FreeRTOS/Demo/CORTEX_M7_SAMV71_Xplained_AtmelStudio/libchip_samv7/source/rtc.c

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/** \addtogroup rtc_module Working with RTC
 *  \ingroup peripherals_module
 * The RTC driver provides the interface to configure and use the RTC
 * peripheral.
 *
 * It manages date, time, and alarms.\n
 * This timer is clocked by the 32kHz system clock, and is not impacted by
 * power management settings (PMC). To be accurate, it is better to use an
 * external 32kHz crystal instead of the internal 32kHz RC.\n
 *
 * It uses BCD format, and time can be set in AM/PM or 24h mode through a
 * configuration bit in the mode register.\n
 *
 * To update date or time, the user has to follow these few steps :
 * <ul>
 * <li>Set UPDTIM and/or UPDCAL bit(s) in RTC_CR,</li>
 * <li>Polling or IRQ on the ACKUPD bit of RTC_CR,</li>
 * <li>Clear ACKUPD bit in RTC_SCCR,</li>
 * <li>Update Time and/or Calendar values in RTC_TIMR/RTC_CALR (BCD format),</li>
 * <li>Clear UPDTIM and/or UPDCAL bit in RTC_CR.</li>
 * </ul>
 * An alarm can be set to happen on month, date, hours, minutes or seconds,
 * by setting the proper "Enable" bit of each of these fields in the Time and
 * Calendar registers.
 * This allows a large number of configurations to be available for the user.
 * Alarm occurrence can be detected even by polling or interrupt.
 *
 * A check of the validity of the date and time format and values written by 
 * the user is automatically done.
 * Errors are reported through the Valid Entry Register.
 *
 * For more accurate information, please look at the RTC section of the
 * Datasheet.
 *
 * Related files :\n
 * \ref rtc.c\n
 * \ref rtc.h.\n
 */
/*@{*/
/*@}*/


/**
 * \file
 *
 * Implementation of Real Time Clock (RTC) controller.
 *
 */

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include "chip.h"

#include <stdint.h>
#include <assert.h>

/*----------------------------------------------------------------------------
 *        Exported functions
 *----------------------------------------------------------------------------*/

/**
 * \brief Sets the RTC in either 12 or 24 hour mode.
 *
 * \param mode  Hour mode.
 */
extern void RTC_SetHourMode( Rtc* pRtc, uint32_t dwMode )
{
	assert((dwMode & 0xFFFFFFFE) == 0);

	pRtc->RTC_MR = dwMode ;
}

/**
 * \brief Gets the RTC mode.
 *
 * \return Hour mode.
 */
extern uint32_t RTC_GetHourMode( Rtc* pRtc )
{
	uint32_t dwMode ;

	TRACE_DEBUG( "RTC_SetHourMode()\n\r" ) ;

	dwMode = pRtc->RTC_MR;
	dwMode &= 0xFFFFFFFE;

	return dwMode ;
}

/**
 * \brief Enables the selected interrupt sources of the RTC.
 *
 * \param sources  Interrupt sources to enable.
 */
extern void RTC_EnableIt( Rtc* pRtc, uint32_t dwSources )
{
	assert((dwSources & (uint32_t)(~0x1F)) == 0);

	TRACE_DEBUG( "RTC_EnableIt()\n\r" ) ;

	pRtc->RTC_IER = dwSources ;
}

/**
 * \brief Disables the selected interrupt sources of the RTC.
 *
 * \param sources  Interrupt sources to disable.
 */
extern void RTC_DisableIt( Rtc* pRtc, uint32_t dwSources )
{
	assert((dwSources & (uint32_t)(~0x1F)) == 0);

