Diff: targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/rtc_api.c

Revision:

0:9b334a45a8ff

Child:

50:a417edff4437

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/rtc_api.c	Thu Oct 01 15:25:22 2015 +0300
@@ -0,0 +1,172 @@
+/***************************************************************************//**
+ * @file rtc_api.c
+ *******************************************************************************
+ * @section License
+ * <b>(C) Copyright 2015 Silicon Labs, 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.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ *
+ * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no
+ * obligation to support this Software. Silicon Labs 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 Labs 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 "device.h"
+#if DEVICE_RTC
+
+#include "rtc_api.h"
+#include "rtc_api_HAL.h"
+#include "em_cmu.h"
+#include "em_rtc.h"
+#include "sleep_api.h"
+#include "sleepmodes.h"
+
+static bool         rtc_inited  = false;
+static time_t       time_base   = 0;
+static uint32_t     useflags    = 0;
+static uint32_t     time_extend = 0;
+
+static void (*comp0_handler)(void) = NULL;
+
+#define RTC_LEAST_ACTIVE_SLEEPMODE  EM2
+#define RTC_NUM_BITS                (24)
+
+void RTC_IRQHandler(void)
+{
+    uint32_t flags;
+    flags = RTC_IntGet();
+    if (flags & RTC_IF_OF) {
+        RTC_IntClear(RTC_IF_OF);
+        /* RTC has overflowed (24 bits). Use time_extend as software counter for 32 more bits. */
+        time_extend += 1;
+    }
+    if (flags & RTC_IF_COMP0) {
+        RTC_IntClear(RTC_IF_COMP0);
+        if (comp0_handler != NULL) {
+            comp0_handler();
+        }
+    }
+}
+
+uint32_t rtc_get_32bit(void) 
+{
+    return (RTC_CounterGet() + (time_extend << RTC_NUM_BITS));
+}
+
+uint64_t rtc_get_full(void) 
+{
+    uint64_t ticks = 0;
+    ticks += time_extend;
+    ticks = ticks << RTC_NUM_BITS;
+    ticks += RTC_CounterGet();
+    return ticks;
+}
+
+void rtc_set_comp0_handler(uint32_t handler)
+{
+    comp0_handler = (void (*)(void)) handler;
+}
+
+void rtc_init(void)
+{
+    /* Register that the RTC is used for timekeeping. */
+    rtc_init_real(RTC_INIT_RTC);
+}
+
+
+void rtc_init_real(uint32_t flags)
+{
+    useflags |= flags;
+
+    if (!rtc_inited) {
+        CMU_ClockEnable(cmuClock_RTC, true);
+
+        /* Enable clock to the interface of the low energy modules */
+        CMU_ClockEnable(cmuClock_CORELE, true);
+
+        /* Scale clock to save power */
+        CMU_ClockDivSet(cmuClock_RTC, RTC_CLOCKDIV);
+
+        /* Initialize RTC */
+        RTC_Init_TypeDef init = RTC_INIT_DEFAULT;
+        init.enable = 1;
+        /* Don't use compare register 0 as top value */
+        init.comp0Top = 0;
+
+        /* Enable Interrupt from RTC */
+        RTC_IntEnable(RTC_IEN_OF);
+        NVIC_EnableIRQ(RTC_IRQn);
+        NVIC_SetVector(RTC_IRQn, (uint32_t)RTC_IRQHandler);
+
+        /* Initialize */
+        RTC_Init(&init);
+
+        blockSleepMode(RTC_LEAST_ACTIVE_SLEEPMODE);
+        rtc_inited = true;
+    }
+}
+
+void rtc_free(void)
+{
+    rtc_free_real(RTC_INIT_RTC);
+}
+
+void rtc_free_real(uint32_t flags)
+{
+    /* Clear use flag */
+    useflags &= ~flags;
+
+    /* Disable the RTC if it was inited and is no longer in use by anyone. */
+    if (rtc_inited && (useflags == 0)) {
+        NVIC_DisableIRQ(RTC_IRQn);
+        RTC_Reset();
+        CMU_ClockEnable(cmuClock_RTC, false);
+        unblockSleepMode(RTC_LEAST_ACTIVE_SLEEPMODE);
+        rtc_inited = false;
+    }
+}
+
+int rtc_isenabled(void)
+{
+    return rtc_inited;
+}
+
+time_t rtc_read(void)
+{
+    return (time_t) (rtc_get_full() >> RTC_FREQ_SHIFT) + time_base;
+}
+
+time_t rtc_read_uncompensated(void) 
+{
+    return (time_t) (rtc_get_full() >> RTC_FREQ_SHIFT);
+}
+
+void rtc_write(time_t t)
+{
+    /* We have to check that the RTC did not tick while doing this. */
+    /* If the RTC ticks we just redo this. */
+    uint32_t time;
+    do {
+        time = rtc_read_uncompensated();
+        time_base = t - time;
+    } while (time != rtc_read_uncompensated());
+}
+
+#endif