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/*
* (C) Copyright 2007
* Sascha Hauer, Pengutronix
*
* (C) Copyright 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 registers */
struct mxc_gpt {
unsigned int control;
unsigned int prescaler;
unsigned int status;
unsigned int nouse[6];
unsigned int counter;
};
static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
/* General purpose timers bitfields */
#define GPTCR_SWR (1 << 15) /* Software reset */
#define GPTCR_FRR (1 << 9) /* Freerun / restart */
#define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source */
#define GPTCR_TEN 1 /* Timer enable */
#define CLK_32KHZ 32768 /* 32Khz input */
DECLARE_GLOBAL_DATA_PTR;
#define timestamp (gd->tbl)
#define lastinc (gd->lastinc)
int timer_init(void)
{
int i;
ulong val;
/* setup GP Timer 1 */
__raw_writel(GPTCR_SWR, &cur_gpt->control);
/* We have no udelay by now */
for (i = 0; i < 100; i++)
__raw_writel(0, &cur_gpt->control);
__raw_writel(0, &cur_gpt->prescaler); /* 32Khz */
/* Freerun Mode, PERCLK1 input */
i = __raw_readl(&cur_gpt->control);
__raw_writel(i | GPTCR_CLKSOURCE_32 | GPTCR_TEN, &cur_gpt->control);
val = __raw_readl(&cur_gpt->counter);
lastinc = val / (CLK_32KHZ / CONFIG_SYS_HZ);
timestamp = 0;
return 0;
}
ulong get_timer_masked(void)
{
ulong val = __raw_readl(&cur_gpt->counter);
val /= (CLK_32KHZ / CONFIG_SYS_HZ);
if (val >= lastinc)
timestamp += (val - lastinc);
else
timestamp += ((0xFFFFFFFF / (CLK_32KHZ / CONFIG_SYS_HZ))
- lastinc) + val;
lastinc = val;
return timestamp;
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
/* delay x useconds AND preserve advance timestamp value */
void __udelay(unsigned long usec)
{
unsigned long now, start, tmo;
tmo = usec * (CLK_32KHZ / 1000) / 1000;
if (!tmo)
tmo = 1;
now = start = readl(&cur_gpt->counter);
while ((now - start) < tmo)
now = readl(&cur_gpt->counter);
}
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