Re: [U-Boot] [RESEND PATCH v2 2/5] Tegra2: Add microsecond timer functions

Hi Simon,

Le 05/07/2011 18:49, Simon Glass a écrit :

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

Signed-off-by: Simon Glasssjg@chromium.org

arch/arm/cpu/armv7/tegra2/timer.c | 27 +++++++++++++++++------ arch/arm/include/asm/arch-tegra2/timer.h | 34 ++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+), 7 deletions(-) create mode 100644 arch/arm/include/asm/arch-tegra2/timer.h

diff --git a/arch/arm/cpu/armv7/tegra2/timer.c b/arch/arm/cpu/armv7/tegra2/timer.c index fb061d0..b69c172 100644 --- a/arch/arm/cpu/armv7/tegra2/timer.c +++ b/arch/arm/cpu/armv7/tegra2/timer.c @@ -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 */ @@ -67,10 +66,10 @@ void set_timer(ulong t) 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

@@ -82,7 +81,7 @@ void __udelay(unsigned long usec) void reset_timer_masked(void) { /* reset time, capture current incrementer value time */

• gd->lastinc = readl(&timer_base->cntr_1us) / (TIMER_CLK/CONFIG_SYS_HZ);

• gd->lastinc = timer_get_us() / (TIMER_CLK/CONFIG_SYS_HZ); gd->tbl = 0; /* start "advancing" time stamp from 0 */ }

@@ -91,7 +90,7 @@ 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 */

@@ -120,3 +119,17 @@ 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);

+}

+unsigned long timer_get_future_us(u32 delay) +{

• return timer_get_us() + delay;

+}

What is the added value in a function that just adds its argument to the return value of another function? Might as well do the addition directly instead of calling this 'future' function.

diff --git a/arch/arm/include/asm/arch-tegra2/timer.h b/arch/arm/include/asm/arch-tegra2/timer.h new file mode 100644 index 0000000..5d5445e --- /dev/null +++ b/arch/arm/include/asm/arch-tegra2/timer.h @@ -0,0 +1,34 @@ +/*

• • 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);

+/* returns what the time will likely be some microseconds into the future */ +unsigned long timer_get_future_us(u32 delay);

+#endif

Amicalement,