| /* | |
| FreeRTOS V7.5.3 - Copyright (C) 2013 Real Time Engineers Ltd. | |
| All rights reserved | |
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| *************************************************************************** | |
| * * | |
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| *************************************************************************** | |
| 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. | |
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| >>! kernel. | |
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| *************************************************************************** | |
| * * | |
| * Having a problem? Start by reading the FAQ "My application does * | |
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| *************************************************************************** | |
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| mission critical applications that require provable dependability. | |
| 1 tab == 4 spaces! | |
| */ | |
| /* | |
| BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART | |
| */ | |
| /* Scheduler includes. */ | |
| #include "FreeRTOS.h" | |
| #include "queue.h" | |
| #include "task.h" | |
| /* Demo application includes. */ | |
| #include "serial.h" | |
| /* Library includes. */ | |
| #include "xparameters.h" | |
| #include "xuartlite.h" | |
| #include "xuartlite_l.h" | |
| /*-----------------------------------------------------------*/ | |
| /* Queues used to hold received characters, and characters waiting to be | |
| transmitted. */ | |
| static xQueueHandle xRxedChars; | |
| static xQueueHandle xCharsForTx; | |
| /* Structure that maintains information on the UART being used. */ | |
| static XUartLite xUART; | |
| /* | |
| * Sample UART interrupt handler. Note this is used to demonstrate the kernel | |
| * features and test the port - it is not intended to represent an efficient | |
| * implementation. | |
| */ | |
| static void vSerialISR( XUartLite *pxUART ); | |
| /*-----------------------------------------------------------*/ | |
| xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) | |
| { | |
| /* NOTE: The baud rate used by this driver is determined by the hardware | |
| parameterization of the UART Lite peripheral, and the baud value passed to | |
| this function has no effect. */ | |
| ( void ) ulWantedBaud; | |
| /* Create the queues used to hold Rx and Tx characters. */ | |
| xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); | |
| xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); | |
| /* Only initialise the UART if the queues were created correctly. */ | |
| if( ( xRxedChars != NULL ) && ( xCharsForTx != NULL ) ) | |
| { | |
| XUartLite_Initialize( &xUART, XPAR_RS232_UART_1_DEVICE_ID ); | |
| XUartLite_ResetFifos( &xUART ); | |
| XUartLite_DisableInterrupt( &xUART ); | |
| if( xPortInstallInterruptHandler( XPAR_XPS_INTC_0_RS232_UART_1_INTERRUPT_INTR, ( XInterruptHandler )vSerialISR, (void *)&xUART ) == pdPASS ) | |
| { | |
| /* xPortInstallInterruptHandler() could fail if | |
| vPortSetupInterruptController() has not been called prior to this | |
| function. */ | |
| XUartLite_EnableInterrupt( &xUART ); | |
| } | |
| } | |
| /* There is only one port so the handle is not used. */ | |
| return ( xComPortHandle ) 0; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime ) | |
| { | |
| /* The port handle is not required as this driver only supports one UART. */ | |
| ( void ) pxPort; | |
| /* 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, portTickType xBlockTime ) | |
| { | |
| portBASE_TYPE xReturn = pdTRUE; | |
| /* Just to remove compiler warning. */ | |
| ( void ) pxPort; | |
| portENTER_CRITICAL(); | |
| { | |
| /* If the UART FIFO is full we can block posting the new data on the | |
| Tx queue. */ | |
| if( XUartLite_mIsTransmitFull( XPAR_RS232_UART_1_BASEADDR ) ) | |
| { | |
| if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS ) | |
| { | |
| xReturn = pdFAIL; | |
| } | |
| } | |
| /* Otherwise, if there is data already in the queue we should add the | |
| new data to the back of the queue to ensure the sequencing is | |
| maintained. */ | |
| else if( uxQueueMessagesWaiting( xCharsForTx ) ) | |
| { | |
| if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS ) | |
| { | |
| xReturn = pdFAIL; | |
| } | |
| } | |
| /* If the UART FIFO is not full and there is no data already in the | |
| queue we can write directly to the FIFO without disrupting the | |
| sequence. */ | |
| else | |
| { | |
| XIo_Out32( XPAR_RS232_UART_1_BASEADDR + XUL_TX_FIFO_OFFSET, cOutChar ); | |
| } | |
| } | |
| portEXIT_CRITICAL(); | |
| return xReturn; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vSerialClose( xComPortHandle xPort ) | |
| { | |
| /* Not supported as not required by the demo application. */ | |
| ( void ) xPort; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| static void vSerialISR( XUartLite *pxUART ) | |
| { | |
| unsigned long ulISRStatus; | |
| portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE, lDidSomething; | |
| char cChar; | |
| /* Just to remove compiler warning. */ | |
| ( void ) pxUART; | |
| do | |
| { | |
| lDidSomething = pdFALSE; | |
| ulISRStatus = XIo_In32( XPAR_RS232_UART_1_BASEADDR + XUL_STATUS_REG_OFFSET ); | |
| if( ( ulISRStatus & XUL_SR_RX_FIFO_VALID_DATA ) != 0 ) | |
| { | |
| /* A character is available - place it in the queue of received | |
| characters. This might wake a task that was blocked waiting for | |
| data. */ | |
| cChar = ( char ) XIo_In32( XPAR_RS232_UART_1_BASEADDR + XUL_RX_FIFO_OFFSET ); | |
| xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken ); | |
| lDidSomething = pdTRUE; | |
| } | |
| if( ( ulISRStatus & XUL_SR_TX_FIFO_EMPTY ) != 0 ) | |
| { | |
| /* There is space in the FIFO - if there are any characters queue for | |
| transmission they can be sent to the UART now. This might unblock a | |
| task that was waiting for space to become available on the Tx queue. */ | |
| if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE ) | |
| { | |
| XIo_Out32( XPAR_RS232_UART_1_BASEADDR + XUL_TX_FIFO_OFFSET, cChar ); | |
| lDidSomething = pdTRUE; | |
| } | |
| } | |
| } while( lDidSomething == pdTRUE ); | |
| /* If we woke any tasks we may require a context switch. */ | |
| if( xHigherPriorityTaskWoken ) | |
| { | |
| portYIELD_FROM_ISR(); | |
| } | |
| } | |