DS18B20模块温转代码

static ssize_t ds18b20_read(struct file* file,char __user* buf, size_t size,loff_t* offset){
  unsigned long flags;
  unsigned char DL= 0,DH = 0;
  unsigned char de1,de2,del;
  unsigned int integer;
  local_irq_save(flags);
  if(ds18b20_reset()){
    local_irq_restore(flags);
    return -ENODEV;
  }
  ds18b20_write_byte(0xcc);
  ds18b20_write_byte(0x44);//启动温转
  gpiod_direction_output(ds18b20_pin,1);
  local_irq_restore(flags); 
  set_current_state(TASK_INTERRUPTIBLE);//使用schedule_timeout先设置状态
  schedule_timeout(HZ);//延时1s，温转需要时间
  local_irq_save(flags);//再次关中断
  ds18b20_write_byte(0xcc);
  ds18b20_write_byte(0xbe);//读取寄存器
  // 读取的字节顺序？
  DL = ds18b20_read_byte();//低八位
  DH = ds18b20_read_byte();//高八位
  if(DH > 0x7f){
    DL = ~DL;
　　//待完善
    
  }
  else{
    //分辨率：0.0625
    integer = DL/16 + DH*16;
    de1 = (DL&0x0f)*10/16;
    de2 = (DL&0x0f)*100/16;
    del = de1*10 + de2;
  }