Initial exploration of mod tap action.

Kconfig

@@ -25,6 +25,14 @@ config ZMK_KSCAN_MOCK_DRIVER
 	bool "Enable mock kscan driver to simulate key presses"
 	default n
 
+menu "ZMK Actions"
+
+config ZMK_ACTION_MOD_TAP
+	bool "Enable the Mod-Tap Action"
+	default true
+	
+endmenu
+
 module = ZMK
 module-str = zmk
 source "subsys/logging/Kconfig.template.log_config"

boards/shields/petejohanson_handwire/keymaps/default/keymap.overlay

@@ -18,7 +18,7 @@
 			label = "DEFAULT";
 			keys =
 	<
-	KC_A KC_B
+	KC_A MT(MOD_LSFT, KC_B)
 	CC_RAIS CC_LOWR
 	>;
 		};

include/dt-bindings/zmk/keys.h

@@ -74,11 +74,22 @@
 
 #define ZC_CSTM(n) (0xFF + n)
 
-#define MOD_LCTL 0x00
-#define MOD_LSFT 0x01
-#define MOD_LALT 0x02
-#define MOD_LGUI 0x03
-#define MOD_RCTL 0x04
-#define MOD_RSFT 0x05
-#define MOD_RALT 0x06
-#define MOD_RGUI 0x07
+#define MOD_LCTL (1 << 0x00)
+#define MOD_LSFT (1 << 0x01)
+#define MOD_LALT (1 << 0x02)
+#define MOD_LGUI (1 << 0x03)
+#define MOD_RCTL (1 << 0x04)
+#define MOD_RSFT (1 << 0x05)
+#define MOD_RALT (1 << 0x06)
+#define MOD_RGUI (1 << 0x07)
+
+#define ZK_ACTION(k) (k >> 24)
+#define _ACTION(a) (a << 24)
+#define _ACTION_MODS(m) (m << 16)
+#define ZK_MODS(a) ((a >> 16) & 0xFF)
+
+#define ZMK_ACTION_KEY 0x01
+#define ZMK_ACTION_MOD_TAP 0x01
+#define ZMK_ACTION_ONE_SHOT 0x02
+
+#define MT(mods, kc) (_ACTION(ZMK_ACTION_MOD_TAP) + _ACTION_MODS(mods) + kc)

include/zmk/endpoints.h

@@ -3,4 +3,5 @@
 #include <zmk/keys.h>
 
 int zmk_endpoints_init();
+int zmk_endpoints_send_report();
 int zmk_endpoints_send_key_event(struct zmk_key_event key_event);

include/zmk/hid.h

@@ -97,12 +97,14 @@ static const u8_t zmk_hid_report_desc[] = {
 
 struct zmk_hid_report
 {
-    u8_t modifiers;
+    zmk_mod_flags modifiers;
     u8_t keys[13];
 } __packed;
 
 int zmk_hid_register_mod(zmk_mod modifier);
 int zmk_hid_unregister_mod(zmk_mod modifier);
+int zmk_hid_register_mods(zmk_mod_flags modifiers);
+int zmk_hid_unregister_mods(zmk_mod_flags modifiers);
 int zmk_hid_press_key(zmk_key key);
 int zmk_hid_release_key(zmk_key key);
 

include/zmk/keys.h

@@ -3,11 +3,15 @@
 #include <zephyr.h>
 #include <dt-bindings/zmk/keys.h>
 
-typedef u64_t zmk_key;
+typedef u32_t zmk_key;
+typedef u8_t zmk_action;
 typedef u8_t zmk_mod;
+typedef u8_t zmk_mod_flags;
 
 struct zmk_key_event
 {
+    u32_t column;
+    u32_t row;
     zmk_key key;
     bool pressed;
 };

include/zmk/kscan-mock.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#define ZMK_MOCK_IS_PRESS(v) (v & (0x01 << 31))
+#define ZMK_MOCK_IS_PRESS(v) ((v & (0x01 << 31)) != 0)
 #define ZMK_MOCK_PRESS(row, col, msec) (row + (col << 8) + (msec << 16) + (0x01 << 31))
 #define ZMK_MOCK_RELEASE(row, col, msec) (row + (col << 8) + (msec << 16))
 #define ZMK_MOCK_ROW(v) (v & 0xFF)

prj.conf

@@ -5,6 +5,7 @@ CONFIG_USB_DEVICE_STACK=y
 CONFIG_USB_DEVICE_HID=y
 CONFIG_USB_DEVICE_PRODUCT="ZMK Firmware"
 CONFIG_ZMK_BLE=y
+CONFIG_ZMK_ACTION_MOD_TAP=y
 # HID GATT notifications sent this way are *not* picked up by Linux, and possibly others.
 CONFIG_BT_GATT_NOTIFY_MULTIPLE=n
 CONFIG_BT_DEVICE_NAME="ZMK Keyboard"

src/endpoints.c

@@ -33,24 +33,10 @@ int zmk_endpoints_init()
     return 0;
 }
 
-int zmk_endpoints_send_key_event(struct zmk_key_event key_event)
+int zmk_endpoints_send_report()
 {
-    struct zmk_hid_report *report;
     int err;
-
-    LOG_DBG("key %lld, state %d\n", key_event.key, key_event.pressed);
-
-
-    if (key_event.pressed)
-    {
-        zmk_hid_press_key(key_event.key);
-    }
-    else
-    {
-        zmk_hid_release_key(key_event.key);
-    }
-
-    report = zmk_hid_get_report();
+    struct zmk_hid_report *report = zmk_hid_get_report();
 
