1.pmic output management subsection
2.runtime pm in kernel
3.pm8921 driver other sections
4.uevent + sysfs, after uevent is sent, userspace also read sysfs interface file
5.what is CPU doing in deep sleep mode, in what mode?
6.how to read current power capacity, gau... ic ?
7.how power status is reported to userspace?
8.new feature in kernel 3.9, lightweight suspend
9.if temperature is too hot, what to do, suspend charging and reduce voltage?