此驱动程序使用了等待队列，信号量，中断注册。另外要特别留意write函数被实现为从用户空间传入数模转换通道号（频道）和分频的值（预分频），read函数则传出转换好的数据。对于预分频传入和读取，本驱动程序并未使用到，当多路转换时，这个值则要充分利用，并且需要一种多路转换的实现方法了。-This driver uses a wait queue, semaphores, interrupt register. Also pay special attention to write function is implemented as passed from the user space digital-analog converter channel number (channel) and frequency division value (prescaler), read good data conversion function of the outgoing. Pre-entry points for frequent and reading, the driver does not use that, when the multiplexer, this value will have to take advantage of, and need a multiplexer implementation methods.