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https://github.com/brain-hackers/u-boot-brain
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3eb90bad65
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>
98 lines
2.6 KiB
C
98 lines
2.6 KiB
C
/*
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* (C) Copyright 2000, 2001
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* Wolfgang Denk, DENX Software Engineering, wd@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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/* ------------------------------------------------------------------------- */
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/*
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* This function is intended for SHORT delays only.
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* It will overflow at around 10 seconds @ 400MHz,
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* or 20 seconds @ 200MHz.
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*/
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unsigned long usec2ticks(unsigned long usec)
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{
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ulong ticks;
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if (usec < 1000) {
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ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
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} else {
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ticks = ((usec / 10) * (get_tbclk() / 100000));
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}
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return (ticks);
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}
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/* ------------------------------------------------------------------------- */
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/*
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* We implement the delay by converting the delay (the number of
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* microseconds to wait) into a number of time base ticks; then we
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* watch the time base until it has incremented by that amount.
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*/
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void __udelay(unsigned long usec)
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{
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ulong ticks = usec2ticks (usec);
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wait_ticks (ticks);
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}
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/* ------------------------------------------------------------------------- */
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#ifndef CONFIG_NAND_SPL
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unsigned long ticks2usec(unsigned long ticks)
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{
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ulong tbclk = get_tbclk();
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/* usec = ticks * 1000000 / tbclk
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* Multiplication would overflow at ~4.2e3 ticks,
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* so we break it up into
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* usec = ( ( ticks * 1000) / tbclk ) * 1000;
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*/
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ticks *= 1000L;
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ticks /= tbclk;
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ticks *= 1000L;
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return ((ulong)ticks);
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}
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#endif
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/* ------------------------------------------------------------------------- */
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int init_timebase (void)
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{
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#if defined(CONFIG_5xx) || defined(CONFIG_8xx)
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volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
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/* unlock */
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immap->im_sitk.sitk_tbk = KAPWR_KEY;
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#endif
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/* reset */
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asm ("li 3,0 ; mttbu 3 ; mttbl 3 ;");
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#if defined(CONFIG_5xx) || defined(CONFIG_8xx)
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/* enable */
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immap->im_sit.sit_tbscr |= TBSCR_TBE;
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#endif
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return (0);
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}
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/* ------------------------------------------------------------------------- */
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