From 2b9b267e8ee1a49c448b5f0f5b9fd634bd6c4489 Mon Sep 17 00:00:00 2001
From: Ryan <fauxpark@gmail.com>
Date: Fri, 23 Oct 2020 12:21:56 +1100
Subject: [PATCH] Fix RGB matrix for ATmegaxxU2 (#10723)

---
 common_features.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/common_features.mk b/common_features.mk
index e0ae1d74c1..5f232d5f0d 100644
--- a/common_features.mk
+++ b/common_features.mk
@@ -184,6 +184,10 @@ ifeq ($(filter $(RGB_MATRIX_ENABLE),$(VALID_MATRIX_TYPES)),)
     $(error RGB_MATRIX_ENABLE="$(RGB_MATRIX_ENABLE)" is not a valid matrix type)
 endif
     OPT_DEFS += -DRGB_MATRIX_ENABLE
+ifneq (,$(filter $(MCU), atmega16u2 atmega32u2))
+    # ATmegaxxU2 does not have hardware MUL instruction - lib8tion must be told to use software multiplication routines
+    OPT_DEFS += -DLIB8_ATTINY
+endif
     SRC += $(QUANTUM_DIR)/color.c
     SRC += $(QUANTUM_DIR)/rgb_matrix.c
     SRC += $(QUANTUM_DIR)/rgb_matrix_drivers.c