说明：  arm-linux 看门狗驱动分析，，如有理解错误，请指正（为了尽量是驱动容易理解，这个驱动暂时将有关电源管理的功能删除了，等理解透彻再完善）
(Analysis of ARM-Linux watchdog driver, if wrong, please correct me ( in order to drive is easy to understand, the driver will be temporarily of the power management functions such as delete, a thorough understanding of perfect ))