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/*
* Copyright 2012 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/io.h>
#include <div64.h>
#include <asm/arch/timer.h>
#include <asm/arch/vybrid-regs.h>
DECLARE_GLOBAL_DATA_PTR;
#define timestamp (gd->tbl)
#define timerticks (gd->tbu)
#define lastinc (gd->lastinc)
static unsigned long ltmstamp = 0;
#define CONFIG_TMR_USEPIT
#ifdef CONFIG_TMR_USEPIT
unsigned long long _usec2ticks(unsigned long long usec);
int timer_init(void)
{
ulong usecs;
ulong ticks;
timestamp = 0;
/*
* nsecs conversion = (1/ipg_clk) * 10^9
* equivalent to 1000 / (ipg_clk / 10^6)
*/
usecs = (gd->ipg_clk / 1000000);
ticks = 1000 / usecs;
clrbits_le32(PIT_MCR, 2); /* enable PIT */
/* ticks per 10 us = 10000 us / usecs = cycles time */
timerticks = (10 * 1000) / ticks;
__raw_writel(0xFFFFFFFF, PIT_LDVAL1);
__raw_writel(0, PIT_TCTRL1);
__raw_writel(4, PIT_TCTRL1);
__raw_writel(5, PIT_TCTRL1);
__raw_writel(timerticks, PIT_LDVAL0);
__raw_writel(1, PIT_TCTRL0);
lastinc = __raw_readl(PIT_LTMR64H);
return 0;
}
ulong get_timer(ulong base)
{
unsigned long now, diff;
now = __raw_readl(PIT_LTMR64H);
diff = -(now - lastinc);
ltmstamp += diff;
while (ltmstamp > 100) {
timestamp++;
ltmstamp -= 100;
}
lastinc = now;
return timestamp - base;
}
/* delay x useconds AND preserve advance timstamp value */
void __udelay(unsigned long usec)
{
ulong nsecs, tmp;
/*
* nsecs conversion = (1/ipg_clk) * 10^9
* equivalent to 1000 / (ipg_clk / 10^6)
*/
if (usec < 5)
usec = 10;
nsecs = gd->ipg_clk / 1000000;
nsecs = 1000 / nsecs;
/* 1 us per ticks = 1000 ns / nsecs = cycles time */
while (usec > 0) {
if (usec > 65000)
tmp = 65000;
else
tmp = usec;
usec = usec - tmp;
tmp = (tmp * 1000) / nsecs;
__raw_writel(tmp, PIT_LDVAL2);
__raw_writel(1, PIT_TCTRL2);
while ((__raw_readl(PIT_TFLG2) & 1) != 1)
;
__raw_writel(0, PIT_TCTRL2);
__raw_writel(1, PIT_TFLG2);
}
}
#endif /* CONFIG_TMR_USEPIT */
/*
* This function is derived from PowerPC code (timebase clock frequency).
* On ARM it returns the number of timer ticks per second.
*/
unsigned long long _usec2ticks(unsigned long long usec)
{
return usec;
}
unsigned long long get_ticks(void)
{
return get_timer(0);
}
ulong get_tbclk(void)
{
return CONFIG_SYS_HZ;
}
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