diff --git a/src/mainboard/google/glados/variants/caroline/overridetree.cb b/src/mainboard/google/glados/variants/caroline/overridetree.cb
index e213d027a4..6f55dce1e0 100644
--- a/src/mainboard/google/glados/variants/caroline/overridetree.cb
+++ b/src/mainboard/google/glados/variants/caroline/overridetree.cb
@@ -17,6 +17,15 @@ chip soc/intel/skylake
 	register "usb3_ports[0]" = "USB3_PORT_DEFAULT(OC_SKIP)" # Type-C Port (main)
 	register "usb3_ports[1]" = "USB3_PORT_DEFAULT(OC_SKIP)" # Type-C Port (sub)
 
+	register "SerialIoDevMode" = "{
+		[PchSerialIoIndexI2C0]  = PchSerialIoPci,	// touchpad
+		[PchSerialIoIndexI2C1]  = PchSerialIoPci,	// touchscreen
+		[PchSerialIoIndexI2C2]  = PchSerialIoPci,	// digitizer
+		[PchSerialIoIndexI2C4]  = PchSerialIoPci,	// audio
+		[PchSerialIoIndexUart0] = PchSerialIoPci,
+		[PchSerialIoIndexUart2] = PchSerialIoSkipInit,
+	}"
+
 	# PL2 override 15W
 	register "power_limits_config" = "{
 		.tdp_pl2_override = 15,