Iftikhar Aziz
4545
Fork of
mbed-dev
by 
Umar Naeem
Diff: targets/TARGET_ONSEMI/TARGET_NCS36510/rtc.c
- Revision:
- 149:156823d33999
- Child:
- 150:02e0a0aed4ec
diff -r 21d94c44109e -r 156823d33999 targets/TARGET_ONSEMI/TARGET_NCS36510/rtc.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_ONSEMI/TARGET_NCS36510/rtc.c Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,285 @@
+/**
+ *******************************************************************************
+ * @file rtc.c
+ * @brief Implementation of a Rtc driver
+ * @internal
+ * @author ON Semiconductor
+ * $Rev: 3525 $
+ * $Date: 2015-07-20 15:24:25 +0530 (Mon, 20 Jul 2015) $
+ ******************************************************************************
+ * Copyright 2016 Semiconductor Components Industries LLC (d/b/a ON Semiconductor).
+ * All rights reserved. This software and/or documentation is licensed by ON Semiconductor
+ * under limited terms and conditions. The terms and conditions pertaining to the software
+ * and/or documentation are available at http://www.onsemi.com/site/pdf/ONSEMI_T&C.pdf
+ * (ON Semiconductor Standard Terms and Conditions of Sale, Section 8 Software) and
+ * if applicable the software license agreement. Do not use this software and/or
+ * documentation unless you have carefully read and you agree to the limited terms and
+ * conditions. By using this software and/or documentation, you agree to the limited
+ * terms and conditions.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED
+ * OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
+ * ON SEMICONDUCTOR SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL,
+ * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
+ * @endinternal
+ *
+ * @ingroup rtc
+ *
+ * @details
+ * A real-time clock (RTC) is a computer clock ,that keeps track of the current time. The heart of the RTC is a series of
+ * freely running counters one for each time unit, The series of counters is linked as follows: a roll over event of
+ * the seconds counter produces a minutes enable pulse; a roll over event of the minutes counter produces an hours
+ * enable pulse, etc.Note that all Counter registers are in an undefined state on power-up.
+ * Use the Reset bit in the Control Register to reset the counters to their default values.
+ * DIVISOR is the register containing the value to divide the clock frequency to produce 1Hz strobe ; 1Hz strobe is used
+ * internally to time the incrementing of the Seconds Counter.
+ * There is a set of register to set the values in the counter for each time unit.from where time is start to increment.
+ * There is another set of register to set the ALARM ...Each of the Alarm Registers can be programmed with a value that
+ * is used to compare to a Counter Register in order to produce an alarm (an interrupt) when the values match.
+ * There is a programmable bit in each Alarm Register that determines if the alarm occurs upon a value match, or
+ * if the alarm occurs upon a Counter increment condition.
+ *
+ */
+#include "rtc.h"
+#include "mbed_assert.h"
+
+static uint16_t SubSecond;
+static uint64_t LastRtcTimeus;
+
+/* See rtc.h for details */
+void fRtcInit(void)
+{
+ CLOCK_ENABLE(CLOCK_RTC); /* enable rtc peripheral */
+ CLOCKREG->CCR.BITS.RTCEN = True; /* Enable RTC clock 32K */
+
+ /* Reset RTC control register */
+ RTCREG->CONTROL.WORD = False;
+
+ /* Initialize all counters */
+ RTCREG->SECOND_COUNTER = False;
+ RTCREG->SUB_SECOND_COUNTER = False;
+ RTCREG->SECOND_ALARM = False;
+ RTCREG->SUB_SECOND_ALARM = False;
+ LastRtcTimeus = 0;
+
+ /* Reset RTC Status register */
+ RTCREG->STATUS.WORD = False;
+
+ /* Clear interrupt status */
+ RTCREG->INT_CLEAR.WORD = False;
+
+ /* Start sec & sub_sec counter */
+ while(RTCREG->STATUS.BITS.BSY_CTRL_REG_WRT == True);/* Wait previous write to complete */
+ RTCREG->CONTROL.WORD |= ((True << RTC_CONTROL_SUBSEC_CNT_START_BIT_POS) |
