2 FreeRTOS.org V5.1.0 - Copyright (C) 2003-2008 Richard Barry.
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4 This file is part of the FreeRTOS.org distribution.
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6 FreeRTOS.org is free software; you can redistribute it and/or modify
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7 it under the terms of the GNU General Public License as published by
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8 the Free Software Foundation; either version 2 of the License, or
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9 (at your option) any later version.
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11 FreeRTOS.org is distributed in the hope that it will be useful,
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12 but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 GNU General Public License for more details.
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16 You should have received a copy of the GNU General Public License
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17 along with FreeRTOS.org; if not, write to the Free Software
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18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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20 A special exception to the GPL can be applied should you wish to distribute
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21 a combined work that includes FreeRTOS.org, without being obliged to provide
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22 the source code for any proprietary components. See the licensing section
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23 of http://www.FreeRTOS.org for full details of how and when the exception
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26 ***************************************************************************
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27 ***************************************************************************
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29 * SAVE TIME AND MONEY! We can port FreeRTOS.org to your own hardware, *
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30 * and even write all or part of your application on your behalf. *
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31 * See http://www.OpenRTOS.com for details of the services we provide to *
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32 * expedite your project. *
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34 ***************************************************************************
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35 ***************************************************************************
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37 Please ensure to read the configuration and relevant port sections of the
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38 online documentation.
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40 http://www.FreeRTOS.org - Documentation, latest information, license and
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43 http://www.SafeRTOS.com - A version that is certified for use in safety
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46 http://www.OpenRTOS.com - Commercial support, development, porting,
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47 licensing and training services.
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52 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART
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55 /* Scheduler includes. */
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56 #include "FreeRTOS.h"
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60 /* Demo application includes. */
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63 /* Library includes. */
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64 #include "xparameters.h"
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65 #include "xuartlite.h"
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66 #include "xuartlite_l.h"
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68 /*-----------------------------------------------------------*/
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70 /* Queues used to hold received characters, and characters waiting to be
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72 static xQueueHandle xRxedChars;
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73 static xQueueHandle xCharsForTx;
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75 /* Structure that maintains information on the UART being used. */
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76 static XUartLite xUART;
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79 * Sample UART interrupt handler. Note this is used to demonstrate the kernel
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80 * features and test the port - it is not intended to represent an efficient
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83 static void vSerialISR( XUartLite *pxUART );
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85 /*-----------------------------------------------------------*/
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87 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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89 /* NOTE: The baud rate used by this driver is determined by the hardware
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90 parameterization of the UART Lite peripheral, and the baud value passed to
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91 this function has no effect. */
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92 ( void ) ulWantedBaud;
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94 /* Create the queues used to hold Rx and Tx characters. */
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95 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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96 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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98 /* Only initialise the UART if the queues were created correctly. */
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99 if( ( xRxedChars != NULL ) && ( xCharsForTx != NULL ) )
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102 XUartLite_Initialize( &xUART, XPAR_RS232_UART_DEVICE_ID );
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103 XUartLite_ResetFifos( &xUART );
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104 XUartLite_DisableInterrupt( &xUART );
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106 if( xPortInstallInterruptHandler( XPAR_XPS_INTC_0_RS232_UART_INTERRUPT_INTR, ( XInterruptHandler )vSerialISR, (void *)&xUART ) == pdPASS )
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108 /* xPortInstallInterruptHandler() could fail if
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109 vPortSetupInterruptController() has not been called prior to this
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111 XUartLite_EnableInterrupt( &xUART );
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115 /* There is only one port so the handle is not used. */
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116 return ( xComPortHandle ) 0;
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118 /*-----------------------------------------------------------*/
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120 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
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122 /* The port handle is not required as this driver only supports one UART. */
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125 /* Get the next character from the buffer. Return false if no characters
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126 are available, or arrive before xBlockTime expires. */
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127 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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136 /*-----------------------------------------------------------*/
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138 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
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140 portBASE_TYPE xReturn = pdTRUE;
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142 /* Just to remove compiler warning. */
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145 portENTER_CRITICAL();
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147 /* If the UART FIFO is full we can block posting the new data on the
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149 if( XUartLite_mIsTransmitFull( XPAR_RS232_UART_BASEADDR ) )
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151 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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156 /* Otherwise, if there is data already in the queue we should add the
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157 new data to the back of the queue to ensure the sequencing is
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159 else if( uxQueueMessagesWaiting( xCharsForTx ) )
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161 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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166 /* If the UART FIFO is not full and there is no data already in the
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167 queue we can write directly to the FIFO without disrupting the
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171 XIo_Out32( XPAR_RS232_UART_BASEADDR + XUL_TX_FIFO_OFFSET, cOutChar );
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174 portEXIT_CRITICAL();
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178 /*-----------------------------------------------------------*/
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180 void vSerialClose( xComPortHandle xPort )
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182 /* Not supported as not required by the demo application. */
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185 /*-----------------------------------------------------------*/
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187 static void vSerialISR( XUartLite *pxUART )
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189 unsigned portLONG ulISRStatus;
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190 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE, lDidSomething;
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193 /* Just to remove compiler warning. */
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198 lDidSomething = pdFALSE;
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200 ulISRStatus = XIo_In32( XPAR_RS232_UART_BASEADDR + XUL_STATUS_REG_OFFSET );
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202 if( ( ulISRStatus & XUL_SR_RX_FIFO_VALID_DATA ) != 0 )
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204 /* A character is available - place it in the queue of received
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205 characters. This might wake a task that was blocked waiting for
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207 cChar = ( portCHAR ) XIo_In32( XPAR_RS232_UART_BASEADDR + XUL_RX_FIFO_OFFSET );
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208 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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209 lDidSomething = pdTRUE;
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212 if( ( ulISRStatus & XUL_SR_TX_FIFO_EMPTY ) != 0 )
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214 /* There is space in the FIFO - if there are any characters queue for
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215 transmission they can be sent to the UART now. This might unblock a
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216 task that was waiting for space to become available on the Tx queue. */
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217 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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219 XIo_Out32( XPAR_RS232_UART_BASEADDR + XUL_TX_FIFO_OFFSET, cChar );
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220 lDidSomething = pdTRUE;
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223 } while( lDidSomething == pdTRUE );
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225 /* If we woke any tasks we may require a context switch. */
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226 if( xHigherPriorityTaskWoken )
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228 portYIELD_FROM_ISR();
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