基于嵌入式Linux系统的键盘驱动设计

摘要：为了适应嵌入式设备外设的多样性，本文以特殊矩阵键盘为例，设计了一套完整的驱动控制模块。硬件电路设计采用外扩3片SN74HCl64芯片的方式，节省了GPIO引脚的使用，大大提高了利用效率。同时，在此基础上引出了Linux内核中input子系统的特性和工作机制，呈现了较为完整的输入事件由内核空间传递到用户空间进程的过程。实验结果表明，设计的驱动模块具有良好的实时性和准确性。

Keyboard Driver Design Based on Embedded Linux

In order to adapt the diversity of embedded device peripheral, this paper takes special matrix keyboard as an example, and a complete set of drive control module is designed. Hardware circuit design takes 3 expanding SN74HC164 chips to save the GPIO pins, and it greatly improves the utilization efficiency. Meanwhile, on the basis it leads to the characteristics and working mechanism of input subsystem in Linux kernel, presenting a complete process of input events from kernel space to user space. The experimental results show that, the driving module has good performance in real-time and accuracy.