2 FreeRTOS V7.6.0 - Copyright (C) 2013 Real Time Engineers Ltd.
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5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS provides completely free yet professionally developed, *
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10 * robust, strictly quality controlled, supported, and cross *
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11 * platform software that has become a de facto standard. *
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13 * Help yourself get started quickly and support the FreeRTOS *
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14 * project by purchasing a FreeRTOS tutorial book, reference *
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15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
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19 ***************************************************************************
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21 This file is part of the FreeRTOS distribution.
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23 FreeRTOS is free software; you can redistribute it and/or modify it under
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24 the terms of the GNU General Public License (version 2) as published by the
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25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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27 >>! NOTE: The modification to the GPL is included to allow you to distribute
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28 >>! a combined work that includes FreeRTOS without being obliged to provide
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29 >>! the source code for proprietary components outside of the FreeRTOS
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32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
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35 link: http://www.freertos.org/a00114.html
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39 ***************************************************************************
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41 * Having a problem? Start by reading the FAQ "My application does *
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42 * not run, what could be wrong?" *
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44 * http://www.FreeRTOS.org/FAQHelp.html *
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46 ***************************************************************************
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48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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49 license and Real Time Engineers Ltd. contact details.
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51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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57 licenses offer ticketed support, indemnification and middleware.
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59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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60 engineered and independently SIL3 certified version for use in safety and
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61 mission critical applications that require provable dependability.
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68 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART
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71 /* Scheduler includes. */
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72 #include "FreeRTOS.h"
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76 /* Demo application includes. */
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79 /* Library includes. */
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80 #include "xparameters.h"
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81 #include "xuartlite.h"
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82 #include "xuartlite_l.h"
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84 /*-----------------------------------------------------------*/
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86 /* Queues used to hold received characters, and characters waiting to be
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88 static xQueueHandle xRxedChars;
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89 static xQueueHandle xCharsForTx;
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91 /* Structure that maintains information on the UART being used. */
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92 static XUartLite xUART;
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95 * Sample UART interrupt handler. Note this is used to demonstrate the kernel
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96 * features and test the port - it is not intended to represent an efficient
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99 static void vSerialISR( XUartLite *pxUART );
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101 /*-----------------------------------------------------------*/
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103 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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105 /* NOTE: The baud rate used by this driver is determined by the hardware
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106 parameterization of the UART Lite peripheral, and the baud value passed to
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107 this function has no effect. */
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108 ( void ) ulWantedBaud;
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110 /* Create the queues used to hold Rx and Tx characters. */
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111 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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112 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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114 /* Only initialise the UART if the queues were created correctly. */
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115 if( ( xRxedChars != NULL ) && ( xCharsForTx != NULL ) )
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118 XUartLite_Initialize( &xUART, XPAR_RS232_UART_DEVICE_ID );
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119 XUartLite_ResetFifos( &xUART );
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120 XUartLite_DisableInterrupt( &xUART );
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122 if( xPortInstallInterruptHandler( XPAR_XPS_INTC_0_RS232_UART_INTERRUPT_INTR, ( XInterruptHandler )vSerialISR, (void *)&xUART ) == pdPASS )
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124 /* xPortInstallInterruptHandler() could fail if
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125 vPortSetupInterruptController() has not been called prior to this
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127 XUartLite_EnableInterrupt( &xUART );
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131 /* There is only one port so the handle is not used. */
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132 return ( xComPortHandle ) 0;
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134 /*-----------------------------------------------------------*/
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136 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
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138 /* The port handle is not required as this driver only supports one UART. */
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141 /* Get the next character from the buffer. Return false if no characters
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142 are available, or arrive before xBlockTime expires. */
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143 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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152 /*-----------------------------------------------------------*/
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154 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
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156 portBASE_TYPE xReturn = pdTRUE;
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158 /* Just to remove compiler warning. */
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161 portENTER_CRITICAL();
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163 /* If the UART FIFO is full we can block posting the new data on the
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165 if( XUartLite_mIsTransmitFull( XPAR_RS232_UART_BASEADDR ) )
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167 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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172 /* Otherwise, if there is data already in the queue we should add the
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173 new data to the back of the queue to ensure the sequencing is
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175 else if( uxQueueMessagesWaiting( xCharsForTx ) )
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177 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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182 /* If the UART FIFO is not full and there is no data already in the
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183 queue we can write directly to the FIFO without disrupting the
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187 XIo_Out32( XPAR_RS232_UART_BASEADDR + XUL_TX_FIFO_OFFSET, cOutChar );
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190 portEXIT_CRITICAL();
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194 /*-----------------------------------------------------------*/
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196 void vSerialClose( xComPortHandle xPort )
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198 /* Not supported as not required by the demo application. */
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201 /*-----------------------------------------------------------*/
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203 static void vSerialISR( XUartLite *pxUART )
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205 unsigned portLONG ulISRStatus;
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206 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE, lDidSomething;
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209 /* Just to remove compiler warning. */
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214 lDidSomething = pdFALSE;
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216 ulISRStatus = XIo_In32( XPAR_RS232_UART_BASEADDR + XUL_STATUS_REG_OFFSET );
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218 if( ( ulISRStatus & XUL_SR_RX_FIFO_VALID_DATA ) != 0 )
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220 /* A character is available - place it in the queue of received
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221 characters. This might wake a task that was blocked waiting for
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223 cChar = ( portCHAR ) XIo_In32( XPAR_RS232_UART_BASEADDR + XUL_RX_FIFO_OFFSET );
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224 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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225 lDidSomething = pdTRUE;
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228 if( ( ulISRStatus & XUL_SR_TX_FIFO_EMPTY ) != 0 )
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230 /* There is space in the FIFO - if there are any characters queue for
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231 transmission they can be sent to the UART now. This might unblock a
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232 task that was waiting for space to become available on the Tx queue. */
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233 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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235 XIo_Out32( XPAR_RS232_UART_BASEADDR + XUL_TX_FIFO_OFFSET, cChar );
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236 lDidSomething = pdTRUE;
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239 } while( lDidSomething == pdTRUE );
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241 /* If we woke any tasks we may require a context switch. */
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242 if( xHigherPriorityTaskWoken )
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244 portYIELD_FROM_ISR();
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