try to implement tick-less mode

os/hal/ports/NRF51/NRF51822/st_lld.c

@@ -31,6 +31,14 @@
 /* Driver local definitions.                                                 */
 /*===========================================================================*/
 
+#if   (OSAL_ST_RESOLUTION == 32)
+#define ST_OVERFLOW_VALUE                         0xFFFFFFFF
+#elif (OSAL_ST_RESOLUTION == 24)
+#define ST_OVERFLOW_VALUE                         0x00FFFFFF
+#elif (OSAL_ST_RESOLUTION == 16)
+#define ST_OVERFLOW_VALUE                         0x0000FFFF
+#endif
+
 /*===========================================================================*/
 /* Driver exported variables.                                                */
 /*===========================================================================*/
@@ -52,7 +60,6 @@
 /*===========================================================================*/
 
 #if (OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC) || defined(__DOXYGEN__)
-
 #if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
 /**
  * @brief   System Timer vector (RTC0)
@@ -98,9 +105,56 @@ OSAL_IRQ_HANDLER(Vector60) {
   OSAL_IRQ_EPILOGUE();
 }
 #endif
-
 #endif /* OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC */
 
+#if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING) || defined(__DOXYGEN__)
+#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
+/**
+ * @brief   System Timer vector (RTC0)
+ * @details This interrupt is used for freerunning mode (tick-less)
+ *          if selected with NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC
+ *
+ * @isr
+ */
+OSAL_IRQ_HANDLER(Vector6C) {
+
+  OSAL_IRQ_PROLOGUE();
+
+  NRF_RTC0->EVENTS_COMPARE[0] = 0;
+      
+  osalSysLockFromISR();
+  osalOsTimerHandlerI();
+  osalSysUnlockFromISR();
+
+  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
+
 /*===========================================================================*/
 /* Driver exported functions.                                                */
 /*===========================================================================*/
@@ -112,11 +166,43 @@ OSAL_IRQ_HANDLER(Vector60) {
  */
 void st_lld_init(void) {
 #if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING)
+#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
+  /* Using RTC with prescaler */
+  NRF_RTC0->TASKS_STOP  = 1;
+  NRF_RTC0->PRESCALER   = (NRF51_LFCLK_FREQUENCY / OSAL_ST_FREQUENCY) - 1; 
+  NRF_RTC0->EVTENCLR    = RTC_EVTEN_COMPARE0_Msk;
+  NRF_RTC0->EVENTS_COMPARE[0] = 0;
 
+  /* 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
-
 #if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
   /* Using RTC with prescaler */
   NRF_RTC0->TASKS_STOP  = 1;
@@ -150,7 +236,6 @@ void st_lld_init(void) {
   nvicEnableVector(TIMER0_IRQn, 8);
   NRF_TIMER0->TASKS_START = 1;
 #endif
-
 #endif
 }
 

os/hal/ports/NRF51/NRF51822/st_lld.h

@@ -27,17 +27,19 @@
 #ifndef _ST_LLD_H_
 #define _ST_LLD_H_
 
+#include "halconf.h"
+
 /*===========================================================================*/
 /* Driver constants.                                                         */
 /*===========================================================================*/
 
 /**
- * @brief   SPI0 interrupt priority level setting.
+ * @brief   System ticks implementer as a timer.
  */
 #define NRF51_SYSTEM_TICKS_AS_TIMER    1
 
 /**
- * @brief   SPI0 interrupt priority level setting.
+ * @brief   System ticks implementer as an rtc.
  */
 #define NRF51_SYSTEM_TICKS_AS_RTC      2
 
@@ -64,6 +66,14 @@
 #error "NRF51_SYSTEM_TICKS illegal value"
 #endif
 
+#if defined(CH_CFG_ST_TIMEDELTA) && CH_CFG_ST_TIMEDELTA < 5
+#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"
+#endif
+
 /*===========================================================================*/
 /* Driver data structures and types.                                         */
 /*===========================================================================*/
@@ -96,8 +106,13 @@ extern "C" {
  * @notapi
  */
 static inline systime_t st_lld_get_counter(void) {
-
+#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_RTC)
-  return (systime_t)0;
+  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
 }
 
 /**
@@ -110,8 +125,16 @@ 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)
-  (void)abstime;
+  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
 }
 
 /**
@@ -120,7 +143,14 @@ 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->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
 }
 
 /**
@@ -131,8 +161,12 @@ 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)
-  (void)abstime;
+    NRF_RTC0->CC[0]             = abstime;
+#endif
+#if (NRF51_SYSTEM_TICKS == NRF51_SYSTEM_TICKS_AS_TIMER)
+    NRF_TIMER0->CC[0]           = abstime;
+#endif
 }
 
 /**
@@ -143,8 +177,12 @@ 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)0;
+  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
 }
 
 /**
@@ -157,8 +195,12 @@ 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
 }
 
 #endif /* _ST_LLD_H_ */