	TRACE_DEBUG( "RTC_DisableIt()\n\r" ) ;

	pRtc->RTC_IDR = dwSources ;
}

/**
 * \brief Sets the current time in the RTC.
 *
 * \note In successive update operations, the user must wait at least one second
 * after resetting the UPDTIM/UPDCAL bit in the RTC_CR before setting these
 * bits again. Please look at the RTC section of the datasheet for detail.
 *
 * \param ucHour    Current hour in 12 or 24 hour mode.
 * \param ucMinute  Current minute.
 * \param ucSecond  Current second.
 *
 * \return 0 success, 1 fail to set
 */
extern int RTC_SetTime( Rtc* pRtc, uint8_t ucHour, uint8_t ucMinute, uint8_t ucSecond )
{
	uint32_t dwTime=0 ;
	uint8_t ucHour_bcd ;
	uint8_t ucMin_bcd ;
	uint8_t ucSec_bcd ;

	TRACE_DEBUG( "RTC_SetTime(%02d:%02d:%02d)\n\r", ucHour, ucMinute, ucSecond ) ;

	/* if 12-hour mode, set AMPM bit */
	if ( (pRtc->RTC_MR & RTC_MR_HRMOD) == RTC_MR_HRMOD ) {
		if ( ucHour > 12 ) {
			ucHour -= 12 ;
			dwTime |= RTC_TIMR_AMPM ;
		}
	}
	ucHour_bcd = (ucHour%10)   | ((ucHour/10)<<4) ;
	ucMin_bcd  = (ucMinute%10) | ((ucMinute/10)<<4) ;
	ucSec_bcd  = (ucSecond%10) | ((ucSecond/10)<<4) ;

	/* value overflow */
	if ( (ucHour_bcd & (uint8_t)(~RTC_HOUR_BIT_LEN_MASK)) |
			(ucMin_bcd & (uint8_t)(~RTC_MIN_BIT_LEN_MASK)) |
			(ucSec_bcd & (uint8_t)(~RTC_SEC_BIT_LEN_MASK))) {
		return 1 ;
	}

	dwTime = ucSec_bcd | (ucMin_bcd << 8) | (ucHour_bcd<<16) ;

	pRtc->RTC_CR |= RTC_CR_UPDTIM ;
	while ((pRtc->RTC_SR & RTC_SR_ACKUPD) != RTC_SR_ACKUPD) ;
	pRtc->RTC_SCCR = RTC_SCCR_ACKCLR ;
	pRtc->RTC_TIMR = dwTime ;
	pRtc->RTC_CR &= (uint32_t)(~RTC_CR_UPDTIM) ;
	pRtc->RTC_SCCR |= RTC_SCCR_SECCLR ;

	return (int)(pRtc->RTC_VER & RTC_VER_NVTIM) ;
}

/**
 * \brief Retrieves the current time as stored in the RTC in several variables.
 *
 * \param pucHour    If not null, current hour is stored in this variable.
 * \param pucMinute  If not null, current minute is stored in this variable.
 * \param pucSecond  If not null, current second is stored in this variable.
 */
extern void RTC_GetTime( Rtc* pRtc, uint8_t *pucHour, 
				uint8_t *pucMinute, uint8_t *pucSecond )
{
	uint32_t dwTime ;

	TRACE_DEBUG( "RTC_GetTime()\n\r" ) ;

	/* Get current RTC time */
	dwTime = pRtc->RTC_TIMR ;
	while ( dwTime != pRtc->RTC_TIMR ) {
		dwTime = pRtc->RTC_TIMR ;
	}

	/* Hour */
	if ( pucHour ) {
		*pucHour = ((dwTime & 0x00300000) >> 20) * 10
			+ ((dwTime & 0x000F0000) >> 16);

		if ( (dwTime & RTC_TIMR_AMPM) == RTC_TIMR_AMPM ) {
			*pucHour += 12 ;
		}
	}

	/* Minute */
	if ( pucMinute ) {
		*pucMinute = ((dwTime & 0x00007000) >> 12) * 10
			+ ((dwTime & 0x00000F00) >> 8);
	}

	/* Second */
	if ( pucSecond ) {
		*pucSecond = ((dwTime & 0x00000070) >> 4) * 10
			+ (dwTime & 0x0000000F);
	}
}

