/*
    FreeRTOS V9.0.0 - Copyright (C) 2016 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

    ***************************************************************************
     *                                                                       *
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*/

/******************************************************************************
 * NOTE 1:  This project provides two demo applications.  A simple blinky style
 * project, and a more comprehensive test and demo application.  The
 * mainCREATE_SIMPLE_BLINKY_DEMO_ONLY setting in main.c is used to select
 * between the two.  See the notes on using mainCREATE_SIMPLE_BLINKY_DEMO_ONLY
 * in main.c.  This file implements the simply blinky style version.
 *
 * NOTE 2:  This file only contains the source code that is specific to the
 * basic demo.  Generic functions, such FreeRTOS hook functions, and functions
 * required to configure the hardware, are defined in main.c.
 ******************************************************************************
 *
 * main_blinky() creates one queue, two tasks, and one software timer.  It then
 * starts the scheduler.
 *
 * The Blinky Software Timer:
 * This demonstrates an auto-reload software timer.  The timer callback function
 * does nothing but toggle an LED.
 *
 * The Queue Send Task:
 * The queue send task is implemented by prvQueueSendTask() in main_blinky.c.
 * prvQueueSendTask() repeatedly blocks for 200 milliseconds before sending the
 * value 100 to the queue that was created in main_blinky().
 *
 * The Queue Receive Task:
 * The queue receive task is implemented by prvQueueReceiveTask() in
 * main_blinky.c.  prvQueueReceiveTask() repeatedly blocks on attempts to read
 * from the queue that was created in main_blinky(), toggling an LED each time
 * data is received. The queue send task sends data to the queue every 200
 * milliseconds, so the LED will toggle every 200 milliseconds.
 */

/* Standard includes. */
#include <stdio.h>

/* Kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "timers.h"

/* Priorities at which the tasks are created. */
#define mainQUEUE_SEND_TASK_PRIORITY	( tskIDLE_PRIORITY + 1 )
#define mainQUEUE_RECEIVE_TASK_PRIORITY	( tskIDLE_PRIORITY + 2 )

/* The rate at which data is sent to the queue.  The 200ms value is converted
to ticks using the portTICK_PERIOD_MS constant. */
#define mainQUEUE_SEND_FREQUENCY_MS		( 200 / portTICK_PERIOD_MS )

/* The number of items the queue can hold.  This is 1 as the receive task
will remove items as they are added, meaning the send task should always find
the queue empty. */
#define mainQUEUE_LENGTH				( 1 )

/* Values passed to the two tasks just to check the task parameter
functionality. */
#define mainQUEUE_SEND_PARAMETER		( 0x1111UL )
#define mainQUEUE_RECEIVE_PARAMETER		( 0x22UL )

/* The period of the blinky software timer.  The period is specified in ms and
converted to ticks using the portTICK_PERIOD_MS constant. */
#define mainBLINKY_TIMER_PERIOD			( 50 / portTICK_PERIOD_MS )

/* The LED used by the communicating tasks and the blinky timer respectively. */
#define mainTASKS_LED					( 0 )
#define mainTIMER_LED					( 1 )

/* Misc. */
#define mainDONT_BLOCK					( 0 )

/*-----------------------------------------------------------*/

/*
 * The tasks as described in the comments at the top of this file.
 */
static void prvQueueReceiveTask( void *pvParameters );
static void prvQueueSendTask( void *pvParameters );

/*
 * The callback function for the blinky software timer, as described at the top
 * of this file.
 */
static void prvBlinkyTimerCallback( TimerHandle_t xTimer );

/*
 * Called by main() to create the simply blinky style application if
 * mainCREATE_SIMPLE_BLINKY_DEMO_ONLY is set to 1.
 */
void main_blinky( void );

/*
 * LED toggle function that uses a critical section to ensure thread safety.
 */
extern void vToggleLED( uint8_t ucLED );

/*-----------------------------------------------------------*/

/* The queue used by both tasks. */
static QueueHandle_t xQueue = NULL;

/*-----------------------------------------------------------*/

void main_blinky( void )
{
TimerHandle_t xTimer;

