feat(combos): initial implementation

app/CMakeLists.txt

@@ -52,6 +52,7 @@ if ((NOT CONFIG_ZMK_SPLIT) OR CONFIG_ZMK_SPLIT_BLE_ROLE_CENTRAL)
   target_sources(app PRIVATE src/behaviors/behavior_none.c)
   target_sources(app PRIVATE src/behaviors/behavior_sensor_rotate_key_press.c)
   target_sources_ifdef(CONFIG_ZMK_EXT_POWER app PRIVATE src/behaviors/behavior_ext_power.c)
+  target_sources(app PRIVATE src/combo.c)
   target_sources(app PRIVATE src/keymap.c)
 endif()
 target_sources_ifdef(CONFIG_ZMK_RGB_UNDERGLOW app PRIVATE src/behaviors/behavior_rgb_underglow.c)

app/Kconfig

@@ -251,6 +251,23 @@ config ZMK_EXT_POWER
 #Power Management
 endmenu
 
+menu "Combo options"
+
+config ZMK_COMBO_MAX_PRESSED_COMBOS
+	int "Maximum number of currently pressed combos"
+	default 4
+
+config ZMK_COMBO_MAX_COMBOS_PER_KEY
+	int "Maximum number of combos per key"
+	default 5
+
+config ZMK_COMBO_MAX_KEYS_PER_COMBO
+	int "Maximum number of keys per combo"
+	default 4
+
+#Display/LED Options
+endmenu
+
 menu "Advanced"
 
 menu "Initialization Priorities"

app/dts/bindings/zmk,combos.yaml

@@ -0,0 +1,22 @@
+# Copyright (c) 2020, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Combos container
+
+compatible: "zmk,combos"
+
+child-binding:
+  description: "A combo"
+
+  properties:
+    bindings:
+      type: phandle-array
+      required: true
+    key-positions:
+      type: array
+      required: true
+    timeout-ms:
+      type: int
+      default: 50
+    slow-release:
+      type: boolean