/**
 * \brief Sets a time alarm on the RTC.
 * The match is performed only on the provided variables;
 * Setting all pointers to 0 disables the time alarm.
 *
 * \note In AM/PM mode, the hour value must have bit #7 set for PM, cleared for
 * AM (as expected in the time registers).
 *
 * \param pucHour    If not null, the time alarm will hour-match this value.
 * \param pucMinute  If not null, the time alarm will minute-match this value.
 * \param pucSecond  If not null, the time alarm will second-match this value.
 *
 * \return 0 success, 1 fail to set
 */
extern int RTC_SetTimeAlarm( Rtc* pRtc, uint8_t *pucHour, 
				uint8_t *pucMinute, uint8_t *pucSecond )
{
	uint32_t dwAlarm=0 ;

	TRACE_DEBUG( "RTC_SetTimeAlarm()\n\r" ) ;

	/* Hour */
	if ( pucHour ) {
		dwAlarm |= RTC_TIMALR_HOUREN | ((*pucHour / 10) << 20) | ((*pucHour % 10) << 16);
	}

	/* Minute */
	if ( pucMinute ) {
		dwAlarm |= RTC_TIMALR_MINEN | ((*pucMinute / 10) << 12) 
				| ((*pucMinute % 10) << 8);
	}

	/* Second */
	if ( pucSecond ) {
		dwAlarm |= RTC_TIMALR_SECEN | ((*pucSecond / 10) << 4) | (*pucSecond % 10);
	}

	pRtc->RTC_TIMALR = dwAlarm ;

	return (int)(pRtc->RTC_VER & RTC_VER_NVTIMALR) ;
}

/**
 * \brief Retrieves the current year, month and day from the RTC.
 * Month, day and week values are numbered starting at 1.
 *
 * \param pYwear  Current year (optional).
 * \param pucMonth  Current month (optional).
 * \param pucDay  Current day (optional).
 * \param pucWeek  Current day in current week (optional).
 */
extern void RTC_GetDate( Rtc* pRtc, uint16_t *pwYear, uint8_t *pucMonth,
				uint8_t *pucDay, uint8_t *pucWeek )
{
	uint32_t dwDate ;

	/* Get current date (multiple reads are necessary to insure a stable value) */
	do {
		dwDate = pRtc->RTC_CALR ;
	}
	while ( dwDate != pRtc->RTC_CALR ) ;

	/* Retrieve year */
	if ( pwYear ) {
		*pwYear = (((dwDate  >> 4) & 0x7) * 1000)
			+ ((dwDate & 0xF) * 100)
			+ (((dwDate >> 12) & 0xF) * 10)
			+ ((dwDate >> 8) & 0xF);
	}

	/* Retrieve month */
	if ( pucMonth ) {
		*pucMonth = (((dwDate >> 20) & 1) * 10) + ((dwDate >> 16) & 0xF);
	}

	/* Retrieve day */
	if ( pucDay ) {
		*pucDay = (((dwDate >> 28) & 0x3) * 10) + ((dwDate >> 24) & 0xF);
	}

	/* Retrieve week */
	if ( pucWeek ) {
		*pucWeek = ((dwDate >> 21) & 0x7);
	}
}

/**
 * \brief Sets the current year, month and day in the RTC.
 * Month, day and week values must be numbered starting from 1.
 *
 * \note In successive update operations, the user must wait at least one second
 * after resetting the UPDTIM/UPDCAL bit in the RTC_CR before setting these
 * bits again. Please look at the RTC section of the datasheet for detail.
 *
 * \param wYear  Current year.
 * \param ucMonth Current month.
 * \param ucDay   Current day.
 * \param ucWeek  Day number in current week.
 *
 * \return 0 success, 1 fail to set
 */
extern int RTC_SetDate( Rtc* pRtc, uint16_t wYear, uint8_t ucMonth, 
						uint8_t ucDay, uint8_t ucWeek )
{
	uint32_t wDate ;
	uint8_t ucCent_bcd ;
	uint8_t ucYear_bcd ;
	uint8_t ucMonth_bcd ;
	uint8_t ucDay_bcd ;
	uint8_t ucWeek_bcd ;

	ucCent_bcd  = ((wYear/100)%10) | ((wYear/1000)<<4);
	ucYear_bcd  = (wYear%10) | (((wYear/10)%10)<<4);
	ucMonth_bcd = ((ucMonth%10) | (ucMonth/10)<<4);
	ucDay_bcd   = ((ucDay%10) | (ucDay/10)<<4);
	ucWeek_bcd  = ((ucWeek%10) | (ucWeek/10)<<4);

