rtc驱动的bug

在sys/class/rtc/rtc0下面没有wakealarm文件节点

echo +100 > /sys/class/rtc/rtc0/wakealarm 可以手动设置rtc的响应时间

wakealarm文件节点出现的条件：

rtc_device_register--->rtc_sysfs_add_device(rtc);--->rtc_does_wakealarm(rtc)的结果为1--->device_create_file(&rtc->dev, &dev_attr_wakealarm);

rtc_does_wakealarm(rtc)的结果为1的条件--->device_can_wakeup(rtc->dev.parent)为1--->dev->power.can_wakeup;为1 同时rtc->ops->set_alarm != NULL;

所以必须先要执行device_init_wakeup(&spmi->dev, 1);函数把dev->power.can_wakeup = capable;

如果把dev->power.can_wakeup = capable;放在rtc_device_register那么就不会生成此文件节点

http://blog.youkuaiyun.com/longwang155069/article/details/52353408