/**************************************************************************** * include/nuttx/clock.h * * 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. * ****************************************************************************/ #ifndef _INCLUDE_NUTTX_CLOCK_H #define _INCLUDE_NUTTX_CLOCK_H /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include /**************************************************************************** * Pro-processor Definitions ****************************************************************************/ /* Configuration ************************************************************/ /* Efficient, direct access to OS global timer variables will be supported * if the execution environment has direct access to kernel global data. * The code in this execution context can access the kernel global data * directly if: (1) this is an un-protected, non-kernel build, or (2) * this code is being built for execution within the kernel. */ #undef __HAVE_KERNEL_GLOBALS #if !defined(CONFIG_NUTTX_KERNEL) || defined(__KERNEL__) # define __HAVE_KERNEL_GLOBALS 1 #else # define __HAVE_KERNEL_GLOBALS 0 #endif /* If CONFIG_SYSTEM_TIME64 is selected and the CPU supports long long types, * then a 64-bit system time will be used. */ #ifndef CONFIG_HAVE_LONG_LONG # undef CONFIG_SYSTEM_TIME64 #endif /* Timing constants *********************************************************/ #define NSEC_PER_SEC 1000000000 #define USEC_PER_SEC 1000000 #define MSEC_PER_SEC 1000 #define DSEC_PER_SEC 10 #define NSEC_PER_DSEC 100000000 #define USEC_PER_DSEC 100000 #define MSEC_PER_DSEC 100 #define NSEC_PER_MSEC 1000000 #define USEC_PER_MSEC 1000 #define NSEC_PER_USEC 1000 /* The interrupt interval of the system timer is given by MSEC_PER_TICK. * This is the expected number of milliseconds between calls from the * processor-specific logic to sched_process_timer(). The default value * of MSEC_PER_TICK is 10 milliseconds (100KHz). However, this default * setting can be overridden by defining the interval in milliseconds as * CONFIG_MSEC_PER_TICK in the board configuration file. * * The following calculations are only accurate when (1) there is no * truncation involved and (2) the underlying system timer is an even * multiple of milliseconds. If (2) is not true, you will probably want * to redefine all of the following. */ #ifdef CONFIG_MSEC_PER_TICK # define MSEC_PER_TICK (CONFIG_MSEC_PER_TICK) #else # define MSEC_PER_TICK (10) #endif #define TICK_PER_DSEC (MSEC_PER_DSEC / MSEC_PER_TICK) /* Truncates! */ #define TICK_PER_SEC (MSEC_PER_SEC / MSEC_PER_TICK) /* Truncates! */ #define NSEC_PER_TICK (MSEC_PER_TICK * NSEC_PER_MSEC) /* Exact */ #define USEC_PER_TICK (MSEC_PER_TICK * USEC_PER_MSEC) /* Exact */ #define NSEC2TICK(nsec) (((nsec)+(NSEC_PER_TICK/2))/NSEC_PER_TICK) /* Rounds */ #define USEC2TICK(usec) (((usec)+(USEC_PER_TICK/2))/USEC_PER_TICK) /* Rounds */ #define MSEC2TICK(msec) (((msec)+(MSEC_PER_TICK/2))/MSEC_PER_TICK) /* Rounds */ #define DSEC2TICK(dsec) MSEC2TICK((dsec)*MSEC_PER_DSEC) #define SEC2TICK(sec) MSEC2TICK((sec)*MSEC_PER_SEC) /* Exact */ #define TICK2NSEC(tick) ((tick)*NSEC_PER_TICK) /* Exact */ #define TICK2USEC(tick) ((tick)*USEC_PER_TICK) /* Exact */ #define TICK2MSEC(tick) ((tick)*MSEC_PER_TICK) /* Exact */ #define TICK2DSEC(tick) (((tick)+(TICK_PER_DSEC/2))/TICK_PER_DSEC) /* Rounds */ #define TICK2SEC(tick) (((tick)+(TICK_PER_SEC/2))/TICK_PER_SEC) /* Rounds */ /**************************************************************************** * Global Data ****************************************************************************/ #if !defined(CONFIG_DISABLE_CLOCK) /* Access to raw system clock ***********************************************/ /* Direct access to the system timer/counter is supported only if (1) the * system timer counter is available (i.e., we are not configured to use * a hardware periodic timer), and (2) the execution environment has direct * access to kernel global data */ #if __HAVE_KERNEL_GLOBALS # ifdef CONFIG_SYSTEM_TIME64 extern volatile uint64_t g_system_timer; #define clock_systimer() (uint32_t)(g_system_timer & 0x00000000ffffffff) #define clock_systimer64() g_system_timer # else extern volatile uint32_t g_system_timer; #define clock_systimer() g_system_timer # endif #endif /**************************************************************************** * Global Function Prototypes ****************************************************************************/ #ifdef __cplusplus #define EXTERN extern "C" extern "C" { #else #define EXTERN extern #endif /**************************************************************************** * Function: 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 EXTERN void clock_synchronize(void); #endif /**************************************************************************** * Function: clock_systimer * * Description: * Return the current value of the 32-bit system timer counter. Indirect * access to the system timer counter is required through this function if * the execution environment does not have direct access to kernel global * data * * Parameters: * None * * Return Value: * The current value of the system timer counter * * Assumptions: * ****************************************************************************/ #if !__HAVE_KERNEL_GLOBALS # ifdef CONFIG_SYSTEM_TIME64 # define clock_systimer() (uint32_t)(clock_systimer64() & 0x00000000ffffffff) # else EXTERN uint32_t clock_systimer(void); # endif #endif /**************************************************************************** * Function: clock_systimer64 * * Description: * Return the current value of the 64-bit system timer counter. Indirect * access to the system timer counter is required through this function if * the execution environment does not have direct access to kernel global * data * * Parameters: * None * * Return Value: * The current value of the system timer counter * * Assumptions: * ****************************************************************************/ #if !__HAVE_KERNEL_GLOBALS && defined(CONFIG_SYSTEM_TIME64) EXTERN uint64_t clock_systimer64(void); #endif #undef EXTERN #ifdef __cplusplus } #endif #endif /* !CONFIG_DISABLE_CLOCK */ #endif /* _INCLUDE_NUTTX_CLOCK_H */