| /* | |
| FreeRTOS V9.0.0rc2 - 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 | |
| *************************************************************************** | |
| * * | |
| * 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 * | |
| * * | |
| *************************************************************************** | |
| http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading | |
| the FAQ page "My application does not run, what could be wrong?". Have you | |
| defined configASSERT()? | |
| http://www.FreeRTOS.org/support - In return for receiving this top quality | |
| embedded software for free we request you assist our global community by | |
| participating in the support forum. | |
| http://www.FreeRTOS.org/training - Investing in training allows your team to | |
| be as productive as possible as early as possible. Now you can receive | |
| FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers | |
| Ltd, and the world's leading authority on the world's leading RTOS. | |
| 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! | |
| */ | |
| /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. | |
| * | |
| * This is not a proper UART driver. It only supports one port, and is not | |
| * intended to show an efficient implementation as queues are used to pass | |
| * individual characters one at a time! This is ok for a slow interface, such | |
| * as a command line interface (which this driver is used for), but is too | |
| * inefficient for higher bandwidth applications. | |
| */ | |
| /* Standard includes. */ | |
| #include <stdlib.h> | |
| /* Scheduler includes. */ | |
| #include "FreeRTOS.h" | |
| #include "queue.h" | |
| #include "task.h" | |
| /* Demo application includes. */ | |
| #include "serial.h" | |
| /* TI includes. */ | |
| #include "driverlib.h" | |
| /* Misc. constants. */ | |
| #define serNO_BLOCK ( ( TickType_t ) 0 ) | |
| /* The queue used to hold received characters. */ | |
| static QueueHandle_t xRxedChars; | |
| /* The queue used to hold characters waiting transmission. */ | |
| static QueueHandle_t xCharsForTx; | |
| /*-----------------------------------------------------------*/ | |
| 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, ( UBaseType_t ) sizeof( signed char ) ); | |
| xCharsForTx = xQueueCreate( uxQueueLength, ( UBaseType_t ) sizeof( signed char ) ); | |
| /* Reset UART. */ | |
| UCA0CTL1 |= UCSWRST; | |
| /* Use SMCLK. */ | |
| UCA0CTL1 = UCSSEL0 | UCSSEL1; | |
| /* Setup baud rate low byte. */ | |
| UCA0BR0 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff ); | |
| /* Setup baud rate high byte. */ | |
| ulBaudRateCount >>= 8UL; | |
| UCA0BR1 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff ); | |
| /* Enable interrupts. */ | |
| UCA0IE |= UCRXIE; | |
| /* Take out of reset. */ | |
| UCA0CTL1 &= ~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 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 ) | |
| { | |
| BaseType_t 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 ); | |
| UCA0IE |= UCTXIE; | |
| return xReturn; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength ) | |
| { | |
| UBaseType_t uxChar; | |
| const TickType_t xMaxBlockTime = pdMS_TO_TICKS( 100 ); | |
| /* The driver only supports one port so the pxPort parameter is not used. */ | |
| ( void ) pxPort; | |
| for( uxChar = 0; uxChar < usStringLength; uxChar++ ) | |
| { | |
| if( xQueueSend( xCharsForTx, &( pcString[ uxChar ] ), xMaxBlockTime ) == pdFALSE ) | |
| { | |
| break; | |
| } | |
| else | |
| { | |
| UCA0IE |= UCTXIE; | |
| } | |
| } | |
| } | |
| /*-----------------------------------------------------------*/ | |
| /* 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_A0_VECTOR | |
| __interrupt void prvUSCI_A0_ISR( void ) | |
| { | |
| signed char cChar; | |
| BaseType_t xHigherPriorityTaskWoken = pdFALSE; | |
| while( ( UCA0IFG & UCRXIFG ) != 0 ) | |
| { | |
| /* Get the character from the UART and post it on the queue of Rxed | |
| characters. */ | |
| cChar = UCA0RXBUF; | |
| xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken ); | |
| } | |
| /* If there is a Tx interrupt pending and the tx interrupts are enabled. */ | |
| if( ( UCA0IFG & 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. */ | |
| UCA0TXBUF = cChar; | |
| } | |
| else | |
| { | |
| /* There were no other characters to transmit - disable the Tx | |
| interrupt. */ | |
| UCA0IE &= ~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 ); | |
| } | |