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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Jens Arnold
*
* 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 <stdbool.h>
#include "config.h"
#include "cpu.h"
#include "system.h"
#include "timer.h"
#ifndef SIMULATOR
static int timer_prio = -1;
static void (*pfn_timer)(void) = NULL; /* timer callback */
static void (*pfn_unregister)(void) = NULL; /* unregister callback */
/* interrupt handler */
#if CONFIG_CPU == SH7034
void IMIA4(void) __attribute__((interrupt_handler));
void IMIA4(void)
{
if (pfn_timer != NULL)
pfn_timer();
and_b(~0x01, &TSR4); /* clear the interrupt */
}
#elif defined CPU_COLDFIRE
void TIMER1(void) __attribute__ ((interrupt_handler));
void TIMER1(void)
{
if (pfn_timer != NULL)
pfn_timer();
TER1 = 0xff; /* clear all events */
}
#endif /* CONFIG_CPU */
static bool timer_set(long cycles, bool start)
{
int phi = 0; /* bits for the prescaler */
int prescale = 1;
#ifdef CPU_COLDFIRE
cycles >>= 1; /* the coldfire timer works on busclk == cpuclk/2 */
#endif
while (cycles > 0x10000)
{ /* work out the smallest prescaler that makes it fit */
#if CONFIG_CPU == SH7034
phi++;
#endif
prescale *= 2;
cycles >>= 1;
}
#if CONFIG_CPU == SH7034
if (prescale > 8)
return false;
if (start)
{
if (pfn_unregister != NULL)
{
pfn_unregister();
pfn_unregister = NULL;
}
and_b(~0x10, &TSTR); /* Stop the timer 4 */
and_b(~0x10, &TSNC); /* No synchronization */
and_b(~0x10, &TMDR); /* Operate normally */
TIER4 = 0xF9; /* Enable GRA match interrupt */
}
TCR4 = 0x20 | phi; /* clear at GRA match, set prescaler */
GRA4 = (unsigned short)(cycles - 1);
if (start || (TCNT4 >= GRA4))
TCNT4 = 0;
and_b(~0x01, &TSR4); /* clear an eventual interrupt */
#elif defined CPU_COLDFIRE
if (prescale > 4096)
return false;
if (prescale > 256)
{
phi = 0x05; /* prescale sysclk/16, timer enabled */
prescale >>= 4;
}
else
phi = 0x03; /* prescale sysclk, timer enabled */
if (start)
{
if (pfn_unregister != NULL)
{
pfn_unregister();
pfn_unregister = NULL;
}
phi &= ~1; /* timer disabled at start */
}
/* We are using timer 1 */
TMR1 = 0x0018 | (unsigned short)phi | ((unsigned short)(prescale - 1) << 8);
TRR1 = (unsigned short)(cycles - 1);
if (start || (TCN1 >= TRR1))
TCN1 = 0; /* reset the timer */
TER1 = 0xff; /* clear all events */
#endif /* CONFIG_CPU */
return true;
}
/* Register a user timer, called every <count> CPU cycles */
bool timer_register(int reg_prio, void (*unregister_callback)(void),
long cycles, int int_prio, void (*timer_callback)(void))
{
if (reg_prio <= timer_prio || cycles == 0)
return false;
#if CONFIG_CPU == SH7034
if (int_prio < 1 || int_prio > 15)
return false;
#elif defined CPU_COLDFIRE
(void)int_prio;
#endif
if (!timer_set(cycles, true))
return false;
pfn_timer = timer_callback;
pfn_unregister = unregister_callback;
timer_prio = reg_prio;
#if CONFIG_CPU == SH7034
IPRD = (IPRD & 0xFF0F) | int_prio << 4; /* interrupt priority */
or_b(0x10, &TSTR); /* start timer 4 */
#elif defined CPU_COLDFIRE
/* ICR2 (Timer1) */
ICR0 = (ICR0 & 0xffff00ff) | 0x00009000; /* interrupt on level 4.0 */
and_l(~(1<<10), &IMR);
TMR1 |= 1; /* start timer */
#endif
return true;
}
bool timer_set_period(long cycles)
{
return timer_set(cycles, false);
}
void timer_unregister(void)
{
#if CONFIG_CPU == SH7034
and_b(~0x10, &TSTR); /* stop the timer 4 */
IPRD = (IPRD & 0xFF0F); /* disable interrupt */
#elif defined CPU_COLDFIRE
TMR1 = 0; /* disable timer 1 */
or_l((1<<10), &IMR); /* disable interrupt */
#endif
pfn_timer = NULL;
pfn_unregister = NULL;
timer_prio = -1;
}
#endif /* !SIMULATOR */
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