anjianqudong

代码说明：

  设备驱动中主要要设计的数据结构是设备结构体，按键的设备结构体中应包含一个缓冲区，因为多次按键可能无法被及时处理，可以用该缓冲区缓存按键。此外，在按键设备结构体中，包含按键状态标志和一个实现过程中要借助的等待队列、cdev结构体。为了实现软件延时，定时器也是必要的(Device drivers in the main data structures to design a device structure, key device structure should contain a buffer, because multiple keys may not be in time, you can use the buffer cache key. In addition, the structure of the device keys, including the key state flag and an implementation process to help the wait queue, cdev structure. In order to achieve software delay timer is also necessary)