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/*
* (C) Copyright 2007
* Sascha Hauer, Pengutronix
*
* (C) Copyright 2008-2009 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 <asm/arch/imx-regs.h>
/* General purpose timers bitfields */
#define GPTCR_SWR (1<<15) /* Software reset */
#define GPTCR_FRR (1<<9) /* Freerun / restart */
#define GPTCR_CLKSOURCE_32 (0x100<<6) /* Clock source */
#define GPTCR_CLKSOURCE_IPG (0x001<<6) /* Clock source */
#define GPTCR_TEN (1) /* Timer enable */
#define GPTPR_VAL (66)
int timer_init(void)
{
int i;
struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
/* setup GP Timer 1 */
writel(GPTCR_SWR, &gpt->ctrl);
for (i = 0; i < 100; i++)
writel(0, &gpt->ctrl); /* We have no udelay by now */
writel(GPTPR_VAL, &gpt->pre);
/* Freerun Mode, PERCLK1 input */
writel(readl(&gpt->ctrl) |
GPTCR_CLKSOURCE_IPG | GPTCR_TEN,
&gpt->ctrl);
return 0;
}
void reset_timer_masked(void)
{
struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
writel(0, &gpt->ctrl);
/* Freerun Mode, PERCLK1 input */
writel(GPTCR_CLKSOURCE_IPG | GPTCR_TEN,
&gpt->ctrl);
}
inline ulong get_timer_masked(void)
{
struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
ulong val = readl(&gpt->counter);
return val;
}
ulong get_timer(ulong base)
{
ulong tmp;
tmp = get_timer_masked();
if (tmp <= (base * 1000)) {
/* Overflow */
tmp += (0xffffffff - base);
}
return (tmp / 1000) - base;
}
/*
* delay x useconds AND preserve advance timstamp value
* GPTCNT is now supposed to tick 1 by 1 us.
*/
void __udelay(unsigned long usec)
{
ulong tmp;
tmp = get_timer_masked(); /* get current timestamp */
/* if setting this forward will roll time stamp */
if ((usec + tmp + 1) < tmp) {
/* reset "advancing" timestamp to 0, set lastinc value */
reset_timer_masked();
} else {
/* else, set advancing stamp wake up time */
tmp += usec;
}
while (get_timer_masked() < tmp) /* loop till event */
/*NOP*/;
}
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