| /* | |
| FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd. | |
| *************************************************************************** | |
| * * | |
| * FreeRTOS tutorial books are available in pdf and paperback. * | |
| * Complete, revised, and edited pdf reference manuals are also * | |
| * available. * | |
| * * | |
| * Purchasing FreeRTOS documentation will not only help you, by * | |
| * ensuring you get running as quickly as possible and with an * | |
| * in-depth knowledge of how to use FreeRTOS, it will also help * | |
| * the FreeRTOS project to continue with its mission of providing * | |
| * professional grade, cross platform, de facto standard solutions * | |
| * for microcontrollers - completely free of charge! * | |
| * * | |
| * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * | |
| * * | |
| * Thank you for using FreeRTOS, and thank you for your support! * | |
| * * | |
| *************************************************************************** | |
| 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. See the GNU General Public License for | |
| more details. You should have received a copy of the GNU General Public | |
| License and the FreeRTOS license exception along with FreeRTOS; if not it | |
| can be viewed here: http://www.freertos.org/a00114.html and also obtained | |
| by writing to Richard Barry, contact details for whom are available on the | |
| FreeRTOS WEB site. | |
| 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, training, latest information, | |
| license and contact details. | |
| http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, | |
| including FreeRTOS+Trace - an indispensable productivity tool. | |
| Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell | |
| the code with commercial support, indemnification, and middleware, under | |
| the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also | |
| provide a safety engineered and independently SIL3 certified version under | |
| the SafeRTOS brand: http://www.SafeRTOS.com. | |
| */ | |
| /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. | |
| * | |
| * This is not a proper UART driver. It only supports one port, uses loopback | |
| * mode, and is used to test interrupts that use the FreeRTOS API as part of | |
| * a wider test suite. Nor is it intended to show an efficient implementation | |
| * of a UART interrupt service routine as queues are used to pass individual | |
| * characters one at a time! | |
| */ | |
| /* Standard includes. */ | |
| #include <stdlib.h> | |
| /* Scheduler includes. */ | |
| #include "FreeRTOS.h" | |
| #include "queue.h" | |
| #include "task.h" | |
| /* Demo application includes. */ | |
| #include "serial.h" | |
| /* Misc. constants. */ | |
| #define serNO_BLOCK ( ( portTickType ) 0 ) | |
| /* The queue used to hold received characters. */ | |
| static xQueueHandle xRxedChars; | |
| /* The queue used to hold characters waiting transmission. */ | |
| static xQueueHandle xCharsForTx; | |
| /*-----------------------------------------------------------*/ | |
| xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) | |
| { | |
| unsigned portLONG 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 portCHAR ) ); | |
| xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) ); | |
| /* Reset UART. */ | |
| UCA1CTL1 |= UCSWRST; | |
| /* Use SMCLK. */ | |
| UCA1CTL1 = UCSSEL0 | UCSSEL1; | |
| /* Setup baud rate low byte. */ | |
| UCA1BR0 = ( unsigned portCHAR ) ( ulBaudRateCount & ( unsigned portLONG ) 0xff ); | |
| /* Setup baud rate high byte. */ | |
| ulBaudRateCount >>= 8UL; | |
| UCA1BR1 = ( unsigned portCHAR ) ( ulBaudRateCount & ( unsigned portLONG ) 0xff ); | |
| /* UCLISTEN sets loopback mode! */ | |
| UCA1STAT = UCLISTEN; | |
| /* Enable interrupts. */ | |
| UCA1IE |= UCRXIE; | |
| /* Take out of reset. */ | |
| UCA1CTL1 &= ~UCSWRST; | |
| } | |
| portEXIT_CRITICAL(); | |
| /* Note the comments at the top of this file about this not being a generic | |
| UART driver. */ | |
| return NULL; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType 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 portCHAR cOutChar, portTickType xBlockTime ) | |
| { | |
| signed portBASE_TYPE xReturn; | |
| /* Send the next character to the queue of characters waiting transmission, | |
| then enable the UART Tx interrupt, just in case UART transmission has already | |
| completed and switched itself off. */ | |
| xReturn = xQueueSend( xCharsForTx, &cOutChar, xBlockTime ); | |
| UCA1IE |= UCTXIE; | |
| return xReturn; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| /* The implementation of this interrupt is provided to demonstrate the use | |
| of queues from inside an interrupt service routine. It is *not* intended to | |
| be an efficient interrupt implementation. A real application should make use | |
| of the DMA. Or, as a minimum, transmission and reception could use a simple | |
| RAM ring buffer, and synchronise with a task using a semaphore when a complete | |
| message has been received or transmitted. */ | |
| #pragma vector=USCI_A1_VECTOR | |
| static __interrupt void prvUSCI_A1_ISR( void ) | |
| { | |
| signed char cChar; | |
| portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; | |
| while( ( UCA1IFG & UCRXIFG ) != 0 ) | |
| { | |
| /* Get the character from the UART and post it on the queue of Rxed | |
| characters. */ | |
| cChar = UCA1RXBUF; | |
| xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken ); | |
| } | |
| /* If there is a Tx interrupt pending and the tx interrupts are enabled. */ | |
| if( ( UCA1IFG & UCTXIFG ) != 0 ) | |
| { | |
| /* The previous character has been transmitted. See if there are any | |
| further characters waiting transmission. */ | |
| if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE ) | |
| { | |
| /* There was another character queued - transmit it now. */ | |
| UCA1TXBUF = cChar; | |
| } | |
| else | |
| { | |
| /* There were no other characters to transmit - disable the Tx | |
| interrupt. */ | |
| UCA1IE &= ~UCTXIE; | |
| } | |
| } | |
| __bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF ); | |
| /* If writing to a queue caused a task to unblock, and the unblocked task | |
| has a priority equal to or above the task that this interrupt interrupted, | |
| then lHigherPriorityTaskWoken will have been set to pdTRUE internally within | |
| xQueuesendFromISR(), and portEND_SWITCHING_ISR() will ensure that this | |
| interrupt returns directly to the higher priority unblocked task. | |
| THIS MUST BE THE LAST THING DONE IN THE ISR. */ | |
| portYIELD_FROM_ISR( xHigherPriorityTaskWoken ); | |
| } | |