+ (True << RTC_CONTROL_SEC_CNT_START_BIT_POS));
+
+ /* enable interruption associated with the rtc at NVIC level */
+ NVIC_SetVector(Rtc_IRQn,(uint32_t)fRtcHandler); /* TODO define lp_ticker_isr */
+ NVIC_ClearPendingIRQ(Rtc_IRQn);
+ NVIC_EnableIRQ(Rtc_IRQn);
+
+ while(RTCREG->STATUS.BITS.BSY_CTRL_REG_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+
+ return;
+}
+
+/* See rtc.h for details */
+void fRtcFree(void)
+{
+ /* Reset RTC control register */
+ RTCREG->CONTROL.WORD = False;
+
+ /* disable interruption associated with the rtc */
+ NVIC_DisableIRQ(Rtc_IRQn);
+
+ while(RTCREG->STATUS.BITS.BSY_CTRL_REG_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+}
+
+/* See rtc.h for details */
+void fRtcSetInterrupt(uint32_t timestamp)
+{
+ SubSecond = False;
+ uint32_t Second = False;
+ uint8_t DividerAdjust = 1;
+
+ if(timestamp) {
+ if(timestamp >= RTC_SEC_TO_US) {
+ /* TimeStamp is big enough to set second alarm */
+ Second = ((timestamp / RTC_SEC_TO_US) & RTC_SEC_MASK); /* Convert micro second to second */
+ RTCREG->SECOND_ALARM = Second; /* Write to alarm register */
+
+ /* Enable second interrupt */
+ RTCREG->CONTROL.WORD |= (True << RTC_CONTROL_SEC_CNT_INT_BIT_POS);
+ }
+ timestamp = timestamp - Second * RTC_SEC_TO_US; /* Take out micro second for sub second alarm */
+ if(timestamp > False) {
+ /* We have some thing for sub second */
+
+ /* Convert micro second to sub_seconds(each count = 30.5 us) */
+ if(timestamp > 131000) {
+ DividerAdjust = 100;
+ }
+
+ volatile uint64_t Temp = (timestamp / DividerAdjust * RTC_CLOCK_HZ);
+ Temp = (uint64_t)(Temp / RTC_SEC_TO_US * DividerAdjust);
+ SubSecond = Temp & RTC_SUB_SEC_MASK;
+
+ if(SubSecond <= 5) {
+ SubSecond = 0;
+ }
+
+
+ if(SubSecond > False) {
+ /* Second interrupt not enabled */
+
+ /* Set SUB SEC_ALARM */
+ RTCREG->SUB_SECOND_ALARM = SubSecond; /* Write to sub second alarm */
+
+ /* Enable sub second interrupt */
+ while(RTCREG->STATUS.BITS.BSY_CTRL_REG_WRT == True);
+ RTCREG->CONTROL.WORD |= (True << RTC_CONTROL_SUBSEC_CNT_INT_BIT_POS);
+ }
+ }
+
+ while(RTCREG->STATUS.BITS.BSY_ANY_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+ }
+ return;
+}
+
+/* See rtc.h for details */
+void fRtcDisableInterrupt(void)
+{
+ /* Disable subsec/sec interrupt */
+ RTCREG->CONTROL.WORD &= ~((RTC_ALL_INTERRUPT_BIT_VAL) << RTC_CONTROL_SUBSEC_CNT_INT_BIT_POS);
+ while(RTCREG->STATUS.BITS.BSY_CTRL_REG_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+}
+
+/* See rtc.h for details */
+void fRtcEnableInterrupt(void)
+{
+ /* Disable subsec/sec interrupt */
+ RTCREG->CONTROL.WORD |= ((RTC_ALL_INTERRUPT_BIT_VAL) << RTC_CONTROL_SUBSEC_CNT_INT_BIT_POS);
+ while(RTCREG->STATUS.BITS.BSY_CTRL_REG_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+}
+
+/* See rtc.h for details */
+void fRtcClearInterrupt(void)
+{
+ /* Disable subsec/sec interrupt */
+ /* Clear sec & sub_sec interrupts */
+ RTCREG->INT_CLEAR.WORD = ((True << RTC_INT_CLR_SUB_SEC_BIT_POS) |
+ (True << RTC_INT_CLR_SEC_BIT_POS));
+ while(RTCREG->STATUS.BITS.BSY_ANY_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+}
+
+/* See rtc.h for details */
+uint64_t fRtcRead(void)
+{
+ uint32_t Second;
+ uint16_t SubSecond;
+
+ /* Hardware Bug fix: The rollover of the sub-second counter initiates the increment of the second counter.
+ * That means there is one cycle where the sub-second has rolled back to zero and the second counter has not incremented
+ * and a read during that cycle will be incorrect. That will occur for one RTC cycle and that is about 31us of exposure.
+ * If you read a zero in the sub-second counter then increment the second counter by 1.
+ * Alternatively, subtract 1 from the Sub-seconds counter to align the Second and Sub-Second rollover.
+ */
+
+ /* Read the Second and Sub-second counters, then read the Second counter again.
+ * If it changed, then the Second rolled over while reading Sub-seconds, so go back and read them both again.
