rockbox/firmware/target/arm/tms320dm320/timer-dm320.c

98 lines
2.4 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 by Karl Kurbjun
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
#include "system.h"
#include "timer.h"
#include "logf.h"
/* GPB0/TOUT0 should already have been configured as output so that pin
should not be a functional pin and TIMER0 output unseen there */
void TIMER0(void)
{
if (pfn_timer != NULL)
pfn_timer();
IO_INTC_IRQ0 |= 1<<IRQ_TIMER0;
}
bool __timer_set(long cycles, bool start)
{
int oldlevel;
unsigned int divider=cycles, prescaler=0;
if(cycles<1)
return false;
IO_TIMER0_TMMD = CONFIG_TIMER0_TMMD_STOP;
if (start && pfn_unregister != NULL)
{
pfn_unregister();
pfn_unregister = NULL;
}
oldlevel = disable_irq_save();
/* Increase prescale values starting from 0 to make the cycle count fit */
while(divider>65535 && prescaler<1024)
{
prescaler++;
divider=cycles/(prescaler+1);
}
IO_TIMER0_TMPRSCL = prescaler;
IO_TIMER0_TMDIV = divider;
restore_irq(oldlevel);
return true;
}
static void stop_timer(void)
{
IO_INTC_EINT0 &= ~(1<<IRQ_TIMER0);
IO_INTC_IRQ0 |= 1<<IRQ_TIMER0;
IO_TIMER0_TMMD = CONFIG_TIMER0_TMMD_STOP;
}
bool __timer_register(void)
{
int oldstatus = set_interrupt_status(IRQ_FIQ_DISABLED, IRQ_FIQ_STATUS);
stop_timer();
/* Turn Timer0 to Free Run mode */
IO_TIMER0_TMMD = CONFIG_TIMER0_TMMD_FREE_RUN;
IO_INTC_EINT0 |= 1<<IRQ_TIMER0;
set_interrupt_status(oldstatus, IRQ_FIQ_STATUS);
return true;
}
void __timer_unregister(void)
{
int oldstatus = set_interrupt_status(IRQ_FIQ_DISABLED, IRQ_FIQ_STATUS);
stop_timer();
set_interrupt_status(oldstatus, IRQ_FIQ_STATUS);
}