2 FreeRTOS V6.0.3 - Copyright (C) 2010 Real Time Engineers Ltd.
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25 This file is part of the FreeRTOS distribution.
27 FreeRTOS is free software; you can redistribute it and/or modify it under
28 the terms of the GNU General Public License (version 2) as published by the
29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
30 ***NOTE*** The exception to the GPL is included to allow you to distribute
31 a combined work that includes FreeRTOS without being obliged to provide the
32 source code for proprietary components outside of the FreeRTOS kernel.
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35 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
36 more details. You should have received a copy of the GNU General Public
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38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
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54 /* Basic interrupt driven serial port driver for uart1.
57 /* Standard includes. */
60 /* Kernel includes. */
65 /* Demo application includes. */
66 #include <machine/uart.h>
67 #include <machine/ic.h>
69 /*-----------------------------------------------------------*/
71 #define comBLOCK_RETRY_TIME 10
72 /*-----------------------------------------------------------*/
74 /* Queues used to hold received characters, and characters waiting to be
76 static xQueueHandle xRxedChars;
77 static xQueueHandle xCharsForTx;
78 extern unsigned portBASE_TYPE *pxVectorTable;
79 /*-----------------------------------------------------------*/
81 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
83 /* Create the queues used to hold Rx and Tx characters. */
84 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
85 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
87 if( ( xRxedChars ) && ( xCharsForTx ) )
89 /* Set up interrupts */
90 /* tx interrupt will be enabled when we need to send something */
93 irq[IRQ_UART1_TX].ien = 1;
94 irq[IRQ_UART1_TX].ipl = portSYSTEM_INTERRUPT_PRIORITY_LEVEL;
95 irq[IRQ_UART1_RX].ien = 1;
96 irq[IRQ_UART1_RX].ipl = portSYSTEM_INTERRUPT_PRIORITY_LEVEL;
99 return ( xComPortHandle ) 0;
101 /*-----------------------------------------------------------*/
103 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
105 /* The port handle is not required as this driver only supports uart1. */
108 /* Get the next character from the buffer. Return false if no characters
109 are available, or arrive before xBlockTime expires. */
110 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
120 /*-----------------------------------------------------------*/
122 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
125 signed char *pChNext;
127 /* Send each character in the string, one at a time. */
128 pChNext = ( signed char * )pcString;
129 for( i = 0; i < usStringLength; i++ )
131 /* Block until character has been transmitted. */
132 while( xSerialPutChar( pxPort, *pChNext, comBLOCK_RETRY_TIME ) != pdTRUE ); pChNext++;
136 /*-----------------------------------------------------------*/
138 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
142 /* Place the character in the queue of characters to be transmitted. */
143 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
148 /* Turn on the Tx interrupt so the ISR will remove the character from the
149 queue and send it. This does not need to be in a critical section as
150 if the interrupt has already removed the character the next interrupt
151 will simply turn off the Tx interrupt again. */
156 /*-----------------------------------------------------------*/
158 void vSerialClose( xComPortHandle xPort )
160 /* Not supported as not required by the demo application. */
163 /*-----------------------------------------------------------*/
165 void interrupt_handler( IRQ_UART1_TX )
167 static signed char cChar;
168 static portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
170 portSAVE_CONTEXT_REDUCED();
172 /* The interrupt was caused by the transmit fifo having space for at least one
173 character. Are there any more characters to transmit? */
174 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
176 /* A character was retrieved from the queue so can be sent to the uart now. */
177 uart1->tx_data = cChar;
181 /* Queue empty, nothing to send so turn off the Tx interrupt. */
185 /* If an event caused a task to unblock then we call "Yield from ISR" to
186 ensure that the unblocked task is the task that executes when the interrupt
187 completes if the unblocked task has a priority higher than the interrupted
189 if( xHigherPriorityTaskWoken )
191 portYIELD_FROM_ISR();
193 portRESTORE_CONTEXT_REDUCED();
195 /*-----------------------------------------------------------*/
197 void interrupt_handler( IRQ_UART1_RX )
199 static signed char cChar;
200 static portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
202 portSAVE_CONTEXT_REDUCED();
204 /* The interrupt was caused by the receiver getting data. */
205 cChar = uart1->rx_data;
207 (void)xQueueSendFromISR(xRxedChars, &cChar, &xHigherPriorityTaskWoken);
209 /* If an event caused a task to unblock then we call "Yield from ISR" to
210 ensure that the unblocked task is the task that executes when the interrupt
211 completes if the unblocked task has a priority higher than the interrupted
213 if( xHigherPriorityTaskWoken )
215 portYIELD_FROM_ISR();
218 portRESTORE_CONTEXT_REDUCED();
220 /*-----------------------------------------------------------*/