Voltage can be read using as3543 adc (i.e. ascodec api, on this target implemented
via ioctl()). TODO: Look into possibly controlling charging more by re-using
powermgmt-ascodec.c. However, charging seems to be controlled by the kernel,
so may not be needed.
Charger state can be read using /dev/minivet. It allows to differentiate between
wall charger and usb charging, but that's not implemented (is it even worthwhile?)
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31470 a1c6a512-1295-4272-9138-f99709370657
