FreeRTOS/Demo/CORTEX_M4_ATSAM4S_Atmel_Studio/src/IntQueueTimer.c

/*
    FreeRTOS V8.2.0rc1 - Copyright (C) 2014 Real Time Engineers Ltd.
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.

    >>!   NOTE: The modification to the GPL is included to allow you to     !<<
    >>!   distribute a combined work that includes FreeRTOS without being   !<<
    >>!   obliged to provide the source code for proprietary components     !<<
    >>!   outside of the FreeRTOS kernel.                                   !<<

    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    FOR A PARTICULAR PURPOSE.  Full license text is available on the following
    link: http://www.freertos.org/a00114.html

    1 tab == 4 spaces!

    ***************************************************************************
     *                                                                       *
     *    Having a problem?  Start by reading the FAQ "My application does   *
     *    not run, what could be wrong?".  Have you defined configASSERT()?  *
     *                                                                       *
     *    http://www.FreeRTOS.org/FAQHelp.html                               *
     *                                                                       *
    ***************************************************************************

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS provides completely free yet professionally developed,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that is more than just the market leader, it     *
     *    is the industry's de facto standard.                               *
     *                                                                       *
     *    Help yourself get started quickly while simultaneously helping     *
     *    to support the FreeRTOS project by purchasing a FreeRTOS           *
     *    tutorial book, reference manual, or both:                          *
     *    http://www.FreeRTOS.org/Documentation                              *
     *                                                                       *
    ***************************************************************************

    ***************************************************************************
     *                                                                       *
     *   Investing in training allows your team to be as productive as       *
     *   possible as early as possible, lowering your overall development    *
     *   cost, and enabling you to bring a more robust product to market     *
     *   earlier than would otherwise be possible.  Richard Barry is both    *
     *   the architect and key author of FreeRTOS, and so also the world's   *
     *   leading authority on what is the world's most popular real time     *
     *   kernel for deeply embedded MCU designs.  Obtaining your training    *
     *   from Richard ensures your team will gain directly from his in-depth *
     *   product knowledge and years of usage experience.  Contact Real Time *
     *   Engineers Ltd to enquire about the FreeRTOS Masterclass, presented  *
     *   by Richard Barry:  http://www.FreeRTOS.org/contact
     *                                                                       *
    ***************************************************************************

    ***************************************************************************
     *                                                                       *
     *    You are receiving this top quality software for free.  Please play *
     *    fair and reciprocate by reporting any suspected issues and         *
     *    participating in the community forum:                              *
     *    http://www.FreeRTOS.org/support                                    *
     *                                                                       *
     *    Thank you!                                                         *
     *                                                                       *
    ***************************************************************************

    http://www.FreeRTOS.org - Documentation, books, training, latest versions,
    license and Real Time Engineers Ltd. contact details.

    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool, a DOS
    compatible FAT file system, and our tiny thread aware UDP/IP stack.

    http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.

    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and commercial middleware.

    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
    engineered and independently SIL3 certified version for use in safety and
    mission critical applications that require provable dependability.

    1 tab == 4 spaces!
*/

/*
 * Provides the two timers sources for the standard demo IntQueue test.  Also
 * includes a high frequency timer to maximise the interrupt nesting achieved.
 */

/* Standard includes. */
#include <limits.h>

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"

/* Demo includes. */
#include "IntQueueTimer.h"
#include "IntQueue.h"

/* System includes. */
#include "board.h"
#include "asf.h"

/* The frequencies at which the first two timers expire are slightly offset to
ensure they don't remain synchronised.  The frequency of the highest priority
interrupt is 20 times faster so really hammers the interrupt entry and exit
code. */
#define tmrTIMER_0_FREQUENCY	( 2000UL )
#define tmrTIMER_1_FREQUENCY	( 1003UL )
#define tmrTIMER_2_FREQUENCY	( 5000UL )

/* Priorities used by the timer interrupts - these are set differently to make
nesting likely/common.  The high frequency timer operates above the max
system call interrupt priority, but does not use the RTOS API. */
#define tmrTIMER_0_PRIORITY		( configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY )
#define tmrTIMER_1_PRIORITY		( configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY + 1 )
#define tmrTIMER_2_PRIORITY		( configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY - 1 )

/* The channels used within the TC0 timer. */
#define tmrTIMER_0_CHANNEL		( 0 )
#define tmrTIMER_1_CHANNEL		( 1 )
#define tmrTIMER_2_CHANNEL		( 2 )

/* TC register bit specifics. */
#define tmrTRIGGER_ON_RC		( 1UL << 4UL )
#define trmDIVIDER				( 128 )

