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          EEPW首頁 > 嵌入式系統(tǒng) > 設(shè)計應(yīng)用 > 字符設(shè)備驅(qū)動-利用次設(shè)備號實現(xiàn)多路LED控制

          字符設(shè)備驅(qū)動-利用次設(shè)備號實現(xiàn)多路LED控制

          作者: 時間:2016-11-21 來源:網(wǎng)絡(luò) 收藏
          驅(qū)動源碼:
          #include
          .
          .
          #include
          int major;
          int minor = 0;
          static struct class *leddrv_class;
          static struct class_device *leddrv_class_devs[4];
          volatile unsigned long *gpfcon = NULL;
          volatile unsigned long *gpfdat = NULL;
          static int led_drv_open(struct inode *inode, struct file *file)
          {
          int minor = MINOR(inode->i_rdev); //MINOR(inode->i_cdev);
          switch(minor)
          {
          case 0:
          {
          // 配置3引腳為輸出
          //s3c2410_gpio_cfgpin(S3C2410_GPF4, S3C2410_GPF4_OUTP);
          *gpfcon &= ~(0x3<<(4*2));
          *gpfcon |= (1<<(4*2));
          //s3c2410_gpio_cfgpin(S3C2410_GPF5, S3C2410_GPF5_OUTP);
          *gpfcon &= ~(0x3<<(5*2));
          *gpfcon |= (1<<(5*2));
          //s3c2410_gpio_cfgpin(S3C2410_GPF6, S3C2410_GPF6_OUTP);
          *gpfcon &= ~(0x3<<(6*2));
          *gpfcon |= (1<<(6*2));
          // 都輸出0
          //s3c2410_gpio_setpin(S3C2410_GPF4, 0);
          *gpfdat &= ~(1<<4);
          //s3c2410_gpio_setpin(S3C2410_GPF5, 0);
          *gpfdat &= ~(1<<5);
          //s3c2410_gpio_setpin(S3C2410_GPF6, 0);
          *gpfdat &= ~(1<<6);
          break;
          }
          case 1:
          {
          s3c2410_gpio_cfgpin(S3C2410_GPF4, S3C2410_GPF4_OUTP);
          s3c2410_gpio_setpin(S3C2410_GPF4, 0);
          break;
          }
          case 2:
          {
          s3c2410_gpio_cfgpin(S3C2410_GPF5, S3C2410_GPF5_OUTP);
          s3c2410_gpio_setpin(S3C2410_GPF5, 0);
          break;
          }
          case 3:
          {
          s3c2410_gpio_cfgpin(S3C2410_GPF6, S3C2410_GPF6_OUTP);
          s3c2410_gpio_setpin(S3C2410_GPF6, 0);
          break;
          }
          }
          return 0;
          }
          static ssize_t led_drv_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
          {
          char val;
          int minor = MINOR(file->f_dentry->d_inode->i_rdev);
          copy_from_user(&val, buf, 1);
          switch (minor)
          {
          case 0:
          {
          s3c2410_gpio_setpin(S3C2410_GPF4, (val & 0x1));
          s3c2410_gpio_setpin(S3C2410_GPF5, (val & 0x1));
          s3c2410_gpio_setpin(S3C2410_GPF6, (val & 0x1));
          break;
          }
          case 1:
          {
          s3c2410_gpio_setpin(S3C2410_GPF4, val);
          break;
          }
          case 2:
          {
          s3c2410_gpio_setpin(S3C2410_GPF5, val);
          break;
          }
          case 3:
          {
          s3c2410_gpio_setpin(S3C2410_GPF6, val);
          break;
          }
          }
          return 0;
          }
          static struct file_operations led_drv_fops = {
          .owner = THIS_MODULE,
          .open = led_drv_open,
          .write = led_drv_write,
          };
          static int led_drv_init(void)
          {
          major = register_chrdev(0, "led_drv", &led_drv_fops); // 注冊字符驅(qū)動, 告訴內(nèi)核
          leddrv_class = class_create(THIS_MODULE, "leddrv"); //創(chuàng)建設(shè)備節(jié)點
          leddrv_class_devs[0] = class_device_create(leddrv_class, NULL, MKDEV(major, 0), NULL, "leddrv");
          for (minor = 1; minor < 4; minor++)
          {
          leddrv_class_devs[minor] = class_device_create(leddrv_class, NULL, MKDEV(major, minor), NULL, "leddrv%d", minor);
          if (unlikely(IS_ERR(leddrv_class_devs[minor])))
          return PTR_ERR(leddrv_class_devs[minor]);
          }
          gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
          gpfdat = gpfcon + 1;
          return 0;
          }
          static void led_drv_exit(void)
          {
          unregister_chrdev(major, "led_drv"); // 卸載
          for (minor = 0; minor < 4; minor++)
          {
          class_device_unregister(leddrv_class_devs[minor]);
          }
          class_destroy(leddrv_class);
          iounmap(gpfcon);
          }
          module_init(led_drv_init);
          module_exit(led_drv_exit);
          MODULE_LICENSE("GPL");
          ==================================================================================================
          測試程序:
          #include
          #include
          #include
          #include
          void print_usage(char *file)
          {
          printf("Usage:n");
          printf("%s n",file);
          printf("eg. n");
          printf("%s /dev/leds onn", file);
          printf("%s /dev/leds offn", file);
          printf("%s /dev/led1 onn", file);
          printf("%s /dev/led1 offn", file);
          }
          int main(int argc, char **argv)
          {
          int fd;
          char* filename;
          char val;
          if (argc != 3)
          {
          print_usage(argv[0]);
          return 0;
          }
          filename = argv[1];
          fd = open(filename, O_RDWR);
          if (fd < 0)
          {
          printf("error, cant open %sn", filename);
          return 0;
          }
          if (!strcmp("on", argv[2]))
          {
          // 亮燈
          val = 0;
          write(fd, &val, 1);
          }
          else if (!strcmp("off", argv[2]))
          {
          // 滅燈
          val = 1;
          write(fd, &val, 1);
          }
          else
          {
          print_usage(argv[0]);
          return 0;
          }
          }
          =================================================================================================
          實驗:
          ls -l /dev/leddrv
          ls -l /dev/leddrv1
          ./leddrvTest /dev/leddrv on
          ./leddrvTest /dev/leddrv off
          ./leddrvTest /dev/leddrv1 on
          ./leddrvTest /dev/leddrv2 on
          ./leddrvTest /dev/leddrv2 off
          ./leddrvTest /dev/leddrv3 on
          ./leddrvTest /dev/leddrv3 off
          運行程序時輸入不同的/dev/leddrv、/dev/leddrv1、/dev/leddrv2、/dev/leddrv3得到的次設(shè)備號不同,驅(qū)動程序中根據(jù)不同的次設(shè)備號控制不同的燈,輸入不同的on、off命令write時寫入的值不同,根據(jù)不同的值執(zhí)行開關(guān)動作。



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