feat: Add split vik cirque shield

boards/shields/vik_cirque_spi_split/vik_cirque_spi_split.dtsi

@@ -0,0 +1,11 @@
+/ {
+	split_inputs {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		glidepoint_split: glidepoint_split@0 {
+			compatible = "zmk,input-split";
+			reg = <0>;
+		};
+	};
+};

boards/shields/vik_cirque_spi_split/vik_cirque_spi_split.zmk.yml

@@ -0,0 +1,8 @@
+file_format: "1"
+id: vik_cirque_spi_split
+name: vik_cirque_spi_split
+type: shield
+url: https://github.com/sadekbaroudi/vik/
+siblings:
+  - vik_cirque_split_split_central
+  - vik_cirque_split_split_peripheral

boards/shields/vik_cirque_spi_split/vik_cirque_spi_split_central.overlay

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "../vik_shield_dts_preprocess.h"
+#include "vik_cirque_spi_split.dtsi"
+
+#include <dt-bindings/zmk/input_transform.h>
+#include <dt-bindings/input/input-event-codes.h>
+
+/ {
+    glidepoint_input_listener: glidepoint_input {
+        compatible = "zmk,input-listener";
+        device = <&glidepoint_split>;
+
+        // input-processors = <&xy_transform (INPUT_TRANSFORM_XY_SWAP | INPUT_TRANSFORM_X_INVERT | INPUT_TRANSFORM_Y_INVERT) &xy_scaler 3 2>;
+    };
+};

boards/shields/vik_cirque_spi_split/vik_cirque_spi_split_peripheral.conf

@@ -0,0 +1,2 @@
+CONFIG_SPI=y
+CONFIG_ZMK_MOUSE=y

boards/shields/vik_cirque_spi_split/vik_cirque_spi_split_peripheral.overlay

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "../vik_shield_dts_preprocess.h"
+#include "vik_cirque_spi_split.dtsi"
+
+#include <input/processors.dtsi>
+#include <dt-bindings/zmk/input_transform.h>
+#include <dt-bindings/input/input-event-codes.h>
+
+&vik_spi {
+    status = "okay";
+    cs-gpios = VIK_SPI_CS_PREFIX_PROCESSED <&vik_conn 6 GPIO_ACTIVE_LOW>;
+
+    glidepoint: glidepoint@VIK_SPI_REG_START {
+        compatible = "cirque,pinnacle";
+        reg = <VIK_SPI_REG_START>;
+        spi-max-frequency = <1000000>;
+        status = "okay";
+        dr-gpios = <&vik_conn 5 (GPIO_ACTIVE_HIGH)>; // DR pin on cirque is always &vik_conn 5
+
+        sensitivity = "1x";
+    };
+};
+
+&glidepoint_split {
+    device = <&glidepoint>;
+    // Input processors that are run before event data is sent
+    // to the central. Mostly useful for orientation fix ups.
+    input-processors = <&zip_xy_transform (INPUT_TRANSFORM_XY_SWAP | INPUT_TRANSFORM_X_INVERT | INPUT_TRANSFORM_Y_INVERT)>;
+};