mirror of
https://github.com/AsahiLinux/u-boot
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105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
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/*
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* Copyright (C) 2012 Altera Corporation <www.altera.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (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, see <http://www.gnu.org/licenses/>.
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*/
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#include <common.h>
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#include <asm/io.h>
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#include <asm/arch/timer.h>
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DECLARE_GLOBAL_DATA_PTR;
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static const struct socfpga_timer *timer_base = (void *)CONFIG_SYS_TIMERBASE;
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/*
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* Timer initialization
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*/
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int timer_init(void)
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{
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writel(TIMER_LOAD_VAL, &timer_base->load_val);
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writel(TIMER_LOAD_VAL, &timer_base->curr_val);
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writel(readl(&timer_base->ctrl) | 0x3, &timer_base->ctrl);
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return 0;
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}
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static u32 read_timer(void)
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{
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return readl(&timer_base->curr_val);
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}
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/*
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* Delay x useconds
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*/
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void __udelay(unsigned long usec)
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{
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unsigned long now, last;
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/*
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* get the tmo value based on timer clock speed
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* tmo = delay required / period of timer clock
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*/
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long tmo = usec * CONFIG_TIMER_CLOCK_KHZ / 1000;
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last = read_timer();
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while (tmo > 0) {
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now = read_timer();
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if (last >= now)
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/* normal mode (non roll) */
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tmo -= last - now;
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else
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/* we have overflow of the count down timer */
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tmo -= TIMER_LOAD_VAL - last + now;
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last = now;
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}
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}
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/*
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* Get the timer value
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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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/*
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* Timer : get the time difference
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* Unit of tick is based on the CONFIG_SYS_HZ
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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 = read_timer() / (CONFIG_TIMER_CLOCK_KHZ/CONFIG_SYS_HZ);
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if (gd->lastinc >= now) {
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/* normal mode (non roll) */
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/* move stamp forward with absolute diff ticks */
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gd->tbl += gd->lastinc - now;
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} else {
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/* we have overflow of the count down timer */
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gd->tbl += TIMER_LOAD_VAL - gd->lastinc + now;
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}
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gd->lastinc = now;
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return gd->tbl;
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}
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/*
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* Reset the timer
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*/
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void reset_timer(void)
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{
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/* capture current decrementer value time */
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gd->lastinc = read_timer() / (CONFIG_TIMER_CLOCK_KHZ/CONFIG_SYS_HZ);
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/* start "advancing" time stamp from 0 */
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gd->tbl = 0;
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}
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