Diff: targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/system_efm32wg.c

Revision:

150:02e0a0aed4ec

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/TARGET_EFM32WG/device/system_efm32wg.c	Tue Nov 08 17:45:16 2016 +0000
@@ -0,0 +1,404 @@
+/***************************************************************************//**
+ * @file system_efm32wg.c
+ * @brief CMSIS Cortex-M4 System Layer for EFM32WG devices.
+ * @version 5.0.0
+ ******************************************************************************
+ * @section License
+ * <b>Copyright 2016 Silicon Laboratories, Inc. http://www.silabs.com</b>
+ ******************************************************************************
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software.@n
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.@n
+ * 3. This notice may not be removed or altered from any source distribution.
+ *
+ * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Laboratories, Inc.
+ * has no obligation to support this Software. Silicon Laboratories, Inc. is
+ * providing the Software "AS IS", with no express or implied warranties of any
+ * kind, including, but not limited to, any implied warranties of
+ * merchantability or fitness for any particular purpose or warranties against
+ * infringement of any proprietary rights of a third party.
+ *
+ * Silicon Laboratories, Inc. will not be liable for any consequential,
+ * incidental, or special damages, or any other relief, or for any claim by
+ * any third party, arising from your use of this Software.
+ *
+ *****************************************************************************/
+
+#include <stdint.h>
+#include "em_device.h"
+
+/*******************************************************************************
+ ******************************   DEFINES   ************************************
+ ******************************************************************************/
+
+/** LFRCO frequency, tuned to below frequency during manufacturing. */
+#define EFM32_LFRCO_FREQ  (32768UL)
+#define EFM32_ULFRCO_FREQ (1000UL)
+
+/*******************************************************************************
+ **************************   LOCAL VARIABLES   ********************************
+ ******************************************************************************/
+
+/* System oscillator frequencies. These frequencies are normally constant */
+/* for a target, but they are made configurable in order to allow run-time */
+/* handling of different boards. The crystal oscillator clocks can be set */
+/* compile time to a non-default value by defining respective EFM32_nFXO_FREQ */
+/* values according to board design. By defining the EFM32_nFXO_FREQ to 0, */
+/* one indicates that the oscillator is not present, in order to save some */
+/* SW footprint. */
+
+#ifndef EFM32_HFXO_FREQ
+#define EFM32_HFXO_FREQ (48000000UL)
+#endif
+
+#define EFM32_HFRCO_MAX_FREQ (28000000UL)
+
+/* Do not define variable if HF crystal oscillator not present */
+#if (EFM32_HFXO_FREQ > 0)
+/** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
+/** System HFXO clock. */
+static uint32_t SystemHFXOClock = EFM32_HFXO_FREQ;
+/** @endcond (DO_NOT_INCLUDE_WITH_DOXYGEN) */
+#endif
+
+#ifndef EFM32_LFXO_FREQ
+#define EFM32_LFXO_FREQ (EFM32_LFRCO_FREQ)
+#endif
+
+/* Do not define variable if LF crystal oscillator not present */
+#if (EFM32_LFXO_FREQ > 0)
+/** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
+/** System LFXO clock. */
+static uint32_t SystemLFXOClock = EFM32_LFXO_FREQ;
+/** @endcond (DO_NOT_INCLUDE_WITH_DOXYGEN) */
+#endif
+
+/* Inline function to get the chip's Production Revision. */
+__STATIC_INLINE uint8_t GetProdRev(void)
+{
+  return ((DEVINFO->PART & _DEVINFO_PART_PROD_REV_MASK)
+                         >> _DEVINFO_PART_PROD_REV_SHIFT);
+}
+
+/*******************************************************************************
+ **************************   GLOBAL VARIABLES   *******************************
+ ******************************************************************************/
+
+/**
+ * @brief
+ *   System System Clock Frequency (Core Clock).
+ *
+ * @details
+ *   Required CMSIS global variable that must be kept up-to-date.
+ */
+uint32_t SystemCoreClock;
+
+/*******************************************************************************
+ **************************   GLOBAL FUNCTIONS   *******************************
+ ******************************************************************************/
+
+/***************************************************************************//**
+ * @brief
+ *   Get the current core clock frequency.
+ *
+ * @details
+ *   Calculate and get the current core clock frequency based on the current
+ *   configuration. Assuming that the SystemCoreClock global variable is
+ *   maintained, the core clock frequency is stored in that variable as well.
+ *   This function will however calculate the core clock based on actual HW
+ *   configuration. It will also update the SystemCoreClock global variable.
