2 FreeRTOS V6.0.0 - Copyright (C) 2009 Real Time Engineers Ltd.
\r
4 This file is part of the FreeRTOS distribution.
\r
6 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
7 the terms of the GNU General Public License (version 2) as published by the
\r
8 Free Software Foundation and modified by the FreeRTOS exception.
\r
9 **NOTE** The exception to the GPL is included to allow you to distribute a
\r
10 combined work that includes FreeRTOS without being obliged to provide the
\r
11 source code for proprietary components outside of the FreeRTOS kernel.
\r
12 Alternative commercial license and support terms are also available upon
\r
13 request. See the licensing section of http://www.FreeRTOS.org for full
\r
16 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
\r
17 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
\r
18 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
21 You should have received a copy of the GNU General Public License along
\r
22 with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
\r
23 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
\r
26 ***************************************************************************
\r
28 * The FreeRTOS eBook and reference manual are available to purchase for a *
\r
29 * small fee. Help yourself get started quickly while also helping the *
\r
30 * FreeRTOS project! See http://www.FreeRTOS.org/Documentation for details *
\r
32 ***************************************************************************
\r
36 Please ensure to read the configuration and relevant port sections of the
\r
37 online documentation.
\r
39 http://www.FreeRTOS.org - Documentation, latest information, license and
\r
42 http://www.SafeRTOS.com - A version that is certified for use in safety
\r
45 http://www.OpenRTOS.com - Commercial support, development, porting,
\r
46 licensing and training services.
\r
50 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
53 /* Library includes. */
\r
58 /* Scheduler includes. */
\r
59 #include "FreeRTOS.h"
\r
62 /* Demo application includes. */
\r
65 #define UART0_Rx_Pin ( 0x0001<< 8 )
\r
66 #define UART0_Tx_Pin ( 0x0001<< 9 )
\r
68 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
\r
69 #define serNO_BLOCK ( ( portTickType ) 0 )
\r
71 /* Macros to turn on and off the Tx empty interrupt. */
\r
72 #define serINTERRUPT_ON() UART0->IER |= UART_TxHalfEmpty
\r
73 #define serINTERRUPT_OFF() UART0->IER &= ~UART_TxHalfEmpty
\r
75 /*-----------------------------------------------------------*/
\r
77 /* Queues used to hold received characters, and characters waiting to be
\r
79 static xQueueHandle xRxedChars;
\r
80 static xQueueHandle xCharsForTx;
\r
82 /*-----------------------------------------------------------*/
\r
84 /* Interrupt entry point written in the assembler file serialISR.s79. */
\r
85 extern void vSerialISREntry( void );
\r
87 /* The interrupt service routine - called from the assembly entry point. */
\r
88 __arm void vSerialISR( void );
\r
90 /*-----------------------------------------------------------*/
\r
93 * See the serial2.h header file.
\r
95 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
97 xComPortHandle xReturn;
\r
99 /* Create the queues used to hold Rx and Tx characters. */
\r
100 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
101 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
103 /* If the queues were created correctly then setup the serial port
\r
105 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
107 portENTER_CRITICAL();
\r
109 /* Setup the UART port pins. */
\r
110 GPIO_Config( GPIO0, UART0_Tx_Pin, GPIO_AF_PP );
\r
111 GPIO_Config( GPIO0, UART0_Rx_Pin, GPIO_IN_TRI_CMOS );
\r
113 /* Configure the UART. */
\r
114 UART_OnOffConfig( UART0, ENABLE );
\r
115 UART_FifoConfig( UART0, DISABLE );
\r
116 UART_FifoReset( UART0, UART_RxFIFO );
\r
117 UART_FifoReset( UART0, UART_TxFIFO );
\r
118 UART_LoopBackConfig(UART0, DISABLE );
\r
119 UART_Config( UART0, ulWantedBaud, UART_NO_PARITY, UART_1_StopBits, UARTM_8D );
\r
120 UART_RxConfig( UART0, ENABLE );
\r
122 /* Configure the IEC for the UART interrupts. */
\r
123 EIC_IRQChannelPriorityConfig( UART0_IRQChannel, 1 );
\r
124 EIC_IRQChannelConfig( UART0_IRQChannel, ENABLE );
\r
125 EIC_IRQConfig( ENABLE );
\r
126 UART_ItConfig( UART0, UART_RxBufFull, ENABLE );
\r
128 portEXIT_CRITICAL();
\r
132 xReturn = ( xComPortHandle ) 0;
\r
135 /* This demo file only supports a single port but we have to return
\r
136 something to comply with the standard demo header file. */
\r
139 /*-----------------------------------------------------------*/
\r
141 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
\r
143 /* The port handle is not required as this driver only supports one port. */
\r
146 /* Get the next character from the buffer. Return false if no characters
\r
147 are available, or arrive before xBlockTime expires. */
\r
148 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
157 /*-----------------------------------------------------------*/
\r
159 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
\r
161 signed char *pxNext;
\r
163 /* A couple of parameters that this port does not use. */
\r
164 ( void ) usStringLength;
\r
167 /* NOTE: This implementation does not handle the queue being full as no
\r
168 block time is used! */
\r
170 /* The port handle is not required as this driver only supports UART0. */
\r
173 /* Send each character in the string, one at a time. */
\r
174 pxNext = ( signed char * ) pcString;
\r
177 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
181 /*-----------------------------------------------------------*/
\r
183 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
\r
185 /* Place the character in the queue of characters to be transmitted. */
\r
186 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
191 /* Turn on the Tx interrupt so the ISR will remove the character from the
\r
192 queue and send it. This does not need to be in a critical section as
\r
193 if the interrupt has already removed the character the next interrupt
\r
194 will simply turn off the Tx interrupt again. */
\r
199 /*-----------------------------------------------------------*/
\r
201 void vSerialClose( xComPortHandle xPort )
\r
203 /* Not supported as not required by the demo application. */
\r
205 /*-----------------------------------------------------------*/
\r
207 /* Serial port ISR. This can cause a context switch so is not defined as a
\r
208 standard ISR using the __irq keyword. Instead a wrapper function is defined
\r
209 within serialISR.s79 which in turn calls this function. See the port
\r
210 documentation on the FreeRTOS.org website for more information. */
\r
211 __arm void vSerialISR( void )
\r
213 unsigned short usStatus;
\r
215 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
217 /* What caused the interrupt? */
\r
218 usStatus = UART_FlagStatus( UART0 );
\r
220 if( usStatus & UART_TxHalfEmpty )
\r
222 /* The interrupt was caused by the THR becoming empty. Are there any
\r
223 more characters to transmit? */
\r
224 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
226 /* A character was retrieved from the queue so can be sent to the
\r
228 UART0->TxBUFR = cChar;
\r
232 /* Queue empty, nothing to send so turn off the Tx interrupt. */
\r
233 serINTERRUPT_OFF();
\r
237 if( usStatus & UART_RxBufFull )
\r
239 /* The interrupt was caused by a character being received. Grab the
\r
240 character from the RHR and place it in the queue of received
\r
242 cChar = UART0->RxBUFR;
\r
243 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
246 /* If a task was woken by either a character being received or a character
\r
247 being transmitted then we may need to switch to another task. */
\r
248 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r
250 /* End the interrupt in the EIC. */
\r