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![Steve Sakoman](/assets/img/avatar_default.png)
The OMAP4 x-load code sets gptimer1 clock source to 32Khz. This isn't acceptable for udelay. This patch changes from gptimer1 to gptimer2, which uses sys_clk at 38.4 Mhz. Signed-off-by: Steve Sakoman <steve@sakoman.com> Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
135 lines
3.3 KiB
C
135 lines
3.3 KiB
C
/*
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* (C) Copyright 2008
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* Texas Instruments
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*
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* Richard Woodruff <r-woodruff2@ti.com>
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* Syed Moahmmed Khasim <khasim@ti.com>
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*
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* (C) Copyright 2002
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* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
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* Marius Groeger <mgroeger@sysgo.de>
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* Alex Zuepke <azu@sysgo.de>
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*
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* (C) Copyright 2002
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* Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <common.h>
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#include <asm/io.h>
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static ulong timestamp;
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static ulong lastinc;
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static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
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/*
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* Nothing really to do with interrupts, just starts up a counter.
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*/
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#define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
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#define TIMER_LOAD_VAL 0xffffffff
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int timer_init(void)
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{
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/* start the counter ticking up, reload value on overflow */
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writel(TIMER_LOAD_VAL, &timer_base->tldr);
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/* enable timer */
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writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST,
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&timer_base->tclr);
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reset_timer_masked(); /* init the timestamp and lastinc value */
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return 0;
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}
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/*
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* timer without interrupts
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*/
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void reset_timer(void)
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{
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reset_timer_masked();
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}
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ulong get_timer(ulong base)
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{
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return get_timer_masked() - base;
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}
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void set_timer(ulong t)
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{
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timestamp = t;
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}
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/* delay x useconds */
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void __udelay(unsigned long usec)
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{
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long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
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unsigned long now, last = readl(&timer_base->tcrr);
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while (tmo > 0) {
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now = readl(&timer_base->tcrr);
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if (last > now) /* count up timer overflow */
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tmo -= TIMER_LOAD_VAL - last + now;
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else
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tmo -= now - last;
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last = now;
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}
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}
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void reset_timer_masked(void)
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{
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/* reset time, capture current incrementer value time */
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lastinc = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
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timestamp = 0; /* start "advancing" time stamp from 0 */
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}
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ulong get_timer_masked(void)
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{
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/* current tick value */
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ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
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if (now >= lastinc) /* normal mode (non roll) */
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/* move stamp fordward with absoulte diff ticks */
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timestamp += (now - lastinc);
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else /* we have rollover of incrementer */
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timestamp += ((TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ))
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- lastinc) + now;
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lastinc = now;
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return timestamp;
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}
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/*
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* This function is derived from PowerPC code (read timebase as long long).
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* On ARM it just returns the timer value.
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*/
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unsigned long long get_ticks(void)
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{
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return get_timer(0);
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}
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/*
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* This function is derived from PowerPC code (timebase clock frequency).
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* On ARM it returns the number of timer ticks per second.
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*/
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ulong get_tbclk(void)
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{
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return CONFIG_SYS_HZ;
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}
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