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https://github.com/AsahiLinux/u-boot
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095a460b49
This sets CONFIG_SYS_HZ to 1000 as required, and completely rewrites timer code, which is now both correct and much smaller. Unused functions like udelay_masked() have been removed as no driver uses them, even the ones that are not currently active for this board. mtu.h is copied literally from the kernel sources. Signed-off-by: Alessandro Rubini <rubini@unipv.it> Acked-by: Andrea Gallo <andrea.gallo@stericsson.com> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
70 lines
2.1 KiB
C
70 lines
2.1 KiB
C
/*
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* (C) Copyright 2009 Alessandro Rubini
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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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#include <asm/arch/mtu.h>
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/*
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* The timer is a decrementer, we'll left it free running at 2.4MHz.
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* We have 2.4 ticks per microsecond and an overflow in almost 30min
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*/
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#define TIMER_CLOCK (24 * 100 * 1000)
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#define COUNT_TO_USEC(x) ((x) * 5 / 12) /* overflows at 6min */
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#define USEC_TO_COUNT(x) ((x) * 12 / 5) /* overflows at 6min */
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#define TICKS_PER_HZ (TIMER_CLOCK / CONFIG_SYS_HZ)
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#define TICKS_TO_HZ(x) ((x) / TICKS_PER_HZ)
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/* macro to read the 32 bit timer: since it decrements, we invert read value */
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#define READ_TIMER() (~readl(CONFIG_SYS_TIMERBASE + MTU_VAL(0)))
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/* Configure a free-running, auto-wrap counter with no prescaler */
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int timer_init(void)
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{
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writel(MTU_CRn_ENA | MTU_CRn_PRESCALE_1 | MTU_CRn_32BITS,
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CONFIG_SYS_TIMERBASE + MTU_CR(0));
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reset_timer();
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return 0;
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}
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/* Restart counting from 0 */
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void reset_timer(void)
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{
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writel(0, CONFIG_SYS_TIMERBASE + MTU_LR(0)); /* Immediate effect */
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}
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/* Return how many HZ passed since "base" */
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ulong get_timer(ulong base)
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{
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return TICKS_TO_HZ(READ_TIMER()) - base;
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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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ulong ini, end;
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ini = READ_TIMER();
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end = ini + USEC_TO_COUNT(usec);
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while ((signed)(end - READ_TIMER()) > 0)
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;
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}
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