wireless-wifi/80-usb-wifi-ap-udev.rules

# stop hostapd when usb device is removed
SUBSYSTEM=="usb", ATTR{idProduct}=="9271", ATTR{idVendor}=="0cf3", ATTR{manufacturer}=="ATHEROS", ATTR{serial}=="12345", TAG+="systemd", ENV{SYSTEMD_WANTS}="hostapd.service"

# make sure hostapd.service can bind/require (start) when our device is plugged in, match sys-subsystem-net-devices name
SUBSYSTEM=="net", ATTR{address}=="00:c0:ca:??:??:??", NAME="wireless_wifi"

# use `udevadm info -q all --attribute-walk /sys/class/leds/ath9k_htc-phy19/` or `udevadm monitor -e` to help write rules
# -- launch the ar9271-blinker service for a given `%k = ath9k_htc-phy##` led
SUBSYSTEM=="leds", ACTION=="add", DEVPATH=="*/leds/ath9k_htc-phy*", TAG+="systemd", ENV{SYSTEMD_WANTS}="ar9271-blinker@%k.service"