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![Ingo van Lil](/assets/img/avatar_default.png)
According to the PPC reference implementation the udelay() function is responsible for resetting the watchdog timer as frequently as needed. Most other architectures do not meet that requirement, so long-running operations might result in a watchdog reset. This patch adds a generic udelay() function which takes care of resetting the watchdog before calling an architecture-specific __udelay(). Signed-off-by: Ingo van Lil <inguin@gmx.de>
159 lines
4.4 KiB
C
159 lines
4.4 KiB
C
/*
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* (C) Copyright 2004
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* Texas Instruments
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* Richard Woodruff <r-woodruff2@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/arch/bits.h>
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#include <asm/arch/omap2420.h>
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#define TIMER_LOAD_VAL 0
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/* macro to read the 32 bit timer */
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#define READ_TIMER (*((volatile ulong *)(CONFIG_SYS_TIMERBASE+TCRR)))
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static ulong timestamp;
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static ulong lastinc;
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int timer_init (void)
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{
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int32_t val;
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/* Start the counter ticking up */
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*((int32_t *) (CONFIG_SYS_TIMERBASE + TLDR)) = TIMER_LOAD_VAL; /* reload value on overflow*/
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val = (CONFIG_SYS_PTV << 2) | BIT5 | BIT1 | BIT0; /* mask to enable timer*/
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*((int32_t *) (CONFIG_SYS_TIMERBASE + TCLR)) = val; /* start timer */
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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 AND perserve advance timstamp value */
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void __udelay (unsigned long usec)
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{
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ulong tmo, tmp;
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if (usec >= 1000) { /* if "big" number, spread normalization to seconds */
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tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
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tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
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tmo /= 1000; /* finish normalize. */
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} else { /* else small number, don't kill it prior to HZ multiply */
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tmo = usec * CONFIG_SYS_HZ;
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tmo /= (1000*1000);
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}
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tmp = get_timer (0); /* get current timestamp */
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if ( (tmo + tmp + 1) < tmp )/* if setting this forward will roll time stamp */
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reset_timer_masked (); /* reset "advancing" timestamp to 0, set lastinc value */
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else
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tmo += tmp; /* else, set advancing stamp wake up time */
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while (get_timer_masked () < tmo)/* loop till event */
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/*NOP*/;
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}
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void reset_timer_masked (void)
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{
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/* reset time */
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lastinc = READ_TIMER; /* capture current incrementer value time */
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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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ulong now = READ_TIMER; /* current tick value */
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if (now >= lastinc) /* normal mode (non roll) */
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timestamp += (now - lastinc); /* move stamp fordward with absoulte diff ticks */
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else /* we have rollover of incrementer */
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timestamp += (0xFFFFFFFF - lastinc) + now;
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lastinc = now;
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return timestamp;
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}
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/* waits specified delay value and resets timestamp */
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void udelay_masked (unsigned long usec)
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{
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ulong tmo;
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ulong endtime;
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signed long diff;
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if (usec >= 1000) { /* if "big" number, spread normalization to seconds */
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tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
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tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
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tmo /= 1000; /* finish normalize. */
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} else { /* else small number, don't kill it prior to HZ multiply */
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tmo = usec * CONFIG_SYS_HZ;
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tmo /= (1000*1000);
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}
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endtime = get_timer_masked () + tmo;
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do {
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ulong now = get_timer_masked ();
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diff = endtime - now;
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} while (diff >= 0);
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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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ulong tbclk;
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tbclk = CONFIG_SYS_HZ;
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return tbclk;
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}
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