FreeRTOS/Demo/msp430_IAR/serial/serial.c - nest-detect/1.0.2/freertos - Git at Google

 /*
     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!
 */


 /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER.
  *
  * This file only supports UART 1
  */

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

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

 /* Demo application includes. */
 #include "serial.h"

 /* Constants required to setup the hardware. */
 #define serTX_AND_RX			( ( unsigned char ) 0x03 )

 /* Misc. constants. */
 #define serNO_BLOCK				( ( TickType_t ) 0 )

 /* Enable the UART Tx interrupt. */
 #define vInterruptOn() IFG2 |= UTXIFG1

 /* The queue used to hold received characters. */
 static QueueHandle_t xRxedChars;

 /* The queue used to hold characters waiting transmission. */
 static QueueHandle_t xCharsForTx;

 static volatile short sTHREEmpty;

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

 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
 {
 unsigned long ulBaudRateCount;

 	/* Initialise the hardware. */

 	/* Generate the baud rate constants for the wanted baud rate. */
 	ulBaudRateCount = configCPU_CLOCK_HZ / ulWantedBaud;

 	portENTER_CRITICAL();
 	{
 		/* Create the queues used by the com test task. */
 		xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
 		xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );

 		/* Reset UART. */
 		UCTL1 |= SWRST;

 		/* Set pin function. */
 		P4SEL |= serTX_AND_RX;

 		/* All other bits remain at zero for n, 8, 1 interrupt driven operation.
 		LOOPBACK MODE!*/
 		U1CTL |= CHAR + LISTEN;
 		U1TCTL |= SSEL1;

 		/* Setup baud rate low byte. */
 		U1BR0 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff );

 		/* Setup baud rate high byte. */
 		ulBaudRateCount >>= 8UL;
 		U1BR1 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff );

 		/* Enable ports. */
 		ME2 |= UTXE1 + URXE1;

 		/* Set. */
 		UCTL1 &= ~SWRST;

 		/* Nothing in the buffer yet. */
 		sTHREEmpty = pdTRUE;

 		/* Enable interrupts. */
 		IE2 |= URXIE1 + UTXIE1;
 	}
 	portEXIT_CRITICAL();

 	/* Unlike other ports, this serial code does not allow for more than one
 	com port.  We therefore don't return a pointer to a port structure and can
 	instead just return NULL. */
 	return NULL;
 }
 /*-----------------------------------------------------------*/

 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
 {
 	/* Get the next character from the buffer.  Return false if no characters
 	are available, or arrive before xBlockTime expires. */
 	if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
 	{
 		return pdTRUE;
 	}
 	else
 	{
 		return pdFALSE;
 	}
 }
 /*-----------------------------------------------------------*/

 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
 {
 signed portBASE_TYPE xReturn;

 	/* Transmit a character. */

 	portENTER_CRITICAL();
 	{
 		if( sTHREEmpty == pdTRUE )
 		{
 			/* If sTHREEmpty is true then the UART Tx ISR has indicated that
 			there are no characters queued to be transmitted - so we can
 			write the character directly to the shift Tx register. */
 			sTHREEmpty = pdFALSE;
 			U1TXBUF = cOutChar;
 			xReturn = pdPASS;
 		}
 		else
 		{
 			/* sTHREEmpty is false, so there are still characters waiting to be
 			transmitted.  We have to queue this character so it gets
 			transmitted	in turn. */

 			/* Return false if after the block time there is no room on the Tx
 			queue.  It is ok to block inside a critical section as each task
 			maintains it's own critical section status. */
 			xReturn = xQueueSend( xCharsForTx, &cOutChar, xBlockTime );

 			/* Depending on queue sizing and task prioritisation:  While we
 			were blocked waiting to post on the queue interrupts were not
 			disabled.  It is possible that the serial ISR has emptied the
 			Tx queue, in which case we need to start the Tx off again
 			writing directly to the Tx register. */
 			if( ( sTHREEmpty == pdTRUE ) && ( xReturn == pdPASS ) )
 			{
 				/* Get back the character we just posted. */
 				xQueueReceive( xCharsForTx, &cOutChar, serNO_BLOCK );
 				sTHREEmpty = pdFALSE;
 				U1TXBUF = cOutChar;
 			}
 		}
 	}
 	portEXIT_CRITICAL();

 	return pdPASS;
 }
 /*-----------------------------------------------------------*/

 #if configINTERRUPT_EXAMPLE_METHOD == 1

 	/*
 	 * UART RX interrupt service routine.
 	 */
 	#pragma vector=UART1RX_VECTOR
 	__interrupt void vRxISR( void )
 	{
 	signed char cChar;
 	portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

