(struct mem_dev));

/*为设备分配内存*/
for (i=0; i < MEMDEV_NR_DEVS; i++)
{
mem_devp[i].size = MEMDEV_SIZE;
mem_devp[i].data = kmalloc(MEMDEV_SIZE, GFP_KERNEL);
memset(mem_devp[i].data, 0, MEMDEV_SIZE);
}

return 0;

fail_malloc:
unregister_chrdev_region(devno, 1);

return result;
}

/*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);

#ifndef _MEMDEV_H_
#define _MEMDEV_H_

#include <linux/ioctl.h>

#ifndef MEMDEV_MAJOR
#define MEMDEV_MAJOR 0   /*预设的mem的主设备号*/
#endif

#ifndef MEMDEV_NR_DEVS
#define MEMDEV_NR_DEVS 2    /*设备数*/
#endif

#ifndef MEMDEV_SIZE
#define MEMDEV_SIZE 4096
#endif

/*mem设备描述结构体*/
struct mem_dev
{
char *data;
unsigned long size;
};

/* 定义幻数 */
#define MEMDEV_IOC_MAGIC  'k'

/* 定义命令 */
#define MEMDEV_IOCPRINT   _IO(MEMDEV_IOC_MAGIC, 1)
#define MEMDEV_IOCGETDATA _IOR(MEMDEV_IOC_MAGIC, 2, int)
#define MEMDEV_IOCSETDATA _IOW(MEMDEV_IOC_MAGIC, 3, int)

#define MEMDEV_IOC_MAXNR 3

#endif /* _MEMDEV_H_ */

ifneq ($(KERNELRELEASE),)

obj-m := memdev.o

else

KDIR := /home/rpi/RpiLinux
all:
make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=/home/rpi/RpiTools/arm-bcm2708/arm-bcm2708hardfp-linux-gnueabi/bin/arm-bcm2708hardfp-linux-gnueabi-

clean:
rm -f *.ko *.o *.mod.o *.mod.c *.symvers  modul*

endif

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

#include "memdev.h"  /* 包含命令定义 */

int main()
{
int fd = 0;
int cmd;
int arg = 0;
char Buf[4096];

/*打开设备文件*/
fd = open("/dev/memdev0",O_RDWR);
if (fd < 0)
{
printf("Open Dev Mem0 Error!\n");
return -1;
}

/* 调用命令MEMDEV_IOCPRINT */
printf("<--- Call MEMDEV_IOCPRINT --->\n");
cmd = MEMDEV_IOCPRINT;
if (ioctl(fd, cmd, &arg) < 0)
{
printf("Call cmd MEMDEV_IOCPRINT fail\n");
return -1;
}

/* 调用命令MEMDEV_IOCSETDATA */
printf("<--- Call MEMDEV_IOCSETDATA --->\n");
cmd = MEMDEV_IOCSETDATA;
arg = 2007;
if (ioctl(fd, cmd, &arg) < 0)
{
printf("Call cmd MEMDEV_IOCSETDATA fail\n");
return -1;
}

/* 调用命令MEMDEV_IOCGETDATA */
printf("<--- Call MEMDEV_IOCGETDATA --->\n");
cmd = MEMDEV_IOCGETDATA;
if (ioctl(fd, cmd, &arg) < 0)
{
printf("Call cmd MEMDEV_IOCGETDATA fail\n");
return -1;
}
printf("<--- In User Space MEMDEV_IOCGETDATA Get Data is %d --->\n\n",arg);

close(fd);
return 0;
}

1 pi@raspberrypi ~/test_driver $ sudo ./a.out
2 <--- Call MEMDEV_IOCPRINT --->
3 <--- Call MEMDEV_IOCSETDATA --->
4 <--- Call MEMDEV_IOCGETDATA --->
5 <--- In User Space MEMDEV_IOCGETDATA Get Data is 1101 --->
6
7 pi@raspberrypi ~/test_driver $ sudo dmesg
8 [ 1382.384123] <--- memdev_ioctl is call @@@ --->
9 [ 1382.384123]
10 [ 1382.384158] <--- CMD MEMDEV_IOCPRINT Done--->
11 [ 1382.384158]
12 [ 1382.384541] <--- memdev_ioctl is call @@@ --->
13 [ 1382.384541]
14 [ 1382.384565] <--- In Kernel MEMDEV_IOCSETDATA ioarg = 2007 --->
15 [ 1382.384565]
16 [ 1382.384816] <--- memdev_ioctl is call @@@ --->
17 [ 1382.384816]