rockbox/firmware/target/arm/tcc77x/kernel-tcc77x.c

48 lines
1.6 KiB
C
Raw Normal View History

/***************************************************************************
* __________ __ ___.
* 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 "system.h"
#include "kernel.h"
#include "timer.h"
#include "thread.h"
void tick_start(unsigned int interval_in_ms)
{
/* configure Timer T-Clock to 2Mhz (clock source 4 (Xin) divided by 6) */
PCLKCFG4 = (1 << 31) | (4 << 28) | (5 << 16);
/* disable Timer0 */
TCFG0 &= ~1;
/* set counter reference value based on 1Mhz tick */
TREF0 = interval_in_ms * 1000;
/* Timer0 = reset to 0, divide=2, IRQ enable, enable (continuous) */
TCFG0 = (1<<8) | (0<<4) | (1<<3) | 1;
/* Unmask timer IRQ */
IEN |= TIMER0_IRQ_MASK;
}
/* NB: Since we are using a single timer IRQ, tick tasks are dispatched as
part of the central timer IRQ processing in timer-tcc77x.c */