feat(mouse): Add mouse move and scroll support

* Use Zephyr input subsystem for all pointers.
* Input processors for modifying events, e.g. scaling, swapping
  codes, temporary (mouse) layers, etc.
* Mouse move/scroll behaviors.
* Infrastructure in place for physical pointer input devices.

Co-authored-by: Alexander Krikun <krikun98@gmail.com>
Co-authored-by: Robert U <urob@users.noreply.github.com>
Co-authored-by: Shawn Meier <ftc@users.noreply.github.com>

app/CMakeLists.txt

@@ -16,6 +16,7 @@ if(CONFIG_ZMK_BEHAVIOR_LOCAL_IDS)
 endif()
 
 zephyr_syscall_header(${APPLICATION_SOURCE_DIR}/include/drivers/behavior.h)
+zephyr_syscall_header(${APPLICATION_SOURCE_DIR}/include/drivers/input_processor.h)
 zephyr_syscall_header(${APPLICATION_SOURCE_DIR}/include/drivers/ext_power.h)
 
 # Add your source file to the "app" target. This must come after
@@ -36,15 +37,14 @@ target_sources_ifdef(CONFIG_ZMK_GPIO_KEY_WAKEUP_TRIGGER app PRIVATE src/gpio_key
 target_sources(app PRIVATE src/events/activity_state_changed.c)
 target_sources(app PRIVATE src/events/position_state_changed.c)
 target_sources(app PRIVATE src/events/sensor_event.c)
-target_sources(app PRIVATE src/events/mouse_button_state_changed.c)
 target_sources_ifdef(CONFIG_ZMK_WPM app PRIVATE src/events/wpm_state_changed.c)
 target_sources_ifdef(CONFIG_USB_DEVICE_STACK app PRIVATE src/events/usb_conn_state_changed.c)
 target_sources(app PRIVATE src/behaviors/behavior_reset.c)
 target_sources_ifdef(CONFIG_ZMK_EXT_POWER app PRIVATE src/behaviors/behavior_ext_power.c)
 target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_SOFT_OFF app PRIVATE src/behaviors/behavior_soft_off.c)
 if ((NOT CONFIG_ZMK_SPLIT) OR CONFIG_ZMK_SPLIT_ROLE_CENTRAL)
  target_sources(app PRIVATE src/hid.c)
- target_sources_ifdef(CONFIG_ZMK_MOUSE app PRIVATE src/mouse.c)
+ add_subdirectory_ifdef(CONFIG_ZMK_MOUSE src/mouse/)
  target_sources(app PRIVATE src/behaviors/behavior_key_press.c)
  target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_KEY_TOGGLE app PRIVATE src/behaviors/behavior_key_toggle.c)
  target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_HOLD_TAP app PRIVATE src/behaviors/behavior_hold_tap.c)
@@ -64,6 +64,7 @@ if ((NOT CONFIG_ZMK_SPLIT) OR CONFIG_ZMK_SPLIT_ROLE_CENTRAL)
  target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_SENSOR_ROTATE_COMMON app PRIVATE src/behaviors/behavior_sensor_rotate_common.c)
  target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_MOUSE_KEY_PRESS app PRIVATE src/behaviors/behavior_mouse_key_press.c)
  target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_STUDIO_UNLOCK app PRIVATE src/behaviors/behavior_studio_unlock.c)
+ target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_INPUT_TWO_AXIS app PRIVATE src/behaviors/behavior_input_two_axis.c)
  target_sources(app PRIVATE src/combo.c)
  target_sources(app PRIVATE src/behaviors/behavior_tap_dance.c)
  target_sources(app PRIVATE src/behavior_queue.c)

app/Kconfig

@@ -395,13 +395,7 @@ endif
 #Display/LED Options
 endmenu
 
-menu "Mouse Options"
-
-config ZMK_MOUSE
- bool "Enable ZMK mouse emulation"
-
-#Mouse Options
-endmenu
+rsource "src/mouse/Kconfig"
 
 menu "Power Management"
 

app/Kconfig.behaviors

@@ -71,8 +71,7 @@ config ZMK_BEHAVIOR_KEY_TOGGLE
 config ZMK_BEHAVIOR_MOUSE_KEY_PRESS
  bool
  default y
- depends on DT_HAS_ZMK_BEHAVIOR_MOUSE_KEY_PRESS_ENABLED
- imply ZMK_MOUSE
+ depends on DT_HAS_ZMK_BEHAVIOR_MOUSE_KEY_PRESS_ENABLED && ZMK_MOUSE
 
 config ZMK_BEHAVIOR_STICKY_KEY
  bool
@@ -94,6 +93,11 @@ config ZMK_BEHAVIOR_SOFT_OFF
  default y
  depends on DT_HAS_ZMK_BEHAVIOR_SOFT_OFF_ENABLED && ZMK_PM_SOFT_OFF
 
