2 FreeRTOS V7.0.1 - Copyright (C) 2011 Real Time Engineers Ltd.
\r
5 ***************************************************************************
\r
7 * FreeRTOS tutorial books are available in pdf and paperback. *
\r
8 * Complete, revised, and edited pdf reference manuals are also *
\r
11 * Purchasing FreeRTOS documentation will not only help you, by *
\r
12 * ensuring you get running as quickly as possible and with an *
\r
13 * in-depth knowledge of how to use FreeRTOS, it will also help *
\r
14 * the FreeRTOS project to continue with its mission of providing *
\r
15 * professional grade, cross platform, de facto standard solutions *
\r
16 * for microcontrollers - completely free of charge! *
\r
18 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
\r
20 * Thank you for using FreeRTOS, and thank you for your support! *
\r
22 ***************************************************************************
\r
25 This file is part of the FreeRTOS distribution.
\r
27 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
28 the terms of the GNU General Public License (version 2) as published by the
\r
29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
30 >>>NOTE<<< The modification to the GPL is included to allow you to
\r
31 distribute a combined work that includes FreeRTOS without being obliged to
\r
32 provide the source code for proprietary components outside of the FreeRTOS
\r
33 kernel. FreeRTOS is distributed in the hope that it will be useful, but
\r
34 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
\r
35 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
36 more details. You should have received a copy of the GNU General Public
\r
37 License and the FreeRTOS license exception along with FreeRTOS; if not it
\r
38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
\r
39 by writing to Richard Barry, contact details for whom are available on the
\r
44 http://www.FreeRTOS.org - Documentation, latest information, license and
\r
47 http://www.SafeRTOS.com - A version that is certified for use in safety
\r
50 http://www.OpenRTOS.com - Commercial support, development, porting,
\r
51 licensing and training services.
\r
55 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
58 /* Library includes. */
\r
63 /* Scheduler includes. */
\r
64 #include "FreeRTOS.h"
\r
67 /* Demo application includes. */
\r
70 #define UART0_Rx_Pin ( 0x0001<< 8 )
\r
71 #define UART0_Tx_Pin ( 0x0001<< 9 )
\r
73 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
\r
74 #define serNO_BLOCK ( ( portTickType ) 0 )
\r
76 /* Macros to turn on and off the Tx empty interrupt. */
\r
77 #define serINTERRUPT_ON() UART0->IER |= UART_TxHalfEmpty
\r
78 #define serINTERRUPT_OFF() UART0->IER &= ~UART_TxHalfEmpty
\r
80 /*-----------------------------------------------------------*/
\r
82 /* Queues used to hold received characters, and characters waiting to be
\r
84 static xQueueHandle xRxedChars;
\r
85 static xQueueHandle xCharsForTx;
\r
87 /*-----------------------------------------------------------*/
\r
89 /* Interrupt entry point written in the assembler file serialISR.s79. */
\r
90 extern void vSerialISREntry( void );
\r
92 /* The interrupt service routine - called from the assembly entry point. */
\r
93 __arm void vSerialISR( void );
\r
95 /*-----------------------------------------------------------*/
\r
98 * See the serial2.h header file.
\r
100 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
102 xComPortHandle xReturn;
\r
104 /* Create the queues used to hold Rx and Tx characters. */
\r
105 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
106 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
108 /* If the queues were created correctly then setup the serial port
\r
110 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
112 portENTER_CRITICAL();
\r
114 /* Setup the UART port pins. */
\r
115 GPIO_Config( GPIO0, UART0_Tx_Pin, GPIO_AF_PP );
\r
116 GPIO_Config( GPIO0, UART0_Rx_Pin, GPIO_IN_TRI_CMOS );
\r
118 /* Configure the UART. */
\r
119 UART_OnOffConfig( UART0, ENABLE );
\r
120 UART_FifoConfig( UART0, DISABLE );
\r
121 UART_FifoReset( UART0, UART_RxFIFO );
\r
122 UART_FifoReset( UART0, UART_TxFIFO );
\r
123 UART_LoopBackConfig(UART0, DISABLE );
\r
124 UART_Config( UART0, ulWantedBaud, UART_NO_PARITY, UART_1_StopBits, UARTM_8D );
\r
125 UART_RxConfig( UART0, ENABLE );
\r
127 /* Configure the IEC for the UART interrupts. */
\r
128 EIC_IRQChannelPriorityConfig( UART0_IRQChannel, 1 );
\r
129 EIC_IRQChannelConfig( UART0_IRQChannel, ENABLE );
\r
130 EIC_IRQConfig( ENABLE );
\r
131 UART_ItConfig( UART0, UART_RxBufFull, ENABLE );
\r
133 portEXIT_CRITICAL();
\r
137 xReturn = ( xComPortHandle ) 0;
\r
140 /* This demo file only supports a single port but we have to return
\r
141 something to comply with the standard demo header file. */
\r
144 /*-----------------------------------------------------------*/
\r
146 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
\r
148 /* The port handle is not required as this driver only supports one port. */
\r
151 /* Get the next character from the buffer. Return false if no characters
\r
152 are available, or arrive before xBlockTime expires. */
\r
153 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
162 /*-----------------------------------------------------------*/
\r
164 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
\r
166 signed char *pxNext;
\r
168 /* A couple of parameters that this port does not use. */
\r
169 ( void ) usStringLength;
\r
172 /* NOTE: This implementation does not handle the queue being full as no
\r
173 block time is used! */
\r
175 /* The port handle is not required as this driver only supports UART0. */
\r
178 /* Send each character in the string, one at a time. */
\r
179 pxNext = ( signed char * ) pcString;
\r
182 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
186 /*-----------------------------------------------------------*/
\r
188 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
\r
190 /* Place the character in the queue of characters to be transmitted. */
\r
191 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
196 /* Turn on the Tx interrupt so the ISR will remove the character from the
\r
197 queue and send it. This does not need to be in a critical section as
\r
198 if the interrupt has already removed the character the next interrupt
\r
199 will simply turn off the Tx interrupt again. */
\r
204 /*-----------------------------------------------------------*/
\r
206 void vSerialClose( xComPortHandle xPort )
\r
208 /* Not supported as not required by the demo application. */
\r
210 /*-----------------------------------------------------------*/
\r
212 /* Serial port ISR. This can cause a context switch so is not defined as a
\r
213 standard ISR using the __irq keyword. Instead a wrapper function is defined
\r
214 within serialISR.s79 which in turn calls this function. See the port
\r
215 documentation on the FreeRTOS.org website for more information. */
\r
216 __arm void vSerialISR( void )
\r
218 unsigned short usStatus;
\r
220 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
222 /* What caused the interrupt? */
\r
223 usStatus = UART_FlagStatus( UART0 );
\r
225 if( usStatus & UART_TxHalfEmpty )
\r
227 /* The interrupt was caused by the THR becoming empty. Are there any
\r
228 more characters to transmit? */
\r
229 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
231 /* A character was retrieved from the queue so can be sent to the
\r
233 UART0->TxBUFR = cChar;
\r
237 /* Queue empty, nothing to send so turn off the Tx interrupt. */
\r
238 serINTERRUPT_OFF();
\r
242 if( usStatus & UART_RxBufFull )
\r
244 /* The interrupt was caused by a character being received. Grab the
\r
245 character from the RHR and place it in the queue of received
\r
247 cChar = UART0->RxBUFR;
\r
248 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
251 /* If a task was woken by either a character being received or a character
\r
252 being transmitted then we may need to switch to another task. */
\r
253 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r
255 /* End the interrupt in the EIC. */
\r