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Tegra2: Add microsecond timer function 

These functions provide access to the high resolution microsecond timer
and tidy up a global variable in the code.

Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Simon Glass 2011-08-30 06:23:12 +00:00 committed by Albert ARIBAUD
parent 1c85752258
commit 39d3416f0a
2 changed files with 42 additions and 6 deletions
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18
arch/arm/cpu/armv7/tegra2/timer.c
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@ -38,13 +38,12 @@
#include <common.h>
#include <asm/io.h>
#include <asm/arch/tegra2.h>
#include <asm/arch/timer.h>
DECLARE_GLOBAL_DATA_PTR;
struct timerus *timer_base = (struct timerus *)NV_PA_TMRUS_BASE;
/* counter runs at 1MHz */
#define TIMER_CLK (1000000)
#define TIMER_CLK 1000000
#define TIMER_LOAD_VAL 0xffffffff
/* timer without interrupts */
@ -57,10 +56,10 @@ ulong get_timer(ulong base)
void __udelay(unsigned long usec)
{
long tmo = usec * (TIMER_CLK / 1000) / 1000;
unsigned long now, last = readl(&timer_base->cntr_1us);
unsigned long now, last = timer_get_us();
while (tmo > 0) {
now = readl(&timer_base->cntr_1us);
now = timer_get_us();
if (last > now) /* count up timer overflow */
tmo -= TIMER_LOAD_VAL - last + now;
else
@ -74,7 +73,7 @@ ulong get_timer_masked(void)
ulong now;
/* current tick value */
now = readl(&timer_base->cntr_1us) / (TIMER_CLK / CONFIG_SYS_HZ);
now = timer_get_us() / (TIMER_CLK / CONFIG_SYS_HZ);
if (now >= gd->lastinc) /* normal mode (non roll) */
/* move stamp forward with absolute diff ticks */
@ -103,3 +102,10 @@ ulong get_tbclk(void)
{
return CONFIG_SYS_HZ;
}
unsigned long timer_get_us(void)
{
struct timerus *timer_base = (struct timerus *)NV_PA_TMRUS_BASE;
return readl(&timer_base->cntr_1us);
}

30
arch/arm/include/asm/arch-tegra2/timer.h Normal file
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@ -0,0 +1,30 @@
/*
* Copyright (c) 2011 The Chromium OS Authors.
* 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
*/
/* Tegra2 timer functions */
#ifndef _TEGRA2_TIMER_H
#define _TEGRA2_TIMER_H
/* returns the current monotonic timer value in microseconds */
unsigned long timer_get_us(void);
#endif