feeature(bt): Add "unpair combo" on startup.

* Especially for splits, we need the ability to
  unpair all paired devices as  sledgehammer
  if we need to "reset things", and doing so via
  keymaps isn't suitable.
* Allows shields to define a collection of key
  positions that if all held 2 seconds after
  startup, will unpair all existing pairs for the
  device.

app/CMakeLists.txt

@@ -42,6 +42,7 @@ target_sources(app PRIVATE src/behaviors/behavior_transparent.c)
 target_sources(app PRIVATE src/behaviors/behavior_sensor_rotate_key_press.c)
 target_sources_ifdef(CONFIG_ZMK_RGB_UNDERGLOW app PRIVATE src/behaviors/behavior_rgb_underglow.c)
 target_sources_ifdef(CONFIG_ZMK_BLE app PRIVATE src/ble.c)
+target_sources_ifdef(CONFIG_ZMK_BLE_UNPAIR_COMBO app PRIVATE src/ble_unpair_combo.c)
 target_sources_ifdef(CONFIG_ZMK_SPLIT_BLE_ROLE_PERIPHERAL app PRIVATE src/split_listener.c)
 target_sources_ifdef(CONFIG_ZMK_SPLIT_BLE_ROLE_PERIPHERAL app PRIVATE src/split/bluetooth/service.c)
 target_sources_ifdef(CONFIG_ZMK_SPLIT_BLE_ROLE_CENTRAL app PRIVATE src/split/bluetooth/central.c)

app/Kconfig

@@ -40,11 +40,17 @@ menuconfig ZMK_BLE
 	select BT_PERIPHERAL
 	select BT_GATT_DIS
 	select BT_GATT_BAS
-	# select SETTINGS
+	select SETTINGS
-	# select BT_SETTINGS
+	select BT_SETTINGS
 
 if ZMK_BLE
 
+config ZMK_BLE_UNPAIR_COMBO
+	bool "Enable BT unpair combo"
+	help
+		Adds a magic key combo that can be held on startup to remove all paired devices
+	default n
+
 config ZMK_BLE_INIT_PRIORITY
 	int "Init Priority"
 	default 50

app/boards/shields/corne/corne.dtsi

@@ -58,6 +58,10 @@ RC(2,1) RC(2,2) RC(2,3) RC(2,4) RC(2,5)  RC(2,6) RC(2,7) RC(2,8) RC(2,9) RC(2,10
 		
 	};
 
+	bt_unpair_combo: bt_unpair_combo {
+		compatible = "zmk,bt-unpair-combo";
+	};
+
 	// TODO: per-key RGB node(s)?
 };
 

app/boards/shields/corne/corne_left.conf

@@ -1,2 +1,3 @@
 CONFIG_ZMK_SPLIT=y
-CONFIG_ZMK_SPLIT_BLE_ROLE_CENTRAL=y
+CONFIG_ZMK_SPLIT_BLE_ROLE_CENTRAL=y
+CONFIG_ZMK_BLE_UNPAIR_COMBO=y

app/boards/shields/corne/corne_left.overlay

@@ -16,3 +16,7 @@
 		, <&pro_micro_d 14 GPIO_ACTIVE_HIGH>
 		;
 };
+
+&bt_unpair_combo {
+	key-positions = <0 38>;
+};

app/boards/shields/corne/corne_right.conf

@@ -1,2 +1,3 @@
 CONFIG_ZMK_SPLIT=y
-CONFIG_ZMK_SPLIT_BLE_ROLE_PERIPHERAL=y
+CONFIG_ZMK_SPLIT_BLE_ROLE_PERIPHERAL=y
+CONFIG_ZMK_BLE_UNPAIR_COMBO=y

app/boards/shields/corne/corne_right.overlay

@@ -21,3 +21,6 @@
 		;
 };
 
+&bt_unpair_combo {
+	key-positions = <11 39>;
+};

app/boards/shields/kyria/kyria.dtsi

@@ -81,6 +81,10 @@ RC(2,0) RC(2,1) RC(2,2) RC(2,3) RC(2,4) RC(2,5) RC(2,6) RC(2,7) RC(2,8) RC(2,9)
 		sensors = <&left_encoder &right_encoder>;
 	};
 
