/* FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd. FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. *************************************************************************** * * * 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 versions, 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. */ /* Changes from V1.00: + Call to the more efficient portSWITCH_CONTEXT() replaces the call to taskYIELD() in the ISR. Changes from V1.01: + The semaphore task is not operational. This does nothing but check the semaphore from ISR functionality. + ISR modified slightly so only Rx or Tx is serviced per ISR - not both. Changes from V1.2.0: + Change so Tx uses a DMA channel, and Rx uses an interrupt. Changes from V1.2.3 + The function xPortInitMinimal() has been renamed to xSerialPortInitMinimal() and the function xPortInit() has been renamed to xSerialPortInit(). Changes from V1.2.5 + Reverted back to the non-DMA serial port driver, with a slightly modified ISR. This is a better test of the scheduler mechanisms. + A critical section is now used in vInterruptOn(). + Flag sTxInterruptOn has been added to the port structure. This allows checking of the interrupt enable status without performing any IO. Changes from V2.0.0 + Use portTickType in place of unsigned pdLONG for delay periods. + Slightly more efficient vSerialSendString() implementation. + cQueueReieveFromISR() used in place of xQueueReceive() in ISR. */ #include #include #include "FreeRTOS.h" #include "queue.h" #include "task.h" #include "portasm.h" #include "semphr.h" #define serMAX_PORTS ( ( unsigned short ) 2 ) #define serPORT_0_INT_REG ( 0xff44 ) #define serPORT_0_BAUD_REG ( 0xff88 ) #define serPORT_0_RX_REG ( 0xff86 ) #define serPORT_0_TX_REG ( 0xff84 ) #define serPORT_0_STATUS_REG ( 0xff82 ) #define serPORT_0_CTRL_REG ( 0xff80 ) #define serPORT_0_IRQ ( 0x14 ) #define serPORT_1_INT_REG ( 0xff42 ) #define serPORT_1_BAUD_REG ( 0xff18 ) #define serPORT_1_RX_REG ( 0xff16 ) #define serPORT_1_TX_REG ( 0xff14 ) #define serPORT_1_STATUS_REG ( 0xff12 ) #define serPORT_1_CTRL_REG ( 0xff10 ) #define serPORT_1_IRQ ( 0x11 ) #define serTX_EMPTY ( ( unsigned short ) 0x40 ) #define serRX_READY ( ( unsigned short ) 0x80 ) #define serRESET_PIC( usEOI_TYPE ) portOUTPUT_WORD( ( unsigned short ) 0xff22, usEOI_TYPE ) #define serTX_HOLD_EMPTY_INT ( ( unsigned short ) 0x100 ) #define serENABLE_INTERRUPTS ( ( unsigned short ) 0x80 ) #define serMODE ( ( unsigned short ) 0x01 ) #define serENABLE_TX_MACHINES ( ( unsigned short ) 0x40 ) #define serENABLE_RX_MACHINES ( ( unsigned short ) 0x20 ) #define serINTERRUPT_MASK ( ( unsigned short ) 0x08 ) #define serCLEAR_ALL_STATUS_BITS ( ( unsigned short ) 0x00 ) #define serINTERRUPT_PRIORITY ( ( unsigned short ) 0x01 ) /*< Just below the scheduler priority. */ #define serDONT_BLOCK ( ( portTickType ) 0 ) typedef enum { serCOM1 = 0, serCOM2, serCOM3, serCOM4, serCOM5, serCOM6, serCOM7, serCOM8 } eCOMPort; typedef enum { serNO_PARITY, serODD_PARITY, serEVEN_PARITY, serMARK_PARITY, serSPACE_PARITY } eParity; typedef enum { serSTOP_1, serSTOP_2 } eStopBits; typedef enum { serBITS_5, serBITS_6, serBITS_7, serBITS_8 } eDataBits; typedef enum { ser50 = 0, ser75, ser110, ser134, ser150, ser200, ser300, ser600, ser1200, ser1800, ser2400, ser4800, ser9600, ser19200, ser38400, ser57600, ser115200 } eBaud; /* Must be same order as eBaud definitions. */ static const unsigned short usBaudRateDivisor[] = { 0, /* Not sure if the first 6 are correct. First cannot be used. */ 29127, 19859, 16302, 14564, 10923, 6879, 3437, 1718, 1145, 859, 429, 214, 107, 54, 35, 18 }; typedef struct xCOM_PORT { /* Hardware parameters for this port. */ short sTxInterruptOn; unsigned short usIntReg; unsigned short usBaudReg; unsigned short usRxReg; unsigned short usTxReg; unsigned