//定义proc文件系统节点 struct proc_dir_entry *dev_dir , *dev_version; //创建一个目录 dev_dir = proc_mkdir("Tiny4412_leds", NULL);  //创建一个文件 dev_version = create_proc_entry("version", S_IRUGO, dev_dir);  //调用读版本的函数 dev_version->read_proc = proc_read_version ;

 #define VERSION_LEN 20 char Tiny4412_LED_version[VERSION_LEN] = "20170908/n"; int proc_read_version(char *page, char **start, off_t off, int count, int *eof,         void *data) {  int len ;   len = sprintf(page,Tiny4412_LED_version); //将字符串写入page,相当于copy到用户层  return len ; }

 #include <linux/kernel.h> #include <linux/module.h> #include <linux/miscdevice.h> #include <linux/fs.h> #include <linux/tyPEs.h> #include <linux/moduleparam.h> #include <linux/slab.h> #include <linux/ioctl.h> #include <linux/cdev.h> #include <linux/delay.h> #include <linux/gpio.h> #include <;mach/gpio.h> #include <plat/gpio-CFg.h> //添加必要的头文件 #include <linux/proc_fs.h> #include <linux/uaccess.h> #define DEVICE_NAME "leds" static int led_gpios[] = {  EXYNOS4212_GPM4(0),  EXYNOS4212_GPM4(1),  EXYNOS4212_GPM4(2),  EXYNOS4212_GPM4(3), }; #define LED_NUM ARRAY_SIZE(led_gpios) static long tiny4412_leds_ioctl(struct file *filp, unsigned int cmd,  unsigned long arg) {  switch(cmd) {  case 0:  case 1:   if (arg > LED_NUM) {   return -eiNVAL;   }   gpio_set_value(led_gpios[arg], !cmd);   //printk(DEVICE_NAME": %d %d/n", arg, cmd);   break;  default:   return -EINVAL;  }  return 0; } static struct file_operations tiny4412_led_dev_fops = {  .owner  = THIS_MODULE,  .unlocked_ioctl = tiny4412_leds_ioctl, }; static struct miscdevice tiny4412_led_dev = {  .minor  = MISC_DYNamiC_MINOR,  .name  = DEVICE_NAME,  .fops  = &tiny4412_led_dev_fops, }; #define VERSION_LEN 20 char Tiny4412_LED_version[VERSION_LEN] = "20170908/n"; int proc_read_version(char *page, char **start, off_t off, int count, int *eof, void *data) {  int len ;   len = sprintf(page,Tiny4412_LED_version);  return len ; } static int __init tiny4412_led_dev_init(void) {  int ret;  int i;  for (i = 0; i < LED_NUM; i++) {  ret = gpio_request(led_gpios[i], "LED");  if (ret) {   printk("%s: request GPIO %d for LED failed, ret = %d/n", DEVICE_NAME,    led_gpios[i], ret);   return ret;  }  s3c_gpio_cfgpin(led_gpios[i], S3C_GPIO_OUTPUT);  gpio_set_value(led_gpios[i], 1);  }  //杂类设备  ret = misc_register(&tiny4412_led_dev);  //定义proc文件系统节点  struct proc_dir_entry *dev_dir , *dev_version;  //创建一个目录  dev_dir = proc_mkdir("Tiny4412_leds", NULL);   //创建一个文件  dev_version = create_proc_entry("version", S_IRUGO, dev_dir);   //调用读版本的函数  dev_version->read_proc = proc_read_version ;  printk(DEVICE_NAME"/tinitialized/n");  return ret; } static void __exit tiny4412_led_dev_exit(void) {  int i;  for (i = 0; i < LED_NUM; i++) {  gpio_free(led_gpios[i]);  }  misc_deregister(&tiny4412_led_dev); } module_init(tiny4412_led_dev_init); module_exit(tiny4412_led_dev_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("FriendlyARM Inc & Y.X.YANG modify");