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/*
* Copyright (c) 2014-2015 Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
* @brief Variables needed needed for system clock
*
*
* Declare variables used by both system timer device driver and kernel
* components that use timer functionality.
*/
#ifndef _SYS_CLOCK__H_
#define _SYS_CLOCK__H_
#ifdef __cplusplus
extern "C" {
#endif
#ifndef _ASMLANGUAGE
#include <stdint.h>
#if defined(CONFIG_SYS_CLOCK_EXISTS) && \
(CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC == 0)
#error "SYS_CLOCK_HW_CYCLES_PER_SEC must be non-zero!"
#endif
#define sys_clock_ticks_per_sec CONFIG_SYS_CLOCK_TICKS_PER_SEC
#if defined(CONFIG_TIMER_READS_ITS_FREQUENCY_AT_RUNTIME)
extern int sys_clock_hw_cycles_per_sec;
#else
#define sys_clock_hw_cycles_per_sec CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC
#endif
/*
* sys_clock_us_per_tick global variable represents a number
* of microseconds in one OS timer tick
*/
extern int sys_clock_us_per_tick;
/*
* sys_clock_hw_cycles_per_tick global variable represents a number
* of platform clock ticks in one OS timer tick.
* sys_clock_hw_cycles_per_tick often represents a value of divider
* of the board clock frequency
*/
extern int sys_clock_hw_cycles_per_tick;
/* number of nsec per usec */
#define NSEC_PER_USEC 1000
/* number of microseconds per millisecond */
#define USEC_PER_MSEC 1000
/* number of milliseconds per second */
#define MSEC_PER_SEC 1000
/* number of microseconds per second */
#define USEC_PER_SEC ((USEC_PER_MSEC) * (MSEC_PER_SEC))
/* number of nanoseconds per second */
#define NSEC_PER_SEC ((NSEC_PER_USEC) * (USEC_PER_MSEC) * (MSEC_PER_SEC))
/* SYS_CLOCK_HW_CYCLES_TO_NS64 converts CPU clock cycles to nanoseconds */
#define SYS_CLOCK_HW_CYCLES_TO_NS64(X) \
(((uint64_t)(X) * sys_clock_us_per_tick * NSEC_PER_USEC) / \
sys_clock_hw_cycles_per_tick)
/*
* SYS_CLOCK_HW_CYCLES_TO_NS_AVG converts CPU clock cycles to nanoseconds
* and calculates the average cycle time
*/
#define SYS_CLOCK_HW_CYCLES_TO_NS_AVG(X, NCYCLES) \
(uint32_t)(SYS_CLOCK_HW_CYCLES_TO_NS64(X) / NCYCLES)
#define SYS_CLOCK_HW_CYCLES_TO_NS(X) (uint32_t)(SYS_CLOCK_HW_CYCLES_TO_NS64(X))
extern int64_t _sys_clock_tick_count;
/*
* Number of ticks for x seconds. NOTE: With MSEC(), since it does an integer
* division, x must be greater or equal to 1000/sys_clock_ticks_per_sec to get
* a non-zero value.
*/
#define SECONDS(x) ((x) * sys_clock_ticks_per_sec)
#define MSEC(x) (SECONDS(x) / 1000)
#endif /* !_ASMLANGUAGE */
#ifdef __cplusplus
}
#endif
#endif /* _SYS_CLOCK__H_ */