+	bt_unpair_combo: bt_unpair_combo {
+		compatible = "zmk,bt-unpair-combo";
+	};
+
 	// TODO: RGB node(s)
 };
 

app/boards/shields/kyria/kyria_left.conf

@@ -1,2 +1,3 @@
 CONFIG_ZMK_SPLIT=y
-CONFIG_ZMK_SPLIT_BLE_ROLE_CENTRAL=y
+CONFIG_ZMK_SPLIT_BLE_ROLE_CENTRAL=y
+CONFIG_ZMK_BLE_UNPAIR_COMBO=y

app/boards/shields/kyria/kyria_left.overlay

@@ -22,3 +22,7 @@
 &left_encoder {
 	status = "okay";
 };
+
+&bt_unpair_combo {
+	key-positions = <0 44>;
+};

app/boards/shields/kyria/kyria_right.conf

@@ -1,2 +1,3 @@
 CONFIG_ZMK_SPLIT=y
-CONFIG_ZMK_SPLIT_BLE_ROLE_PERIPHERAL=y
+CONFIG_ZMK_SPLIT_BLE_ROLE_PERIPHERAL=y
+CONFIG_ZMK_BLE_UNPAIR_COMBO=y

app/boards/shields/kyria/kyria_right.overlay

@@ -27,3 +27,7 @@
 &right_encoder {
 	status = "okay";
 };
+
+&bt_unpair_combo {
+	key-positions = <11 45>;
+};

app/boards/shields/lily58/lily58.dtsi

@@ -44,6 +44,10 @@ RC(3,0) RC(3,1) RC(3,2) RC(3,3) RC(3,4) RC(3,5) RC(4,5) RC(4,6) RC(3,6) RC(3,7)
 			;
 		
 	};
+
+	bt_unpair_combo: bt_unpair_combo {
+		compatible = "zmk,bt-unpair-combo";
+	};
 };
 
 &pro_micro_i2c {

app/boards/shields/lily58/lily58_left.conf

@@ -1,2 +1,3 @@
 CONFIG_ZMK_SPLIT=y
-CONFIG_ZMK_SPLIT_BLE_ROLE_CENTRAL=y
+CONFIG_ZMK_SPLIT_BLE_ROLE_CENTRAL=y
+CONFIG_ZMK_BLE_UNPAIR_COMBO=y

app/boards/shields/lily58/lily58_left.overlay

@@ -17,3 +17,6 @@
 		;
 };
 
+&bt_unpair_combo {
+	key-positions = <0 42>;
+};

app/boards/shields/lily58/lily58_right.conf

@@ -1,2 +1,3 @@
 CONFIG_ZMK_SPLIT=y
 CONFIG_ZMK_SPLIT_BLE_ROLE_PERIPHERAL=y
+CONFIG_ZMK_BLE_UNPAIR_COMBO=y

app/boards/shields/lily58/lily58_right.overlay

@@ -21,3 +21,6 @@
 		;
 };
 
+&bt_unpair_combo {
+	key-positions = <11 43>;
+};

app/drivers/zephyr/kscan_gpio_matrix.c

@@ -205,7 +205,13 @@ static int kscan_gpio_config_interrupts(struct device **devices,
 		}                                                                                                                                                                                                                                   \
 		data->callback = callback;                                                                                                                                                                                                          \
 		return 0;                                                                                                                                                                                                                           \
-	}                                                                                                                                                                                                                                       \
+	};                                                                                                                                                                                                                                      \
+	static int kscan_gpio_enable_##n(struct device *dev) \
+	{ \
+		int err = kscan_gpio_enable_interrupts_##n(dev); \
+		if (err) { return err; } \
+		return kscan_gpio_read_##n(dev); \
+	}; \
 	static int kscan_gpio_init_##n(struct device *dev)                                                                                                                                                                                      \
 	{                                                                                                                                                                                                                                       \
 		struct kscan_gpio_data_##n *data = dev->driver_data;                                                                                                                                                                                \
@@ -258,7 +264,7 @@ static int kscan_gpio_config_interrupts(struct device **devices,
 	}                                                                                                                                                                                                                                       \
 	static const struct kscan_driver_api gpio_driver_api_##n = {                                                                                                                                                                            \
 		.config = kscan_gpio_configure_##n,                                                                                                                                                                                                 \
-		.enable_callback = kscan_gpio_enable_interrupts_##n,                                                                                                                                                                                \
+		.enable_callback = kscan_gpio_enable_##n,                                                                                                                                                                                \
 		.disable_callback = kscan_gpio_disable_interrupts_##n,                                                                                                                                                                              \
 	};                                                                                                                                                                                                                                      \
 	static const struct kscan_gpio_config_##n kscan_gpio_config_##n = {                                                                                                                                                                     \

