• 驱动开发LED灯绑定设备文件

    头文件

    1. #ifndef __HEAD_H__
    2. #define __HEAD_H__
    3.  
    4. typedef struct 
    5. {
    6.     unsigned int MODER;
    7.     unsigned int OTYPER;
    8.     unsigned int OSPEEDR;
    9.     unsigned int PUPDR;
    10.     unsigned int IDR;
    11.     unsigned int ODR;
    12. }gpio_t;
    13.  
    14.  
    15. #define PHY_LED1_ADDR 0x50006000
    16. #define PHY_LED2_ADDR 0x50007000
    17. #define PHY_LED3_ADDR 0x50006000
    18. #define PHY_RCC_ADDR 0x50000A28
    19. #define LED_ON _IOW('l',1,int)
    20. #define LED_OFF _IOW('l',0,int)
    21.  
    22. #endif

    应用程序

    1. #include 
    2. #include 
    3. #include 
    4. #include 
    5. #include 
    6. #include 
    7. #include 
    8. #include 
    9. #include "head.h"
    10. int main(int argc,char const *argv[])
    11. {
    12.     char buf[128]={0};
    13.     int a,b;
    14.     int fd=open("/dev/demo0",O_RDWR);
    15.     if(fd<0)
    16.     {
    17.         printf("打开设备文件失败\n");
    18.         exit(-1);
    19.     }
    20.     while(1)
    21.     {
    22.         //从终端读取
    23.         printf("请输入要实现的功能 ");
    24.         printf("0(关灯) 1(开灯)\n");
    25.         printf("请输入>");
    26.         scanf("%d",&a);
    27.         printf("请选择要控制的灯：1（LED1）2(LED2) 3(LED3)\n");
    28.         printf("请输入>");
    29.         scanf("%d",&b);
    30.         switch(a)
    31.         {
    32.             case 1:
    33.                 ioctl(fd,LED_ON,&b);
    34.                 break;
    35.             case 0:
    36.                 ioctl(fd,LED_OFF,&b);
    37.                 break;
    38.         }
    39.     }
    40.  
    41.     
    42.     close(fd);
    43.  
    44.     return 0;
    45. }

