forked from len0rd/rockbox
e0640c3c4b
registering and unregistering are handled by the non target-specific functions of timer.c Remove arguments from the new TIMER_START since they are unused by targets git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21553 a1c6a512-1295-4272-9138-f99709370657
83 lines
2.2 KiB
C
83 lines
2.2 KiB
C
/***************************************************************************
|
|
* __________ __ ___.
|
|
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
|
|
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
|
|
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
|
|
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
|
|
* \/ \/ \/ \/ \/
|
|
* $Id$
|
|
*
|
|
* Copyright (C) 2008 by Rob Purchase
|
|
*
|
|
* 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 "cpu.h"
|
|
#include "system.h"
|
|
#include "timer.h"
|
|
#include "logf.h"
|
|
|
|
static const int prescale_shifts[] = {1, 2, 3, 4, 5, 10, 12};
|
|
|
|
bool __timer_set(long cycles, bool start)
|
|
{
|
|
bool found = false;
|
|
|
|
int prescale_option = 0;
|
|
int actual_cycles = 0;
|
|
|
|
/* Use the first prescale that fits Timer4's 20-bit counter */
|
|
while (!found && prescale_option < 7)
|
|
{
|
|
actual_cycles = cycles >> prescale_shifts[prescale_option];
|
|
|
|
if (actual_cycles < 0x100000)
|
|
found = true;
|
|
else
|
|
prescale_option++;
|
|
}
|
|
|
|
if (!found)
|
|
return false;
|
|
|
|
/* Stop the timer and set new prescale & ref count */
|
|
TCFG(4) &= ~TCFG_EN;
|
|
TCFG(4) = prescale_option << TCFG_SEL;
|
|
TREF(4) = actual_cycles;
|
|
|
|
if (start && pfn_unregister != NULL)
|
|
{
|
|
pfn_unregister();
|
|
pfn_unregister = NULL;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool __timer_start(void)
|
|
{
|
|
int oldstatus = disable_interrupt_save(IRQ_STATUS);
|
|
|
|
TCFG(4) |= TCFG_CLEAR | TCFG_IEN | TCFG_EN;
|
|
|
|
restore_interrupt(oldstatus);
|
|
|
|
return true;
|
|
}
|
|
|
|
void __timer_stop(void)
|
|
{
|
|
int oldstatus = disable_interrupt_save(IRQ_STATUS);
|
|
|
|
TCFG(4) &= ~TCFG_EN;
|
|
|
|
restore_interrupt(oldstatus);
|
|
}
|