/*
    FreeRTOS V8.0.0 - 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!
*/

/* FreeRTOS includes. */
#include "FreeRTOS.h"

/* Utility functions to implement run time stats on Cortex-M CPUs.  The collected
run time data can be viewed through the CLI interface.  See the following URL for
more information on run time stats:
http://www.freertos.org/rtos-run-time-stats.html */

/* Addresses of registers in the Cortex-M debug hardware. */
#define rtsDWT_CYCCNT 			( *( ( unsigned long * ) 0xE0001004 ) )
#define rtsDWT_CONTROL 			( *( ( unsigned long * ) 0xE0001000 ) )
#define rtsSCB_DEMCR 			( *( ( unsigned long * ) 0xE000EDFC ) )
#define rtsTRCENA_BIT			( 0x01000000UL )
#define rtsCOUNTER_ENABLE_BIT	( 0x01UL )

/* Simple shift divide for scaling to avoid an overflow occurring too soon.  The
number of bits to shift depends on the clock speed. */
#define runtimeSLOWER_CLOCK_SPEEDS	( 70000000UL )
#define runtimeSHIFT_13				13
#define runtimeOVERFLOW_BIT_13		( 1UL << ( 32UL - runtimeSHIFT_13 ) )
#define runtimeSHIFT_14				14
#define runtimeOVERFLOW_BIT_14		( 1UL << ( 32UL - runtimeSHIFT_14 ) )

/*-----------------------------------------------------------*/

void vConfigureTimerForRunTimeStats( void )
{
	/* Enable TRCENA. */
	rtsSCB_DEMCR = rtsSCB_DEMCR | rtsTRCENA_BIT;

	/* Reset counter. */
	rtsDWT_CYCCNT = 0;

	/* Enable counter. */
	rtsDWT_CONTROL = rtsDWT_CONTROL | rtsCOUNTER_ENABLE_BIT;
}
/*-----------------------------------------------------------*/

uint32_t ulGetRunTimeCounterValue( void )
{
static unsigned long ulLastCounterValue = 0UL, ulOverflows = 0;
unsigned long ulValueNow;

	ulValueNow = rtsDWT_CYCCNT;

	/* Has the value overflowed since it was last read. */
	if( ulValueNow < ulLastCounterValue )
	{
		ulOverflows++;
	}
	ulLastCounterValue = ulValueNow;

	/* Cannot use configCPU_CLOCK_HZ directly as it may itself not be a constant
	but instead map to a variable that holds the clock speed. */

	/* There is no prescale on the counter, so simulate in software. */
	if( configCPU_CLOCK_HZ < runtimeSLOWER_CLOCK_SPEEDS )
	{
		ulValueNow >>= runtimeSHIFT_13;
		ulValueNow += ( runtimeOVERFLOW_BIT_13 * ulOverflows );
	}
	else
	{
		ulValueNow >>= runtimeSHIFT_14;
		ulValueNow += ( runtimeOVERFLOW_BIT_14 * ulOverflows );
	}

	return ulValueNow;
}
/*-----------------------------------------------------------*/