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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
*
*
* Copyright (C) 2009 by Jorge Pinto
*
* 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"
#include "at91sam9260.h"
/*-----------------------------------------------------------------------------
* Function Name : pitc_handler
* Object : Handler for PITC interrupt
*---------------------------------------------------------------------------*/
void pitc_handler(void)
{
unsigned long pivr = 0;
unsigned long pisr = 0;
/* Read the PISR */
pisr = AT91C_PITC_PISR & AT91C_PITC_PITS;
/* Read the PIVR. It acknowledges the IT */
pivr = AT91C_PITC_PIVR;
/* Run through the list of tick tasks */
call_tick_tasks();
}
void tick_start(unsigned int interval_in_ms)
{
volatile unsigned long pimr = 0;
/* Configure a resolution of 1 ms */
AT91C_PITC_PIMR = MCK_FREQ / (((16 * 1000) - 1) / interval_in_ms);
/* Enable interrupts */
/* Disable the interrupt on the interrupt controller */
AT91C_AIC_IDCR = (1 << AT91C_ID_SYS);
/* Save the interrupt handler routine pointer and the interrupt priority */
AT91C_AIC_SVR(AT91C_ID_SYS) = (unsigned long) pitc_handler;
/* Store the Source Mode Register */
AT91C_AIC_SMR(AT91C_ID_SYS) = AT91C_AIC_SRCTYPE_INT_LEVEL_SENSITIVE | \
AT91C_AIC_PRIOR_LOWEST;
/* Clear the interrupt on the interrupt controller */
AT91C_AIC_ICCR = (1 << AT91C_ID_SYS);
/* Enable the interrupt on the interrupt controller */
AT91C_AIC_IECR = (1 << AT91C_ID_SYS);
/* Enable the interrupt on the pit */
pimr = AT91C_PITC_PIMR;
AT91C_PITC_PIMR = pimr | AT91C_PITC_PITIEN;
/* Enable the pit */
pimr = AT91C_PITC_PIMR;
AT91C_PITC_PIMR = pimr | AT91C_PITC_PITEN;
}
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