2 FreeRTOS V7.5.1 - Copyright (C) 2013 Real Time Engineers Ltd.
\r
4 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
6 ***************************************************************************
\r
8 * FreeRTOS provides completely free yet professionally developed, *
\r
9 * robust, strictly quality controlled, supported, and cross *
\r
10 * platform software that has become a de facto standard. *
\r
12 * Help yourself get started quickly and support the FreeRTOS *
\r
13 * project by purchasing a FreeRTOS tutorial book, reference *
\r
14 * manual, or both from: http://www.FreeRTOS.org/Documentation *
\r
18 ***************************************************************************
\r
20 This file is part of the FreeRTOS distribution.
\r
22 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
23 the terms of the GNU General Public License (version 2) as published by the
\r
24 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
\r
26 >>! NOTE: The modification to the GPL is included to allow you to distribute
\r
27 >>! a combined work that includes FreeRTOS without being obliged to provide
\r
28 >>! the source code for proprietary components outside of the FreeRTOS
\r
31 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
\r
32 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
\r
33 FOR A PARTICULAR PURPOSE. Full license text is available from the following
\r
34 link: http://www.freertos.org/a00114.html
\r
38 ***************************************************************************
\r
40 * Having a problem? Start by reading the FAQ "My application does *
\r
41 * not run, what could be wrong?" *
\r
43 * http://www.FreeRTOS.org/FAQHelp.html *
\r
45 ***************************************************************************
\r
47 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
\r
48 license and Real Time Engineers Ltd. contact details.
\r
50 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
51 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
\r
52 compatible FAT file system, and our tiny thread aware UDP/IP stack.
\r
54 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
\r
55 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
\r
56 licenses offer ticketed support, indemnification and middleware.
\r
58 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
\r
59 engineered and independently SIL3 certified version for use in safety and
\r
60 mission critical applications that require provable dependability.
\r
66 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
69 /* Library includes. */
\r
74 /* Scheduler includes. */
\r
75 #include "FreeRTOS.h"
\r
78 /* Demo application includes. */
\r
81 #define UART0_Rx_Pin ( 0x0001<< 8 )
\r
82 #define UART0_Tx_Pin ( 0x0001<< 9 )
\r
84 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
\r
85 #define serNO_BLOCK ( ( portTickType ) 0 )
\r
87 /* Macros to turn on and off the Tx empty interrupt. */
\r
88 #define serINTERRUPT_ON() UART0->IER |= UART_TxHalfEmpty
\r
89 #define serINTERRUPT_OFF() UART0->IER &= ~UART_TxHalfEmpty
\r
91 /*-----------------------------------------------------------*/
\r
93 /* Queues used to hold received characters, and characters waiting to be
\r
95 static xQueueHandle xRxedChars;
\r
96 static xQueueHandle xCharsForTx;
\r
98 /*-----------------------------------------------------------*/
\r
100 /* Interrupt entry point written in the assembler file serialISR.s79. */
\r
101 extern void vSerialISREntry( void );
\r
103 /* The interrupt service routine - called from the assembly entry point. */
\r
104 __arm void vSerialISR( void );
\r
106 /*-----------------------------------------------------------*/
\r
109 * See the serial2.h header file.
\r
111 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
113 xComPortHandle xReturn;
\r
115 /* Create the queues used to hold Rx and Tx characters. */
\r
116 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
117 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
119 /* If the queues were created correctly then setup the serial port
\r
121 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
123 portENTER_CRITICAL();
\r
125 /* Setup the UART port pins. */
\r
126 GPIO_Config( GPIO0, UART0_Tx_Pin, GPIO_AF_PP );
\r
127 GPIO_Config( GPIO0, UART0_Rx_Pin, GPIO_IN_TRI_CMOS );
\r
129 /* Configure the UART. */
\r
130 UART_OnOffConfig( UART0, ENABLE );
\r
131 UART_FifoConfig( UART0, DISABLE );
\r
132 UART_FifoReset( UART0, UART_RxFIFO );
\r
133 UART_FifoReset( UART0, UART_TxFIFO );
\r
134 UART_LoopBackConfig(UART0, DISABLE );
\r
135 UART_Config( UART0, ulWantedBaud, UART_NO_PARITY, UART_1_StopBits, UARTM_8D );
\r
136 UART_RxConfig( UART0, ENABLE );
\r
138 /* Configure the IEC for the UART interrupts. */
\r
139 EIC_IRQChannelPriorityConfig( UART0_IRQChannel, 1 );
\r
140 EIC_IRQChannelConfig( UART0_IRQChannel, ENABLE );
\r
141 EIC_IRQConfig( ENABLE );
\r
142 UART_ItConfig( UART0, UART_RxBufFull, ENABLE );
\r
144 portEXIT_CRITICAL();
\r
148 xReturn = ( xComPortHandle ) 0;
\r
151 /* This demo file only supports a single port but we have to return
\r
152 something to comply with the standard demo header file. */
\r
155 /*-----------------------------------------------------------*/
\r
157 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
\r
159 /* The port handle is not required as this driver only supports one port. */
\r
162 /* Get the next character from the buffer. Return false if no characters
\r
163 are available, or arrive before xBlockTime expires. */
\r
164 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
173 /*-----------------------------------------------------------*/
\r
175 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
\r
177 signed char *pxNext;
\r
179 /* A couple of parameters that this port does not use. */
\r
180 ( void ) usStringLength;
\r
183 /* NOTE: This implementation does not handle the queue being full as no
\r
184 block time is used! */
\r
186 /* The port handle is not required as this driver only supports UART0. */
\r
189 /* Send each character in the string, one at a time. */
\r
190 pxNext = ( signed char * ) pcString;
\r
193 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
197 /*-----------------------------------------------------------*/
\r
199 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
\r
201 /* Place the character in the queue of characters to be transmitted. */
\r
202 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
207 /* Turn on the Tx interrupt so the ISR will remove the character from the
\r
208 queue and send it. This does not need to be in a critical section as
\r
209 if the interrupt has already removed the character the next interrupt
\r
210 will simply turn off the Tx interrupt again. */
\r
215 /*-----------------------------------------------------------*/
\r
217 void vSerialClose( xComPortHandle xPort )
\r
219 /* Not supported as not required by the demo application. */
\r
221 /*-----------------------------------------------------------*/
\r
223 /* Serial port ISR. This can cause a context switch so is not defined as a
\r
224 standard ISR using the __irq keyword. Instead a wrapper function is defined
\r
225 within serialISR.s79 which in turn calls this function. See the port
\r
226 documentation on the FreeRTOS.org website for more information. */
\r
227 __arm void vSerialISR( void )
\r
229 unsigned short usStatus;
\r
231 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
233 /* What caused the interrupt? */
\r
234 usStatus = UART_FlagStatus( UART0 );
\r
236 if( usStatus & UART_TxHalfEmpty )
\r
238 /* The interrupt was caused by the THR becoming empty. Are there any
\r
239 more characters to transmit? */
\r
240 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
242 /* A character was retrieved from the queue so can be sent to the
\r
244 UART0->TxBUFR = cChar;
\r
248 /* Queue empty, nothing to send so turn off the Tx interrupt. */
\r
249 serINTERRUPT_OFF();
\r
253 if( usStatus & UART_RxBufFull )
\r
255 /* The interrupt was caused by a character being received. Grab the
\r
256 character from the RHR and place it in the queue of received
\r
258 cChar = UART0->RxBUFR;
\r
259 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
262 /* If a task was woken by either a character being received or a character
\r
263 being transmitted then we may need to switch to another task. */
\r
264 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r
266 /* End the interrupt in the EIC. */
\r