| /* | |
| FreeRTOS V8.1.2 - 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! | |
| */ | |
| /* | |
| Changes from V3.0.0 | |
| + ISRcode removed. Is now pulled inline to reduce stack-usage. | |
| Changes from V3.0.1 | |
| */ | |
| /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. */ | |
| /* Scheduler header files. */ | |
| #include "FreeRTOS.h" | |
| #include "task.h" | |
| #include "queue.h" | |
| #include "serial.h" | |
| /* Hardware pin definitions. */ | |
| #define serTX_PIN bTRC6 | |
| #define serRX_PIN bTRC7 | |
| /* Bit/register definitions. */ | |
| #define serINPUT ( 1 ) | |
| #define serOUTPUT ( 0 ) | |
| #define serINTERRUPT_ENABLED ( 1 ) | |
| /* All ISR's use the PIC18 low priority interrupt. */ | |
| #define serLOW_PRIORITY ( 0 ) | |
| /*-----------------------------------------------------------*/ | |
| /* Queues to interface between comms API and interrupt routines. */ | |
| QueueHandle_t xRxedChars; | |
| QueueHandle_t xCharsForTx; | |
| portBASE_TYPE xHigherPriorityTaskWoken; | |
| /*-----------------------------------------------------------*/ | |
| xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned char ucQueueLength ) | |
| { | |
| unsigned short usSPBRG; | |
| /* Create the queues used by the ISR's to interface to tasks. */ | |
| xRxedChars = xQueueCreate( ucQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) ); | |
| xCharsForTx = xQueueCreate( ucQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) ); | |
| portENTER_CRITICAL(); | |
| /* Setup the IO pins to enable the USART IO. */ | |
| serTX_PIN = serINPUT; // YES really! See datasheet | |
| serRX_PIN = serINPUT; | |
| /* Set the TX config register. */ | |
| TXSTA = 0b00100000; | |
| // ||||||||--bit0: TX9D = n/a | |
| // |||||||---bit1: TRMT = ReadOnly | |
| // ||||||----bit2: BRGH = High speed | |
| // |||||-----bit3: SENDB = n/a | |
| // ||||------bit4: SYNC = Asynchronous mode | |
| // |||-------bit5: TXEN = Transmit enable | |
| // ||--------bit6: TX9 = 8-bit transmission | |
| // |---------bit7: CSRC = n/a | |
| /* Set the Receive config register. */ | |
| RCSTA = 0b10010000; | |
| // ||||||||--bit0: RX9D = ReadOnly | |
| // |||||||---bit1: OERR = ReadOnly | |
| // ||||||----bit2: FERR = ReadOnly | |
| // |||||-----bit3: ADDEN = n/a | |
| // ||||------bit4: CREN = Enable receiver | |
| // |||-------bit5: SREN = n/a | |
| // ||--------bit6: RX9 = 8-bit reception | |
| // |---------bit7: SPEN = Serial port enabled | |
| /* Calculate the baud rate generator value. | |
| We use low-speed (BRGH=0), the formula is | |
| SPBRG = ( ( FOSC / Desired Baud Rate ) / 64 ) - 1 */ | |
| usSPBRG = ( ( APROCFREQ / ulWantedBaud ) / 64 ) - 1; | |
| if( usSPBRG > 255 ) | |
| { | |
| SPBRG = 255; | |
| } | |
| else | |
| { | |
| SPBRG = usSPBRG; | |
| } | |
| /* Set the serial interrupts to use the same priority as the tick. */ | |
| bTXIP = serLOW_PRIORITY; | |
| bRCIP = serLOW_PRIORITY; | |
| /* Enable the Rx interrupt now, the Tx interrupt will get enabled when | |
| we have data to send. */ | |
| bRCIE = serINTERRUPT_ENABLED; | |
| 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; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned char ucBufferLength ) | |
| { | |
| /* This is not implemented in this port. | |
| Use xSerialPortInitMinimal() instead. */ | |
| return NULL; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, 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 ( char ) pdTRUE; | |
| } | |
| return ( char ) pdFALSE; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, TickType_t xBlockTime ) | |
| { | |
| /* Return false if after the block time there is no room on the Tx queue. */ | |
| if( xQueueSend( xCharsForTx, ( const void * ) &cOutChar, xBlockTime ) != ( char ) pdPASS ) | |
| { | |
| return pdFAIL; | |
| } | |
| /* Turn interrupt on - ensure the compiler only generates a single | |
| instruction for this. */ | |
| bTXIE = serINTERRUPT_ENABLED; | |
| return pdPASS; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vSerialClose( xComPortHandle xPort ) | |
| { | |
| /* Not implemented for this port. | |
| To implement, turn off the interrupts and delete the memory | |
| allocated to the queues. */ | |
| } |