 		/* Get the character from the UART and post it on the queue of Rxed
 		characters. */
 		cChar = U1RXBUF;

 		xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );

 		if( xHigherPriorityTaskWoken )
 		{
 			/*If the post causes a task to wake force a context switch
 			as the woken task may have a higher priority than the task we have
 			interrupted. */
 			taskYIELD();
 		}

         /* Make sure any low power mode bits are clear before leaving the ISR. */
         __bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF );
 	}
 	/*-----------------------------------------------------------*/

 	/*
 	 * UART Tx interrupt service routine.
 	 */
 	#pragma vector=UART1TX_VECTOR
 	__interrupt void vTxISR( void )
 	{
 	signed char cChar;
 	portBASE_TYPE xTaskWoken = pdFALSE;

 		/* The previous character has been transmitted.  See if there are any
 		further characters waiting transmission. */

 		if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
 		{
 			/* There was another character queued - transmit it now. */
 			U1TXBUF = cChar;
 		}
 		else
 		{
 			/* There were no other characters to transmit. */
 			sTHREEmpty = pdTRUE;
 		}

         /* Make sure any low power mode bits are clear before leaving the ISR. */
         __bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF );
 	}
     /*-----------------------------------------------------------*/

 #elif configINTERRUPT_EXAMPLE_METHOD == 2

     /* This is a standard C function as an assembly file wrapper is used as an
     interrupt entry point. */
 	void vRxISR( void )
 	{
 	signed char cChar;
 	portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

 		/* Get the character from the UART and post it on the queue of Rxed
 		characters. */
 		cChar = U1RXBUF;

 		xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );

         /*If the post causes a task to wake force a context switch
         as the woken task may have a higher priority than the task we have
         interrupted. */
         portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
 	}
 	/*-----------------------------------------------------------*/

     /* This is a standard C function as an assembly file wrapper is used as an
     interrupt entry point. */
 	void vTxISR( void )
 	{
 	signed char cChar;
 	portBASE_TYPE xTaskWoken = pdFALSE;

 		/* The previous character has been transmitted.  See if there are any
 		further characters waiting transmission. */

 		if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
 		{
 			/* There was another character queued - transmit it now. */
 			U1TXBUF = cChar;
 		}
 		else
 		{
 			/* There were no other characters to transmit. */
 			sTHREEmpty = pdTRUE;
 		}
 	}

 #endif /* configINTERRUPT_EXAMPLE_METHOD */
 /*-----------------------------------------------------------*/
	/*
	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!
	*/


	/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER.
	*
	* This file only supports UART 1
	*/

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

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

	/* Demo application includes. */
	#include "serial.h"

	/* Constants required to setup the hardware. */
	#define serTX_AND_RX ( ( unsigned char ) 0x03 )

	/* Misc. constants. */
	#define serNO_BLOCK ( ( TickType_t ) 0 )

	/* Enable the UART Tx interrupt. */
	#define vInterruptOn() IFG2 \|= UTXIFG1

	/* The queue used to hold received characters. */
	static QueueHandle_t xRxedChars;

	/* The queue used to hold characters waiting transmission. */
	static QueueHandle_t xCharsForTx;

	static volatile short sTHREEmpty;

	/-----------------------------------------------------------/

	xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
	{
	unsigned long ulBaudRateCount;

	/* Initialise the hardware. */

	/* Generate the baud rate constants for the wanted baud rate. */
	ulBaudRateCount = configCPU_CLOCK_HZ / ulWantedBaud;

	portENTER_CRITICAL();
	{
	/* Create the queues used by the com test task. */
	xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
	xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );

	/* Reset UART. */
	UCTL1 \|= SWRST;

	/* Set pin function. */
	P4SEL \|= serTX_AND_RX;

	/* All other bits remain at zero for n, 8, 1 interrupt driven operation.
	LOOPBACK MODE!*/
	U1CTL \|= CHAR + LISTEN;
	U1TCTL \|= SSEL1;

	/* Setup baud rate low byte. */
	U1BR0 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff );

	/* Setup baud rate high byte. */
	ulBaudRateCount >>= 8UL;
	U1BR1 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff );

	/* Enable ports. */
	ME2 \|= UTXE1 + URXE1;

	/* Set. */
	UCTL1 &= ~SWRST;

	/* Nothing in the buffer yet. */
	sTHREEmpty = pdTRUE;

	/* Enable interrupts. */
	IE2 \|= URXIE1 + UTXIE1;
	}
	portEXIT_CRITICAL();