app/dts/bindings/zmk,bt-unpair-combo.yaml

@@ -0,0 +1,12 @@
+# Copyright (c) 2020, Pete Johanson
+# SPDX-License-Identifier: MIT
+
+description: |
+  Defines a set of key positions that will unpair all BT devices if held on startup.
+
+compatible: "zmk,bt-unpair-combo"
+
+properties:
+  key-positions:
+    type: array
+    required: true

app/include/zmk/ble.h

@@ -3,5 +3,5 @@
 
 #include <zmk/keys.h>
 
-int zmk_ble_init();
+int zmk_ble_unpair_all();
 bool zmk_ble_handle_key_user(struct zmk_key_event *key_event);

app/src/ble.c

@@ -190,6 +190,12 @@ static int zmk_ble_init(struct device *_arg)
     return 0;
 }
 
+int zmk_ble_unpair_all()
+{
+    LOG_DBG("");
+    return bt_unpair(BT_ID_DEFAULT, NULL);
+};
+
 bool zmk_ble_handle_key_user(struct zmk_key_event *key_event)
 {
     zmk_key key = key_event->key;

app/src/ble_unpair_combo.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2020 Peter Johanson
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <device.h>
+#include <init.h>
+
+#include <logging/log.h>
+
+#define DT_DRV_COMPAT zmk_bt_unpair_combo
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#include <zmk/ble.h>
+#include <zmk/event-manager.h>
+#include <zmk/events/position-state-changed.h>
+
+
+static u8_t combo_state;
+
+const u32_t key_positions[] = DT_INST_PROP(0, key_positions);
+#define KP_LEN DT_INST_PROP_LEN(0, key_positions)
+
+int index_for_key_position(u32_t kp)
+{
+    for (int i = 0; i < KP_LEN; i++) {
+        if (key_positions[i] == kp) {
+            return i;
+        }
+    }
+
+    return -1;
+}
+
+int unpair_combo_listener(const struct zmk_event_header *eh)
+{
+    if (is_position_state_changed(eh)) {
+        const struct position_state_changed *psc = cast_position_state_changed(eh);
+
+        int kp_index = index_for_key_position(psc->position);
+        if (kp_index < 0) {
+            return 0;
+        }
+
+        WRITE_BIT(combo_state, kp_index, psc->state);
+    }
+
+    return 0;
+};
+
+void unpair_combo_work_handler(struct k_work *work)
+{
+    for (int i = 0; i < KP_LEN; i++) {
+        if (!(combo_state & BIT(i))) {
+            LOG_DBG("Key position %d not held, skipping unpair combo", key_positions[i]);
+            return;
+        }
+    }
+
+    zmk_ble_unpair_all();
+};
+
+struct k_delayed_work unpair_combo_work;
+
+int zmk_ble_unpair_combo_init(struct device *_unused)
+{
+    k_delayed_work_init(&unpair_combo_work, unpair_combo_work_handler);
+    k_delayed_work_submit(&unpair_combo_work, K_SECONDS(2));
+
+    return 0;
+};
+
+ZMK_LISTENER(zmk_ble_unpair_combo, unpair_combo_listener);
+ZMK_SUBSCRIPTION(zmk_ble_unpair_combo, position_state_changed);
+
+SYS_INIT(zmk_ble_unpair_combo_init,
+        APPLICATION,
+        CONFIG_APPLICATION_INIT_PRIORITY);