/**************************************************************************** * sched/clock/clock_initialize.c * * Copyright (C) 2007, 2009, 2011-2012, 2017-2018 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/clock.h" #ifdef CONFIG_CLOCK_TIMEKEEPING # include "clock/clock_timekeeping.h" #endif /**************************************************************************** * Public Data ****************************************************************************/ #ifndef CONFIG_SCHED_TICKLESS #ifdef CONFIG_SYSTEM_TIME64 volatile uint64_t g_system_timer; #else volatile uint32_t g_system_timer; #endif #endif #ifndef CONFIG_CLOCK_TIMEKEEPING struct timespec g_basetime; #ifdef CONFIG_CLOCK_MONOTONIC struct timespec g_monotonic_basetime; #endif #endif /**************************************************************************** * 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 int clock_basetime(FAR struct timespec *tp) { struct tm rtctime; long nsecs = 0; int ret; /* Get the broken-out time from the date/time RTC. */ #ifdef CONFIG_ARCH_HAVE_RTC_SUBSECONDS ret = up_rtc_getdatetime_with_subseconds(&rtctime, &nsecs); #else ret = up_rtc_getdatetime(&rtctime); #endif if (ret >= 0) { /* And use the broken-out time to initialize the system time */ tp->tv_sec = mktime(&rtctime); tp->tv_nsec = nsecs; } return ret; } #elif defined(CONFIG_RTC_HIRES) /* Initialize the system time using a high-resolution structure */ static inline int clock_basetime(FAR struct timespec *tp) { /* Get the complete time from the hi-res RTC. */ return up_rtc_gettime(tp); } #else /* Initialize the system time using seconds only */ static inline int 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; return OK; } #endif /* CONFIG_RTC_HIRES */ #else /* CONFIG_RTC */ static inline int 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 - 1, CONFIG_START_DAY); /* Set the base time as seconds into this julian day. */ tp->tv_sec = jdn * SEC_PER_DAY; tp->tv_nsec = 0; return OK; } #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 */ #ifndef CONFIG_CLOCK_TIMEKEEPING #ifndef CONFIG_RTC_HIRES clock_basetime(&g_basetime); #endif #ifndef CONFIG_SCHED_TICKLESS g_system_timer = INITIAL_SYSTEM_TIMER_TICKS; if (g_system_timer > 0) { struct timespec ts; (void)clock_ticks2time((sclock_t)g_system_timer, &ts); /* Adjust base time to hide initial timer ticks. */ g_basetime.tv_sec -= ts.tv_sec; g_basetime.tv_nsec -= ts.tv_nsec; while (g_basetime.tv_nsec < 0) { g_basetime.tv_nsec += NSEC_PER_SEC; g_basetime.tv_sec--; } #ifdef CONFIG_CLOCK_MONOTONIC /* Adjust monotonic clock offset to hide initial timer ticks. */ g_monotonic_basetime.tv_sec -= ts.tv_sec; g_monotonic_basetime.tv_nsec -= ts.tv_nsec; while (g_monotonic_basetime.tv_nsec < 0) { g_monotonic_basetime.tv_nsec += NSEC_PER_SEC; g_monotonic_basetime.tv_sec--; } #endif /* CONFIG_CLOCK_MONOTONIC */ } #endif /* !CONFIG_SCHED_TICKLESS */ #else clock_inittimekeeping(); #endif } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: clock_initialize * * Description: * Perform one-time initialization of the timing facilities. * ****************************************************************************/ void clock_initialize(void) { #if defined(CONFIG_RTC) && !defined(CONFIG_RTC_EXTERNAL) /* Initialize the internal RTC hardware. Initialization of external RTC * must be deferred until the system has booted. */ up_rtc_initialize(); #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. * * Input Parameters: * None * * Returned Value: * None * * Assumptions: * ****************************************************************************/ #ifdef CONFIG_RTC void clock_synchronize(void) { irqstate_t flags; /* Re-initialize the time value to match the RTC */ flags = enter_critical_section(); clock_inittime(); leave_critical_section(flags); } #endif /**************************************************************************** * Name: clock_resynchronize * * Description: * Resynchronize the system timer to a hardware RTC. The user can * 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. Function