(hopefully) better serial read-out for devices

lib/logitech/unifying_receiver/hidpp10.py

@@ -183,22 +183,6 @@ def parse_battery_reply_07(level, battery_status):
 	return charge, status
 
 
-def get_serial(device):
-	assert device
-
-	if device.kind is None:
-		dev_id = 0x03
-		receiver = device
-	else:
-		dev_id = 0x30 + device.number - 1
-		receiver = device.receiver
-		assert receiver.unifying_supported
-
-	serial = read_register(receiver, 0x2B5, dev_id)
-	if serial is not None:
-		return _strhex(serial[1:5])
-
-
 def get_firmware(device):
 	assert device
 

lib/logitech/unifying_receiver/receiver.py

@@ -199,9 +199,18 @@ class PairedDevice(object):
 	@property
 	def serial(self):
 		if self._serial is None:
-			if self.receiver.unifying_supported:
+			serial = self.receiver.read_register(0x2B5, 0x30 + self.number - 1)
-				self._serial = _hidpp10.get_serial(self)
+			if serial:
+				ps = ord(serial[9:10]) & 0x0F
+				self._power_switch = _hidpp10.POWER_SWITCH_LOCATION[ps]
 			else:
+				# some Nano receivers?
+				serial = self.receiver.read_register(0x2D5)
+
+			if serial:
+				self._serial = _strhex(serial[1:5])
+			else:
+				# fallback...
 				self._serial = self.receiver.serial
 		return self._serial or '?'