《Linux驱动》GPIO配置并操作Led

驱动代码：

#include 
#include 

/*驱动注册的头文件，包含驱动的结构体和注册和卸载的函数*/
#include 
/*注册杂项设备头文件*/
#include 
/*注册设备节点的文件结构体*/
#include 

/*Linux中申请GPIO的头文件*/
#include 
/*三星平台的GPIO配置函数头文件*/
/*三星平台EXYNOS系列平台，GPIO配置参数宏定义头文件*/
#include 
#include 
/*三星平台4412平台，GPIO宏定义头文件*/
#include 

#define DRIVER_NAME "hello_ctl"
#define DEVICE_NAME "hello_ctl"


MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("HerGhost");

static long hello_ioctl( struct file *files, unsigned int cmd, unsigned long arg){
    printk("cmd is %d,arg is %d\n",cmd,arg);

    if(cmd > 1){
        printk(KERN_EMERG "cmd is 0 or 1\n");
    }
    if(arg > 1){
        printk(KERN_EMERG "arg is only 1\n");
    }

    gpio_set_value(EXYNOS4_GPL2(0),cmd);

    return 0;
}

static int hello_release(struct inode *inode, struct file *file){
    printk(KERN_EMERG "hello release\n");
    return 0;
}

static int hello_open(struct inode *inode, struct file *file){
    printk(KERN_EMERG "hello open\n");
    return 0;
}

static struct file_operations hello_ops = {
    .owner = THIS_MODULE,
    .open = hello_open,
    .release = hello_release,
    .unlocked_ioctl = hello_ioctl,
};

static  struct miscdevice hello_dev = {
    .minor = MISC_DYNAMIC_MINOR,
    .name = DEVICE_NAME,
    .fops = &hello_ops,
};


static int hello_probe(struct platform_device *pdv){
    int ret;

    printk(KERN_EMERG "\tinitialized\n");

    ret = gpio_request(EXYNOS4_GPL2(0),"LEDS");//申请GPIO
    if(ret < 0){
        printk(KERN_EMERG "gpio_request EXYNOS4_GPL2(0) failed!\n");
        return ret;
    }

    s3c_gpio_cfgpin(EXYNOS4_GPL2(0),S3C_GPIO_OUTPUT);//配置GPIO输出输入等模式

    gpio_set_value(EXYNOS4_GPL2(0),0);//设置GPIO的电平

    misc_register(&hello_dev);

    return 0;
}

static int hello_remove(struct platform_device *pdv){

    printk(KERN_EMERG "\tremove\n");
    misc_deregister(&hello_dev);
    return 0;
}

static void hello_shutdown(struct platform_device *pdv){

    ;
}

static int hello_suspend(struct platform_device *pdv,pm_message_t pmt){

    return 0;
}

static int hello_resume(struct platform_device *pdv){

    return 0;
}

struct platform_driver hello_driver = {
    .probe = hello_probe,
    .remove = hello_remove,
    .shutdown = hello_shutdown,
    .suspend = hello_suspend,
    .resume = hello_resume,
    .driver = {
        .name = DRIVER_NAME,
        .owner = THIS_MODULE,
    }
};


static int hello_init(void)
{
    int DriverState;

    printk(KERN_EMERG "HELLO WORLD enter!\n");
    DriverState = platform_driver_register(&hello_driver);

    printk(KERN_EMERG "\tDriverState is %d\n",DriverState);
    return 0;
}


static void hello_exit(void)
{
    printk(KERN_EMERG "HELLO WORLD exit!\n");

    platform_driver_unregister(&hello_driver);  
}

module_init(hello_init);
module_exit(hello_exit);

调用驱动的C代码：

#include 

#include 
#include 
#include 
#include 
#include 

main(){
    int fd;
    char *hello_node = "/dev/hello_ctl";

/*O_RDWR只读打开,O_NDELAY非阻塞方式*/    
    if((fd = open(hello_node,O_RDWR|O_NDELAY))<0){
        printf("APP open %s failed",hello_node);
    }
    else{
        printf("APP open %s success",hello_node);
        ioctl(fd,1,1);
        sleep(3);
        ioctl(fd,0,1);
        sleep(3);
        ioctl(fd,1,1);
    }

    close(fd);
}