10.20

.ko

#include 
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#include 
#include 
#include 
#include 
#include 
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#include
#include
#include
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#include
#include
#include
#define CNAME  "myzhondduan"
 
struct resource *res;
//定义队列头
wait_queue_head_t wq_head;
unsigned int condition=0;//判断是否有数据准备好的标识变量
//定义一个指向设备节点的指针
struct device_node *node1;
struct property *pr1;//属性结构体指针
struct gpio_desc *desc;
/*myleds{
     led1=<&gpioe 10 0>; //&gpioe表示引用的是gpioe控制器 //10表示gpioe10
     //0表示默认状态
     led2=<&gpiof 10 0>; 
     led3=<&gpioe 8 0>; 
 };    */
 
//定义一个指向设备节点的指针
struct device_node *node;
struct property *pr;//属性结构体指针
int gpiono1;
 
/*  myirq{
        interrupt-parent=<&gpiof>;
        interrupts=<7 0>, <8 0>,<9 0>;
    };
*/
struct device_node *node;
unsigned int irqno;//接收软中断号
char count = '0';
 
int major;//定义变量接收主设备号
char kbuf[128]={};//定义数组用于存放和用户之间拷贝的数据
struct class *cls;//句柄
struct device *dev;
 
//中断处理函数
irqreturn_t irq_handler(int irq, void *dev)
{
   if(count == '0')
        count = '1';
    else
        count = '0';
    kbuf[0] = count;
    //电位反转
    gpiod_set_value(desc,!gpiod_get_value(desc));
    //唤醒 
    condition=1;
    wake_up_interruptible(&wq_head);  
    return IRQ_HANDLED;
}
 
int pdrv_probe(struct platform_device *pdr)
 {
        //获取设备信息
       printk("%s:%d\n",__FILE__,__LINE__);
       res=platform_get_resource(pdr,IORESOURCE_MEM,0);
       if(res==NULL)
       {
            printk("获取资源失败\n");
            return -ENODATA;
       }
       irqno=platform_get_irq(pdr,0);
       if(irqno<0)
       {
             printk("获取资源失败\n");
             return irqno;
       }
     printk("%#x    %d\n",res->start,irqno);
     //获取GPIO编号
     desc=gpiod_get_from_of_node(pdr->dev.of_node,"led1",0,GPIOD_OUT_HIGH,NULL);
     if(IS_ERR(desc))
     {
      printk("获取GPIO编号失败\n");
      return PTR_ERR(desc);
     }
       return 0;
 }
 int pdrv_remove(struct platform_device *pdr)
 {
       printk("%s:%d\n",__FILE__,__LINE__);
       return 0;
 }
 //定义compatible表
 struct of_device_id oftable[]={
      {.compatible="hqyj,platform"},
      {},
 };
MODULE_DEVICE_TABLE(of,oftable);
//定义并初始化对象
struct platform_driver pdrv ={
      .probe=pdrv_probe,
      .remove=pdrv_remove,
      .driver={
          .name= "test",
          .of_match_table= oftable,//设备树匹配 
      },
 };
 
//对应的是open()
int mycdev_open(struct inode *inode, struct file *file)
{
      printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
      return 0;
}
//read()
ssize_t mycdev_read(struct file *   file, char __user *ubuf, size_t size, loff_t *loff)
{
    //size参数是用户期待读到的字节长度
    int ret;
    if(file->f_flags&O_NONBLOCK)
    {
        //非阻塞
        return -EINVAL;
    }
    else{
        //阻塞
        ret=wait_event_interruptible(wq_head,condition);
        if(ret)
        {
            printk("接收阻塞休眠\n");
            return ret;
        }
    }
    //把内核里的数据拷贝给用户
    if(size>sizeof(kbuf))
    size=sizeof(kbuf);
    ret=copy_to_user(ubuf,kbuf,size);
    if(ret)
    {
        printk("数据从内核向用户拷贝失败\n");
        return -EIO;
    }
    //condition=0;
    condition=0;
     
       return size;
}
//write()
ssize_t mycdev_write(struct file *file, const char __user *ubuf, size_t size, loff_t *loff)
{
    int ret;
    if(size>sizeof(kbuf))
    size=sizeof(kbuf);
    ret=copy_from_user(kbuf,ubuf,size);
    if(ret)
    {
        printk("数据从内核向用户拷贝失败\n");
        return -EIO;
    }
       return size;
}
//close()
int mycdev_close(struct inode *inode, struct file *file)
{
      printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
       return 0;
}
//操作方法结构体的初始化
struct file_operations fops=
{
    .open=mycdev_open,
    .read=mycdev_read,
    .write=mycdev_write,
    .release=mycdev_close,
};
//入口函数，当驱动安装的时候执行
static int __init demo_init(void)
{
     int ret;
     //注册对象
    platform_driver_register(&pdrv);
    //动态注册字符设备驱动
    major=register_chrdev(0,CNAME,&fops);
    if(major<0)
    {
        printk("字符设备驱动注册失败\n");
        return major;
    }
    printk("字符设备驱动注册成功major=%d\n",major);
    //向上提交节点目录
    cls=class_create(THIS_MODULE,"ZD");
    if(IS_ERR(cls))
    {
        printk("向上提交目录失败\n");
        return PTR_ERR(cls);
    }
     printk("向上提交目录成功\n");
     //创建设备节点
     dev=device_create(cls,NULL,MKDEV(major,0),NULL,"myshebeishu");
     if(IS_ERR(dev))
     {
        printk("创建节点失败\n");
        return PTR_ERR(dev);
     }
     printk("创建节点成功\n");
 
    //注册中断
    ret=request_irq(irqno,irq_handler,IRQF_TRIGGER_FALLING,"key2_inte",NULL);
    if(ret)
    {
        printk("注册中断失败\n");
        return ret;
    }
    printk("注册中断成功\n");
 
 
  //初始化对头
  init_waitqueue_head(&wq_head);
    return 0;
}
 
//出口函数，卸载驱动的时候执行
static void __exit demo_exit(void)
{
    //注销
    platform_driver_unregister(&pdrv);
    //销毁节点
    device_destroy(cls,MKDEV(major,0));
    //销毁目录
    class_destroy(cls);
    //注销字符设备驱动
    unregister_chrdev(major,CNAME);
    //注销中断
    free_irq(irqno,NULL);
    //释放GPIO编号
    gpiod_set_value(desc,0);
    gpiod_put(desc);
   
}
module_init(demo_init);
module_exit(demo_exit);
MODULE_LICENSE("GPL");

.c

#include
#include
#include
#include
#include
#include
#include
#include 
 
int main(int argc, char const *argv[])
{
    char buf[128]={};
    int fd=open("/dev/myshebeishu",O_RDWR);
    if(fd<0)
    {
 
        printf("设备文件打开失败\n");
        exit(-1);
    }
    printf("设备文件打开成功\n");
    while(1)
    {
        read(fd,buf,sizeof(buf));
        printf("%s\n",buf);
    }
    close(fd);
    return 0;
}