代码示例_ioctl

//头文件

#include <linux/init.h>

#include

#include

#include

#include

#include

#include

#include

#define LED_NUM_ON        _IOW('L',0x1122,int)

#define LED_NUM_OFF        _IOW('L',0x3344,int)

#define LED_ALL_ON        _IO('L',0x1234)

#define LED_ALL_OFF        _IO('L',0x5678)

//面向对象编程----设计设备的类型

struct s5pv210_led{

    unsigned int major;

    struct class * cls;

    struct device * dev;

    int data;

};

struct s5pv210_led *led_dev;

volatile unsigned long *gpco_conf;

volatile unsigned long *gpco_data;

//实现设备操作接口

int led_open(struct inode *inode, struct file *filp)

{

    printk('--------^_^ %s------------n',__FUNCTION__);

    //将对应的管脚设置为输出

    *gpco_conf &= ~(0xff<<12);   //19--12清0

    *gpco_conf |= 0x11<<12;        //19---12赋值:00010001

    return 0;

}

ssize_t led_write(struct file *filp, const char __user *buf, size_t size, loff_t *flags)

{

    int ret;

    printk('--------^_^ %s------------n',__FUNCTION__);

    //应用空间数据转换为内核空间数据

    ret = copy_from_user(&led_dev->data,buf,size);

    if(ret != 0){

        printk('copy_from_user error!n');

        return -EFAULT;

    }

    if(led_dev->data){

        //点灯

        *gpco_data |= 0x3<<3;

    }else{

        //灭灯

        *gpco_data &= ~(0x3<<3);

    }

    return size;

}

long led_ioctl(struct file *filp, unsigned int cmd , unsigned long args)

{

    int num = args+2;

    printk('--------^_^ %s------------n',__FUNCTION__);

    switch(cmd){

        case LED_NUM_ON:        //将某个灯点亮

            if(num != 3 && num != 4)

                return -EINVAL;

            else

                *gpco_data |= 0x1 << num;

            break;

        case LED_NUM_OFF:        //将某个灯点灭掉

            if(num != 3 && num != 4)

                return -EINVAL;

            else

                *gpco_data &= ~(0x1 << num);

            break;

        case LED_ALL_ON:        //两个灯同时亮

            *gpco_data |= 0x3<<3;

            break;

        case LED_ALL_OFF:        //两个灯同时灭

            *gpco_data &= ~(0x3<<3);

            break;

        default:

            printk('unknow cmd!n');

    }

    return 0;

}

int led_close(struct inode *inode, struct file *filp)

{

    printk('--------^_^ %s------------n',__FUNCTION__);

    //灭灯

        *gpco_data &= ~(0x3<<3);

    return 0;

}

static struct file_operations fops = {

    .open = led_open,

    .write = led_write,

    .unlocked_ioctl = led_ioctl,

    .release = led_close,

};

//加载函数和卸载函数

static int __init led_init(void)   //加载函数-----在驱动被加载时执行

{

    int ret;

    printk('--------^_^ %s------------n',__FUNCTION__);

    //0,实例化设备对象

    //参数1 ---- 要申请的空间的大小

    //参数2 ---- 申请的空间的标识

    led_dev = kzalloc(sizeof(struct s5pv210_led),GFP_KERNEL);

    if(IS_ERR(led_dev)){

        printk('kzalloc error!n');

        ret = PTR_ERR(led_dev);

        return -ENOMEM;

    }

    //1,申请设备号

#if 0

    //静态申请主设备号

    led_dev->major = 256;

    ret = register_chrdev(led_dev->major,'led_drv',&fops);

    if(ret < 0){

        printk('register_chrdev error!n');

        return -EINVAL;

    }

#else

    //动态申请主设备号

    led_dev->major = register_chrdev(0,'led_drv',&fops);

    if(led_dev->major < 0){

        printk('register_chrdev error!n');

        ret =  -EINVAL;

        goto err_kfree;

    }

#endif

    //2,创建设备文件-----/dev/led1

    led_dev->cls = class_create(THIS_MODULE,'led_cls');

    if(IS_ERR(led_dev->cls)){

        printk('class_create error!n');

        ret = PTR_ERR(led_dev->cls);

        goto err_unregister;

    }

    led_dev->dev = device_create(led_dev->cls,NULL,MKDEV(led_dev->major,0),NULL,'led');

    if(IS_ERR(led_dev->dev)){

        printk('device_create error!n');

        ret = PTR_ERR(led_dev->dev);

        goto err_class;

    }

    //3,硬件初始化----地址映射

        gpco_conf = ioremap(0xE0200060,8);

        gpco_data = gpco_conf+1;

    return 0;

err_class:

    class_destroy(led_dev->cls);

err_unregister:

    unregister_chrdev(led_dev->major,'led_drv');

err_kfree:

    kfree(led_dev);

    return ret;

}

static void __exit led_exit(void)   //卸载函数-----在驱动被卸载时执行

{

    printk('--------^_^ %s------------n',__FUNCTION__);

    device_destroy(led_dev->cls,MKDEV(led_dev->major,0));

    class_destroy(led_dev->cls);

    unregister_chrdev(led_dev->major,'led_drv');

    kfree(led_dev);

}

//声明和认证

module_init(led_init);

module_exit(led_exit);

MODULE_LICENSE('GPL');

#include

#include

#include

#include

#include

#include

#include

#define LED_NUM_ON        _IOW('L',0x1122,int)

#define LED_NUM_OFF        _IOW('L',0x3344,int)

#define LED_ALL_ON        _IO('L',0x1234)

#define LED_ALL_OFF        _IO('L',0x5678)

int main(void)

{

    int fd;

    fd = open('/dev/led',O_RDWR);

    if(fd < 0){

    perror('open');

    exit(1);

    }

    //闪灯

    while(1){

    //第一个灯闪

    ioctl(fd,LED_NUM_ON,1);

    sleep(1);

    ioctl(fd,LED_NUM_OFF,1);

    sleep(1);

    //第二个灯闪

    ioctl(fd,LED_NUM_ON,2);

    sleep(1);

    ioctl(fd,LED_NUM_OFF,2);

    sleep(1);

    //两个灯同时闪

    ioctl(fd,LED_ALL_ON);

    sleep(1);

    ioctl(fd,LED_ALL_OFF);

    sleep(1);

    }

    close(fd);

    return 0;

}

#指定内核源码路径

KERNEL_DIR = /home/farsight/s5pv210/kernel/linux-3.0.8

CUR_DIR = $(shell pwd)

MYAPP = test

all:

    #让make进入内核源码编译，同时将当前目录中的c程序作为内核模块一起编译

    make -C $(KERNEL_DIR) M=$(CUR_DIR) modules

    arm-none-linux-gnueabi-gcc -o $(MYAPP) $(MYAPP).c

clean:

    #删除上面编译生成的文件

    make -C $(KERNEL_DIR) M=$(CUR_DIR) clean

    rm -rf $(MYAPP)

install:

    cp *.ko $(MYAPP) /opt/rootfs/drv_module

#指定当前目录下哪个文件作为内核模块编

obj-m = led_drv.o