also keeps monotonic clock at rate of RTC. * * Calling this function will not result in system time going "backward" in * time. If setting system time with RTC would result time going "backward" * then resynchronization is not performed. * * Input Parameters: * rtc_diff: amount of time system-time is adjusted forward with RTC * * Returned Value: * None * * Assumptions: * ****************************************************************************/ #if defined(CONFIG_RTC) && !defined(CONFIG_SCHED_TICKLESS) && \ !defined(CONFIG_CLOCK_TIMEKEEPING) void clock_resynchronize(FAR struct timespec *rtc_diff) { struct timespec rtc_time, bias, curr_ts; struct timespec rtc_diff_tmp; irqstate_t flags; int32_t carry; int ret; if (rtc_diff == NULL) { rtc_diff = &rtc_diff_tmp; } /* Set the time value to match the RTC */ flags = enter_critical_section(); /* Get RTC time */ ret = clock_basetime(&rtc_time); if (ret < 0) { /* Error reading RTC, skip resynchronization. */ sinfo("rtc error %d, skip resync\n", ret); rtc_diff->tv_sec = 0; rtc_diff->tv_nsec = 0; goto skip; } /* Get the elapsed time since power up (in milliseconds). This is a * bias value that we need to use to correct the base time. */ (void)clock_systimespec(&bias); /* Add the base time to this. The base time is the time-of-day * setting. When added to the elapsed time since the time-of-day * was last set, this gives us the current time. */ curr_ts.tv_sec = bias.tv_sec + g_basetime.tv_sec; curr_ts.tv_nsec = bias.tv_nsec + g_basetime.tv_nsec; /* Handle carry to seconds. */ if (curr_ts.tv_nsec >= NSEC_PER_SEC) { carry = curr_ts.tv_nsec / NSEC_PER_SEC; curr_ts.tv_sec += carry; curr_ts.tv_nsec -= (carry * NSEC_PER_SEC); } /* Check if RTC has advanced past system time. */ if (curr_ts.tv_sec > rtc_time.tv_sec || (curr_ts.tv_sec == rtc_time.tv_sec && curr_ts.tv_nsec >= rtc_time.tv_nsec)) { /* Setting system time with RTC now would result time going * backwards. Skip resynchronization. */ sinfo("skip resync\n"); rtc_diff->tv_sec = 0; rtc_diff->tv_nsec = 0; } else { /* Save RTC time as the new base time. */ g_basetime.tv_sec = rtc_time.tv_sec; g_basetime.tv_nsec = rtc_time.tv_nsec; /* Subtract that bias from the basetime so that when the system * timer is again added to the base time, the result is the current * time relative to basetime. */ if (g_basetime.tv_nsec < bias.tv_nsec) { g_basetime.tv_nsec += NSEC_PER_SEC; g_basetime.tv_sec--; } /* Result could be negative seconds */ g_basetime.tv_nsec -= bias.tv_nsec; g_basetime.tv_sec -= bias.tv_sec; sinfo("basetime=(%ld,%lu) bias=(%ld,%lu)\n", (long)g_basetime.tv_sec, (unsigned long)g_basetime.tv_nsec, (long)bias.tv_sec, (unsigned long)bias.tv_nsec); /* Output difference between time at entry and new current time. */ rtc_diff->tv_sec = (bias.tv_sec + g_basetime.tv_sec) - curr_ts.tv_sec; rtc_diff->tv_nsec = (bias.tv_nsec + g_basetime.tv_nsec) - curr_ts.tv_nsec; /* Handle carry to seconds. */ if (rtc_diff->tv_nsec < 0) { carry = -((-(rtc_diff->tv_nsec + 1)) / NSEC_PER_SEC + 1); } else if (rtc_diff->tv_nsec >= NSEC_PER_SEC) { carry = rtc_diff->tv_nsec / NSEC_PER_SEC; } else { carry = 0; } if (carry) { rtc_diff->tv_sec += carry; rtc_diff->tv_nsec -= (carry * NSEC_PER_SEC); } #ifdef CONFIG_CLOCK_MONOTONIC /* Monotonic clock follows wall time since system start-up. Adjust * CLOCK_MONOTONIC same amount as CLOCK_REALTIME. */ g_monotonic_basetime.tv_sec += (uint32_t)rtc_diff->tv_sec; g_monotonic_basetime.tv_nsec += (uint32_t)rtc_diff->tv_nsec; /* Handle carry to seconds. */ if (g_monotonic_basetime.tv_nsec >= NSEC_PER_SEC) { carry = g_monotonic_basetime.tv_nsec / NSEC_PER_SEC; g_monotonic_basetime.tv_sec += carry; g_monotonic_basetime.tv_nsec -= (carry * NSEC_PER_SEC); } #endif } skip: leave_critical_section(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 * USEC_PER_TICK * ****************************************************************************/ #ifndef CONFIG_SCHED_TICKLESS void clock_timer(void) { /* Increment the per-tick system counter */ g_system_timer++; } #endif