91 lines
3.2 KiB
C
91 lines
3.2 KiB
C
/* Variables needed needed for system clock */
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/*
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* Copyright (c) 2014-2015 Wind River Systems, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1) Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2) Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* 3) Neither the name of Wind River Systems nor the names of its contributors
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* may be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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DESCRIPTION
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Declare variables used by both system timer device driver and kernel components
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that use timer functionality.
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*/
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#ifndef _SYS_CLOCK__H_
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#define _SYS_CLOCK__H_
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#ifndef _ASMLANGUAGE
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#include <stdint.h>
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#if defined(CONFIG_SYS_CLOCK_EXISTS) && \
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(CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC == 0)
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#error "SYS_CLOCK_HW_CYCLES_PER_SEC must be non-zero!"
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#endif
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#define sys_clock_ticks_per_sec CONFIG_SYS_CLOCK_TICKS_PER_SEC
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#define sys_clock_hw_cycles_per_sec CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC
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/*
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* sys_clock_us_per_tick global variable represents a number
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* of microseconds in one OS timer tick
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*/
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extern int sys_clock_us_per_tick;
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/*
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* sys_clock_hw_cycles_per_tick global variable represents a number
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* of platform clock ticks in one OS timer tick.
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* sys_clock_hw_cycles_per_tick often represents a value of divider
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* of the board clock frequency
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*/
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extern int sys_clock_hw_cycles_per_tick;
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/* number of nsec per usec */
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#define NSEC_PER_USEC 1000
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/* SYS_CLOCK_HW_CYCLES_TO_NS64 converts CPU clock cycles to nanoseconds */
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#define SYS_CLOCK_HW_CYCLES_TO_NS64(X) \
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(((uint64_t)(X) * sys_clock_us_per_tick * NSEC_PER_USEC) / \
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sys_clock_hw_cycles_per_tick)
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/*
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* SYS_CLOCK_HW_CYCLES_TO_NS_AVG converts CPU clock cycles to nanoseconds
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* and calculates the average cycle time
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*/
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#define SYS_CLOCK_HW_CYCLES_TO_NS_AVG(X, NCYCLES) \
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(uint32_t)(SYS_CLOCK_HW_CYCLES_TO_NS64(X) / NCYCLES)
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#define SYS_CLOCK_HW_CYCLES_TO_NS(X) (uint32_t)(SYS_CLOCK_HW_CYCLES_TO_NS64(X))
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extern int64_t _nano_ticks;
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extern struct nano_timer *_nano_timer_list;
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#endif /* !_ASMLANGUAGE */
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#endif /* _SYS_CLOCK__H_ */
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