From 90800edb90ad0fcf8e7f53e5d32a4df9a0c62c6c Mon Sep 17 00:00:00 2001
From: Stephane D'Alu <sdalu@sdalu.com>
Date: Sat, 6 Feb 2016 02:15:26 +0100
Subject: [PATCH] fixed tickless for RTC, removed it for TIMER

---
 os/hal/ports/NRF51/NRF51822/st_lld.c | 48 +---------------------------
 os/hal/ports/NRF51/NRF51822/st_lld.h | 45 ++++----------------------
 2 files changed, 7 insertions(+), 86 deletions(-)

diff --git a/os/hal/ports/NRF51/NRF51822/st_lld.c b/os/hal/ports/NRF51/NRF51822/st_lld.c
index 51f942bb..e3ae3f24 100644
--- a/os/hal/ports/NRF51/NRF51822/st_lld.c
+++ b/os/hal/ports/NRF51/NRF51822/st_lld.c
@@ -129,30 +129,6 @@ OSAL_IRQ_HANDLER(Vector6C) {
   OSAL_IRQ_EPILOGUE();
 }
 #endif
-
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
-/**
- * @brief   System Timer vector. (TIMER0)
- * @details This interrupt is used for freerunning mode (tick-less)
- *          if selected with NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER
- *
- * @isr
- */
-OSAL_IRQ_HANDLER(Vector60) {
-
-  OSAL_IRQ_PROLOGUE();
-
-  /* Clear timer compare event */
-  if (NRF_TIMER0->EVENTS_COMPARE[0] != 0)
-    NRF_TIMER0->EVENTS_COMPARE[0] = 0;
-
-  osalSysLockFromISR();
-  osalOsTimerHandlerI();
-  osalSysUnlockFromISR();
-
-  OSAL_IRQ_EPILOGUE();
-}
-#endif
 #endif
 
 /*===========================================================================*/
@@ -172,34 +148,12 @@ void st_lld_init(void) {
   NRF_RTC0->PRESCALER   = (NRF51_LFCLK_FREQUENCY / OSAL_ST_FREQUENCY) - 1; 
   NRF_RTC0->EVTENCLR    = RTC_EVTEN_COMPARE0_Msk;
   NRF_RTC0->EVENTS_COMPARE[0] = 0;
+  NRF_RTC0->INTENSET    = RTC_INTENSET_COMPARE0_Msk;
 
   /* Start timer */
   nvicEnableVector(RTC0_IRQn, 8);
   NRF_RTC0->TASKS_START = 1;
 #endif
-
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
-  NRF_TIMER0->TASKS_CLEAR = 1;
-
-  /*
-   * Using 32-bit mode with prescaler 16 configures this
-   * timer with a 1MHz clock.
-   */
-  NRF_TIMER0->BITMODE = 3;
-  NRF_TIMER0->PRESCALER = 4;
-
-  /*
-   * Configure timer 0 compare capture 1 to generate interrupt
-   * for overflow according to ST_OVERFLOW_VALUE
-   */
-  NRF_TIMER0->CC[0] = (1000000 / OSAL_ST_FREQUENCY) - 1;
-  NRF_TIMER0->SHORTS = 1;
-  NRF_TIMER0->INTENSET = 0x10000;
-
-  /* Start timer */
-  nvicEnableVector(TIMER0_IRQn, 8);
-  NRF_TIMER0->TASKS_START = 1;
-#endif
 #endif /* OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING */
 
 #if OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC
diff --git a/os/hal/ports/NRF51/NRF51822/st_lld.h b/os/hal/ports/NRF51/NRF51822/st_lld.h
index 3f47a115..412f4fd2 100644
--- a/os/hal/ports/NRF51/NRF51822/st_lld.h
+++ b/os/hal/ports/NRF51/NRF51822/st_lld.h
@@ -70,8 +70,9 @@
 #error "CH_CFG_ST_TIMEDELTA is too low"
 #endif
 
-#if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING)
-#error "Freeruning (tick-less) mode currently not working"
+#if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING) && \
+    (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
+#error "Freeruning (tick-less) mode not supported with TIMER, use RTC"
 #endif
 
 /*===========================================================================*/
@@ -106,13 +107,7 @@ extern "C" {
  * @notapi
  */
 static inline systime_t st_lld_get_counter(void) {
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
   return (systime_t)NRF_RTC0->COUNTER;
-#endif
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
-  NRF_TIMER0->TASKS_CAPTURE[1] = 1;
-  return (systime_t)NRF_TIMER0->CC[1];
-#endif
 }
 
 /**
@@ -125,16 +120,9 @@ static inline systime_t st_lld_get_counter(void) {
  * @notapi
  */
 static inline void st_lld_start_alarm(systime_t abstime) {
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
   NRF_RTC0->CC[0]               = abstime;
   NRF_RTC0->EVENTS_COMPARE[0]   = 0;
-  NRF_RTC0->EVTENSET            = RTC_EVTEN_COMPARE0_Msk;
-#endif
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
-  NRF_TIMER0->CC[0]             = abstime;
-  NRF_TIMER0->EVENTS_COMPARE[0] = 0;
-  NRF_TIMER0->INTENSET          = TIMER_INTENSET_COMPARE0_Msk;
-#endif
+  NRF_RTC0->EVTENSET            = RTC_EVTENSET_COMPARE0_Msk;
 }
 
 /**
@@ -143,14 +131,8 @@ static inline void st_lld_start_alarm(systime_t abstime) {
  * @notapi
  */
 static inline void st_lld_stop_alarm(void) {
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
-  NRF_RTC0->EVTENCLR            = RTC_EVTEN_COMPARE0_Msk;
+  NRF_RTC0->EVTENCLR            = RTC_EVTENCLR_COMPARE0_Msk;
   NRF_RTC0->EVENTS_COMPARE[0]   = 0;
-#endif
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
-  NRF_TIMER0->INTENCLR          = TIMER_INTENCLR_COMPARE0_Msk;
-  NRF_TIMER0->EVENTS_COMPARE[0] = 0;
-#endif
 }
 
 /**
@@ -161,12 +143,7 @@ static inline void st_lld_stop_alarm(void) {
  * @notapi
  */
 static inline void st_lld_set_alarm(systime_t abstime) {
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
     NRF_RTC0->CC[0]             = abstime;
-#endif
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
-    NRF_TIMER0->CC[0]           = abstime;
-#endif
 }
 
 /**
@@ -177,12 +154,7 @@ static inline void st_lld_set_alarm(systime_t abstime) {
  * @notapi
  */
 static inline systime_t st_lld_get_alarm(void) {
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
   return (systime_t)NRF_RTC0->CC[0];
-#endif
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
-  return (systime_t)NRF_TIMER0->CC[0];
-#endif
 }
 
 /**
@@ -195,12 +167,7 @@ static inline systime_t st_lld_get_alarm(void) {
  * @notapi
  */
 static inline bool st_lld_is_alarm_active(void) {
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
-  return NRF_RTC0->EVTEN & RTC_INTENSET_COMPARE0_Msk;
-#endif
-#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
-  return false;
-#endif
+  return NRF_RTC0->EVTEN & RTC_EVTEN_COMPARE0_Msk;
 }
 
 #endif /* _ST_LLD_H_ */