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/*
* (C) Copyright 2004
* Texas Instruments
* Richard Woodruff <r-woodruff2@ti.com>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
* Alex Zuepke <azu@sysgo.de>
*
* (C) Copyright 2002
* Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
*
* 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/bits.h>
#include <asm/arch/omap2420.h>
#define TIMER_LOAD_VAL 0
/* macro to read the 32 bit timer */
#define READ_TIMER (*((volatile ulong *)(CONFIG_SYS_TIMERBASE+TCRR)))
DECLARE_GLOBAL_DATA_PTR;
int timer_init (void)
{
int32_t val;
/* Start the counter ticking up */
*((int32_t *) (CONFIG_SYS_TIMERBASE + TLDR)) = TIMER_LOAD_VAL; /* reload value on overflow*/
val = (CONFIG_SYS_PTV << 2) | BIT5 | BIT1 | BIT0; /* mask to enable timer*/
*((int32_t *) (CONFIG_SYS_TIMERBASE + TCLR)) = val; /* start timer */
reset_timer_masked(); /* init the timestamp and lastinc value */
return(0);
}
/*
* timer without interrupts
*/
ulong get_timer (ulong base)
{
return get_timer_masked () - base;
}
/* delay x useconds AND preserve advance timestamp value */
void __udelay (unsigned long usec)
{
ulong tmo, tmp;
if (usec >= 1000) { /* if "big" number, spread normalization to seconds */
tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
tmo /= 1000; /* finish normalize. */
} else { /* else small number, don't kill it prior to HZ multiply */
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000*1000);
}
tmp = get_timer (0); /* get current timestamp */
if ( (tmo + tmp + 1) < tmp ) /* if setting this forward will roll time stamp */
reset_timer_masked (); /* reset "advancing" timestamp to 0, set lastinc value */
else
tmo += tmp; /* else, set advancing stamp wake up time */
while (get_timer_masked () < tmo)/* loop till event */
/*NOP*/;
}
void reset_timer_masked (void)
{
/* reset time */
gd->lastinc = READ_TIMER; /* capture current incrementer value time */
gd->tbl = 0; /* start "advancing" time stamp from 0 */
}
ulong get_timer_masked (void)
{
ulong now = READ_TIMER; /* current tick value */
if (now >= gd->lastinc) /* normal mode (non roll) */
gd->tbl += (now - gd->lastinc); /* move stamp fordward with absoulte diff ticks */
else /* we have rollover of incrementer */
gd->tbl += (0xFFFFFFFF - gd->lastinc) + now;
gd->lastinc = now;
return gd->tbl;
}
/* waits specified delay value and resets timestamp */
void udelay_masked (unsigned long usec)
{
ulong tmo;
ulong endtime;
signed long diff;
if (usec >= 1000) { /* if "big" number, spread normalization to seconds */
tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
tmo /= 1000; /* finish normalize. */
} else { /* else small number, don't kill it prior to HZ multiply */
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000*1000);
}
endtime = get_timer_masked () + tmo;
do {
ulong now = get_timer_masked ();
diff = endtime - now;
} while (diff >= 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.
*/
ulong get_tbclk (void)
{
ulong tbclk;
tbclk = CONFIG_SYS_HZ;
return tbclk;
}
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