From baaa6086e60cafe937826c7d99ab305cdb62c7de Mon Sep 17 00:00:00 2001
From: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
Date: Wed, 11 Jan 2017 11:24:06 +0100
Subject: [PATCH] nrf52840: add workaround for RTC errata 20 include thered
 main stack for cmsis rtos

---
 rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h            |  2 +-
 .../TARGET_NORDIC/TARGET_NRF5_SDK13/us_ticker.c  | 16 ++++++++++++++++
 targets/targets.json                             |  4 ++--
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h b/rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h
index 410007facb..40aa2fff76 100644
--- a/rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h
+++ b/rtos/rtx/TARGET_CORTEX_M/RTX_CM_lib.h
@@ -354,7 +354,7 @@ __attribute__((used)) void _mutex_release (OS_ID *mutex) {
 /* Main Thread definition */
 extern void pre_main (void);
 
-#if defined(TARGET_MCU_NRF52832) ||\
+#if defined(TARGET_MCU_NRF52840) ||\
     defined(TARGET_MCU_NRF51822) || defined(TARGET_MCU_NRF52832) || defined (TARGET_STM32F334R8) ||\
     defined(TARGET_STM32F070RB) || defined(TARGET_STM32F072RB) || \
     defined(TARGET_STM32F302R8) || defined(TARGET_STM32F303K8) || defined (TARGET_STM32F334C8) ||\
diff --git a/targets/TARGET_NORDIC/TARGET_NRF5_SDK13/us_ticker.c b/targets/TARGET_NORDIC/TARGET_NRF5_SDK13/us_ticker.c
index d7267b81cc..a4d4bc5d89 100644
--- a/targets/TARGET_NORDIC/TARGET_NRF5_SDK13/us_ticker.c
+++ b/targets/TARGET_NORDIC/TARGET_NRF5_SDK13/us_ticker.c
@@ -76,6 +76,20 @@ void COMMON_RTC_IRQ_HANDLER(void)
     }
 }
 
+// Function for fix errata 20: RTC Register values are invalid
+__STATIC_INLINE void errata_20(void)
+{
+#if defined(NRF52_ERRATA_20)
+    if (!softdevice_handler_is_enabled())
+    {
+    	NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
+        NRF_CLOCK->TASKS_LFCLKSTART = 1;
+        while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0) {}
+    }
+	NRF_RTC1->TASKS_STOP = 0;
+#endif    
+}
+
 #if (defined (__ICCARM__)) && defined(TARGET_MCU_NRF51822)//IAR
 __stackless __task 
 #endif
@@ -87,6 +101,8 @@ void common_rtc_init(void)
         return;
     }
 
+    errata_20();
+    
     NVIC_SetVector(RTC1_IRQn, (uint32_t)RTC1_IRQHandler);
     
     // RTC is driven by the low frequency (32.768 kHz) clock, a proper request
diff --git a/targets/targets.json b/targets/targets.json
index f5d2210020..860f3fdd52 100644
--- a/targets/targets.json
+++ b/targets/targets.json
@@ -2657,7 +2657,7 @@
     "MCU_NRF52840": {
         "inherits": ["Target"],
         "core": "Cortex-M4F",
-        "macros": ["TARGET_NRF52840", "BLE_STACK_SUPPORT_REQD", "SOFTDEVICE_PRESENT", "S140", "NRF_SD_BLE_API_VERSION=5", "NRF52840_XXAA", "NRF_DFU_SETTINGS_VERSION=1"],
+        "macros": ["TARGET_NRF52840", "BLE_STACK_SUPPORT_REQD", "SOFTDEVICE_PRESENT", "S140", "NRF_SD_BLE_API_VERSION=5", "NRF52840_XXAA", "NRF_DFU_SETTINGS_VERSION=1", "NRF_SD_BLE_API_VERSION=5"],
         "extra_labels": ["NORDIC", "MCU_NRF52840", "NRF5_SDK13"],
         "OUTPUT_EXT": "hex",
         "is_disk_virtual": true,
@@ -2695,7 +2695,7 @@
     "NRF52840_DK": {
         "supported_form_factors": ["ARDUINO"],
         "inherits": ["MCU_NRF52840"],
-        "macros_add": ["BOARD_PCA10056", "CONFIG_GPIO_AS_PINRESET", "SWI_DISABLE0"],
+        "macros_add": ["BOARD_PCA10056", "CONFIG_GPIO_AS_PINRESET", "SWI_DISABLE0", "NRF52_ERRATA_20"],
         "device_has": ["ANALOGIN", "ERROR_PATTERN", "I2C", "I2C_ASYNCH", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_ASYNCH", "SERIAL_FC", "SLEEP", "SPI", "SPI_ASYNCH", "SPISLAVE"],
         "release_versions": ["2", "5"],
         "device_name": "nRF52840_xxAA"