short usStatusReg; unsigned short usCtrlReg; unsigned short usIRQVector; /* Queues used for communications with com test task. */ xQueueHandle xRxedChars; xQueueHandle xCharsForTx; /* This semaphore does nothing useful except test a feature of the scheduler. */ xSemaphoreHandle xTestSem; } xComPort; static xComPort xPorts[ serMAX_PORTS ] = { { pdFALSE, serPORT_0_INT_REG, serPORT_0_BAUD_REG, serPORT_0_RX_REG, serPORT_0_TX_REG, serPORT_0_STATUS_REG, serPORT_0_CTRL_REG, serPORT_0_IRQ, NULL, NULL, NULL }, { pdFALSE, serPORT_1_INT_REG, serPORT_1_BAUD_REG, serPORT_1_RX_REG, serPORT_1_TX_REG, serPORT_1_STATUS_REG, serPORT_1_CTRL_REG, serPORT_1_IRQ, NULL, NULL, NULL } }; typedef xComPort * xComPortHandle; /* These prototypes are repeated here so we don't have to include the serial header. This allows the xComPortHandle structure details to be private to this file. */ xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength ); portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime ); portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime ); void vSerialClose( xComPortHandle xPort ); short sSerialWaitForSemaphore( xComPortHandle xPort ); /*-----------------------------------------------------------*/ static short xComPortISR( xComPort * const pxPort ); #define vInterruptOn( pxPort, usInterrupt ) \ { \ unsigned short usIn; \ \ portENTER_CRITICAL(); \ { \ if( pxPort->sTxInterruptOn == pdFALSE ) \ { \ usIn = portINPUT_WORD( pxPort->usCtrlReg ); \ portOUTPUT_WORD( pxPort->usCtrlReg, usIn | usInterrupt ); \ \ pxPort->sTxInterruptOn = pdTRUE; \ } \ } \ portEXIT_CRITICAL(); \ } /*-----------------------------------------------------------*/ #define vInterruptOff( pxPort, usInterrupt ) \ { \ unsigned short usIn = portINPUT_WORD( pxPort->usCtrlReg ); \ if( usIn & usInterrupt ) \ { \ portOUTPUT_WORD( pxPort->usCtrlReg, usIn & ~usInterrupt); \ pxPort->sTxInterruptOn = pdFALSE; \ } \ } /*-----------------------------------------------------------*/ /* Define an interrupt handler for each port */ #define COM_IRQ_WRAPPER(N) \ static void __interrupt COM_IRQ##N##_WRAPPER( void ) \ { \ if( xComPortISR( &( xPorts[##N##] ) ) ) \ { \ portSWITCH_CONTEXT(); \ } \ } COM_IRQ_WRAPPER( 0 ) COM_IRQ_WRAPPER( 1 ) static pxISR xISRs[ serMAX_PORTS ] = { COM_IRQ0_WRAPPER, COM_IRQ1_WRAPPER }; /*-----------------------------------------------------------*/ xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength ) { unsigned short usPort; xComPortHandle pxPort = NULL; /* BAUDDIV = ( Microprocessor Clock / Baud Rate ) / 16 */ /* Only n, 8, 1 is supported so these parameters are not required for this port. */ ( void ) eWantedParity; ( void ) eWantedDataBits; ( void ) eWantedStopBits; /* Currently only n,8,1 is supported. */ usPort = ( unsigned short ) ePort; if( usPort < serMAX_PORTS ) { pxPort = &( xPorts[ usPort ] ); portENTER_CRITICAL(); { unsigned short usInWord; /* Create the queues used by the com test task. */ pxPort->xRxedChars = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( char ) ); pxPort->xCharsForTx = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( char ) ); /* Create the test semaphore. This does nothing useful except test a feature of the scheduler. */ vSemaphoreCreateBinary( pxPort->xTestSem ); /* There is no ISR here already to restore later. */ _dos_setvect( ( short ) pxPort->usIRQVector, xISRs[ usPort ] ); usInWord = portINPUT_WORD( pxPort->usIntReg ); usInWord &= ~serINTERRUPT_MASK; usInWord |= serINTERRUPT_PRIORITY; portOUTPUT_WORD( pxPort->usIntReg, usInWord ); portOUTPUT_WORD( pxPort->usBaudReg, usBaudRateDivisor[ eWantedBaud ] ); portOUTPUT_WORD( pxPort->usCtrlReg, serENABLE_INTERRUPTS | serMODE | serENABLE_TX_MACHINES | serENABLE_RX_MACHINES ); portOUTPUT_WORD( pxPort->usStatusReg, serCLEAR_ALL_STATUS_BITS ); } portEXIT_CRITICAL(); } return pxPort; } /*lint !e715 Some parameters are not used as only a subset of the serial port functionality is currently implemented. */ /*-----------------------------------------------------------*/ void vSerialPutString( xComPortHandle pxPort, const char * const pcString, unsigned short usStringLength ) { unsigned short usByte; char *pcNextChar; pcNextChar = ( char * ) pcString; for( usByte = 0; usByte < usStringLength; usByte++ ) { xQueueSend( pxPort->xCharsForTx, pcNextChar, serDONT_BLOCK ); pcNextChar++; } vInterruptOn( pxPort, serTX_HOLD_EMPTY_INT ); } /*-----------------------------------------------------------*/ portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime ) { /* Get the next character from the buffer, note that this routine is only called having checked that the is (at least) one to get */ if( xQueueReceive( pxPort->xRxedChars, pcRxedChar, xBlockTime ) ) { return pdTRUE; } else { return pdFALSE; } } /*-----------------------------------------------------------*/ portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime ) { if( xQueueSend( pxPort->xCharsForTx, &cOutChar, xBlockTime ) != pdPASS ) { return pdFAIL; } vInterruptOn( pxPort, serTX_HOLD_EMPTY_INT ); return pdPASS; } /*-----------------------------------------------------------*/ portBASE_TYPE xSerialWaitForSemaphore( xComPortHandle xPort ) { const portTickType xBlockTime = ( portTickType ) 0xffff; /* This function does nothing interesting, but test the semaphore from ISR mechanism. */ return xSemaphoreTake( xPort->xTestSem, xBlockTime ); } /*-----------------------------------------------------------*/ void vSerialClose( xComPortHandle xPort ) { unsigned short usOutput; /* Turn off the interrupts. We may also want to delete the queues and/or re-install the original ISR. */ portENTER_CRITICAL(); { usOutput = portINPUT_WORD( xPort->usCtrlReg ); usOutput &= ~serENABLE_INTERRUPTS; usOutput &= ~serENABLE_TX_MACHINES; usOutput &= ~serENABLE_RX_MACHINES; portOUTPUT_WORD( xPort->usCtrlReg, usOutput ); usOutput = portINPUT_WORD( xPort->usIntReg ); usOutput |= serINTERRUPT_MASK; portOUTPUT_WORD( xPort->usIntReg, usOutput ); } portEXIT_CRITICAL(); } /*-----------------------------------------------------------*/ static portBASE_TYPE xComPortISR( xComPort * const pxPort ) { unsigned short usStatusRegister; char cChar; portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE, xContinue = pdTRUE; /* NOTE: THIS IS NOT AN EFFICIENT ISR AS IT IS DESIGNED SOLELY TO TEST THE SCHEDULER FUNCTIONALITY. REAL APPLICATIONS SHOULD NOT USE THIS FUNCTION. */ while( xContinue == pdTRUE ) { xContinue = pdFALSE; usStatusRegister = portINPUT_WORD( pxPort->usStatusReg ); if( usStatusRegister & serRX_READY ) { cChar = ( char ) portINPUT_WORD( pxPort->usRxReg ); xQueueSendFromISR( pxPort->xRxedChars, &cChar, &xHigherPriorityTaskWoken ); /* Also release the semaphore - this does nothing interesting and is just a test. */ xSemaphoreGiveFromISR( pxPort->xTestSem, &xHigherPriorityTaskWoken ); /* We have performed an action this cycle - there may be other to perform. */ xContinue = pdTRUE; } if( pxPort->sTxInterruptOn && ( usStatusRegister & serTX_EMPTY ) ) { if( xQueueReceiveFromISR( pxPort->xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE ) { portOUTPUT_WORD( pxPort->usTxReg, ( unsigned short ) cChar ); /* We have performed an action this cycle - there may be others to perform. */ xContinue = pdTRUE; } else { /* Queue empty, nothing to send */ vInterruptOff( pxPort, serTX_HOLD_EMPTY_INT ); } } } serRESET_PIC( pxPort->usIRQVector ); /* If posting to the queue woke a task that was blocked on the queue we may want to switch to the woken task - depending on its priority relative to the task interrupted by this ISR. */ return xHigherPriorityTaskWoken; }