/* | |
FreeRTOS V5.4.2 - Copyright (C) 2009 Real Time Engineers Ltd. | |
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 exception 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. | |
Alternative commercial license and support terms are also available upon | |
request. See the licensing section of http://www.FreeRTOS.org for full | |
license details. | |
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 along | |
with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59 | |
Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
*************************************************************************** | |
* * | |
* Looking for a quick start? Then check out the FreeRTOS eBook! * | |
* See http://www.FreeRTOS.org/Documentation for details * | |
* * | |
*************************************************************************** | |
1 tab == 4 spaces! | |
Please ensure to read the configuration and relevant port sections of the | |
online documentation. | |
http://www.FreeRTOS.org - Documentation, latest information, license and | |
contact details. | |
http://www.SafeRTOS.com - A version that is certified for use in safety | |
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licensing and training services. | |
*/ | |
/* | |
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 portLONG 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 portCHAR ) ); | |
xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) ); | |
/* 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 portCHAR *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 portCHAR 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 portLONG ulISRStatus; | |
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE, lDidSomething; | |
portCHAR 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 = ( portCHAR ) 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(); | |
} | |
} | |