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

/* Handers for the timer interrupts. */
void TC0_Handler( void );
void TC1_Handler( void );
void TC2_Handler( void );

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

/* Incremented by the high frequency timer, which operates above the max
syscall interrupt priority.  This is just for inspection. */
volatile uint32_t ulHighFrequencyTimerInterrupts = 0;

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

void vInitialiseTimerForIntQueueTest( void )
{
uint32_t ulInputFrequency;

	/* Calculate the frequency of the clock that feeds the TC. */
	ulInputFrequency = configCPU_CLOCK_HZ;
	ulInputFrequency /= trmDIVIDER;

	/* Three channels are used - two that run at or under 
	configMAX_SYSCALL_INTERRUPT_PRIORITY, and one that runs over
	configMAX_SYSCALL_INTERRUPT_PRIORITY. */
	sysclk_enable_peripheral_clock( ID_TC0 );
	sysclk_enable_peripheral_clock( ID_TC1 );
	sysclk_enable_peripheral_clock( ID_TC2 );
	
	/* Init TC channels to waveform mode - up mode clean on RC match. */
	tc_init( TC0, tmrTIMER_0_CHANNEL, TC_CMR_TCCLKS_TIMER_CLOCK4 | TC_CMR_WAVE | TC_CMR_ACPC_CLEAR | TC_CMR_CPCTRG );
	tc_init( TC0, tmrTIMER_1_CHANNEL, TC_CMR_TCCLKS_TIMER_CLOCK4 | TC_CMR_WAVE | TC_CMR_ACPC_CLEAR | TC_CMR_CPCTRG );
	tc_init( TC0, tmrTIMER_2_CHANNEL, TC_CMR_TCCLKS_TIMER_CLOCK4 | TC_CMR_WAVE | TC_CMR_ACPC_CLEAR | TC_CMR_CPCTRG );
	
	tc_enable_interrupt( TC0, tmrTIMER_0_CHANNEL, tmrTRIGGER_ON_RC );
	tc_enable_interrupt( TC0, tmrTIMER_1_CHANNEL, tmrTRIGGER_ON_RC );
	tc_enable_interrupt( TC0, tmrTIMER_2_CHANNEL, tmrTRIGGER_ON_RC );
	
	tc_write_rc( TC0, tmrTIMER_0_CHANNEL, ( ulInputFrequency / tmrTIMER_0_FREQUENCY ) );
	tc_write_rc( TC0, tmrTIMER_1_CHANNEL, ( ulInputFrequency / tmrTIMER_1_FREQUENCY ) );
	tc_write_rc( TC0, tmrTIMER_2_CHANNEL, ( ulInputFrequency / tmrTIMER_2_FREQUENCY ) );

	NVIC_SetPriority( TC0_IRQn, tmrTIMER_0_PRIORITY );
	NVIC_SetPriority( TC1_IRQn, tmrTIMER_1_PRIORITY );
	NVIC_SetPriority( TC2_IRQn, tmrTIMER_2_PRIORITY );

	NVIC_EnableIRQ( TC0_IRQn );
	NVIC_EnableIRQ( TC1_IRQn );
	NVIC_EnableIRQ( TC2_IRQn );

	tc_start( TC0, tmrTIMER_0_CHANNEL );
	tc_start( TC0, tmrTIMER_1_CHANNEL );
	tc_start( TC0, tmrTIMER_2_CHANNEL );
}
/*-----------------------------------------------------------*/

void TC0_Handler( void )
{
	/* Handler for the first timer in the IntQueue test.  Was the interrupt
	caused by a compare on RC? */
	if( ( tc_get_status( TC0, tmrTIMER_0_CHANNEL ) & ~TC_SR_CPCS ) != 0 )
	{
		portYIELD_FROM_ISR( xFirstTimerHandler() );	
	}
}
/*-----------------------------------------------------------*/

void TC1_Handler( void )
{
	/* Handler for the second timer in the IntQueue test.  Was the interrupt
	caused by a compare on RC? */
	if( ( tc_get_status( TC0, tmrTIMER_1_CHANNEL ) & ~TC_SR_CPCS ) != 0 )
	{
		portYIELD_FROM_ISR( xSecondTimerHandler() );
	}
}
/*-----------------------------------------------------------*/

void TC2_Handler( void )
{
	/* Handler for the high frequency timer that does nothing but increment a
	variable to give an indication that it is running.  Was the interrupt caused
	by a compare on RC? */
	if( ( tc_get_status( TC0, tmrTIMER_2_CHANNEL ) & ~TC_SR_CPCS ) != 0 )
	{
		ulHighFrequencyTimerInterrupts++;
	}
}