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rockbox/firmware/timer.c
Tomasz Malesinski cd630c9e0a PNX0101 changes: 
Make PNX0101-specific system.c and crt0.S.
Add new register names from LPC2880 user manual.
Add support for timer.
Enable CPU frequency changing. 


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@12904 a1c6a512-1295-4272-9138-f99709370657
2007-03-24 19:26:13 +00:00

299 lines
8 KiB
C
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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"
static int timer_prio = -1;
static void (*pfn_timer)(void) = NULL; /* timer callback */
static void (*pfn_unregister)(void) = NULL; /* unregister callback */
#ifdef CPU_COLDFIRE
static int base_prescale;
#elif defined CPU_PP || CONFIG_CPU == PNX0101
static long cycles_new = 0;
#endif
/* 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 */
}
#elif defined(CPU_PP)
void TIMER2(void)
{
TIMER2_VAL; /* ACK interrupt */
if (cycles_new > 0)
{
TIMER2_CFG = 0xc0000000 | (cycles_new - 1);
cycles_new = 0;
}
if (pfn_timer != NULL)
{
cycles_new = -1;
/* "lock" the variable, in case timer_set_period()
* is called within pfn_timer() */
pfn_timer();
cycles_new = 0;
}
}
#elif CONFIG_CPU == PNX0101
void TIMER1_ISR(void)
{
if (cycles_new > 0)
{
TIMER1.load = cycles_new - 1;
cycles_new = 0;
}
if (pfn_timer != NULL)
{
cycles_new = -1;
/* "lock" the variable, in case timer_set_period()
* is called within pfn_timer() */
pfn_timer();
cycles_new = 0;
}
TIMER1.clr = 1; /* clear the interrupt */
}
#endif /* CONFIG_CPU */
static bool timer_set(long cycles, bool start)
{
#if (CONFIG_CPU == SH7034) || defined(CPU_COLDFIRE)
int phi = 0; /* bits for the prescaler */
int prescale = 1;
while (cycles > 0x10000)
{ /* work out the smallest prescaler that makes it fit */
#if CONFIG_CPU == SH7034
phi++;
#endif
prescale *= 2;
cycles >>= 1;
}
#endif
#if CONFIG_CPU == PNX0101
if (start)
{
if (pfn_unregister != NULL)
{
pfn_unregister();
pfn_unregister = NULL;
}
TIMER1.ctrl &= ~0x80; /* disable the counter */
TIMER1.ctrl |= 0x40; /* reload after counting down to zero */
TIMER1.ctrl &= ~0xc; /* no prescaler */
TIMER1.clr = 1; /* clear an interrupt event */
}
if (start || (cycles_new == -1)) /* within isr, cycles_new is "locked" */
{ /* enable timer */
TIMER1.load = cycles - 1;
TIMER1.ctrl |= 0x80; /* enable the counter */
}
else
cycles_new = cycles;
#endif
#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/CPUFREQ_MAX_MULT)
return false;
if (prescale > 256/CPUFREQ_MAX_MULT)
{
phi = 0x05; /* prescale sysclk/16, timer enabled */
prescale >>= 4;
}
else
phi = 0x03; /* prescale sysclk, timer enabled */
base_prescale = prescale;
prescale *= (cpu_frequency / CPU_FREQ);
if (start)
{
if (pfn_unregister != NULL)
{
pfn_unregister();
pfn_unregister = NULL;
}
phi &= ~1; /* timer disabled at start */
/* If it is already enabled, writing a 0 to the RST bit will clear
the register, so we clear RST explicitly before writing the real
data. */
TMR1 = 0;
}
/* 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 */
#elif defined(CPU_PP)
if (cycles > 0x20000000 || cycles < 2)
return false;
if (start)
{
if (pfn_unregister != NULL)
{
pfn_unregister();
pfn_unregister = NULL;
}
}
if (start || (cycles_new == -1)) /* within isr, cycles_new is "locked" */
TIMER2_CFG = 0xc0000000 | (cycles - 1); /* enable timer */
else
cycles_new = cycles;
#elif CONFIG_CPU == S3C2440 /* TODO: Implement for the Gigabeat */
(void)start;
(void)cycles;
#endif /* CONFIG_CPU */
return true;
}
#ifdef CPU_COLDFIRE
void timers_adjust_prescale(int multiplier, bool enable_irq)
{
/* tick timer */
TMR0 = (TMR0 & 0x00ef)
| ((unsigned short)(multiplier - 1) << 8)
| (enable_irq ? 0x10 : 0);
if (pfn_timer)
{
/* user timer */
int prescale = base_prescale * multiplier;
TMR1 = (TMR1 & 0x00ef)
| ((unsigned short)(prescale - 1) << 8)
| (enable_irq ? 0x10 : 0);
}
}
#endif
/* Register a user timer, called every <cycles> TIMER_FREQ 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 defined(CPU_PP) || (CONFIG_CPU==PNX0101) || (CONFIG_CPU==S3C2440)
/* TODO: Implement for PortalPlayer and iFP (if possible) */
(void)int_prio;
#endif
#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 = 0x90; /* interrupt on level 4.0 */
and_l(~(1<<10), &IMR);
TMR1 |= 1; /* start timer */
#elif defined(CPU_PP)
/* unmask interrupt source */
CPU_INT_EN = TIMER2_MASK;
#elif CONFIG_CPU == PNX0101
irq_set_int_handler(IRQ_TIMER1, TIMER1_ISR);
irq_enable_int(IRQ_TIMER1);
#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 */
#elif defined(CPU_PP)
TIMER2_CFG = 0; /* stop timer 2 */
CPU_INT_CLR = TIMER2_MASK;
#elif CONFIG_CPU == PNX0101
TIMER1.ctrl &= ~0x80; /* disable timer 1 */
irq_disable_int(5);
#endif
pfn_timer = NULL;
pfn_unregister = NULL;
timer_prio = -1;
}
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