FreeRTOS/Demo/NEC_78K0R_IAR/ButtonTask.c - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
     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!
 */

 /*
  * This file defines the button push task and ISR as described at the top of
  * main.c.  The ISR is called from a wrapper function defined in ButtonISR.s26.
  */

 /* Kernel includes. */
 #include "FreeRTOS.h"
 #include "task.h"
 #include "semphr.h"

 /* The LED output used by the button push task. */
 #define butLED1   P7_bit.no7

 /* A short delay used for button debouncing. */
 #define butDEBOUNCE_DELAY	( 200 / portTICK_PERIOD_MS )

 /* The semaphore used to synchronise the button push task with the interrupt. */
 static SemaphoreHandle_t xButtonSemaphore;

 /*
  * The definition of the button task itself.  See the comments at the top of
  * main.c.
  */
 void vButtonTask( void *pvParameters )
 {
 	/* Ensure the semaphore is created before it gets used. */
 	vSemaphoreCreateBinary( xButtonSemaphore );

 	for( ;; )
 	{
 		/* Block on the semaphore to wait for an interrupt event.  The semaphore
 		is 'given' from vButtonISRHandler() below.  Using portMAX_DELAY as the
 		block time will cause the task to block indefinitely provided
 		INCLUDE_vTaskSuspend is set to 1 in FreeRTOSConfig.h. */
 		xSemaphoreTake( xButtonSemaphore, portMAX_DELAY );

 		/* The button must have been pushed for this line to be executed.
 		Simply toggle the LED. */
 		butLED1 = !butLED1;

 		/* Wait a short time then clear any pending button pushes as a crude
 		method of debouncing the switch.  xSemaphoreTake() uses a block time of
 		zero this time so it returns immediately rather than waiting for the
 		interrupt to occur. */
 		vTaskDelay( butDEBOUNCE_DELAY );
 		xSemaphoreTake( xButtonSemaphore, 0 );
 	}
 }
 /*-----------------------------------------------------------*/

 /*
  * The C portion of the interrupt handler.  Interrupts are triggered by pushing
  * the button on the target board.  This interrupt can cause a context switch
  * so has an assembly file wrapper defined within ButtonISR.s26.
  */
 void vButtonISRHandler( void )
 {
 short sHigherPriorityTaskWoken = pdFALSE;

 	/* 'Give' the semaphore to unblock the button task. */
 	xSemaphoreGiveFromISR( xButtonSemaphore, &sHigherPriorityTaskWoken );

 	/* If giving the semaphore unblocked a task, and the unblocked task has a
 	priority that is higher than the currently running task, then
 	sHigherPriorityTaskWoken will have been set to pdTRUE.  Passing a pdTRUE
 	value to portYIELD_FROM_ISR() will cause this interrupt to return directly
 	to the higher priority unblocked task. */
 	portYIELD_FROM_ISR( sHigherPriorityTaskWoken );
 }
 /*-----------------------------------------------------------*/
	/*
	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!
	*/

	/*
	* This file defines the button push task and ISR as described at the top of
	* main.c. The ISR is called from a wrapper function defined in ButtonISR.s26.
	*/

	/* Kernel includes. */
	#include "FreeRTOS.h"
	#include "task.h"
	#include "semphr.h"

	/* The LED output used by the button push task. */
	#define butLED1 P7_bit.no7

	/* A short delay used for button debouncing. */
	#define butDEBOUNCE_DELAY ( 200 / portTICK_PERIOD_MS )

	/* The semaphore used to synchronise the button push task with the interrupt. */
	static SemaphoreHandle_t xButtonSemaphore;

	/*
	* The definition of the button task itself. See the comments at the top of
	* main.c.
	*/
	void vButtonTask( void *pvParameters )
	{
	/* Ensure the semaphore is created before it gets used. */
	vSemaphoreCreateBinary( xButtonSemaphore );

	for( ;; )
	{
	/* Block on the semaphore to wait for an interrupt event. The semaphore
	is 'given' from vButtonISRHandler() below. Using portMAX_DELAY as the
	block time will cause the task to block indefinitely provided
	INCLUDE_vTaskSuspend is set to 1 in FreeRTOSConfig.h. */
	xSemaphoreTake( xButtonSemaphore, portMAX_DELAY );

	/* The button must have been pushed for this line to be executed.
	Simply toggle the LED. */
	butLED1 = !butLED1;

	/* Wait a short time then clear any pending button pushes as a crude
	method of debouncing the switch. xSemaphoreTake() uses a block time of
	zero this time so it returns immediately rather than waiting for the
	interrupt to occur. */
	vTaskDelay( butDEBOUNCE_DELAY );
	xSemaphoreTake( xButtonSemaphore, 0 );
	}
	}
	/-----------------------------------------------------------/

	/*
	* The C portion of the interrupt handler. Interrupts are triggered by pushing
	* the button on the target board. This interrupt can cause a context switch
	* so has an assembly file wrapper defined within ButtonISR.s26.
	*/
	void vButtonISRHandler( void )
	{
	short sHigherPriorityTaskWoken = pdFALSE;

	/* 'Give' the semaphore to unblock the button task. */
	xSemaphoreGiveFromISR( xButtonSemaphore, &sHigherPriorityTaskWoken );

	/* If giving the semaphore unblocked a task, and the unblocked task has a
	priority that is higher than the currently running task, then
	sHigherPriorityTaskWoken will have been set to pdTRUE. Passing a pdTRUE
	value to portYIELD_FROM_ISR() will cause this interrupt to return directly
	to the higher priority unblocked task. */
	portYIELD_FROM_ISR( sHigherPriorityTaskWoken );
	}
	/-----------------------------------------------------------/