    驱动程序

    1. #include 
    2. #include 
    3. #include 
    4. #include 
    5. #include 
    6. #include 
    7. #include 
    8. #include 
    9. #include "head.h"
    10. unsigned int major=0;
    11. unsigned int minor=0;
    12. char kbuf[128]={};
    13. gpio_t *vir_led1;
    14. gpio_t *vir_led2;
    15. gpio_t *vir_led3;
    16. unsigned int *vir_rcc;
    17. struct cdev *cdev;
    18. dev_t devno;
    19. struct class *cls;
    20. struct device *dev;
    21.  
    22. int mycdev_open(struct inode *inode, struct file *file)
    23. {
    24.     int min=MINOR(inode->i_rdev);
    25.     file->private_data=(void *)min;
    26.     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    27.     return 0;
    28. }
    29.  
    30. long mycdev_ioctl(struct file *file,unsigned int cmd,unsigned long arg)
    31. {
    32.     int min=(int)file->private_data;
    33.     switch (min)
    34.     {
    35.     case 0: // 操作LED1
    36.         switch (cmd)
    37.         {
    38.         case LED_ON: //开灯
    39.             vir_led1->ODR |= (0x1<<10);
    40.             break;
    41.         case LED_OFF://关灯
    42.             vir_led1->ODR &= (~(0x1<<10));
    43.             break;
    44.         }
    45.         break;
    46.     case 1: // 操作LED2
    47.         switch (cmd)
    48.         {
    49.         case LED_ON: //开灯
    50.             vir_led2->ODR |= (0x1<<10);
    51.             break;
    52.         case LED_OFF://关灯
    53.             vir_led2->ODR &= (~(0x1<<10));
    54.             break;
    55.         }
    56.         break;
    57.     case 2: // 操作LED3
    58.         switch (cmd)
    59.         {
    60.         case LED_ON: //开灯
    61.             vir_led3->ODR |= (0x1<<8);
    62.             break;
    63.         case LED_OFF://关灯
    64.             vir_led3->ODR &= (~(0x1<<8));
    65.             break;
    66.         }
    67.         break;
    68.     }
    69.     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    70.     return 0;
    71. }
    72. int mycdev_close(struct inode *inode, struct file *file)
    73. {
    74.     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    75.     return 0;
    76. }
    77.  
    78. struct file_operations fops =
    79. {
    80.     .open=mycdev_open,
    81.     .unlocked_ioctl=mycdev_ioctl,
    82.     .release=mycdev_close,
    83. };
    84.  
    85. int all_led_init(void)
    86. {
    87.     //寄存器地址的映射
    88.     vir_led1=ioremap(PHY_LED1_ADDR,sizeof(gpio_t));
    89.     if(vir_led1==NULL)
    90.     {
    91.         printk("ioremap filed：%d\n",__LINE__);
    92.         return -ENOMEM;
    93.     }
    94.      vir_led2=ioremap(PHY_LED2_ADDR,sizeof(gpio_t));
    95.     if(vir_led2==NULL)
    96.     {
    97.         printk("ioremap filed：%d\n",__LINE__);
    98.         return -ENOMEM;
    99.     }
    100.      vir_led3=vir_led1;
    101.     vir_rcc=ioremap(PHY_RCC_ADDR,4);
    102.     if(vir_rcc==NULL)
    103.     {
    104.         printk("ioremap filed：%d\n",__LINE__);
    105.         return -ENOMEM;
    106.     }
    107.     printk("物理地址映射成功\n");
    108.     //寄存器的初始化
    109.     //rcc
    110.     (*vir_rcc) |= (3<<4);
    111.     //led1
    112.     vir_led1->MODER &= (~(3<<20));
    113.     vir_led1->MODER |= (1<<20);
    114.     vir_led1->ODR &= (~(1<<10));
    115.     //led2
    116.     vir_led2->MODER &= (~(3<<20));
    117.     vir_led2->MODER |= (1<<20);
    118.     vir_led2->ODR &= (~(1<<10));
    119.     //led3
    120.     vir_led3->MODER &= (~(3<<16));
    121.     vir_led1->MODER |= (1<<16);
    122.     vir_led1->ODR &= (~(1<<8));
    123.     printk("寄存器初始化成功\n");
    124.  
    125.     return 0;
    126. }
    127.  
    128. static int __init mycdev_init(void)
    129. {
    130.         //1.申请一个对象空间cdev_alloc
    131.     int ret;
    132.     cdev= cdev_alloc();
    133.     if(cdev==NULL)
    134.     {
    135.         printk("申请字符设备驱动对象失败\n");
    136.         ret=-EFAULT;
    137.         goto out1;
    138.  
    139.     }
    140.     printk("字符设备驱动对象申请成功\n");
    141.     //2.初始化对象cdev_init
    142.     cdev_init(cdev,&fops);
    143.     //3.申请设备号  register_chrdev_region()/alloc_chrdev_region()
    144.     if(major==0)//动态申请
    145.     {
    146.         ret=alloc_chrdev_region(&devno,minor,3,"demo");
    147.         if(ret)
    148.         {
    149.             printk("动态申请设备号失败\n");
    150.             goto out2;
    151.         }
    152.         major=MAJOR(devno);//根据设备号获取主设备号
    153.         minor=MINOR(devno);//根据设备号获取次设备号
    154.     }
    155.     else
    156.     {
    157.         ret=register_chrdev_region(MKDEV(major,minor),3,"demo");
    158.         if(ret)
    159.         {
    160.             printk("静态指定设备号失败\n");
    161.             goto out2;
    162.         }
    163.     }
    164.     printk("设备号申请成功\n");
    165.     //4.注册驱动对象  cdev_add
    166.     ret=cdev_add(cdev,MKDEV(major,minor),3);
    167.     if(ret)
    168.     {
    169.         printk("注册字符设备驱动对象失败\n");
    170.         goto out3;
    171.     }
    172.     printk("注册字符设备驱动对象成功\n");
    173.     //5.向上提交目录  class_create
    174.     cls=class_create(THIS_MODULE,"demo");
    175.     if(IS_ERR(cls))
    176.     {
    177.         printk("向上提交目录失败\n");
    178.         goto out4;
    179.     }
    180.     printk("向上提交目录成功\n");
    181.     //6.向上提交设备节点信息  device_create
    182.     int i;
    183.     for(i=0;i<3;i++)
    184.     {
    185.         dev=device_create(cls,NULL,MKDEV(major,i),NULL,"demo%d",i);
    186.         if(IS_ERR(dev))
    187.         {
    188.             printk("向上提交设备节点失败\n");
    189.             goto out5;
    190.         }
    191.     }
    192.     printk("向上提交设备节点信息成功\n");
    193.     
    194.     all_led_init();
    195.     return 0;
    196. out5:
    197. //将提交成功的节点信息释放
    198.     for(--i;i>=0;i--)
    199.     {
    200.         device_destroy(cls,MKDEV(major,i));
    201.     }
    202.     //销毁目录
    203.     class_destroy(cls);
    204. out4:
    205.     cdev_del(cdev);
    206. out3:
    207.     unregister_chrdev_region(MKDEV(major,minor),3);
    208. out2:
    209.     kfree(cdev);
    210. out1:
    211.     return ret;
    212.  
    213. }
    214. static void __exit mycdev_exit(void)
    215. {
    216.     iounmap(vir_led1);
    217.     iounmap(vir_led2);
    218.     iounmap(vir_rcc);
    219.  
    220. //1.销毁设备节点信息
    221.     int i;
    222.     for(i=0;i<3;i++)
    223.     {
    224.         device_destroy(cls,MKDEV(major,i));
    225.     }
    226.     //2.销毁目录
    227.     class_destroy(cls);
    228.     //3.注销字符设备驱动对象
    229.     cdev_del(cdev);
    230.     //4.释放设备号
    231.     unregister_chrdev_region(MKDEV(major,minor),3);
    232.     //5.释放申请到的字符设备驱动对象空间
    233.     kfree(cdev);
    234. }
    235.  
    236. module_init(mycdev_init);
    237. module_exit(mycdev_exit);
    238. MODULE_LICENSE("GPL");

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  • 原文地址：https://blog.csdn.net/weixin_53373681/article/details/133997687