The four modules are apple_smc for the core functions, apple_smc_acpi
for attachment at acpi, and apple_smc_fan & apple_smc_temp for stuff
on the SMC.
Seems like there's a lot more bookkeeping necessary to maintain
children of an applesmc device implemented by loadable modules.
Maybe there's a better way I just haven't figured out yet.
Device interface derived by reading the Linux driver source code and
<http:///www.parhelia.ch/blog/statics/k3_keys.html> as of 2012-12-05.
Includes support for attaching fan and temperature sensors to sysmon.
No accelerometer yet.
Compile-tested only, based on some run-testing of experiments from
userland. Module attachment is not quite finished, so it won't work
yet.