2 FreeRTOS V6.0.3 - Copyright (C) 2010 Real Time Engineers Ltd.
4 ***************************************************************************
9 * + Wanting to learn FreeRTOS or multitasking in general quickly *
10 * + Looking for basic training, *
11 * + Wanting to improve your FreeRTOS skills and productivity *
13 * then take a look at the FreeRTOS eBook *
15 * "Using the FreeRTOS Real Time Kernel - a Practical Guide" *
16 * http://www.FreeRTOS.org/Documentation *
18 * A pdf reference manual is also available. Both are usually delivered *
19 * to your inbox within 20 minutes to two hours when purchased between 8am *
20 * and 8pm GMT (although please allow up to 24 hours in case of *
21 * exceptional circumstances). Thank you for your support! *
23 ***************************************************************************
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.
33 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
34 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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
37 License and the FreeRTOS license exception along with FreeRTOS; if not it
38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
39 by writing to Richard Barry, contact details for whom are available on the
44 http://www.FreeRTOS.org - Documentation, latest information, license and
47 http://www.SafeRTOS.com - A version that is certified for use in safety
50 http://www.OpenRTOS.com - Commercial support, development, porting,
51 licensing and training services.
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 COM_BLOCK_RETRYTIME 10
72 /*-----------------------------------------------------------*/
74 void vUARTInterruptHandlerTxWrapper(void) __attribute((naked));
75 void vUARTInterruptHandlerRxWrapper(void) __attribute((naked));
76 /*-----------------------------------------------------------*/
78 /* Queues used to hold received characters, and characters waiting to be
80 static xQueueHandle xRxedChars;
81 static xQueueHandle xCharsForTx;
82 extern unsigned portBASE_TYPE *pxVectorTable;
83 /*-----------------------------------------------------------*/
85 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
87 /* Create the queues used to hold Rx and Tx characters. */
88 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
89 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
91 if( ( xRxedChars ) && ( xCharsForTx ) )
93 /* Set up interrupts */
94 /* tx interrupt will be enabled when we need to send something */
97 irq[IRQ_UART1_TX].ien = 1;
98 irq[IRQ_UART1_TX].ipl = portSYSTEM_INTERRUPT_PRIORITY_LEVEL;
99 irq[IRQ_UART1_RX].ien = 1;
100 irq[IRQ_UART1_RX].ipl = portSYSTEM_INTERRUPT_PRIORITY_LEVEL;
102 return ( xComPortHandle ) 0;
104 /*-----------------------------------------------------------*/
106 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
108 /* The port handle is not required as this driver only supports uart1. */
111 /* Get the next character from the buffer. Return false if no characters
112 are available, or arrive before xBlockTime expires. */
113 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
123 /*-----------------------------------------------------------*/
125 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
128 signed char *pChNext;
130 /* Send each character in the string, one at a time. */
131 pChNext = ( signed char * )pcString;
132 for( i = 0; i < usStringLength; i++ )
134 /* Block until character has been transmitted. */
135 while( xSerialPutChar( pxPort, *pChNext, COM_BLOCK_RETRYTIME ) != pdTRUE ); pChNext++;
139 /*-----------------------------------------------------------*/
141 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
145 /* Place the character in the queue of characters to be transmitted. */
146 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
151 /* Turn on the Tx interrupt so the ISR will remove the character from the
152 queue and send it. This does not need to be in a critical section as
153 if the interrupt has already removed the character the next interrupt
154 will simply turn off the Tx interrupt again. */
159 /*-----------------------------------------------------------*/
161 void vSerialClose( xComPortHandle xPort )
163 /* Not supported as not required by the demo application. */
166 /*-----------------------------------------------------------*/
168 void interrupt_handler( IRQ_UART1_TX )
170 static signed char cChar;
171 static portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
173 portSAVE_CONTEXT_REDUCED();
175 /* The interrupt was caused by the transmit fifo having space for at least one
176 character. Are there any more characters to transmit? */
177 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
179 /* A character was retrieved from the queue so can be sent to the uart now. */
180 uart1->tx_data = cChar;
184 /* Queue empty, nothing to send so turn off the Tx interrupt. */
188 /* If an event caused a task to unblock then we call "Yield from ISR" to
189 ensure that the unblocked task is the task that executes when the interrupt
190 completes if the unblocked task has a priority higher than the interrupted
192 if( xHigherPriorityTaskWoken )
194 portYIELD_FROM_ISR();
196 portRESTORE_CONTEXT_REDUCED();
198 /*-----------------------------------------------------------*/
200 void interrupt_handler( IRQ_UART1_RX )
202 static signed char cChar;
203 static portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
205 portSAVE_CONTEXT_REDUCED();
207 /* The interrupt was caused by the receiver getting data. */
208 cChar = uart1->rx_data;
210 (void)xQueueSendFromISR(xRxedChars, &cChar, &xHigherPriorityTaskWoken);
212 /* If an event caused a task to unblock then we call "Yield from ISR" to
213 ensure that the unblocked task is the task that executes when the interrupt
214 completes if the unblocked task has a priority higher than the interrupted
216 if( xHigherPriorityTaskWoken )
218 portYIELD_FROM_ISR();
221 portRESTORE_CONTEXT_REDUCED();
223 /*-----------------------------------------------------------*/