+ *
+ * @note
+ *   This is an EFM32 proprietary function, not part of the CMSIS definition.
+ *
+ * @return
+ *   The current core clock frequency in Hz.
+ ******************************************************************************/
+uint32_t SystemCoreClockGet(void)
+{
+  uint32_t ret;
+
+  ret = SystemHFClockGet();
+  ret >>= (CMU->HFCORECLKDIV & _CMU_HFCORECLKDIV_HFCORECLKDIV_MASK) >>
+          _CMU_HFCORECLKDIV_HFCORECLKDIV_SHIFT;
+
+  /* Keep CMSIS variable up-to-date just in case */
+  SystemCoreClock = ret;
+
+  return ret;
+}
+
+
+/***************************************************************************//**
+ * @brief
+ *   Get the maximum core clock frequency.
+ *
+ * @note
+ *   This is an EFR32 proprietary function, not part of the CMSIS definition.
+ *
+ * @return
+ *   The maximum core clock frequency in Hz.
+ ******************************************************************************/
+uint32_t SystemMaxCoreClockGet(void)
+{
+  return (EFM32_HFRCO_MAX_FREQ > EFM32_HFXO_FREQ ? \
+          EFM32_HFRCO_MAX_FREQ : EFM32_HFXO_FREQ);
+}
+
+
+/***************************************************************************//**
+ * @brief
+ *   Get the current HFCLK frequency.
+ *
+ * @note
+ *   This is an EFM32 proprietary function, not part of the CMSIS definition.
+ *
+ * @return
+ *   The current HFCLK frequency in Hz.
+ ******************************************************************************/
+uint32_t SystemHFClockGet(void)
+{
+  uint32_t ret;
+
+  switch (CMU->STATUS & (CMU_STATUS_HFRCOSEL | CMU_STATUS_HFXOSEL |
+                         CMU_STATUS_LFRCOSEL | CMU_STATUS_LFXOSEL))
+  {
+    case CMU_STATUS_LFXOSEL:
+#if (EFM32_LFXO_FREQ > 0)
+      ret = SystemLFXOClock;
+#else
+      /* We should not get here, since core should not be clocked. May */
+      /* be caused by a misconfiguration though. */
+      ret = 0;
+#endif
+      break;
+
+    case CMU_STATUS_LFRCOSEL:
+      ret = EFM32_LFRCO_FREQ;
+      break;
+
+    case CMU_STATUS_HFXOSEL:
+#if (EFM32_HFXO_FREQ > 0)
+      ret = SystemHFXOClock;
+#else
+      /* We should not get here, since core should not be clocked. May */
+      /* be caused by a misconfiguration though. */
+      ret = 0;
+#endif
+      break;
+
+    default: /* CMU_STATUS_HFRCOSEL */
+      switch (CMU->HFRCOCTRL & _CMU_HFRCOCTRL_BAND_MASK)
+      {
+      case CMU_HFRCOCTRL_BAND_28MHZ:
+        ret = 28000000;
+        break;
+
+      case CMU_HFRCOCTRL_BAND_21MHZ:
+        ret = 21000000;
+        break;
+
+      case CMU_HFRCOCTRL_BAND_14MHZ:
+        ret = 14000000;
+        break;
+
+      case CMU_HFRCOCTRL_BAND_11MHZ:
+        ret = 11000000;
+        break;
+
+      case CMU_HFRCOCTRL_BAND_7MHZ:
+        if ( GetProdRev() >= 19 )
+          ret = 6600000;
+        else
+          ret = 7000000;
+        break;
+
+      case CMU_HFRCOCTRL_BAND_1MHZ:
+        if ( GetProdRev() >= 19 )
+          ret = 1200000;
+        else
+          ret = 1000000;
+        break;
+
+      default:
+        ret = 0;
+        break;
+      }
+      break;
+  }
+
+  return ret / (1U + ((CMU->CTRL & _CMU_CTRL_HFCLKDIV_MASK)
+                      >> _CMU_CTRL_HFCLKDIV_SHIFT));
+}
+
+
+/**************************************************************************//**
+ * @brief
+ *   Get high frequency crystal oscillator clock frequency for target system.
+ *
+ * @note
+ *   This is an EFM32 proprietary function, not part of the CMSIS definition.
+ *
+ * @return
+ *   HFXO frequency in Hz.
+ *****************************************************************************/
+uint32_t SystemHFXOClockGet(void)
+{
+  /* External crystal oscillator present? */
+#if (EFM32_HFXO_FREQ > 0)
+  return SystemHFXOClock;
+#else
+  return 0;
+#endif
+}
+
+
+/**************************************************************************//**
+ * @brief
+ *   Set high frequency crystal oscillator clock frequency for target system.