+ */
+
+ do {
+ Second = RTCREG->SECOND_COUNTER; /* Get SEC_COUNTER reg value */
+ SubSecond = (RTCREG->SUB_SECOND_COUNTER - 1) & 0x7FFF; /* Get SUB_SEC_COUNTER reg value */
+ } while (Second != RTCREG->SECOND_COUNTER); /* Repeat if the second has changed */
+
+ //note: casting to float removed to avoid reduction in resolution
+ uint64_t RtcTimeus = ((uint64_t)SubSecond * RTC_SEC_TO_US / RTC_CLOCK_HZ) + ((uint64_t)Second * RTC_SEC_TO_US);
+
+ /*check that the time did not go backwards */
+ MBED_ASSERT(RtcTimeus >= LastRtcTimeus);
+ LastRtcTimeus = RtcTimeus;
+
+ return RtcTimeus;
+}
+
+/* See rtc.h for details */
+void fRtcWrite(uint64_t RtcTimeus)
+{
+ uint32_t Second = 0;
+ uint16_t SubSecond = 0;
+ /* Stop RTC */
+ RTCREG->CONTROL.WORD &= ~((True << RTC_CONTROL_SUBSEC_CNT_START_BIT_POS) |
+ (True << RTC_CONTROL_SEC_CNT_START_BIT_POS));
+
+ if(RtcTimeus > RTC_SEC_TO_US) {
+ /* TimeStamp is big enough to set second counter */
+ Second = ((RtcTimeus / RTC_SEC_TO_US) & RTC_SEC_MASK);
+ }
+ RTCREG->SECOND_COUNTER = Second;
+ RtcTimeus = RtcTimeus - (Second * RTC_SEC_TO_US);
+ if(RtcTimeus > False) {
+ /* Convert TimeStamp to sub_seconds */
+ SubSecond = (uint16_t)((float)(RtcTimeus * RTC_CLOCK_HZ / RTC_SEC_TO_US)) & RTC_SUB_SEC_MASK;
+ }
+ /* Set SUB_SEC_ALARM */
+ RTCREG->SUB_SECOND_COUNTER = SubSecond;
+
+ while(RTCREG->STATUS.BITS.BSY_CTRL_REG_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+ /* Start RTC */
+ RTCREG->CONTROL.WORD |= ((True << RTC_CONTROL_SUBSEC_CNT_START_BIT_POS) |
+ (True << RTC_CONTROL_SEC_CNT_START_BIT_POS));
+
+ while(RTCREG->STATUS.BITS.BSY_ANY_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+}
+
+/* See rtc.h for details */
+void fRtcHandler(void)
+{
+ /* SUB_SECOND/SECOND interrupt occured */
+ volatile uint32_t TempStatus = RTCREG->STATUS.WORD;
+
+ /* Disable RTC interrupt */
+ NVIC_DisableIRQ(Rtc_IRQn);
+
+ /* Clear sec & sub_sec interrupts */
+ RTCREG->INT_CLEAR.WORD = ((True << RTC_INT_CLR_SUB_SEC_BIT_POS) |
+ (True << RTC_INT_CLR_SEC_BIT_POS));
+
+ /* TODO ANDing SUB_SEC & SEC interrupt - work around for RTC issue - will be resolved in REV G */
+ if(TempStatus & RTC_SEC_INT_STATUS_MASK) {
+ /* Second interrupt occured */
+ if(SubSecond > False) {
+ /* Set SUB SEC_ALARM */
+ RTCREG->SUB_SECOND_ALARM = SubSecond + RTCREG->SUB_SECOND_COUNTER;
+ /* Enable sub second interrupt */
+ RTCREG->CONTROL.WORD |= (True << RTC_CONTROL_SUBSEC_CNT_INT_BIT_POS);
+ } else {
+ /* We reach here after second interrupt is occured */
+ RTCREG->CONTROL.WORD &= ~(True << RTC_CONTROL_SUBSEC_CNT_INT_BIT_POS) |
+ (True << RTC_CONTROL_SEC_CNT_INT_BIT_POS);
+ }
+ } else {
+ /* We reach here after sub_second or (Sub second + second) interrupt occured */
+ /* Disable Second and sub_second interrupt */
+ RTCREG->CONTROL.WORD &= ~(True << RTC_CONTROL_SUBSEC_CNT_INT_BIT_POS) |
+ (True << RTC_CONTROL_SEC_CNT_INT_BIT_POS);
+ }
+
+ NVIC_EnableIRQ(Rtc_IRQn);
+
+ while(RTCREG->STATUS.BITS.BSY_ANY_WRT == True); /* Wait for RTC to finish writing register - RTC operates on 32K clock as compared to 32M core*/
+
+ lp_ticker_irq_handler();
+}
+
+boolean fIsRtcEnabled(void)
+{
+ if(RTCREG->CONTROL.BITS.SUB_SEC_COUNTER_EN | RTCREG->CONTROL.BITS.SEC_COUNTER_EN) {
+ return True;
+ } else {
+ return False;
+ }
+}