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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();
}
int timer_init(void)
{
/* PWM Timer 4 */
pwm_init(4, MUX_DIV_2, 0);
pwm_config(4, 0, 0);
pwm_enable(4);
reset_timer_masked();
return 0;
}
/*
* timer without interrupts
*/
unsigned long get_timer(unsigned long base)
{
return get_timer_masked() - base;
}
/* delay x useconds */
void __udelay(unsigned long usec)
{
struct s5p_timer *const timer = s5p_get_base_timer();
unsigned long tmo, tmp, count_value;
count_value = readl(&timer->tcntb4);
if (usec >= 1000) {
/*
* if "big" number, spread normalization
* to seconds
* 1. start to normalize for usec to ticks per sec
* 2. find number of "ticks" to wait to achieve target
* 3. finish normalize.
*/
tmo = usec / 1000;
tmo *= (CONFIG_SYS_HZ * count_value);
tmo /= 1000;
} else {
/* else small number, don't kill it prior to HZ multiply */
tmo = usec * CONFIG_SYS_HZ * count_value;
tmo /= (1000 * 1000);
}
/* get current timestamp */
tmp = get_current_tick();
/* if setting this fordward will roll time stamp */
/* reset "advancing" timestamp to 0, set lastinc value */
/* else, set advancing stamp wake up time */
if ((tmo + tmp + 1) < tmp)
reset_timer_masked();
else
tmo += tmp;
/* loop till event */
while (get_current_tick() < tmo)
; /* nop */
}
void reset_timer_masked(void)
{
struct s5p_timer *const timer = s5p_get_base_timer();
/* reset time */
gd->lastinc = readl(&timer->tcnto4);
gd->arch.tbl = 0;
}
unsigned long get_timer_masked(void)
{
struct s5p_timer *const timer = s5p_get_base_timer();
unsigned long count_value = readl(&timer->tcntb4);
return get_current_tick() / count_value;
}
unsigned long get_current_tick(void)
{
struct s5p_timer *const timer = s5p_get_base_timer();
unsigned long now = readl(&timer->tcnto4);
unsigned long count_value = readl(&timer->tcntb4);
if (gd->lastinc >= now)
gd->arch.tbl += gd->lastinc - now;
else
gd->arch.tbl += gd->lastinc + count_value - now;
gd->lastinc = now;
return gd->arch.tbl;
}
/*
* 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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