[deliverable/linux.git] / arch / c6x / kernel / time.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();
}
Commit	Line	Data
546a3954 AJ	1	/*
	2	* Port on Texas Instruments TMS320C6x architecture
	3	*
	4	* Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
	5	* Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/clocksource.h>
	14	#include <linux/errno.h>
	15	#include <linux/sched.h>
	16	#include <linux/param.h>
	17	#include <linux/string.h>
	18	#include <linux/mm.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/timex.h>
	21	#include <linux/profile.h>
	22
6a846f3f	23	#include <asm/special_insns.h>
546a3954 AJ	24	#include <asm/timer64.h>
	25
	26	static u32 sched_clock_multiplier;
	27	#define SCHED_CLOCK_SHIFT 16
	28
	29	static cycle_t tsc_read(struct clocksource *cs)
	30	{
	31	return get_cycles();
	32	}
	33
	34	static struct clocksource clocksource_tsc = {
	35	.name = "timestamp",
	36	.rating = 300,
	37	.read = tsc_read,
	38	.mask = CLOCKSOURCE_MASK(64),
	39	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
	40	};
	41
	42	/*
	43	* scheduler clock - returns current time in nanoseconds.
	44	*/
	45	u64 sched_clock(void)
	46	{
	47	u64 tsc = get_cycles();
	48
	49	return (tsc * sched_clock_multiplier) >> SCHED_CLOCK_SHIFT;
	50	}
	51
f4831605	52	void __init time_init(void)
546a3954 AJ	53	{
	54	u64 tmp = (u64)NSEC_PER_SEC << SCHED_CLOCK_SHIFT;
	55
	56	do_div(tmp, c6x_core_freq);
	57	sched_clock_multiplier = tmp;
	58
	59	clocksource_register_hz(&clocksource_tsc, c6x_core_freq);
	60
	61	/* write anything into TSCL to enable counting */
	62	set_creg(TSCL, 0);
	63
	64	/* probe for timer64 event timer */
	65	timer64_init();
	66	}