	/* Unlike other ports, this serial code does not allow for more than one
	com port. We therefore don't return a pointer to a port structure and can
	instead just return NULL. */
	return NULL;
	}
	/-----------------------------------------------------------/

	signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
	{
	/* Get the next character from the buffer. Return false if no characters
	are available, or arrive before xBlockTime expires. */
	if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
	{
	return pdTRUE;
	}
	else
	{
	return pdFALSE;
	}
	}
	/-----------------------------------------------------------/

	signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
	{
	signed portBASE_TYPE xReturn;

	/* Transmit a character. */

	portENTER_CRITICAL();
	{
	if( sTHREEmpty == pdTRUE )
	{
	/* If sTHREEmpty is true then the UART Tx ISR has indicated that
	there are no characters queued to be transmitted - so we can
	write the character directly to the shift Tx register. */
	sTHREEmpty = pdFALSE;
	U1TXBUF = cOutChar;
	xReturn = pdPASS;
	}
	else
	{
	/* sTHREEmpty is false, so there are still characters waiting to be
	transmitted. We have to queue this character so it gets
	transmitted in turn. */

	/* Return false if after the block time there is no room on the Tx
	queue. It is ok to block inside a critical section as each task
	maintains it's own critical section status. */
	xReturn = xQueueSend( xCharsForTx, &cOutChar, xBlockTime );

	/* Depending on queue sizing and task prioritisation: While we
	were blocked waiting to post on the queue interrupts were not
	disabled. It is possible that the serial ISR has emptied the
	Tx queue, in which case we need to start the Tx off again
	writing directly to the Tx register. */
	if( ( sTHREEmpty == pdTRUE ) && ( xReturn == pdPASS ) )
	{
	/* Get back the character we just posted. */
	xQueueReceive( xCharsForTx, &cOutChar, serNO_BLOCK );
	sTHREEmpty = pdFALSE;
	U1TXBUF = cOutChar;
	}
	}
	}
	portEXIT_CRITICAL();

	return pdPASS;
	}
	/-----------------------------------------------------------/

	#if configINTERRUPT_EXAMPLE_METHOD == 1

	/*
	* UART RX interrupt service routine.
	*/
	#pragma vector=UART1RX_VECTOR
	__interrupt void vRxISR( void )
	{
	signed char cChar;
	portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

	/* Get the character from the UART and post it on the queue of Rxed
	characters. */
	cChar = U1RXBUF;

	xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );

	if( xHigherPriorityTaskWoken )
	{
	/*If the post causes a task to wake force a context switch
	as the woken task may have a higher priority than the task we have
	interrupted. */
	taskYIELD();
	}

	/* Make sure any low power mode bits are clear before leaving the ISR. */
	__bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF );
	}
	/-----------------------------------------------------------/

	/*
	* UART Tx interrupt service routine.
	*/
	#pragma vector=UART1TX_VECTOR
	__interrupt void vTxISR( void )
	{
	signed char cChar;
	portBASE_TYPE xTaskWoken = pdFALSE;

	/* The previous character has been transmitted. See if there are any
	further characters waiting transmission. */

	if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
	{
	/* There was another character queued - transmit it now. */
	U1TXBUF = cChar;
	}
	else
	{
	/* There were no other characters to transmit. */
	sTHREEmpty = pdTRUE;
	}

	/* Make sure any low power mode bits are clear before leaving the ISR. */
	__bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF );
	}
	/-----------------------------------------------------------/

	#elif configINTERRUPT_EXAMPLE_METHOD == 2

	/* This is a standard C function as an assembly file wrapper is used as an
	interrupt entry point. */
	void vRxISR( void )
	{
	signed char cChar;
	portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

	/* Get the character from the UART and post it on the queue of Rxed
	characters. */
	cChar = U1RXBUF;

	xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );

	/*If the post causes a task to wake force a context switch
	as the woken task may have a higher priority than the task we have
	interrupted. */
	portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
	}
	/-----------------------------------------------------------/

	/* This is a standard C function as an assembly file wrapper is used as an
	interrupt entry point. */
	void vTxISR( void )
	{
	signed char cChar;
	portBASE_TYPE xTaskWoken = pdFALSE;

	/* The previous character has been transmitted. See if there are any
	further characters waiting transmission. */

	if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
	{
	/* There was another character queued - transmit it now. */
	U1TXBUF = cChar;
	}
	else
	{
	/* There were no other characters to transmit. */
	sTHREEmpty = pdTRUE;
	}
	}

	#endif /* configINTERRUPT_EXAMPLE_METHOD */
	/-----------------------------------------------------------/