1 files changed, 115 insertions, 0 deletions
diff --git a/os/hal/ports/NRF51/NRF51822/st_lld.c b/os/hal/ports/NRF51/NRF51822/st_lld.c
new file mode 100644
index 0000000..526db35
--- /dev/null
+++ b/os/hal/ports/NRF51/NRF51822/st_lld.c
@@ -0,0 +1,115 @@
+/*
+    ChibiOS - Copyright (C) 2015 Fabio Utzig
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
+
+/**
+ * @file    st_lld.c
+ * @brief   NRF51822 ST subsystem low level driver source.
+ *
+ * @addtogroup ST
+ * @{
+ */
+
+#include "hal.h"
+
+#if (OSAL_ST_MODE != OSAL_ST_MODE_NONE) || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver local definitions.                                                 */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported variables.                                                */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local types.                                                       */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local variables and types.                                         */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions.                                                   */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver interrupt handlers.                                                */
+/*===========================================================================*/
+
+#if (OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC) || defined(__DOXYGEN__)
+/**
+ * @brief   System Timer vector.
+ * @details This interrupt is used for system tick in periodic mode.
+ *
+ * @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 /* OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC */
+
+/*===========================================================================*/
+/* Driver exported functions.                                                */
+/*===========================================================================*/
+
+/**
+ * @brief   Low level ST driver initialization.
+ *
+ * @notapi
+ */
+void st_lld_init(void) {
+
+#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;
+
+  /*
+   * 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);
+
+  /* Start timer */
+  NRF_TIMER0->TASKS_START = 1;
+#endif
+
+}
+
+#endif /* OSAL_ST_MODE != OSAL_ST_MODE_NONE */
+
+/** @} */