单片机教程网

电脑版
提示:原网页已由神马搜索转码, 内容由www.51hei.com提供.
查看:3637|回复:0

TQ2440开发板 Linux第一个驱动--点灯

[复制链接]
ID:72519发表于 2015-1-20 02:33|显示全部楼层

我用的是TQ2440开发板,这个程序是参考韦东山的.

4盏LED灯

以下是驱动程序

  1. #include< linux/module.h>
  2. #include< linux/kernel.h>
  3. #include< linux/fs.h>
  4. #include< linux/init.h>
  5. #include< linux/delay.h>
  6. #include< asm/uaccess.h>
  7. #include< asm/irq.h>
  8. #include< asm/io.h>
  9. #include< asm/arch/regs-gpio.h>
  10. #include< asm/hardware.h>

  12. static struct class *firstdrv_class;
  13. static struct class_device     *firstdrv_class_dev;

  15. volatile unsigned long *gpbcon = NULL;
  16. volatile unsigned long *gpbdat = NULL;


  19. static int first_drv_open(struct inode *inode, struct file *file)
  20. {
  21.      //printk("first_drv_open\n");
  22.      /* 配置gpb5,6,7,8为输出 */
  23.      *gpbcon& = ~((0x3<<(5*2)) | (0x3<<(6*2)) | (0x3<<(7*2)) | (0x3<<(8*2)));
  24.      *gpbcon |= ((0x1<<(5*2)) |(0x1<<(6*2)) | (0x1<<(7*2)) | (0x1<<(8*2)));
  25.      return 0;
  26. }

  28. static ssize_t first_drv_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
  29. {
  30.      int val;

  32.      //printk("first_drv_write\n");

  34.      copy_from_user(&val, buf, count); //     copy_to_user();

  36.      if (val == 1)
  37.      {
  38.          // 点灯
  39.          *gpbdat& = ~((1<<5) | (1<<6) | (1<<7) | (1<<8));
  40.      }
  41.      else
  42.      {
  43.          // 灭灯
  44.          *gpbdat |= (1<<5) | (1<<6) | (1<<7) | (1<<8);
  45.      }
  46.     
  47.      return 0;
  48. }

  50. static struct file_operations first_drv_fops = {
  51.    .owner  =   THIS_MODULE,   /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */
  52.    .open   =   first_drv_open,    
  53.      .write     =     first_drv_write,      
  54. };


  57. int major;
  58. static int first_drv_init(void)
  59. {
  60.      major = register_chrdev(0, "first_drv",& first_drv_fops); // 注册, 告诉内核

  62.      firstdrv_class = class_create(THIS_MODULE, "firstdrv");

  64.      firstdrv_class_dev = class_device_create(firstdrv_class, NULL, MKDEV(major, 0), NULL, "xyz"); /* /dev/xyz */

  66.      gpbcon = (volatile unsigned long *)ioremap(0x56000010, 16); //0x56000010是的GPIOB的
  67.      gpbdat = gpbcon + 1;
  68.      printk("first_drv_init...\n");

  70.      return 0;
  71. }

  73. static void first_drv_exit(void)
  74. {
  75.      unregister_chrdev(major, "first_drv"); // 卸载

  77.      class_device_unregister(firstdrv_class_dev);
  78.      class_destroy(firstdrv_class);
  79.      iounmap(gpbcon);
  80.      printk("first_drv_exit...\n");
  81. }

  83. module_init(first_drv_init);
  84. module_exit(first_drv_exit);


  87. MODULE_LICENSE("GPL");
复制代码


以下是测试程序

  1. #include< sys/types.h>
  2. #include< sys/stat.h>
  3. #include< fcntl.h>
  4. #include< stdio.h>

  6. /* firstdrvtest on
  7.   * firstdrvtest off
  8.   */
  9. int main(int argc, char **argv)
  10. {
  11.      int fd;
  12.      int val = 1;
  13.      fd = open("/dev/xyz", O_RDWR);
  14.      if (fd< 0)
  15.      {
  16.          printf("can't open!\n");
  17.      }
  18.      if (argc != 2)
  19.      {
  20.          printf("Usage :\n");
  21.          printf("%s< on|off>\n", argv[0]);
  22.          return 0;
  23.      }

  25.      if (strcmp(argv[1], "on") == 0)
  26.      {
  27.          val  = 1;
  28.      }
  29.      else
  30.      {
  31.          val = 0;
  32.      }
  33.     
  34.      write(fd,& val, 4);
  35.      return 0;
  36. }
复制代码



手机版|小黑屋|51黑电子论坛|51黑电子论坛6群QQ管理员QQ:125739409;技术交流QQ群281945664

Powered by 单片机教程网