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/*
* (C) Copyright 2007
* Sascha Hauer, Pengutronix
*
* Copyright (C) 2010-2011 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/arch/mx6.h>
#include <div64.h>
#define TIMER_BASE GPT_BASE_ADDR /* General purpose timer 1 */
/* General purpose timers registers */
#define GPTCR __REG(TIMER_BASE) /* Control register */
#define GPTPR __REG(TIMER_BASE + 0x4) /* Prescaler register */
#define GPTSR __REG(TIMER_BASE + 0x8) /* Status register */
#define GPTCNT __REG(TIMER_BASE + 0x24) /* Counter register */
/* General purpose timers bitfields */
#define GPTCR_SWR (1 << 15) /* Software reset */
#define GPTCR_FRR (1 << 9) /* Freerun / restart */
#define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source */
#define GPTCR_TEN (1) /* Timer enable */
static ulong timestamp;
static ulong lastinc;
/* "time" is measured in 1 / CONFIG_SYS_HZ seconds,
* "tick" is internal timer period */
#ifdef CONFIG_TIMER_HIGH_PRECISION
/* ~0.4% error - measured with stop-watch on 100s boot-delay */
static inline unsigned long long tick_to_time(unsigned long long tick)
{
tick *= CONFIG_SYS_HZ;
do_div(tick, CONFIG_MX6_CLK32);
return tick;
}
static inline unsigned long long time_to_tick(unsigned long long time)
{
time *= CONFIG_MX6_CLK32;
do_div(time, CONFIG_SYS_HZ);
return time;
}
static inline unsigned long long us_to_tick(unsigned long long us)
{
us = us * CONFIG_MX6_CLK32 + 999999;
do_div(us, 1000000);
return us;
}
#else
/* ~2% error */
#define TICK_PER_TIME ((CONFIG_MX6_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ)
#define US_PER_TICK (1000000 / CONFIG_MX6_CLK32)
static inline unsigned long long tick_to_time(unsigned long long tick)
{
do_div(tick, TICK_PER_TIME);
return tick;
}
static inline unsigned long long time_to_tick(unsigned long long time)
{
return time * TICK_PER_TIME;
}
static inline unsigned long long us_to_tick(unsigned long long us)
{
us += US_PER_TICK - 1;
do_div(us, US_PER_TICK);
return us;
}
#endif
static inline void setup_gpt(void)
{
int i;
static int init_done;
if (init_done)
return;
init_done = 1;
/* setup GP Timer 1 */
GPTCR = GPTCR_SWR;
for (i = 0; i < 100; i++)
GPTCR = 0; /* We have no udelay by now */
GPTPR = 0; /* 32KHz */
/* Freerun Mode, CLK32 input */
GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN;
}
int timer_init(void)
{
setup_gpt();
return 0;
}
void reset_timer_masked(void)
{
/* reset time */
lastinc = GPTCNT; /* capture current incrementer value time */
timestamp = 0; /* start "advancing" time stamp from 0 */
}
void reset_timer(void)
{
reset_timer_masked();
}
unsigned long long get_ticks(void)
{
ulong now = GPTCNT; /* current tick value */
if (now >= lastinc) /* normal mode (non roll) */
/* move stamp forward with absolut diff ticks */
timestamp += (now - lastinc);
else /* we have rollover of incrementer */
timestamp += (0xFFFFFFFF - lastinc) + now;
lastinc = now;
return timestamp;
}
ulong get_timer_masked(void)
{
/*
* get_ticks() returns a long long (64 bit), it wraps in
* 2^64 / CONFIG_MX31_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
* 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
* 5 * 10^6 days - long enough.
*/
return tick_to_time(get_ticks());
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
void set_timer(ulong t)
{
timestamp = time_to_tick(t);
}
/* delay x useconds AND perserve advance timstamp value */
/* GPTCNT is now supposed to tick 1 by 1 us. */
void udelay(unsigned long usec)
{
unsigned long long tmp;
ulong tmo;
setup_gpt();
tmo = us_to_tick(usec);
tmp = get_ticks() + tmo; /* get current timestamp */
while (get_ticks() < tmp) /* loop till event */
/*NOP*/;
}
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