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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2008 by Maurus Cuelenaere
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "jz4740.h"
#include "system.h"
#include "timer.h"
/* Interrupt handler */
void TCU1(void)
{
__tcu_clear_full_match_flag(1);
if (pfn_timer != NULL)
pfn_timer();
}
bool timer_set(long cycles, bool start)
{
unsigned int divider = cycles, prescaler_bit = 0, prescaler = 1, old_irq;
if(cycles < 1)
return false;
if(start && pfn_unregister != NULL)
{
pfn_unregister();
pfn_unregister = NULL;
}
/* Increase prescale values starting from 0 to make the cycle count fit */
while(divider > 65535 && prescaler <= 1024)
{
prescaler <<= 2; /* 1, 4, 16, 64, 256, 1024 */
prescaler_bit++;
divider = cycles / prescaler;
}
old_irq = disable_irq_save();
__tcu_stop_counter(1);
if(start)
{
__tcu_disable_pwm_output(1);
__tcu_mask_half_match_irq(1);
__tcu_unmask_full_match_irq(1);
/* EXTAL clock = CFG_EXTAL (12Mhz in most targets) */
__tcu_select_extalclk(1);
}
REG_TCU_TCSR(1) = (REG_TCU_TCSR(1) & ~TCU_TCSR_PRESCALE_MASK) | (prescaler_bit << TCU_TCSR_PRESCALE_BIT);
REG_TCU_TCNT(1) = 0;
REG_TCU_TDHR(1) = 0;
REG_TCU_TDFR(1) = divider;
__tcu_clear_full_match_flag(1);
if(start)
{
system_enable_irq(IRQ_TCU1);
__tcu_start_counter(1);
}
restore_irq(old_irq);
return true;
}
bool timer_start(void)
{
__tcu_start_counter(1);
return true;
}
void timer_stop(void)
{
unsigned int old_irq = disable_irq_save();
__tcu_stop_counter(1);
restore_irq(old_irq);
}
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