refactor: Move reset logic to a new function

Moved the logic to select the type of reboot from behavior_reset.c to a
new zmk_reset() function. This allows rebooting to bootloader from
other code, and it gives us a starting point for future work to support
other bootloaders aside from the Adafruit nrf52 bootloader.

app/CMakeLists.txt

@@ -24,6 +24,7 @@ target_sources(app PRIVATE src/stdlib.c)
 target_sources(app PRIVATE src/activity.c)
 target_sources(app PRIVATE src/kscan.c)
 target_sources(app PRIVATE src/matrix_transform.c)
+target_sources(app PRIVATE src/reset.c)
 target_sources(app PRIVATE src/sensors.c)
 target_sources_ifdef(CONFIG_ZMK_WPM app PRIVATE src/wpm.c)
 target_sources(app PRIVATE src/event_manager.c)

app/dts/behaviors/reset.dtsi

@@ -17,7 +17,7 @@
         bootloader: behavior_reset_dfu {
             compatible = "zmk,behavior-reset";
             label = "BOOTLOAD";
-            type = <RST_UF2>;
+            type = <ZMK_RESET_BOOTLOADER>;
             #binding-cells = <0>;
         };
     };

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

@@ -4,10 +4,6 @@
  * SPDX-License-Identifier: MIT
  */
 
-#define RST_WARM 0x00
+#define ZMK_RESET_WARM 0
-#define RST_COLD 0x01
+#define ZMK_RESET_COLD 1
-
+#define ZMK_RESET_BOOTLOADER 2
-// AdaFruit nrf52 Bootloader Specific. See
-// https://github.com/adafruit/Adafruit_nRF52_Bootloader/blob/d6b28e66053eea467166f44875e3c7ec741cb471/src/main.c#L107
-
-#define RST_UF2 0x57

app/include/zmk/reset.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2023 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <zephyr/toolchain.h>
+#include <dt-bindings/zmk/reset.h>
+
+/**
+ * Reboot the system.
+ * @param type A ZMK_RESET_* value indicating how to reboot.
+ */
+FUNC_NORETURN void zmk_reset(int type);

app/src/behaviors/behavior_reset.c

@@ -7,12 +7,12 @@
 #define DT_DRV_COMPAT zmk_behavior_reset
 
 #include <zephyr/device.h>
-#include <zephyr/sys/reboot.h>
 #include <zephyr/logging/log.h>
 
 #include <drivers/behavior.h>
 
 #include <zmk/behavior.h>
+#include <zmk/reset.h>
 
 LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 
@@ -28,10 +28,7 @@ static int on_keymap_binding_pressed(struct zmk_behavior_binding *binding,
     const struct device *dev = device_get_binding(binding->behavior_dev);
     const struct behavior_reset_config *cfg = dev->config;
 
-    // TODO: Correct magic code for going into DFU?
+    zmk_reset(cfg->type);
-    // See
-    // https://github.com/adafruit/Adafruit_nRF52_Bootloader/blob/d6b28e66053eea467166f44875e3c7ec741cb471/src/main.c#L107
-    sys_reboot(cfg->type);
     return ZMK_BEHAVIOR_OPAQUE;
 }
 

app/src/reset.c

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2023 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <zephyr/sys/reboot.h>
+#include <zephyr/logging/log.h>
+
+#include <zmk/reset.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+// AdaFruit nrf52 Bootloader Specific. See
+// https://github.com/adafruit/Adafruit_nRF52_Bootloader/blob/d6b28e66053eea467166f44875e3c7ec741cb471/src/main.c#L107
+#define ADAFRUIT_MAGIC_UF2 0x57
+
+FUNC_NORETURN void zmk_reset(int type) {
+    switch (type) {
+    case ZMK_RESET_WARM:
+        sys_reboot(SYS_REBOOT_WARM);
+        break;
+
+    case ZMK_RESET_COLD:
+        sys_reboot(SYS_REBOOT_COLD);
+        break;
+
+    case ZMK_RESET_BOOTLOADER:
+        // TODO: Add support for other types of bootloaders.
+        sys_reboot(ADAFRUIT_MAGIC_UF2);
+        break;
+
+    default:
+        LOG_ERR("Unknown reset type %d", type);
+        break;
+    }
+}