| /* | |
| 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 2 | |
| */ | |
| /* Standard includes. */ | |
| #include <stdlib.h> | |
| /* Scheduler includes. */ | |
| #include "FreeRTOS.h" | |
| #include "queue.h" | |
| #include "task.h" | |
| /* Demo application includes. */ | |
| #include "serial.h" | |
| /* 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 ) | |
| { | |
| 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 ) ); | |
| /* Initialize UART asynchronous mode */ | |
| BGR02 = configPER_CLOCK_HZ / ulWantedBaud; | |
| SCR02 = 0x17; /* 8N1 */ | |
| SMR02 = 0x0d; /* enable SOT3, Reset, normal mode */ | |
| SSR02 = 0x02; /* LSB first, enable receive interrupts */ | |
| PFR20_D0 = 1; /* enable UART */ | |
| PFR20_D1 = 1; /* enable UART */ | |
| EPFR20_D1 = 0; /* enable UART */ | |
| } | |
| 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; | |
| TDR02 = 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. */ | |
| if (xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) == pdTRUE) | |
| { | |
| xReturn = pdPASS; | |
| } | |
| else | |
| { | |
| xReturn = pdFAIL; | |
| } | |
| } | |
| if (pdPASS == xReturn) | |
| { | |
| /* Turn on the Tx interrupt so the ISR will remove the character from the | |
| queue and send it. This does not need to be in a critical section as | |
| if the interrupt has already removed the character the next interrupt | |
| will simply turn off the Tx interrupt again. */ | |
| SSR02_TIE = 1; | |
| } | |
| } | |
| portEXIT_CRITICAL(); | |
| return pdPASS; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| /* | |
| * UART RX interrupt service routine. | |
| */ | |
| __interrupt void UART2_RxISR (void) | |
| { | |
| signed char cChar; | |
| portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; | |
| /* Get the character from the UART and post it on the queue of Rxed | |
| characters. */ | |
| cChar = RDR02; | |
| 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. */ | |
| portYIELD_FROM_ISR(); | |
| } | |
| } | |
| /*-----------------------------------------------------------*/ | |
| /* | |
| * UART Tx interrupt service routine. | |
| */ | |
| __interrupt void UART2_TxISR (void) | |
| { | |
| signed char cChar; | |
| signed 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. */ | |
| TDR02 = cChar; | |
| } | |
| else | |
| { | |
| /* There were no other characters to transmit. */ | |
| sTHREEmpty = pdTRUE; | |
| /* Disable transmit interrupts */ | |
| SSR02_TIE = 0; | |
| } | |
| } | |