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/*
FreeRTOS V8.1.0 - 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!
*/
/*
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 QueueHandle_t xRxedChars;
static QueueHandle_t 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, TickType_t 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, TickType_t 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();
}
}
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