     // if (zmk_usb_hid_send_report(report) != 0)
     // {
@@ -67,3 +53,22 @@ int zmk_endpoints_send_key_event(struct zmk_key_event key_event)
 
     return 0;
 }
+
+int zmk_endpoints_send_key_event(struct zmk_key_event key_event)
+{
+    struct zmk_hid_report *report;
+    int err;
+
+    LOG_DBG("key %d, state %d\n", key_event.key, key_event.pressed);
+
+    if (key_event.pressed)
+    {
+        zmk_hid_press_key(key_event.key);
+    }
+    else
+    {
+        zmk_hid_release_key(key_event.key);
+    }
+
+    return zmk_endpoints_send_report();
+}

src/handlers.c

@@ -2,20 +2,71 @@
 #include <zmk/ble.h>
 #include <zmk/handlers.h>
 #include <zmk/endpoints.h>
+#include <zmk/hid.h>
+#include <zmk/matrix.h>
+
+#ifdef CONFIG_ZMK_ACTION_MOD_TAP
+u16_t action_effect_pending = 0;
+#endif
 
 __attribute__((weak)) bool zmk_handle_key_user(struct zmk_key_event *key_event)
 {
 	return true;
 };
 
+bool zmk_handle_action(zmk_action action, struct zmk_key_event *key_event)
+{
+	zmk_mod mods = ZK_MODS(key_event->key);
+	u8_t flattened_index = (key_event->row * ZMK_MATRIX_COLS) + key_event->column;
+	switch (action)
+	{
+#ifdef CONFIG_ZMK_ACTION_MOD_TAP
+	case ZMK_ACTION_MOD_TAP:
+		if (key_event->pressed)
+		{
+			WRITE_BIT(action_effect_pending, flattened_index, true);
+			zmk_hid_register_mods(mods);
+		}
+		else
+		{
+			zmk_hid_unregister_mods(mods);
+			if (action_effect_pending & BIT(flattened_index))
+			{
+				// Allow baseline keycode to flow to the endpoints!
+				return true;
+			}
+			else
+			{
+				// Since not sending a keycode, at least send the report w/ the mod removed
+				zmk_endpoints_send_report();
+			}
+		}
+		break;
+#endif
+	}
+	return false;
+};
+
 void zmk_handle_key(struct zmk_key_event key_event)
 {
+	zmk_action action = ZK_ACTION(key_event.key);
+
 	if (!zmk_handle_key_user(&key_event))
 	{
 		return;
 	}
 
+	if (action && !zmk_handle_action(action, &key_event))
+	{
+		return;
+	}
+
+#ifdef CONFIG_ZMK_ACTION_MOD_TAP
+	action_effect_pending = 0;
+#endif
+
 #ifdef CONFIG_ZMK_BLE
+	/* Used for intercepting key presses when doing passkey verification */
 	if (!zmk_ble_handle_key_user(&key_event))
 	{
 		return;

src/hid.c

@@ -21,6 +21,18 @@ int zmk_hid_unregister_mod(zmk_mod modifier)
     _TOGGLE_MOD(modifier, false);
 }
 
+int zmk_hid_register_mods(zmk_mod_flags modifiers)
+{
+    report.modifiers |= modifiers;
+    printk("After register mods %d have %d\n", modifiers, report.modifiers);
+}
+
+int zmk_hid_unregister_mods(zmk_mod_flags modifiers)
+{
+    report.modifiers &= ~modifiers;
+    printk("After unregister mods %d have %d\n", modifiers, report.modifiers);
+}
+
 #define KEY_OFFSET 0x02
 #define MAX_KEYS 6
 

src/kscan.c

@@ -50,9 +50,9 @@ void zmk_kscan_process_msgq(struct k_work *item)
 	{
 		bool pressed = (ev.state == ZMK_KSCAN_EVENT_STATE_PRESSED);
 		zmk_key key = zmk_keymap_keycode_from_position(ev.row, ev.column);
-		struct zmk_key_event kev = (struct zmk_key_event){.key = key, .pressed = pressed};
+		struct zmk_key_event kev = (struct zmk_key_event){.row = ev.row, .column = ev.column, .key = key, .pressed = pressed};
 
-		LOG_DBG("Row: %d, col: %d, key: %lld, pressed: %s\n", ev.row, ev.column, key, (pressed ? "true" : "false"));
+		LOG_DBG("Row: %d, col: %d, key: %d, pressed: %s\n", ev.row, ev.column, key, (pressed ? "true" : "false"));
 		zmk_handle_key(kev);
 	}
 }

src/kscan_mock.c

@@ -68,7 +68,7 @@ static void kscan_mock_work_handler(struct k_work *work)
     struct kscan_mock_config *cfg = data->dev->config_info;
 
     u32_t ev = cfg->events[data->event_index++];
-    LOG_DBG("Triggering ev %d\n", ev);
+    LOG_DBG("ev %u row %d column %d state %d\n", ev, ZMK_MOCK_ROW(ev), ZMK_MOCK_COL(ev), ZMK_MOCK_IS_PRESS(ev));
     data->callback(data->dev, ZMK_MOCK_ROW(ev), ZMK_MOCK_COL(ev), ZMK_MOCK_IS_PRESS(ev));
     kscan_mock_schedule_next_event(data->dev);
 }
@@ -93,10 +93,6 @@ static int kscan_mock_init(struct device *dev)
     struct kscan_mock_data *data = dev->driver_data;
     const struct kscan_mock_config *cfg = dev->config_info;
 
-    printk("Init first event: %d\n", cfg->events[0]);
-
-    int err;
-
     data->dev = dev;
     k_delayed_work_init(&data->work, kscan_mock_work_handler);