Last device behavior

app/CMakeLists.txt

@@ -57,6 +57,8 @@ if ((NOT CONFIG_ZMK_SPLIT) OR CONFIG_ZMK_SPLIT_ROLE_CENTRAL)
   target_sources(app PRIVATE src/behaviors/behavior_momentary_layer.c)
   target_sources(app PRIVATE src/behaviors/behavior_mod_morph.c)
   target_sources(app PRIVATE src/behaviors/behavior_outputs.c)
+  target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_LAST_DEVICE app PRIVATE src/behaviors/behavior_last_device.c)
+  target_sources(app PRIVATE src/behaviors/behavior_tap_dance.c)
   target_sources(app PRIVATE src/behaviors/behavior_toggle_layer.c)
   target_sources(app PRIVATE src/behaviors/behavior_to_layer.c)
   target_sources(app PRIVATE src/behaviors/behavior_transparent.c)

app/Kconfig

@@ -692,6 +692,17 @@ config ZMK_KEYMAP_SENSORS_DEFAULT_TRIGGERS_PER_ROTATION
 
 endif # ZMK_KEYMAP_SENSORS
 
+choice CBPRINTF_IMPLEMENTATION
+    default CBPRINTF_NANO
+
+endchoice
+
+DT_COMPAT_ZMK_BEHAVIOR_LAST_DEVICE := zmk,behavior-last-device
+
+config ZMK_BEHAVIOR_LAST_DEVICE
+    bool
+    default $(dt_compat_enabled,$(DT_COMPAT_ZMK_BEHAVIOR_LAST_DEVICE))
+
 module = ZMK
 module-str = zmk
 source "subsys/logging/Kconfig.template.log_config"

app/dts/behaviors.dtsi

@@ -21,6 +21,7 @@
 #include <behaviors/bluetooth.dtsi>
 #include <behaviors/ext_power.dtsi>
 #include <behaviors/outputs.dtsi>
+#include <behaviors/last_device.dtsi>
 #include <behaviors/caps_word.dtsi>
 #include <behaviors/key_repeat.dtsi>
 #include <behaviors/backlight.dtsi>

app/dts/behaviors/last_device.dtsi

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <dt-bindings/zmk/keys.h>
+
+/ {
+    behaviors {
+        /omit-if-no-ref/ last_dev: last_device {
+            compatible = "zmk,behavior-last-device";
+            label = "LAST_DEVICE";
+            #binding-cells = <0>;
+        };
+    };
+};

app/dts/bindings/behaviors/zmk,behavior-last-device.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2022 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Last Device Behavior
+
+compatible: "zmk,behavior-last-device"
+
+include: zero_param.yaml

app/include/zmk/ble.h

@@ -26,6 +26,7 @@ int zmk_ble_prof_select(uint8_t index);
 void zmk_ble_clear_all_bonds(void);
 int zmk_ble_prof_disconnect(uint8_t index);
 
+int zmk_ble_last_profile_index();
 int zmk_ble_active_profile_index(void);
 int zmk_ble_profile_index(const bt_addr_le_t *addr);
 bt_addr_le_t *zmk_ble_profile_address(uint8_t index);

app/include/zmk/endpoints.h

@@ -68,6 +68,8 @@ int zmk_endpoints_toggle_transport(void);
  */
 struct zmk_endpoint_instance zmk_endpoints_selected(void);
 
+struct zmk_endpoint_instance zmk_last_endpoint();
+
 int zmk_endpoints_send_report(uint16_t usage_page);
 
 #if IS_ENABLED(CONFIG_ZMK_POINTING)