	/* Create the queue. */
	xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( unsigned long ) );
	configASSERT( xQueue );

	if( xQueue != NULL )
	{
		/* Create the two tasks as described in the comments at the top of this
		file. */
		xTaskCreate(	prvQueueReceiveTask,					/* The function that implements the task. */
						"Rx", 									/* The text name assigned to the task - for debug only as it is not used by the kernel. */
						configMINIMAL_STACK_SIZE, 				/* The size of the stack to allocate to the task. */
						( void * ) mainQUEUE_RECEIVE_PARAMETER,	/* The parameter passed to the task - just to check the functionality. */
						mainQUEUE_RECEIVE_TASK_PRIORITY,		/* The priority assigned to the task. */
						NULL );									/* The task handle is not required, so NULL is passed. */

		xTaskCreate( prvQueueSendTask, "TX", configMINIMAL_STACK_SIZE, ( void * ) mainQUEUE_SEND_PARAMETER, mainQUEUE_SEND_TASK_PRIORITY, NULL );


		/* Create the blinky software timer as described at the top of this file. */
		xTimer = xTimerCreate(	"Blinky",					/* A text name, purely to help debugging. */
								( mainBLINKY_TIMER_PERIOD ),/* The timer period. */
								pdTRUE,						/* This is an auto-reload timer, so xAutoReload is set to pdTRUE. */
								( void * ) 0,				/* The ID is not used, so can be set to anything. */
								prvBlinkyTimerCallback );	/* The callback function that inspects the status of all the other tasks. */
		configASSERT( xTimer );

		if( xTimer != NULL )
		{
			xTimerStart( xTimer, mainDONT_BLOCK );
		}

		/* Start the tasks and timer running. */
		vTaskStartScheduler();
	}

	/* If all is well, the scheduler will now be running, and the following
	line will never be reached.  If the following line does execute, then
	there was insufficient FreeRTOS heap memory available for the idle and/or
	timer tasks	to be created.  See the memory management section on the
	FreeRTOS web site for more details. http://www.freertos.org/a00111.html */
	for( ;; );
}
/*-----------------------------------------------------------*/

static void prvQueueSendTask( void *pvParameters )
{
TickType_t xNextWakeTime;
const unsigned long ulValueToSend = 100UL;

	/* Remove compiler warnings in the case that configASSERT() is not defined. */
	( void ) pvParameters;

	/* Check the task parameter is as expected. */
	configASSERT( ( ( unsigned long ) pvParameters ) == mainQUEUE_SEND_PARAMETER );

	/* Initialise xNextWakeTime - this only needs to be done once. */
	xNextWakeTime = xTaskGetTickCount();

	for( ;; )
	{
		/* Place this task in the blocked state until it is time to run again.
		The block time is specified in ticks, the constant used converts ticks
		to ms.  While in the Blocked state this task will not consume any CPU
		time. */
		vTaskDelayUntil( &xNextWakeTime, mainQUEUE_SEND_FREQUENCY_MS );

		/* Send to the queue - causing the queue receive task to unblock and
		toggle the LED.  0 is used as the block time so the sending operation
		will not block - it shouldn't need to block as the queue should always
		be empty at this point in the code. */
		xQueueSend( xQueue, &ulValueToSend, 0U );
	}
}
/*-----------------------------------------------------------*/

static void prvQueueReceiveTask( void *pvParameters )
{
unsigned long ulReceivedValue;

	/* Remove compiler warnings in the case where configASSERT() is not defined. */
	( void ) pvParameters;

	/* Check the task parameter is as expected. */
	configASSERT( ( ( unsigned long ) pvParameters ) == mainQUEUE_RECEIVE_PARAMETER );

	for( ;; )
	{
		/* Wait until something arrives in the queue - this task will block
		indefinitely provided INCLUDE_vTaskSuspend is set to 1 in
		FreeRTOSConfig.h. */
		xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY );

		/*  To get here something must have been received from the queue, but
		is it the expected value?  If it is, toggle the LED. */
		if( ulReceivedValue == 100UL )
		{
			vToggleLED( mainTASKS_LED );
			ulReceivedValue = 0U;
		}
	}
}
/*-----------------------------------------------------------*/

static void prvBlinkyTimerCallback( TimerHandle_t xTimer )
{
	/* Avoid compiler warnings. */
	( void ) xTimer;

	/* This function is called when the blinky software time expires.  All the
	function does is toggle the LED.  LED mainTIMER_LED should therefore toggle
	with the period set by mainBLINKY_TIMER_PERIOD. */
	vToggleLED( mainTIMER_LED );
}
/*-----------------------------------------------------------*/