mirror of https://gitee.com/openkylin/linux.git
66 lines
1.5 KiB
C
66 lines
1.5 KiB
C
/*
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* Port on Texas Instruments TMS320C6x architecture
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*
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* Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
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* Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/clocksource.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/param.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/timex.h>
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#include <linux/profile.h>
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#include <asm/timer64.h>
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static u32 sched_clock_multiplier;
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#define SCHED_CLOCK_SHIFT 16
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static cycle_t tsc_read(struct clocksource *cs)
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{
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return get_cycles();
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}
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static struct clocksource clocksource_tsc = {
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.name = "timestamp",
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.rating = 300,
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.read = tsc_read,
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.mask = CLOCKSOURCE_MASK(64),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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/*
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* scheduler clock - returns current time in nanoseconds.
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*/
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u64 sched_clock(void)
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{
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u64 tsc = get_cycles();
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return (tsc * sched_clock_multiplier) >> SCHED_CLOCK_SHIFT;
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}
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void time_init(void)
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{
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u64 tmp = (u64)NSEC_PER_SEC << SCHED_CLOCK_SHIFT;
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do_div(tmp, c6x_core_freq);
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sched_clock_multiplier = tmp;
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clocksource_register_hz(&clocksource_tsc, c6x_core_freq);
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/* write anything into TSCL to enable counting */
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set_creg(TSCL, 0);
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/* probe for timer64 event timer */
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timer64_init();
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}
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