/****************************************************************************
* sched/clock_initialize.c
*
* Copyright (C) 2007, 2009, 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <stdint.h>
#include <time.h>
#include <errno.h>
#include <debug.h>
#ifdef CONFIG_RTC
# include <arch/irq.h>
#endif
#include <nuttx/clock.h>
#include <nuttx/time.h>
#include <nuttx/rtc.h>
#include "clock_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/* Standard time definitions (in units of seconds) */
#define SEC_PER_MIN ((time_t)60)
#define SEC_PER_HOUR ((time_t)60 * SEC_PER_MIN)
#define SEC_PER_DAY ((time_t)24 * SEC_PER_HOUR)
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/**************************************************************************
* Public Constant Data
**************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
#ifdef CONFIG_SYSTEM_TIME64
volatile uint64_t g_system_timer;
uint64_t g_tickbias;
#else
volatile uint32_t g_system_timer;
uint32_t g_tickbias;
#endif
struct timespec g_basetime;
/**************************************************************************
* Private Variables
**************************************************************************/
/**************************************************************************
* Private Functions
**************************************************************************/
/****************************************************************************
* Name: clock_basetime
*
* Description:
* Get the initial time value from the best source available.
*
****************************************************************************/
#ifdef CONFIG_RTC
#if defined(CONFIG_RTC_DATETIME)
/* Initialize the system time using a broken out date/time structure */
static inline void clock_basetime(FAR struct timespec *tp)
{
struct tm rtctime;
/* Get the broken-out time from the date/time RTC. */
(void)up_rtc_getdatetime(&rtctime);
/* And use the broken-out time to initialize the system time */
tp->tv_sec = mktime(&rtctime);
tp->tv_nsec = 0;
}
#elif defined(CONFIG_RTC_HIRES)
/* Initialize the system time using a high-resolution structure */
static inline void clock_basetime(FAR struct timespec *tp)
{
/* Get the complete time from the hi-res RTC. */
(void)up_rtc_gettime(tp);
}
#else
/* Initialize the system time using seconds only */
static inline void clock_basetime(FAR struct timespec *tp)
{
/* Get the seconds (only) from the lo-resolution RTC */
tp->tv_sec = up_rtc_time();
tp->tv_nsec = 0;
}
#endif /* CONFIG_RTC_HIRES */
#else /* CONFIG_RTC */
static inline void clock_basetime(FAR struct timespec *tp)
{
time_t jdn = 0;
/* Get the EPOCH-relative julian date from the calendar year,
* month, and date
*/
jdn = clock_calendar2utc(CONFIG_START_YEAR, CONFIG_START_MONTH,
CONFIG_START_DAY);
/* Set the base time as seconds into this julian day. */
tp->tv_sec = jdn * SEC_PER_DAY;
tp->tv_nsec = 0;
}
#endif /* CONFIG_RTC */
/****************************************************************************
* Name: clock_inittime
*
* Description:
* Get the initial time value from the best source available.
*
****************************************************************************/
static void clock_inittime(void)
{
/* (Re-)initialize the time value to match the RTC */
clock_basetime(&g_basetime);
g_system_timer = 0;
g_tickbias = 0;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: clock_initialize
*
* Description:
* Perform one-time initialization of the timing facilities.
*
****************************************************************************/
void clock_initialize(void)
{
/* Initialize the RTC hardware */
#ifdef CONFIG_RTC
up_rtcinitialize();
#endif
/* Initialize the time value to match the RTC */
clock_inittime();
}
/****************************************************************************
* Name: clock_synchronize
*
* Description:
* Synchronize the system timer to a hardware RTC. This operation is
* normally performed automatically by the system during clock
* initialization. However, the user may also need to explicitly re-
* synchronize the system timer to the RTC under certain conditions where
* the system timer is known to be in error. For example, in certain low-
* power states, the system timer may be stopped but the RTC will continue
* keep correct time. After recovering from such low-power state, this
* function should be called to restore the correct system time.
*
* Calling this function could result in system time going "backward" in
* time, especially with certain lower resolution RTC implementations.
* Time going backward could have bad consequences if there are ongoing
* timers and delays. So use this interface with care.
*
* Parameters:
* None
*
* Return Value:
* None
*
* Assumptions:
*
****************************************************************************/
#ifdef CONFIG_RTC
void clock_synchronize(void)
{
irqstate_t flags;
/* Re-initialize the time value to match the RTC */
flags = irqsave();
clock_inittime();
irqrestore(flags);
}
#endif
/****************************************************************************
* Name: clock_timer
*
* Description:
* This function must be called once every time the real time clock
* interrupt occurs. The interval of this clock interrupt must be
* MSEC_PER_TICK
*
****************************************************************************/
void clock_timer(void)
{
/* Increment the per-tick system counter */
g_system_timer++;
}
