From cfe6b695340382f77307625b87869b2b43cbb92c Mon Sep 17 00:00:00 2001
From: Daniel Thompson <daniel@redfelineninja.org.uk>
Date: Sat, 18 Jan 2020 20:56:08 +0000
Subject: [PATCH] boards/main: Enable the WDT and related entry modes

---
 src/boards.c | 30 ++++++++++++++++++++++++++++++
 src/boards.h |  4 ++++
 src/main.c   | 28 +++++++++++++++++++---------
 3 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/src/boards.c b/src/boards.c
index 7ad305a..548fcaf 100644
--- a/src/boards.c
+++ b/src/boards.c
@@ -24,6 +24,7 @@
 
 #include "boards.h"
 #include "nrf_pwm.h"
+#include "nrf_wdt.h"
 #include "app_scheduler.h"
 #include "app_timer.h"
 
@@ -126,12 +127,26 @@ void board_teardown(void)
 }
 
 static uint32_t _systick_count = 0;
+static uint32_t _long_press_count = 0;
 void SysTick_Handler(void)
 {
   _systick_count++;
 #if LEDS_NUMBER > 0
   led_tick();
 #endif
+
+  /*
+   * Detect a long press of the DFU button. When found try to launch the
+   * application regardless of the DFU button state.
+   */
+  if (button_pressed(BUTTON_DFU)) {
+    if (_long_press_count++ >  (2 * 1000)) {
+      NRF_POWER->GPREGRET = BOARD_MAGIC_FORCE_APP_BOOT;
+      NVIC_SystemReset();
+    }
+  } else {
+    _long_press_count = 0;
+  }
 }
 
 
@@ -453,3 +468,18 @@ void neopixel_write (uint8_t *pixels)
   led_pwm_duty_cycle(LED_RGB_BLUE, pixels[0]);
 }
 #endif
+
+void wdt_init(void)
+{
+  // 1 => keep running during a sleep, stop during SWD debug
+  nrf_wdt_behaviour_set(NRF_WDT, 1);
+
+  // timeout after 5 seconds
+  nrf_wdt_reload_value_set(NRF_WDT, 5 * 32768);
+
+  // enable the 0th channel
+  nrf_wdt_reload_request_enable(NRF_WDT, NRF_WDT_RR0);
+
+  // set it running
+  nrf_wdt_task_trigger(NRF_WDT, NRF_WDT_TASK_START);
+}
diff --git a/src/boards.h b/src/boards.h
index 28cc5c6..ac0a798 100644
--- a/src/boards.h
+++ b/src/boards.h
@@ -60,6 +60,8 @@
 #define BOARD_RGB_BRIGHTNESS 0x101010
 #endif
 
+#define BOARD_MAGIC_FORCE_APP_BOOT 0x65
+
 // Helper function
 #define memclr(buffer, size)                memset(buffer, 0, size)
 #define varclr(_var)                        memclr(_var, sizeof(*(_var)))
@@ -106,6 +108,8 @@ bool button_pressed(uint32_t pin);
 
 bool is_ota(void);
 
+void wdt_init(void);
+
 //--------------------------------------------------------------------+
 // DEBUG
 //--------------------------------------------------------------------+
diff --git a/src/main.c b/src/main.c
index ec334a3..c854dcb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -103,6 +103,7 @@ void usb_teardown(void);
 #define DFU_MAGIC_OTA_RESET             0xA8
 #define DFU_MAGIC_SERIAL_ONLY_RESET     0x4e
 #define DFU_MAGIC_UF2_RESET             0x57
+#define DFU_MAGIC_FORCE_APP_BOOT        BOARD_MAGIC_FORCE_APP_BOOT       // 0x65
 
 #define DFU_DBL_RESET_MAGIC             0x5A1AD5      // SALADS
 #define DFU_DBL_RESET_DELAY             500
@@ -155,7 +156,9 @@ int main(void)
   bool sd_inited = (NRF_POWER->GPREGRET == DFU_MAGIC_OTA_APPJUM);
 
   // Start Bootloader in BLE OTA mode
-  _ota_dfu = (NRF_POWER->GPREGRET == DFU_MAGIC_OTA_APPJUM) || (NRF_POWER->GPREGRET == DFU_MAGIC_OTA_RESET);
+  _ota_dfu = (NRF_POWER->GPREGRET == DFU_MAGIC_OTA_APPJUM) ||
+	     (NRF_POWER->GPREGRET == DFU_MAGIC_OTA_RESET) ||
+	     (NRF_POWER->RESETREAS & NRF_POWER_RESETREAS_DOG_MASK);
 
   // Serial only mode
   bool serial_only_dfu = (NRF_POWER->GPREGRET == DFU_MAGIC_SERIAL_ONLY_RESET);
@@ -164,8 +167,14 @@ int main(void)
   bool dfu_start = _ota_dfu || serial_only_dfu || (NRF_POWER->GPREGRET == DFU_MAGIC_UF2_RESET) ||
                     (((*dbl_reset_mem) == DFU_DBL_RESET_MAGIC) && (NRF_POWER->RESETREAS & POWER_RESETREAS_RESETPIN_Msk));
 
+  // override the button status (but not GPREGREG or RESETREAS)
+  bool force_app_boot = (NRF_POWER->GPREGRET == DFU_MAGIC_FORCE_APP_BOOT);
+
   // Clear GPREGRET if it is our values
-  if (dfu_start) NRF_POWER->GPREGRET = 0;
+  if (dfu_start || force_app_boot) {
+    NRF_POWER->GPREGRET = 0;
+    nrf_power_resetreas_clear(NRF_POWER, NRF_POWER_RESETREAS_DOG_MASK);
+  }
 
   // Save bootloader version to pre-defined register, retrieved by application
   BOOTLOADER_VERSION_REGISTER = (MK_BOOTLOADER_VERSION);
@@ -191,11 +200,14 @@ int main(void)
 
   /*------------- Determine DFU mode (Serial, OTA, FRESET or normal) -------------*/
   // DFU button pressed
-  dfu_start  = dfu_start || button_pressed(BUTTON_DFU);
+  dfu_start  = dfu_start || (!force_app_boot && button_pressed(BUTTON_DFU));
 
-#if BUTTONS_NUMBER > 1
+#if BUTTONS_NUMBER >= 2
   // DFU + FRESET are pressed --> OTA
   _ota_dfu = _ota_dfu  || ( button_pressed(BUTTON_DFU) && button_pressed(BUTTON_FRESET) ) ;
+#else
+  // No FRESET button so set OTA mode unless a magic reset requested serial mode
+  _ota_dfu = _ota_dfu  || !serial_only_dfu;
 #endif
 
   bool const valid_app = bootloader_app_is_valid(DFU_BANK_0_REGION_START);
@@ -222,11 +234,6 @@ int main(void)
 
   (*dbl_reset_mem) = 0;
 
-#if BUTTONS_NUMBER < 2
-  // set BLE/ota DFU by default unless asked for serial as we don't have button to select it
-  _ota_dfu = _ota_dfu  || !serial_only_dfu;
-#endif
-
   if ( dfu_start || !valid_app )
   {
     if ( _ota_dfu )
@@ -266,6 +273,9 @@ int main(void)
   // Jump to application if valid
   if (bootloader_app_is_valid(DFU_BANK_0_REGION_START) && !bootloader_dfu_sd_in_progress())
   {
+    // Set the watchdog running before we start the payload
+    wdt_init();
+
     // MBR must be init before start application
     if ( !sd_inited ) softdev_mbr_init();