From a3a0be11dc5a81a36fb2b36b37780ea5d733d9fe Mon Sep 17 00:00:00 2001
From: Stephane D'Alu <sdalu@sdalu.com>
Date: Fri, 5 Feb 2016 18:58:31 +0100
Subject: moved from HFCLK TIMER to RTC LFCLK

---
 os/hal/boards/NRF51-DK/board.h        |  2 +-
 os/hal/boards/WVSHARE_BLE400/board.h  |  2 +-
 os/hal/ports/NRF51/NRF51822/hal_lld.c | 29 ++++++++++++++++++++++++++
 os/hal/ports/NRF51/NRF51822/hal_lld.h |  4 +++-
 os/hal/ports/NRF51/NRF51822/st_lld.c  | 38 ++++++++++++-----------------------
 5 files changed, 47 insertions(+), 28 deletions(-)

(limited to 'os/hal')

diff --git a/os/hal/boards/NRF51-DK/board.h b/os/hal/boards/NRF51-DK/board.h
index 5e0c738..abd8f7a 100644
--- a/os/hal/boards/NRF51-DK/board.h
+++ b/os/hal/boards/NRF51-DK/board.h
@@ -22,7 +22,7 @@
 #define BOARD_NAME              "nRF51 DK"
 
 /* Board oscillators-related settings. */
-#define XTAL_VALUE              16000000
+#define NRF51_XTAL_VALUE        16000000
 
 /* GPIO pins. */
 #define BTN1           17
diff --git a/os/hal/boards/WVSHARE_BLE400/board.h b/os/hal/boards/WVSHARE_BLE400/board.h
index 57578b5..536b7f6 100644
--- a/os/hal/boards/WVSHARE_BLE400/board.h
+++ b/os/hal/boards/WVSHARE_BLE400/board.h
@@ -22,7 +22,7 @@
 #define BOARD_NAME              "WvShare BLE400"
 
 /* Board oscillators-related settings. */
-#define XTAL_VALUE              16000000
+#define NRF51_XTAL_VALUE        16000000
 
 /* GPIO pins. */
 #define KEY1           16
diff --git a/os/hal/ports/NRF51/NRF51822/hal_lld.c b/os/hal/ports/NRF51/NRF51822/hal_lld.c
index e1d2ed5..3e74068 100644
--- a/os/hal/ports/NRF51/NRF51822/hal_lld.c
+++ b/os/hal/ports/NRF51/NRF51822/hal_lld.c
@@ -55,6 +55,35 @@
  */
 void hal_lld_init(void)
 {
+  /* High frequency clock initialisation
+   *  (If NRF51_XTAL_VALUE is not defined assume its an RC oscillator)
+   */
+#if defined(NRF51_XTAL_VALUE)
+#if   NRF51_XTAL_VALUE == 16000000
+  NRF_CLOCK->XTALFREQ = 0xFF;
+#elif NRF51_XTAL_VALUE == 32000000
+  NRF_CLOCK->XTALFREQ = 0x00;
+#endif
+#endif
+  NRF_CLOCK->TASKS_HFCLKSTOP = 1;
+  
+  /* Low frequency clock initialisation
+   * If source not specified, use the internal RC (0) which is prefered 
+   * over synthetized clock from the high frequency clock (2)
+   */
+#if defined(NRF51_LFCLK_SOURCE)
+#if (NRF51_LFCLK_SOURCE >=0) && (NRF51_LFCLK_SOURCE <= 2)
+  NRF_CLOCK->LFCLKSRC = NRF51_LFCLK_SOURCE;
+#else
+#error "Possible value for NRF51_LFCLK_SOURCE are 0=RC, 1=XTAL, 2=Synth"
+#endif
+#else
+  NRF_CLOCK->LFCLKSRC = 0;
+#endif
+  
+#if (OSAL_ST_MODE != OSAL_ST_MODE_NONE)
+  NRF_CLOCK->TASKS_LFCLKSTART = 1;
+#endif
 }
 
 /**
diff --git a/os/hal/ports/NRF51/NRF51822/hal_lld.h b/os/hal/ports/NRF51/NRF51822/hal_lld.h
index 1cc9057..b685667 100644
--- a/os/hal/ports/NRF51/NRF51822/hal_lld.h
+++ b/os/hal/ports/NRF51/NRF51822/hal_lld.h
@@ -44,9 +44,11 @@
 /*===========================================================================*/
 
 /*===========================================================================*/
-/* Derived constants and error checks.                                       */
+/* Driver constants and error checks.                                       */
 /*===========================================================================*/
 
+#define NRF51_LFCLK_FREQUENCY  32768
+
 /*===========================================================================*/
 /* Driver data structures and types.                                         */
 /*===========================================================================*/
diff --git a/os/hal/ports/NRF51/NRF51822/st_lld.c b/os/hal/ports/NRF51/NRF51822/st_lld.c
index 526db35..d8c7b6c 100644
--- a/os/hal/ports/NRF51/NRF51822/st_lld.c
+++ b/os/hal/ports/NRF51/NRF51822/st_lld.c
@@ -52,19 +52,17 @@
 
 #if (OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC) || defined(__DOXYGEN__)
 /**
- * @brief   System Timer vector.
+ * @brief   System Timer vector (RTC0)
  * @details This interrupt is used for system tick in periodic mode.
  *
  * @isr
  */
-OSAL_IRQ_HANDLER(Vector60) {
+OSAL_IRQ_HANDLER(Vector6C) {
 
   OSAL_IRQ_PROLOGUE();
 
-  /* Clear timer compare event */
-  if (NRF_TIMER0->EVENTS_COMPARE[0] != 0)
-    NRF_TIMER0->EVENTS_COMPARE[0] = 0;
-
+  NRF_RTC0->EVENTS_TICK = 0;
+      
   osalSysLockFromISR();
   osalOsTimerHandlerI();
   osalSysUnlockFromISR();
@@ -83,29 +81,19 @@ OSAL_IRQ_HANDLER(Vector60) {
  * @notapi
  */
 void st_lld_init(void) {
+#if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING)
 
-#if OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC
-  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;
+#endif /* OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING */
 
-  /*
-   * Configure timer 0 compare capture 0 to generate interrupt
-   * and clear timer value when event is generated.
-   */
-  NRF_TIMER0->CC[0] = (1000000 / OSAL_ST_FREQUENCY) - 1;
-  NRF_TIMER0->SHORTS = 1;
-  NRF_TIMER0->INTENSET = 0x10000;
-
-  nvicEnableVector(TIMER0_IRQn, 8);
+#if OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC
+  /* Using RTC with prescaler */
+  NRF_RTC0->TASKS_STOP  = 1;
+  NRF_RTC0->PRESCALER   = (NRF51_LFCLK_FREQUENCY / OSAL_ST_FREQUENCY) - 1; 
+  NRF_RTC0->INTENSET    = RTC_INTENSET_TICK_Msk;
 
   /* Start timer */
-  NRF_TIMER0->TASKS_START = 1;
+  nvicEnableVector(RTC0_IRQn, 8);
+  NRF_RTC0->TASKS_START = 1;
 #endif
 
 }
-- 
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