+config ZMK_BEHAVIOR_INPUT_TWO_AXIS
+ bool
+ default y
+ depends on DT_HAS_ZMK_BEHAVIOR_INPUT_TWO_AXIS_ENABLED && ZMK_MOUSE
+
 config ZMK_BEHAVIOR_SENSOR_ROTATE_COMMON
  bool
 

app/dts/behaviors.dtsi

@@ -1,3 +1,9 @@
+/*
+ * Copyright (c) 2024 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
 #include <behaviors/key_press.dtsi>
 #include <behaviors/key_toggle.dtsi>
 #include <behaviors/transparent.dtsi>
@@ -19,6 +25,6 @@
 #include <behaviors/key_repeat.dtsi>
 #include <behaviors/backlight.dtsi>
 #include <behaviors/macros.dtsi>
-#include <behaviors/mouse_key_press.dtsi>
 #include <behaviors/soft_off.dtsi>
 #include <behaviors/studio_unlock.dtsi>
+#include <behaviors/mouse_keys.dtsi>

app/dts/behaviors/mouse_key_press.dtsi

@@ -16,4 +16,9 @@
  #binding-cells = <1>;
  };
  };
+
+ mkp_input_listener: mkp_input_listener {
+ compatible = "zmk,input-listener";
+ device = <&mkp>;
+ };
 };

app/dts/behaviors/mouse_keys.dtsi

@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) 2024 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "mouse_key_press.dtsi"
+#include "mouse_move.dtsi"
+#include "mouse_scroll.dtsi"

app/dts/behaviors/mouse_move.dtsi

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2024 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <zephyr/dt-bindings/input/input-event-codes.h>
+
+/ {
+ behaviors {
+ /omit-if-no-ref/ mmv: mouse_move {
+ compatible = "zmk,behavior-input-two-axis";
+ #binding-cells = <1>;
+ trigger-period-ms = <3>;
+ x-input-code = <INPUT_REL_X>;
+ y-input-code = <INPUT_REL_Y>;
+ time-to-max-speed-ms = <300>;
+ acceleration-exponent = <1>;
+ };
+ };
+
+ mmv_input_listener: mmv_input_listener {
+ compatible = "zmk,input-listener";
+ device = <&mmv>;
+ };
+};

app/dts/behaviors/mouse_scroll.dtsi

@@ -0,0 +1,27 @@
+
+/*
+ * Copyright (c) 2024 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <zephyr/dt-bindings/input/input-event-codes.h>
+
+/ {
+ behaviors {
+ /omit-if-no-ref/ msc: mouse_scroll {
+ compatible = "zmk,behavior-input-two-axis";
+ #binding-cells = <1>;
+ trigger-period-ms = <3>;
+ x-input-code = <INPUT_REL_HWHEEL>;
+ y-input-code = <INPUT_REL_WHEEL>;
+ time-to-max-speed-ms = <300>;
+ acceleration-exponent = <1>;
+ };
+ };
+
+ msc_input_listener: msc_input_listener {
+ compatible = "zmk,input-listener";
+ device = <&msc>;
+ };
+};

app/dts/bindings/behaviors/zmk,behavior-input-two-axis.yaml

@@ -0,0 +1,25 @@
+description: Two axis input behavior
+
+compatible: "zmk,behavior-input-two-axis"
+
+include: one_param.yaml
+
+properties:
+ x-input-code:
+ type: int
+ required: true
+ y-input-code:
+ type: int
+ required: true
+ trigger-period-ms:
+ type: int
+ default: 5
+ description: The time (in ms) between generated inputs when an input has non-zero speed.
+ delay-ms:
+ type: int
+ time-to-max-speed-ms:
+ type: int
+ required: true
+ acceleration-exponent:
+ type: int
+ default: 1

app/dts/bindings/input_processors/ip_common.yaml

@@ -0,0 +1,6 @@
+# Copyright (c) 2024 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+properties:
+ track-remainders:
+ type: boolean

app/dts/bindings/input_processors/ip_one_param.yaml

@@ -0,0 +1,13 @@
+# Copyright (c) 2024 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+include: ip_common.yaml
+
+properties:
+ "#input-processor-cells":
+ type: int
+ required: true
+ const: 1
+
+input-processor-cells:
+ - param1

app/dts/bindings/input_processors/ip_two_param.yaml

@@ -0,0 +1,14 @@
+# Copyright (c) 2024 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+include: ip_common.yaml
+
+properties:
+ "#input-processor-cells":
+ type: int
+ required: true
+ const: 2
+
+input-processor-cells:
+ - param1
+ - param2