app/src/behaviors/behavior_last_device.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <device.h>
+#include <drivers/behavior.h>
+#include <logging/log.h>
+#include <zmk/behavior.h>
+#include <zmk/ble.h>
+#include <zmk/endpoints.h>
+#include <zmk/hid.h>
+#include <dt-bindings/zmk/hid_usage_pages.h>
+#include <zmk/usb_hid.h>
+#include <zmk/hog.h>
+#include <zmk/event_manager.h>
+#include <zmk/events/ble_active_profile_changed.h>
+#include <zmk/events/usb_conn_state_changed.h>
+#include <zmk/events/endpoint_selection_changed.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#define DT_DRV_COMPAT zmk_behavior_last_device
+
+int8_t last_device;
+bool skip_next_endpoint_change = false;
+
+static int on_keymap_binding_pressed(struct zmk_behavior_binding *binding,
+                                     struct zmk_behavior_binding_event event) {
+    if (last_device == -1) {
+        LOG_DBG("Toggling output");
+        zmk_endpoints_toggle();
+    } else {
+        LOG_DBG("Switching to last ble device: %d", last_device);
+        zmk_ble_prof_select(last_device);
+        if (zmk_endpoints_selected() == ZMK_ENDPOINT_USB) {
+            LOG_DBG("Toggling output");
+            zmk_endpoints_toggle();
+        }
+    }
+
+    return ZMK_BEHAVIOR_OPAQUE;
+}
+
+static int behavior_last_device_init(const struct device *dev) { return 0; }
+
+static const struct behavior_driver_api behavior_last_device_driver_api = {
+    .binding_pressed = on_keymap_binding_pressed,
+};
+
+static void update_last_device_ble_index(uint8_t profile) {
+    if (!zmk_ble_profile_is_open(profile)) {
+        last_device = profile;
+        LOG_DBG("Last device set to %d", last_device);
+    }
+};
+
+static int last_device_listener(const zmk_event_t *eh) {
+    if (as_zmk_endpoint_selection_changed(eh) != NULL) {
+        if (zmk_preferred_endpoint() == zmk_endpoints_selected()) {
+            if (!skip_next_endpoint_change) {
+                if (zmk_endpoints_selected() == ZMK_ENDPOINT_USB) {
+                    update_last_device_ble_index(zmk_ble_active_profile_index());
+                } else {
+                    last_device = -1;
+                    LOG_DBG("Last device set to %d", last_device);
+                }
+            } else {
+                skip_next_endpoint_change = false;
+            }
+        } else if (zmk_endpoints_selected() == ZMK_ENDPOINT_BLE &&
+                   zmk_preferred_endpoint() == ZMK_ENDPOINT_USB) {
+            LOG_DBG("USB disconnected");
+            update_last_device_ble_index(zmk_ble_last_profile_index());
+        } else {
+            LOG_DBG("Skipping next endpoint change");
+            skip_next_endpoint_change = true;
+        }
+    }
+    if (as_zmk_ble_active_profile_changed(eh) != NULL &&
+        zmk_endpoints_selected() == ZMK_ENDPOINT_BLE) {
+        update_last_device_ble_index(zmk_ble_last_profile_index());
+    }
+    return 0;
+}
+
+ZMK_LISTENER(last_device_listener, last_device_listener);
+ZMK_SUBSCRIPTION(last_device_listener, zmk_endpoint_selection_changed);
+ZMK_SUBSCRIPTION(last_device_listener, zmk_ble_active_profile_changed);
+
+#define LAST_DEVICE_INST(n)                                                                        \
+    DEVICE_DT_INST_DEFINE(n, behavior_last_device_init, NULL, NULL, NULL, APPLICATION,             \
+                          CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, &behavior_last_device_driver_api);
+
+DT_INST_FOREACH_STATUS_OKAY(LAST_DEVICE_INST)

app/src/ble.c

@@ -60,6 +60,7 @@ enum advertising_type {
                     BT_GAP_ADV_FAST_INT_MIN_2, BT_GAP_ADV_FAST_INT_MAX_2, NULL)
 
 static struct zmk_ble_profile profiles[ZMK_BLE_PROFILE_COUNT];
+static uint8_t last_profile;
 static uint8_t active_profile;
 
 #define DEVICE_NAME CONFIG_BT_DEVICE_NAME
@@ -252,6 +253,7 @@ void zmk_ble_clear_all_bonds(void) {
     update_advertising();
 };
 
+int zmk_ble_last_profile_index() { return last_profile; }
 int zmk_ble_active_profile_index(void) { return active_profile; }
 
 int zmk_ble_profile_index(const bt_addr_le_t *addr) {
@@ -296,6 +298,7 @@ int zmk_ble_prof_select(uint8_t index) {
         return 0;
     }
 
+    last_profile = active_profile;
     active_profile = index;
     ble_save_profile();
 

app/src/endpoints.c

@@ -27,6 +27,7 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
     COND_CODE_1(IS_ENABLED(CONFIG_ZMK_BLE), (ZMK_TRANSPORT_BLE), (ZMK_TRANSPORT_USB))
 
 static struct zmk_endpoint_instance current_instance = {};
+static struct zmk_endpoint_instance last_instance = {};
 static enum zmk_transport preferred_transport =
     ZMK_TRANSPORT_USB; /* Used if multiple endpoints are ready */
 
@@ -347,6 +348,7 @@ static void update_current_endpoint(void) {
         // Cancel all current keypresses so keys don't stay held on the old endpoint.
         zmk_endpoints_clear_current();
 
+        last_instance = current_instance;
         current_instance = new_instance;
 
         char endpoint_str[ZMK_ENDPOINT_STR_LEN];

docs/docs/keymaps/behaviors/last-device.md

@@ -0,0 +1,19 @@
+---
+title: Last Device Behavior
+sidebar_label: Reset
+---
+
+## Summary
+
+The last device behavior switches to the last connected device, whether it be bluetooth or USB.
+
+### Behavior Binding
+
+- Reference: `&last_dev`
+- Parameters: None
+
+Example:
+
+```
+&last_dev
+```

docs/sidebars.js

@@ -80,6 +80,7 @@ module.exports = {
             "keymaps/behaviors/reset",
             "keymaps/behaviors/bluetooth",
             "keymaps/behaviors/outputs",
+            "keymaps/behaviors/last-device",
             "keymaps/behaviors/underglow",
             "keymaps/behaviors/backlight",
             "keymaps/behaviors/power",