/*
    FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd. 
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS provides completely free yet professionally developed,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that has become a de facto standard.             *
     *                                                                       *
     *    Help yourself get started quickly and support the FreeRTOS         *
     *    project by purchasing a FreeRTOS tutorial book, reference          *
     *    manual, or both from: http://www.FreeRTOS.org/Documentation        *
     *                                                                       *
     *    Thank you!                                                         *
     *                                                                       *
    ***************************************************************************

    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 from 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?"                                     *
     *                                                                       *
     *    http://www.FreeRTOS.org/FAQHelp.html                               *
     *                                                                       *
    ***************************************************************************

    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.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
    Integrity Systems to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and 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!
*/

/* High speed timer test as described in main.c. */


/* Scheduler includes. */
#include "FreeRTOS.h"

/* The maximum value the 16bit timer can contain. */
#define timerMAX_COUNT				0xffff

/* The timer 2 interrupt handler.  As this interrupt uses the FreeRTOS assembly
entry point the IPL setting in the following function prototype has no effect.
The interrupt priority is set by ConfigIntTimer2() in vSetupTimerTest(). */
void __attribute__( (interrupt(ipl0), vector(_TIMER_2_VECTOR))) vT2InterruptWrapper( void );

/*-----------------------------------------------------------*/

/* Incremented every 20,000 interrupts, so should count in seconds. */
unsigned long ulHighFrequencyTimerInterrupts = 0;

/* The frequency at which the timer is interrupting. */
static unsigned long ulFrequencyHz;

/*-----------------------------------------------------------*/

void vSetupTimerTest( unsigned short usFrequencyHz )
{
	/* Remember the frequency so it can be used from the ISR. */
	ulFrequencyHz = ( unsigned long ) usFrequencyHz;

	/* T2 is used to generate interrupts above the kernel and max syscall 
	interrupt priority. */
	T2CON = 0;
	TMR2 = 0;

	/* Timer 2 is going to interrupt at usFrequencyHz Hz. */
	PR2 = ( unsigned short ) ( ( configPERIPHERAL_CLOCK_HZ / ( unsigned long ) usFrequencyHz ) - 1 );

	/* Setup timer 2 interrupt priority to be above the kernel priority so
	the timer jitter is not effected by the kernel activity. */
	IPC2bits.T2IP = ( configMAX_SYSCALL_INTERRUPT_PRIORITY + 1 );

	/* Clear the interrupt as a starting condition. */
	IFS0bits.T2IF = 0;

	/* Enable the interrupt. */
	IEC0bits.T2IE = 1;

	/* Start the timer. */
	T2CONbits.TON = 1;
}
/*-----------------------------------------------------------*/

void vT2InterruptHandler( void )
{
extern unsigned long uxInterruptNesting;
static unsigned long ulMaxNestingDepth = 0;

	/* Keep a count of interrupts so the check timer can ensure they are
	occurring at the expected rate. */
	ulHighFrequencyTimerInterrupts++;

	/* Establish the maximum nesting count reached to ensure the test is doing
	what it is supposed to. */
	if( uxInterruptNesting > ulMaxNestingDepth )
	{
		ulMaxNestingDepth = uxInterruptNesting;
	}

	/* Clear the timer interrupt. */
	IFS0CLR = _IFS0_T2IF_MASK;
}