• 底层驱动day4作业

    分布注册设备，实现文件和设备的绑定

    代码：

    1. //head.h
    2. #ifndef __HEAD_H__
    3. #define __HEAD_H__
    4. #define PHY_RCC 0x50000A28
    5. #define PHY_GPIOE_MODER 0x50006000
    6. #define PHY_GPIOF_MODER 0x50007000
    7. #define PHY_GPIOE_ODR 0x50006014
    8. #define PHY_GPIOF_ODR 0x50007014
    9.  
    10. typedef struct 
    11. {
    12.     unsigned int MODER;
    13.     unsigned int OTYPER;
    14.     unsigned int OSPEEDR;
    15.     unsigned int PUPDR;
    16.     unsigned int IDR;
    17.     unsigned int ODR;
    18. }gpio_t;
    19.  
    20. #define GPIOE 0x50006000
    21. #define GPIOF 0x50007000
    22. #define PHY_RCC_ADDR 0x50000A28
    23. #define LED_ON _IOW('l',1,int)
    24. #define LED_OFF _IOW('l',0,int)
    25.  
    26.  
    27. #endif
    1. //mycdev.c
    2. #include<linux/init.h>
    3. #include<linux/module.h>
    4. #include<linux/io.h>
    5. #include<linux/device.h>
    6. #include<linux/fs.h>
    7. #include<linux/cdev.h>
    8. #include<linux/uaccess.h>
    9. #include<linux/slab.h>
    10. #include"include/head.h"
    11. unsigned int major = 0,minor = 0;
    12. dev_t devno;
    13. struct class *cls;
    14. struct cdev* cdev;
    15. struct device *dev;
    16. gpio_t *vir_led1;
    17. gpio_t *vir_led2;
    18.  
    19. unsigned int *vir_rcc;
    20.  
    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:
    36.             switch(cmd)
    37.             {
    38.                 case LED_OFF:
    39.                     vir_led1->ODR &= (~(0x1 << 10));
    40.                     break;
    41.                 case LED_ON:
    42.                     vir_led1->ODR |= (0x1 << 10);
    43.                     break;
    44.             }
    45.             break;
    46.         case 1:
    47.             switch(cmd)
    48.             {
    49.                 case LED_OFF:
    50.                     vir_led2->ODR &= (~(0x1 << 10));
    51.                     break;
    52.                 case LED_ON:
    53.                     vir_led2->ODR |= (0x1 << 10);
    54.                     break;
    55.             }
    56.             break;
    57.         case 2:
    58.             switch(cmd)
    59.             {
    60.                 case LED_OFF:
    61.                     vir_led1->ODR &= (~(0x1 << 8));
    62.                     break;
    63.                 case LED_ON:
    64.                     vir_led1->ODR |= (0x1 << 8);
    65.                     break;
    66.             }
    67.             break;
    68.         default:
    69.             break;
    70.     }
    71.     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    72.     return 0;
    73. }
    74.  
    75. int mycdev_close(struct inode *inode,struct file *file)
    76. {
    77.     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    78.     return 0;
    79. }
    80.  
    81. int all_led_init(void)
    82. {
    83.     vir_led1 = ioremap(GPIOE,sizeof(gpio_t));
    84.     if(NULL == vir_led1)
    85.     {
    86.         printk("ioremap failed : %d\n",__LINE__);
    87.         return -ENOMEM;
    88.     }
    89.     vir_led2 = ioremap(GPIOF,sizeof(gpio_t));
    90.     if(NULL == vir_led2)
    91.     {
    92.         printk("ioremap failed : %d\n",__LINE__);
    93.         return -ENOMEM;
    94.     } 
    95.     vir_rcc = ioremap(PHY_RCC,4);
    96.     if(NULL == vir_rcc)
    97.     {
    98.         printk("ioremap failed : %d\n",__LINE__);
    99.         return -ENOMEM;
    100.     }
    101.     
    102.     printk("寄存器内存映射成功\n");
    103.     (*vir_rcc) |= (0x1 << 4);
    104.     (*vir_rcc) |= (0x1 << 5);
    105.     (vir_led1->MODER) &= (~(0x3 << 20));    //led1_moder
    106.     (vir_led1->MODER) |= (0x1 << 20);
    107.     (vir_led1->MODER) &= (~(0x3 << 16));    //led3_moder
    108.     (vir_led1->MODER) |= (0x1 << 16);
    109.     (vir_led1->ODR) &= (~(0x1 << 10));      //led1_odr
    110.     (vir_led1->ODR) &= (~(0x1 << 8));      //led3_odr
    111.     (vir_led2->MODER) &= (~(0x3 << 20));    //led2_moder
    112.     (vir_led2->MODER) |= (0x1 << 20);
    113.     (vir_led2->ODR) &= (~(0X1 << 10));      //led2_odr
    114.     return 0;
    115. }
    116.  
    117. struct file_operations fops = {
    118.     .open = mycdev_open,
    119.     .unlocked_ioctl = mycdev_ioctl,
    120.     .release = mycdev_close,
    121. };
    122.  
    123. static int __init mycdev_init(void)
    124. {
    125.     int ret;
    126.     all_led_init();
    127.     //申请对象空间
    128.     cdev = cdev_alloc();
    129.     if(NULL == cdev)
    130.     {
    131.         printk("申请字符设备驱动对象空间失败\n");
    132.         ret = -EFAULT;
    133.         goto out;
    134.     }
    135.     printk("申请字符设备驱动对象空间成功\n");   
    136.     //初始化对象
    137.     cdev_init(cdev,&fops);
    138.     //申请设备号
    139.     
    140.     if(0 == major)
    141.     {
    142.         ret = alloc_chrdev_region(&devno,0,3,"mychrdev");
    143.         if(0 != ret)
    144.         {
    145.             printk("动态申请设备号失败\n");
    146.             goto out2;
    147.         }
    148.         major = MAJOR(devno);
    149.         minor = MINOR(devno);
    150.     }
    151.     else
    152.     {
    153.         ret = register_chrdev_region(MKDEV(major,minor),3,"mychrdev");
    154.         if(0 != ret)
    155.         {
    156.             printk("静态申请设备号失败\n");
    157.             goto out2;
    158.         }
    159.     }
    160.     printk("申请设备号成功\n");
    161.     
    162.         
    163.     //注册驱动对象
    164.     int ret2 = cdev_add(cdev,devno,3);
    165.     if(0 != ret2)
    166.     {
    167.         printk("注册驱动对象失败\n");
    168.         goto out3;
    169.     }
    170.     printk("注册字符设备驱动对象成功\n");
    171.     //向上提交目录
    172.     cls = class_create(THIS_MODULE,"mychrdev");
    173.     if(IS_ERR(cls))
    174.     {
    175.         printk("向上提交目录失败\n");
    176.         goto out4;
    177.     }
    178.     printk("向上提交目录成功\n");
    179.     //向上提交设备节点信息
    180.     int i;
    181.     for(i = 0;i < 3;i++)
    182.     {
    183.         dev = device_create(cls,NULL,MKDEV(major,i),NULL,"mychrdev%d",i);
    184.         if(IS_ERR(dev))
    185.         {
    186.             printk("向上提交设备节点失败\n");
    187.             goto out5;
    188.         }
    189.     }   
    190.     printk("向上提交设备节点成功\n");
    191.     return 0;
    192.     out5:
    193.         for(--i;i >= 0;i--)
    194.         {
    195.             device_destroy(cls,MKDEV(major,i));
    196.         }
    197.         class_destroy(cls);
    198.     out4:
    199.         cdev_del(cdev);
    200.     out3:
    201.         unregister_chrdev_region(MKDEV(major,minor),3);
    202.     out2:
    203.         kfree(cdev);
    204.     
    205.     out:
    206.         
    207.         return ret;
    208.     
    209. }
    210.  
    211. static void __exit mycdev_exit(void)
    212. {
    213.     //销毁设备节点信息
    214.     int i;
    215.     for(i = 0;i < 3;i++)
    216.     {
    217.         device_destroy(cls,MKDEV(major,i));
    218.     }
    219.     //销毁设备目录
    220.     class_destroy(cls);
    221.     //销毁字符设备驱动对象
    222.     cdev_del(cdev);
    223.     //释放设备号
    224.     unregister_chrdev_region(MKDEV(major,minor),3);
    225.     kfree(cdev);
    226.     return;
    227. }
    228.  
    229.  
    230.  
    231. module_init(mycdev_init);
    232. module_exit(mycdev_exit);
    233. MODULE_LICENSE("GPL");

