u-boot-brain/arch/arm/cpu/armv7/mx5/timer.c
Stefano Babic db106ef7eb MX5: Reuse the gd->tbl value for timestamp and add gd->lastinc for lastinc bss
The usage of bss values in drivers before initialisation of bss is forbidden.
In that special case some data in .rel.dyn gets corrupted.

This patch is the same as recently applied for arm926js architecture.

Signed-off-by: Stefano Babic <sbabic@denx.de>
CC: Heiko Schocher <hs@denx.de>
2011-02-02 00:54:43 +01:00

122 lines
2.9 KiB
C

/*
* (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 */
DECLARE_GLOBAL_DATA_PTR;
#define timestamp (gd->tbl)
#define lastinc (gd->lastinc)
int timer_init(void)
{
int i;
/* 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);
reset_timer_masked();
return 0;
}
void reset_timer(void)
{
reset_timer_masked();
}
void reset_timer_masked(void)
{
ulong val = __raw_readl(&cur_gpt->counter);
lastinc = val / (CONFIG_SYS_MX5_CLK32 / CONFIG_SYS_HZ);
timestamp = 0;
}
ulong get_timer_masked(void)
{
ulong val = __raw_readl(&cur_gpt->counter);
val /= (CONFIG_SYS_MX5_CLK32 / CONFIG_SYS_HZ);
if (val >= lastinc)
timestamp += (val - lastinc);
else
timestamp += ((0xFFFFFFFF / (CONFIG_SYS_MX5_CLK32 / CONFIG_SYS_HZ))
- lastinc) + val;
lastinc = val;
return timestamp;
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
void set_timer(ulong t)
{
timestamp = t;
}
/* delay x useconds AND preserve advance timestamp value */
void __udelay(unsigned long usec)
{
unsigned long now, start, tmo;
tmo = usec * (CONFIG_SYS_MX5_CLK32 / 1000) / 1000;
if (!tmo)
tmo = 1;
now = start = readl(&cur_gpt->counter);
while ((now - start) < tmo)
now = readl(&cur_gpt->counter);
}