/**************************************************************************** * sched/clock_initialize.c * * Copyright (C) 2007, 2009, 2011-2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #ifdef CONFIG_RTC # include #endif #include #include #include #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++; }