     

    1. //test.c
    2. #include<unistd.h>
    3. #include<fcntl.h>
    4. #include<sys/stat.h>
    5. #include<sys/types.h>
    6. #include<sys/ioctl.h>
    7. #include<stdio.h>
    8. #include<string.h>
    9. #include"include/head.h"
    10.  
    11. int main(int argc, char const *argv[])
    12. {
    13.     char buf[128] = {0};
    14.     int led_id,led_state;
    15.     fgets(buf,sizeof(buf),stdin);
    16.     buf[strlen(buf) - 1] = 0;
    17.  
    18.     int fd = open(buf,O_RDWR);
    19.     if(fd < 0)
    20.     {
    21.  
    22.         printf("打开设备文件失败\n");
    23.         return -1;
    24.     }
    25.     printf("打开设备文件成功\n");
    26.     while(1)
    27.     {
    28.         // fgets(buf,sizeof(buf),stdin);
    29.         // buf[strlen(buf) - 1] = 0;
    30.         // write(fd,buf,sizeof(buf));
    31.         // scanf("%d",&led_id);
    32.         scanf("%d",&led_state);
    33.         switch(led_state)
    34.         {
    35.             case 1:
    36.                 ioctl(fd,LED_ON);
    37.                 break;
    38.             case 0:
    39.                 ioctl(fd,LED_OFF);
    40.                 break;
    41.             default:
    42.                 break;
    43.         }
    44.     }
    45.     
    46.     //read(fd,buf,sizeof(buf));
    47.     
    48.     // memset(buf,0,sizeof(buf));
    49.     // read(fd,buf,sizeof(buf));
    50.     // printf("buf:%s\n",buf);
    51.     close(fd);
    52.     return 0;
    53. }

    实现效果：

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  • 原文地址：https://blog.csdn.net/a136630108/article/details/133996494