+ *
+ * @note
+ *   This function is mainly provided for being able to handle target systems
+ *   with different HF crystal oscillator frequencies run-time. If used, it
+ *   should probably only be used once during system startup.
+ *
+ * @note
+ *   This is an EFM32 proprietary function, not part of the CMSIS definition.
+ *
+ * @param[in] freq
+ *   HFXO frequency in Hz used for target.
+ *****************************************************************************/
+void SystemHFXOClockSet(uint32_t freq)
+{
+  /* External crystal oscillator present? */
+#if (EFM32_HFXO_FREQ > 0)
+  SystemHFXOClock = freq;
+
+  /* Update core clock frequency if HFXO is used to clock core */
+  if (CMU->STATUS & CMU_STATUS_HFXOSEL)
+  {
+    /* The function will update the global variable */
+    SystemCoreClockGet();
+  }
+#else
+  (void)freq; /* Unused parameter */
+#endif
+}
+
+
+/**************************************************************************//**
+ * @brief
+ *   Initialize the system.
+ *
+ * @details
+ *   Do required generic HW system init.
+ *
+ * @note
+ *   This function is invoked during system init, before the main() routine
+ *   and any data has been initialized. For this reason, it cannot do any
+ *   initialization of variables etc.
+ *****************************************************************************/
+void SystemInit(void)
+{
+#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
+  /* Set floating point coprosessor access mode. */
+  SCB->CPACR |= ((3UL << 10*2) |                    /* set CP10 Full Access */
+                 (3UL << 11*2)  );                  /* set CP11 Full Access */
+#endif
+}
+
+
+/**************************************************************************//**
+ * @brief
+ *   Get low frequency RC oscillator clock frequency for target system.
+ *
+ * @note
+ *   This is an EFM32 proprietary function, not part of the CMSIS definition.
+ *
+ * @return
+ *   LFRCO frequency in Hz.
+ *****************************************************************************/
+uint32_t SystemLFRCOClockGet(void)
+{
+  /* Currently we assume that this frequency is properly tuned during */
+  /* manufacturing and is not changed after reset. If future requirements */
+  /* for re-tuning by user, we can add support for that. */
+  return EFM32_LFRCO_FREQ;
+}
+
+
+/**************************************************************************//**
+ * @brief
+ *   Get ultra low frequency RC oscillator clock frequency for target system.
+ *
+ * @note
+ *   This is an EFM32 proprietary function, not part of the CMSIS definition.
+ *
+ * @return
+ *   ULFRCO frequency in Hz.
+ *****************************************************************************/
+uint32_t SystemULFRCOClockGet(void)
+{
+  /* The ULFRCO frequency is not tuned, and can be very inaccurate */
+  return EFM32_ULFRCO_FREQ;
+}
+
+
+/**************************************************************************//**
+ * @brief
+ *   Get low frequency crystal oscillator clock frequency for target system.
+ *
+ * @note
+ *   This is an EFM32 proprietary function, not part of the CMSIS definition.
+ *
+ * @return
+ *   LFXO frequency in Hz.
+ *****************************************************************************/
+uint32_t SystemLFXOClockGet(void)
+{
+  /* External crystal oscillator present? */
+#if (EFM32_LFXO_FREQ > 0)
+  return SystemLFXOClock;
+#else
+  return 0;
+#endif
+}
+
+
+/**************************************************************************//**
+ * @brief
+ *   Set low frequency crystal oscillator clock frequency for target system.
+ *
+ * @note
+ *   This function is mainly provided for being able to handle target systems
+ *   with different HF crystal oscillator frequencies run-time. If used, it
+ *   should probably only be used once during system startup.
+ *
+ * @note
+ *   This is an EFM32 proprietary function, not part of the CMSIS definition.
+ *
+ * @param[in] freq
+ *   LFXO frequency in Hz used for target.
+ *****************************************************************************/
+void SystemLFXOClockSet(uint32_t freq)
+{
+  /* External crystal oscillator present? */
+#if (EFM32_LFXO_FREQ > 0)
+  SystemLFXOClock = freq;
+
+  /* Update core clock frequency if LFXO is used to clock core */
+  if (CMU->STATUS & CMU_STATUS_LFXOSEL)
+  {
+    /* The function will update the global variable */
+    SystemCoreClockGet();
+  }
+#else
+  (void)freq; /* Unused parameter */
+#endif
+}