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/*
* (C) Copyright 2007
* Sascha Hauer, Pengutronix
*
* Copyright (C) 2010 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/arch/mx50.h>
/* General purpose timers registers */
#define GPTCR __REG(GPT1_BASE_ADDR) /* Control register */
#define GPTPR __REG(GPT1_BASE_ADDR + 0x4) /* Prescaler register */
#define GPTSR __REG(GPT1_BASE_ADDR + 0x8) /* Status register */
#define GPTCNT __REG(GPT1_BASE_ADDR + 0x24) /* Counter register */
/* 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 (50)
static inline void setup_gpt(void)
{
int i;
static int init_done;
if (init_done)
return;
init_done = 1;
/* setup GP Timer 1 */
GPTCR = GPTCR_SWR;
for (i = 0; i < 100; i++)
GPTCR = 0; /* We have no udelay by now */
GPTPR = GPTPR_VAL; /* 50Mhz / 50 */
/* Freerun Mode, PERCLK1 input */
GPTCR |= GPTCR_CLKSOURCE_IPG | GPTCR_TEN;
}
int timer_init(void)
{
setup_gpt();
return 0;
}
void reset_timer_masked(void)
{
GPTCR = 0;
/* Freerun Mode, PERCLK1 input */
GPTCR = GPTCR_CLKSOURCE_IPG | GPTCR_TEN;
}
inline ulong get_timer_masked(void)
{
ulong val = GPTCNT;
return val;
}
void reset_timer(void)
{
reset_timer_masked();
}
ulong get_timer(ulong base)
{
ulong tmp;
tmp = get_timer_masked();
if (tmp <= (base * 1000)) {
/* Overflow */
tmp += (0xffffffff - base);
}
return (tmp / 1000) - base;
}
void set_timer(ulong t)
{
}
/* delay x useconds AND perserve advance timstamp value */
/* GPTCNT is now supposed to tick 1 by 1 us. */
void udelay(unsigned long usec)
{
ulong tmp;
setup_gpt();
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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