Bluetooth LE battery reporting?

[Bastien Nocera <hadess@hadess.net>]

Hey,

I'm back looking into Bluetooth LE battery reporting, and I'm a bit
stumped as to what would need to be done to add support for it.

First, I've already found a few old implementations:

- I cleaned this up a couple of years ago, to try it out, and it spit
debug information as expected. Doesn't compile anymore:
https://gfiber.googlesource.com/vendor/opensource/bluez/+/42bc327d464b1f7c2c73b3fecb2e9a8d3dc01035/profiles/battery/battery.c

- chen.ganir@ti.com 's "Add Battery Service GATT Client" patchset that
was posted to the list in 2012 (!)

- and finally, there's bluez' very own "bas", the last commit touching it says:
commit b6cb2d3ec320bdfdf1cdcdf750e767d214170efd
Author: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Date:   Wed Nov 11 13:08:52 2015 +0200

    bas: Move code from android to profiles
    
    This is a place holder until the code is ported to use shared API so it
    can be shared by android and D-Bus daemon.

That last one is compiled, but doesn't seem to be hooked up (?). I
tested this with a Microsoft Arc Touch Mouse SE (the same mouse I
tested that first patch with).

Is this all hooked up and I'd just need to export the battery
information through D-Bus?

Or does it need fixing, in which case, which plugin could I use as an
example of what porting to that elusive "shared API" should look like?

Cheers