/**************************************************************************** * include/nuttx/clock.h * * Copyright (C) 2007-2009, 2011-2012, 2014 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 /**************************************************************************** * Pre-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. We are not running tick-less (in which case there is no global timer * data), * 2. This is an un-protected, non-kernel build, * 3. This is a protected build, but this code is being built for execution * within the kernel space. * 4. It we are building with SYSCALLs enabled, but not in a kernel build, * then we can't know a priori whether the code has access to the * global variables or not. In that case we have to assume not. */ #undef __HAVE_KERNEL_GLOBALS #if defined(CONFIG_SCHED_TICKLESS) /* Case 1: There is no global timer data */ #elif defined(CONFIG_BUILD_PROTECTED) && defined(__KERNEL__) /* Case 3: Kernel mode of protected kernel build */ # define __HAVE_KERNEL_GLOBALS 1 #elif defined(CONFIG_BUILD_KERNEL) && defined(__KERNEL__) /* Case 3: Kernel only build */ # define __HAVE_KERNEL_GLOBALS 1 #elif defined(CONFIG_LIB_SYSCALL) /* Case 4: Building with SYSCALLs enabled, but not part of a kernel build */ #else /* Case 2: Un-protected, non-kernel build */ # define __HAVE_KERNEL_GLOBALS 1 #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 /* If CONFIG_SCHED_TICKLESS is not defined, then the interrupt interval of * the system timer is given by USEC_PER_TICK. This is the expected number * of microseconds between calls from the processor-specific logic to * sched_process_timer(). The default value of USEC_PER_TICK is 10000 * microseconds (100KHz). However, this default setting can be overridden * by defining the interval in microseconds as CONFIG_USEC_PER_TICK in the * NuttX 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 microseconds. If (2) is not true, you will probably want * to redefine all of the following. */ #ifdef CONFIG_USEC_PER_TICK # define USEC_PER_TICK (CONFIG_USEC_PER_TICK) #else # define USEC_PER_TICK (10000) #endif /* MSEC_PER_TICK can be very inaccurate if CONFIG_USEC_PER_TICK is not an * even multiple of milliseconds. Calculations using USEC_PER_TICK are * preferred for that reason (at the risk of overflow) */ #define TICK_PER_DSEC (USEC_PER_DSEC / USEC_PER_TICK) /* Truncates! */ #define TICK_PER_SEC (USEC_PER_SEC / USEC_PER_TICK) /* Truncates! */ #define TICK_PER_MSEC (USEC_PER_MSEC / USEC_PER_TICK) /* Truncates! */ #define MSEC_PER_TICK (USEC_PER_TICK / USEC_PER_MSEC) /* Truncates! */ #define NSEC_PER_TICK (USEC_PER_TICK * NSEC_PER_USEC) /* 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 */ #if (MSEC_PER_TICK * USEC_PER_MSEC) == USEC_PER_TICK # define MSEC2TICK(msec) (((msec)+(MSEC_PER_TICK/2))/MSEC_PER_TICK) /* Rounds */ #else # define MSEC2TICK(msec) USEC2TICK(msec * 1000) /* Rounds */ #endif #define DSEC2TICK(dsec) MSEC2TICK((dsec) * MSEC_PER_DSEC) /* Rounds */ #define SEC2TICK(sec) MSEC2TICK((sec) * MSEC_PER_SEC) /* Rounds */ #define TICK2NSEC(tick) ((tick) * NSEC_PER_TICK) /* Exact */ #define TICK2USEC(tick) ((tick) * USEC_PER_TICK) /* Exact */ #if (MSEC_PER_TICK * USEC_PER_MSEC) == USEC_PER_TICK # define TICK2MSEC(tick) ((tick)*MSEC_PER_TICK) /* Exact */ #else # define TICK2MSEC(tick) (((tick)*USEC_PER_TICK)/USEC_PER_MSEC) /* Rounds */ #endif #define TICK2DSEC(tick) (((tick)+(TICK_PER_DSEC/2))/TICK_PER_DSEC) /* Rounds */ #define TICK2SEC(tick) (((tick)+(TICK_PER_SEC/2))/TICK_PER_SEC) /* Rounds */ /**************************************************************************** * Public Types ****************************************************************************/ /* This structure is used to report CPU usage for a particular thread */ #ifdef CONFIG_SCHED_CPULOAD struct cpuload_s { volatile uint32_t total; /* Total number of clock ticks */ volatile uint32_t active; /* Number of ticks while this thread was active */ }; #endif /**************************************************************************** * Public Data ****************************************************************************/ /* 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 */ #ifdef __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 /**************************************************************************** * Public 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 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: * ****************************************************************************/ #ifndef __HAVE_KERNEL_GLOBALS # ifdef CONFIG_SYSTEM_TIME64 # define clock_systimer() (uint32_t)(clock_systimer64() & 0x00000000ffffffff) # else 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 !defined(__HAVE_KERNEL_GLOBALS) && defined(CONFIG_SYSTEM_TIME64) uint64_t clock_systimer64(void); #endif /**************************************************************************** * Name: clock_systimespec * * Description: * Return the current value of the system timer counter as a struct * timespec. * * Parameters: * ts - Location to return the time * * Return Value: * Current version always returns OK * * Assumptions: * ****************************************************************************/ int clock_systimespec(FAR struct timespec *ts); /**************************************************************************** * Function: clock_cpuload * * Description: * Return load measurement data for the select PID. * * Parameters: * pid - The task ID of the thread of interest. pid == 0 is the IDLE thread. * cpuload - The location to return the CPU load * * Return Value: * OK (0) on success; a negated errno value on failure. The only reason * that this function can fail is if 'pid' no longer refers to a valid * thread. * * Assumptions: * ****************************************************************************/ #ifdef CONFIG_SCHED_CPULOAD int clock_cpuload(int pid, FAR struct cpuload_s *cpuload); #endif #undef EXTERN #ifdef __cplusplus } #endif #endif /* _INCLUDE_NUTTX_CLOCK_H */