From 0f49f224cebbcfe278c6cb92c2bfd0117f155029 Mon Sep 17 00:00:00 2001
From: Xudong Zheng <7pkvm5aw@slicealias.com>
Date: Fri, 2 Jun 2023 16:47:06 -0400
Subject: [PATCH] slicemk: implement &sys_off (EXPERIMENTAL 2023-06-14)

---
 app/dts/behaviors/reset.dtsi        |  9 ++++++++-
 app/include/dt-bindings/zmk/reset.h |  5 ++++-
 app/src/behaviors/behavior_reset.c  | 12 ++++++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/app/dts/behaviors/reset.dtsi b/app/dts/behaviors/reset.dtsi
index 2e775269aff1..cc315e494172 100644
--- a/app/dts/behaviors/reset.dtsi
+++ b/app/dts/behaviors/reset.dtsi
@@ -20,5 +20,12 @@
             type = <RST_UF2>;
             #binding-cells = <0>;
         };
-    };
+
+		sys_off: behavior_reset_sysoff {
+			compatible = "zmk,behavior-reset";
+			label = "SYSOFF";
+			type = <RST_SYSOFF>;
+			#binding-cells = <0>;
+		};
+	};
 };
diff --git a/app/include/dt-bindings/zmk/reset.h b/app/include/dt-bindings/zmk/reset.h
index 2b3d8760d5c2..c34a38b8d070 100644
--- a/app/include/dt-bindings/zmk/reset.h
+++ b/app/include/dt-bindings/zmk/reset.h
@@ -7,7 +7,10 @@
 #define RST_WARM 0x00
 #define RST_COLD 0x01
 
+// Custom SliceMK magic token for SYSOFF.
+#define RST_SYSOFF 0x56
+
 // AdaFruit nrf52 Bootloader Specific. See
 // https://github.com/adafruit/Adafruit_nRF52_Bootloader/blob/d6b28e66053eea467166f44875e3c7ec741cb471/src/main.c#L107
 
-#define RST_UF2 0x57
\ No newline at end of file
+#define RST_UF2 0x57
diff --git a/app/src/behaviors/behavior_reset.c b/app/src/behaviors/behavior_reset.c
index 7c93cbbfe44a..8c066ab997ed 100644
--- a/app/src/behaviors/behavior_reset.c
+++ b/app/src/behaviors/behavior_reset.c
@@ -13,6 +13,7 @@
 #include <drivers/behavior.h>
 
 #include <zmk/behavior.h>
+#include <dt-bindings/zmk/reset.h>
 
 LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 
@@ -50,3 +51,14 @@ static const struct behavior_driver_api behavior_reset_driver_api = {
 DT_INST_FOREACH_STATUS_OKAY(RST_INST)
 
 #endif /* DT_HAS_COMPAT_STATUS_OKAY(DT_DRV_COMPAT) */
+
+static int sysoff_init_prekernel(const struct device *dev) {
+	uint32_t const gpregret = NRF_POWER->GPREGRET;
+	if (gpregret == RST_SYSOFF) {
+		NRF_POWER->GPREGRET = 0;
+		NRF_POWER->SYSTEMOFF = 1;
+	}
+	return 0;
+}
+
+SYS_INIT(sysoff_init_prekernel, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);