linux/arch/c6x/kernel/time.c

67 lines
1.5 KiB
C

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