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/*

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This file is part of CanFestival, a library implementing CanOpen Stack.

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Copyright (C): Edouard TISSERANT and Francis DUPIN

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AT91 Port: Peter CHRISTEN

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See COPYING file for copyrights details.

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This library is free software; you can redistribute it and/or

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modify it under the terms of the GNU Lesser General Public

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License as published by the Free Software Foundation; either

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version 2.1 of the License, or (at your option) any later version.

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This library is distributed in the hope that it will be useful,

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but WITHOUT ANY WARRANTY; without even the implied warranty of

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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

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Lesser General Public License for more details.

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You should have received a copy of the GNU Lesser General Public

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License along with this library; if not, write to the Free Software

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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

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*/

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// Includes for the Canfestival driver

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#include "canfestival.h"

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#include "timer.h"

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// Define the timer registers

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#define AT91C_BASE_TC	AT91C_BASE_TC2

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#define AT91C_ID_TC	AT91C_ID_TC2

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#define TimerAlarm      AT91C_BASE_TC2->TC_RC

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#define TimerCounter    AT91C_BASE_TC2->TC_CV

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#define TIMER_INTERRUPT_LEVEL		1

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void timer_can_irq_handler(void);

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/************************** Modul variables **********************************/

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// Store the last timer value to calculate the elapsed time

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static TIMEVAL last_time_set = TIMEVAL_MAX;

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void initTimer(void)

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/******************************************************************************

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Initializes the timer, turn on the interrupt and put the interrupt time to zero

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INPUT	void

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OUTPUT	void

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******************************************************************************/

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{

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  unsigned int dummy;

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  // First, enable the clock of the TIMER

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  AT91F_PMC_EnablePeriphClock (AT91C_BASE_PMC, 1 << AT91C_ID_TC);

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  // Disable the clock and the interrupts

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  AT91C_BASE_TC->TC_CCR = AT91C_TC_CLKDIS ;

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  AT91C_BASE_TC->TC_IDR = 0xFFFFFFFF ;

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  // Clear status bit

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  dummy = AT91C_BASE_TC->TC_SR;

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  // Suppress warning variable "dummy" was set but never used

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  dummy = dummy;

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  // Set the Mode of the Timer Counter (MCK / 128)

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  AT91C_BASE_TC->TC_CMR = AT91C_TC_CLKS_TIMER_DIV4_CLOCK;

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  // Enable the clock

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  AT91C_BASE_TC->TC_CCR = AT91C_TC_CLKEN ;

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  // Open Timer interrupt

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  AT91F_AIC_ConfigureIt (AT91C_BASE_AIC, AT91C_ID_TC, TIMER_INTERRUPT_LEVEL,

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			 AT91C_AIC_SRCTYPE_INT_POSITIVE_EDGE, timer_can_irq_handler);

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  AT91C_BASE_TC->TC_IER = AT91C_TC_CPCS;  //  IRQ enable CPC

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  AT91F_AIC_EnableIt (AT91C_BASE_AIC, AT91C_ID_TC2);

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  // Start Timer

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  AT91C_BASE_TC->TC_CCR = AT91C_TC_SWTRG ;

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}

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void setTimer(TIMEVAL value)

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/******************************************************************************

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Set the timer for the next alarm.

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INPUT	value TIMEVAL (unsigned long)

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OUTPUT	void

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******************************************************************************/

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{

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  TimerAlarm += value;	// Add the desired time to timer interrupt time

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}

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TIMEVAL getElapsedTime(void)

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/******************************************************************************

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Return the elapsed time to tell the stack how much time is spent since last call.

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INPUT	void

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OUTPUT	value TIMEVAL (unsigned long) the elapsed time

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******************************************************************************/

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{

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  unsigned int timer = TimerCounter;	// Copy the value of the running timer

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  // Calculate the time difference

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  return timer > last_time_set ? timer - last_time_set : last_time_set - timer;

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}

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//*----------------------------------------------------------------------------

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//* Function Name       : timer_can_irq_handler

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//* Object              : C handler interrupt function by the interrupts

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//*                       assembling routine

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//* Output Parameters   : calls TimeDispatch

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//*----------------------------------------------------------------------------

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void timer_can_irq_handler(void)

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{

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  AT91PS_TC TC_pt = AT91C_BASE_TC;

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  unsigned int dummy;

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  // AcknowAT91B_LEDge interrupt status

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  dummy = TC_pt->TC_SR;

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  // Suppress warning variable "dummy" was set but never used

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  dummy = dummy;

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  last_time_set = TimerCounter;

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  TimeDispatch();	// Call the time handler of the stack to adapt the elapsed time

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}

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