	/* value over flow */
	if ( (ucCent_bcd & (uint8_t)(~RTC_CENT_BIT_LEN_MASK)) |
			(ucYear_bcd & (uint8_t)(~RTC_YEAR_BIT_LEN_MASK)) |
			(ucMonth_bcd & (uint8_t)(~RTC_MONTH_BIT_LEN_MASK)) |
			(ucWeek_bcd & (uint8_t)(~RTC_WEEK_BIT_LEN_MASK)) |
			(ucDay_bcd & (uint8_t)(~RTC_DATE_BIT_LEN_MASK))
	   ) {
		return 1 ;
	}


	/* Convert values to date register value */
	wDate = ucCent_bcd |
		(ucYear_bcd << 8) |
		(ucMonth_bcd << 16) |
		(ucWeek_bcd << 21) |
		(ucDay_bcd << 24);

	/* Update calendar register  */
	pRtc->RTC_CR |= RTC_CR_UPDCAL ;
	while ((pRtc->RTC_SR & RTC_SR_ACKUPD) != RTC_SR_ACKUPD) ;

	pRtc->RTC_SCCR = RTC_SCCR_ACKCLR;
	pRtc->RTC_CALR = wDate ;
	pRtc->RTC_CR &= (uint32_t)(~RTC_CR_UPDCAL) ;
	pRtc->RTC_SCCR |= RTC_SCCR_SECCLR; /* clear SECENV in SCCR */

	return (int)(pRtc->RTC_VER & RTC_VER_NVCAL) ;
}

/**
 * \brief Sets a date alarm in the RTC.
 * The alarm will match only the provided values;
 * Passing a null-pointer disables the corresponding field match.
 *
 * \param pucMonth If not null, the RTC alarm will month-match this value.
 * \param pucDay   If not null, the RTC alarm will day-match this value.
 *
 * \return 0 success, 1 fail to set
 */
extern int RTC_SetDateAlarm( Rtc* pRtc, uint8_t *pucMonth, uint8_t *pucDay )
{
	uint32_t dwAlarm ;

	dwAlarm = ((pucMonth) || (pucDay)) ? (0) : (0x01010000);

	TRACE_DEBUG( "RTC_SetDateAlarm()\n\r" ) ;

	/* Compute alarm field value */
	if ( pucMonth ) {
		dwAlarm |= RTC_CALALR_MTHEN | ((*pucMonth / 10) << 20) 
					| ((*pucMonth % 10) << 16);
	}

	if ( pucDay ) {
		dwAlarm |= RTC_CALALR_DATEEN | ((*pucDay / 10) << 28) 
					| ((*pucDay % 10) << 24);
	}

	/* Set alarm */
	pRtc->RTC_CALALR = dwAlarm ;

	return (int)(pRtc->RTC_VER & RTC_VER_NVCALALR) ;
}

/**
 * \brief Clear flag bits of status clear command register in the RTC.
 *
 * \param mask Bits mask of cleared events
 */
extern void RTC_ClearSCCR( Rtc* pRtc, uint32_t dwMask )
{
	/* Clear all flag bits in status clear command register */
	dwMask &= RTC_SCCR_ACKCLR | RTC_SCCR_ALRCLR | RTC_SCCR_SECCLR 
				| RTC_SCCR_TIMCLR | RTC_SCCR_CALCLR ;

	pRtc->RTC_SCCR = dwMask ;
}

/**
 * \brief Get flag bits of status register in the RTC.
 *
 * \param mask Bits mask of Status Register
 *
 * \return Status register & mask
 */
extern uint32_t RTC_GetSR( Rtc* pRtc, uint32_t dwMask )
{
	uint32_t dwEvent ;

	dwEvent = pRtc->RTC_SR ;

	return (dwEvent & dwMask) ;
}