This is a custom FreeBSD HAL method that is used by the TDMA code
to program the beacon timers directly without any guesswork/assumptions
by the HAL.
This brings up basic TDMA master/slave support on the AR9380 HAL,
however there are other issues preventing it from being stable.
(I'm seeing beacon interval instability, which may be due to
busy 2GHz air, but also may be due to some HAL configuration
issues with regards to ANI, or hardware timer programming, etc.)
Tested:
* AR9331 (Carambola2), STA, AP, adhoc and TDMA master mode.
I've been sitting on this for a year or so now; I've finally
tested it on enough devices to be reasonably sure it won't
cause too much drama. But, if you see issues, please email me.
Tested (all STA mode):
PCIe:
* AR9380
* AR9390
* AR9580
* AR9462
* AR9485
SoC:
* QCA9550
* AR9331
* AR9342
work in FreeBSD.
This is still heavily a work in progress but I'd rather it start
shipping in -HEAD sooner rather than later.
This doesn't (yet) link it into the build system either for a static
kernel or as a module; that will come later (after many, many make universe
tests.)
