85 lines
2.3 KiB
C
85 lines
2.3 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2021 Aidan MacDonald
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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
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "timer.h"
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#include "x1000/tcu.h"
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#define TIMER_CHN 5
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bool timer_set(long cycles, bool start)
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{
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if(cycles <= 0)
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return false;
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/* Calculate timer interval */
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unsigned long counter = cycles;
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unsigned prescale = 0;
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while(counter > 0xffff && prescale < 5) {
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counter /= 4;
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prescale += 1;
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}
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/* Duration too long */
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if(counter > 0xffff)
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return false;
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/* Unregister old function */
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if(start && pfn_unregister) {
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pfn_unregister();
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pfn_unregister = 0;
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}
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/* Configure the timer */
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jz_clr(TCU_STOP, 1 << TIMER_CHN);
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jz_clr(TCU_ENABLE, 1 << TIMER_CHN);
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jz_overwritef(TCU_CTRL(TIMER_CHN), SOURCE_V(EXT), PRESCALE(prescale));
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jz_write(TCU_CMP_FULL(TIMER_CHN), counter);
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jz_write(TCU_CMP_HALF(TIMER_CHN), 0);
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jz_clr(TCU_FLAG, 1 << TIMER_CHN);
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jz_clr(TCU_MASK, 1 << TIMER_CHN);
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if(start)
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return timer_start();
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else
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return true;
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}
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bool timer_start(void)
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{
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jz_set(TCU_ENABLE, 1 << TIMER_CHN);
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return true;
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}
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void timer_stop(void)
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{
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jz_clr(TCU_ENABLE, 1 << TIMER_CHN);
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jz_set(TCU_MASK, 1 << TIMER_CHN);
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jz_clr(TCU_FLAG, 1 << TIMER_CHN);
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jz_set(TCU_STOP, 1 << TIMER_CHN);
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}
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void TCU1(void)
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{
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jz_clr(TCU_FLAG, 1 << TIMER_CHN);
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if(pfn_timer)
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pfn_timer();
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}
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