These variants have a few differences from the default AR9485 NIC,
namely:
* a non-default antenna switch config;
* slightly different RX gain table setup;
* an external XLNA hooked up to a GPIO pin;
* (and not yet done) RSSI threshold differences when
doing slow diversity.
To make this possible:
* Add the PCI device list from Linux ath9k, complete with vendor and
sub-vendor IDs for various things to be enabled;
* .. and until FreeBSD learns about a PCI device list like this,
write a search function inspired by the USB device enumeration code;
* add HAL_OPS_CONFIG to the HAL attach methods; the HAL can use this
to initialise its local driver parameters upon attach;
* copy these parameters over in the AR9300 HAL;
* don't default to override the antenna switch - only do it for
the chips that require it;
* I brought over ar9300_attenuation_apply() from ath9k which is cleaner
and easier to read for this particular NIC.
This is a work in progress. I'm worried that there's some post-AR9380
NIC out there which doesn't work without the antenna override set as
I currently haven't implemented bluetooth coexistence for the AR9380
and later HAL. But I'd rather have this code in the tree and fix it
up before 11.0-RELEASE happens versus having a set of newer NICs
in laptops be effectively RX deaf.
Tested:
* AR9380 (STA)
* AR9485 CUS198 (STA)
Obtained from: Qualcomm Atheros, Linux ath9k
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