app/dts/bindings/input_processors/ip_zero_param.yaml

@@ -0,0 +1,10 @@
+# Copyright (c) 2024 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+include: ip_common.yaml
+
+properties:
+ "#input-processor-cells":
+ type: int
+ required: true
+ const: 0

app/dts/bindings/input_processors/zmk,input-processor-code-mapper.yaml

@@ -0,0 +1,16 @@
+# Copyright (c) 2024, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Input Processor for remapping certain input codes to other codes
+
+compatible: "zmk,input-processor-code-mapper"
+
+include: ip_zero_param.yaml
+
+properties:
+ type:
+ type: int
+ required: true
+ map:
+ type: array
+ required: true

app/dts/bindings/input_processors/zmk,input-processor-scaler.yaml

@@ -0,0 +1,16 @@
+# Copyright (c) 2024, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Input Processor for scaling values
+
+compatible: "zmk,input-processor-scaler"
+
+include: ip_two_param.yaml
+
+properties:
+ type:
+ type: int
+ required: true
+ codes:
+ type: array
+ required: true

app/dts/bindings/input_processors/zmk,input-processor-temp-layer.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2024, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Input Processor for temporarily enabling a layer after input events
+
+compatible: "zmk,input-processor-temp-layer"
+
+include: ip_two_param.yaml

app/dts/bindings/input_processors/zmk,input-processor-transform.yaml

@@ -0,0 +1,18 @@
+# Copyright (c) 2024, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Input Processor for transforming values in various ways
+
+compatible: "zmk,input-processor-transform"
+
+include: ip_one_param.yaml
+
+properties:
+ type:
+ type: int
+ x-codes:
+ type: array
+ required: true
+ y-codes:
+ type: array
+ required: true

app/dts/bindings/zmk,input-listener.yaml

@@ -0,0 +1,23 @@
+description: |
+ Listener to subscribe to input events and send HID updates after processing
+
+compatible: "zmk,input-listener"
+
+properties:
+ device:
+ type: phandle
+ required: true
+ input-processors:
+ type: phandle-array
+
+child-binding:
+ description: "Listener overrides for certain layers"
+
+ properties:
+ layers:
+ type: array
+ required: true
+ inherit:
+ type: boolean
+ input-processors:
+ type: phandle-array

app/include/drivers/input_processor.h

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <zephyr/types.h>
+#include <stddef.h>
+#include <zephyr/sys/util.h>
+#include <string.h>
+#include <zephyr/device.h>
+#include <zephyr/input/input.h>
+
+struct zmk_input_processor_state {
+ float *remainder;
+};
+
+// TODO: Need the ability to store remainders? Some data passed in?
+typedef int (*zmk_input_processor_handle_event_callback_t)(const struct device *dev,
+ struct input_event *event,
+ uint32_t param1, uint32_t param2,
+ struct zmk_input_processor_state *state);
+
+__subsystem struct zmk_input_processor_driver_api {
+ zmk_input_processor_handle_event_callback_t handle_event;
+};
+
+__syscall int zmk_input_processor_handle_event(const struct device *dev, struct input_event *event,
+ uint32_t param1, uint32_t param2,
+ struct zmk_input_processor_state *state);
+
+static inline int z_impl_zmk_input_processor_handle_event(const struct device *dev,
+ struct input_event *event,
+ uint32_t param1, uint32_t param2,
+ struct zmk_input_processor_state *state) {
+ const struct zmk_input_processor_driver_api *api =
+ (const struct zmk_input_processor_driver_api *)dev->api;
+
+ if (api->handle_event == NULL) {
+ return -ENOTSUP;
+ }
+
+ return api->handle_event(dev, event, param1, param2, state);
+}
+
+#include <syscalls/input_processor.h>

app/include/dt-bindings/input.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2024 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#define ZMK_INPUT_EXPLICIT_CODE(type, code) ((type << 16) & code)
+
+#define ZMK_INPUT_EXPLICIT_CODE_TYPE(val) ((val >> 16) & 0xFF)
+#define ZMK_INPUT_EXPLICIT_CODE_CODE(val) (val & 0xFFFF)

app/include/dt-bindings/zmk/input_transform.h

@@ -0,0 +1,5 @@
+#include <zephyr/dt-bindings/dt-util.h>
+
+#define INPUT_TRANSFORM_XY_SWAP BIT(0)
+#define INPUT_TRANSFORM_X_INVERT BIT(1)
+#define INPUT_TRANSFORM_Y_INVERT BIT(2)