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/*
* Copyright (C) 2009 Samsung Electronics
* Heungjun Kim <riverful.kim@samsung.com>
* Inki Dae <inki.dae@samsung.com>
* Minkyu Kang <mk7.kang@samsung.com>
*
* 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/io.h>
#include <asm/arch/pwm.h>
#include <asm/arch/clk.h>
#include <pwm.h>
DECLARE_GLOBAL_DATA_PTR;
unsigned long get_current_tick(void);
/* macro to read the 16 bit timer */
static inline struct s5p_timer *s5p_get_base_timer(void)
{
return (struct s5p_timer *)samsung_get_base_timer();
}
/**
* Read the countdown timer.
*
* This operates at 1MHz and counts downwards. It will wrap about every
* hour (2^32 microseconds).
*
* @return current value of timer
*/
static unsigned long timer_get_us_down(void)
{
struct s5p_timer *const timer = s5p_get_base_timer();
return readl(&timer->tcnto4);
}
int timer_init(void)
{
/* PWM Timer 4 */
pwm_init(4, MUX_DIV_4, 0);
pwm_config(4, 0, 0);
pwm_enable(4);
/* Use this as the current monotonic time in us */
gd->arch.timer_reset_value = 0;
/* Use this as the last timer value we saw */
gd->arch.lastinc = timer_get_us_down();
reset_timer_masked();
return 0;
}
/*
* timer without interrupts
*/
unsigned long get_timer(unsigned long base)
{
ulong now = timer_get_us_down();
/*
* Increment the time by the amount elapsed since the last read.
* The timer may have wrapped around, but it makes no difference to
* our arithmetic here.
*/
gd->arch.timer_reset_value += gd->arch.lastinc - now;
gd->arch.lastinc = now;
/* Divide by 1000 to convert from us to ms */
return gd->arch.timer_reset_value / 1000 - base;
}
unsigned long timer_get_us(void)
{
static unsigned long base_time_us;
struct s5p_timer *const timer =
(struct s5p_timer *)samsung_get_base_timer();
unsigned long now_downward_us = readl(&timer->tcnto4);
if (!base_time_us)
base_time_us = now_downward_us;
/* Note that this timer counts downward. */
return base_time_us - now_downward_us;
}
/* delay x useconds */
void __udelay(unsigned long usec)
{
unsigned long count_value;
count_value = timer_get_us_down();
while ((int)(count_value - timer_get_us_down()) < (int)usec)
;
}
void reset_timer_masked(void)
{
struct s5p_timer *const timer = s5p_get_base_timer();
/* reset time */
gd->arch.lastinc = readl(&timer->tcnto4);
gd->arch.tbl = 0;
}
/*
* This function is derived from PowerPC code (read timebase as long long).
* On ARM it just returns the timer value.
*/
unsigned long long get_ticks(void)
{
return get_timer(0);
}
/*
* This function is derived from PowerPC code (timebase clock frequency).
* On ARM it returns the number of timer ticks per second.
*/
unsigned long get_tbclk(void)
{
return CONFIG_SYS_HZ;
}
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