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/*
* (C) Copyright 2007-2008
* Stelian Pop <stelian.pop <at> leadtechdesign.com>
* Lead Tech Design <www.leadtechdesign.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/arch/hardware.h>
#include <asm/arch/at91_pit.h>
#include <asm/arch/at91_pmc.h>
#include <asm/arch/at91_rstc.h>
#include <asm/arch/io.h>
/*
* We're using the AT91CAP9/SAM9 PITC in 32 bit mode, by
* setting the 20 bit counter period to its maximum (0xfffff).
*/
#define TIMER_LOAD_VAL 0xfffff
#define READ_RESET_TIMER at91_sys_read(AT91_PIT_PIVR)
#define READ_TIMER at91_sys_read(AT91_PIT_PIIR)
#define TIMER_FREQ (AT91C_MASTER_CLOCK << 4)
#define TICKS_TO_USEC(ticks) ((ticks) / 6)
ulong get_timer_masked(void);
ulong resettime;
/* nothing really to do with interrupts, just starts up a counter. */
int timer_init(void)
{
/*
* Enable PITC Clock
* The clock is already enabled for system controller in boot
*/
at91_sys_write(AT91_PMC_PCER, 1 << AT91_ID_SYS);
/* Enable PITC */
at91_sys_write(AT91_PIT_MR, TIMER_LOAD_VAL | AT91_PIT_PITEN);
reset_timer_masked();
return 0;
}
/*
* timer without interrupts
*/
static inline ulong get_timer_raw(void)
{
ulong now = READ_TIMER;
if (now >= resettime)
return now - resettime;
else
return 0xFFFFFFFFUL - (resettime - now) ;
}
void reset_timer_masked(void)
{
resettime = READ_TIMER;
}
ulong get_timer_masked(void)
{
return TICKS_TO_USEC(get_timer_raw());
}
void udelay_masked(unsigned long usec)
{
ulong tmp;
tmp = get_timer(0);
while (get_timer(tmp) < usec) /* our timer works in usecs */
; /* NOP */
}
void reset_timer(void)
{
reset_timer_masked();
}
ulong get_timer(ulong base)
{
ulong now = get_timer_masked();
if (now >= base)
return now - base;
else
return TICKS_TO_USEC(0xFFFFFFFFUL) - (base - now) ;
}
void udelay(unsigned long usec)
{
udelay_masked(usec);
}
/*
* 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 = CFG_HZ;
return tbclk;
}
/*
* Reset the cpu by setting up the watchdog timer and let him time out.
*/
void reset_cpu(ulong ignored)
{
/* this is the way Linux does it */
at91_sys_write(AT91_RSTC_CR, AT91_RSTC_KEY |
AT91_RSTC_PROCRST |
AT91_RSTC_PERRST);
while (1);
/* Never reached */
}
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