/* 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! */ /* * BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. * * This file only supports UART 2 */ /* Standard includes. */ #include /* 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; } }