2 FreeRTOS.org V4.0.2 - Copyright (C) 2003-2006 Richard Barry.
\r
4 This file is part of the FreeRTOS.org distribution.
\r
6 FreeRTOS.org is free software; you can redistribute it and/or modify
\r
7 it under the terms of the GNU General Public License as published by
\r
8 the Free Software Foundation; either version 2 of the License, or
\r
9 (at your option) any later version.
\r
11 FreeRTOS.org is distributed in the hope that it will be useful,
\r
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
\r
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\r
14 GNU General Public License for more details.
\r
16 You should have received a copy of the GNU General Public License
\r
17 along with FreeRTOS.org; if not, write to the Free Software
\r
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
\r
20 A special exception to the GPL can be applied should you wish to distribute
\r
21 a combined work that includes FreeRTOS.org, without being obliged to provide
\r
22 the source code for any proprietary components. See the licensing section
\r
23 of http://www.FreeRTOS.org for full details of how and when the exception
\r
26 ***************************************************************************
\r
27 See http://www.FreeRTOS.org for documentation, latest information, license
\r
28 and contact details. Please ensure to read the configuration and relevant
\r
29 port sections of the online documentation.
\r
30 ***************************************************************************
\r
34 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
37 /* Library includes. */
\r
42 /* Scheduler includes. */
\r
43 #include "FreeRTOS.h"
\r
46 /* Demo application includes. */
\r
49 #define UART0_Rx_Pin ( 0x0001<< 8 )
\r
50 #define UART0_Tx_Pin ( 0x0001<< 9 )
\r
52 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
\r
53 #define serNO_BLOCK ( ( portTickType ) 0 )
\r
55 /* Macros to turn on and off the Tx empty interrupt. */
\r
56 #define serINTERRUPT_ON() UART0->IER |= UART_TxHalfEmpty
\r
57 #define serINTERRUPT_OFF() UART0->IER &= ~UART_TxHalfEmpty
\r
59 /*-----------------------------------------------------------*/
\r
61 /* Queues used to hold received characters, and characters waiting to be
\r
63 static xQueueHandle xRxedChars;
\r
64 static xQueueHandle xCharsForTx;
\r
66 /*-----------------------------------------------------------*/
\r
68 /* Interrupt entry point written in the assembler file serialISR.s79. */
\r
69 extern void vSerialISREntry( void );
\r
71 /* The interrupt service routine - called from the assembly entry point. */
\r
72 __arm void vSerialISR( void );
\r
74 /*-----------------------------------------------------------*/
\r
77 * See the serial2.h header file.
\r
79 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
81 xComPortHandle xReturn;
\r
83 /* Create the queues used to hold Rx and Tx characters. */
\r
84 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
85 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
87 /* If the queues were created correctly then setup the serial port
\r
89 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
91 portENTER_CRITICAL();
\r
93 /* Setup the UART port pins. */
\r
94 GPIO_Config( GPIO0, UART0_Tx_Pin, GPIO_AF_PP );
\r
95 GPIO_Config( GPIO0, UART0_Rx_Pin, GPIO_IN_TRI_CMOS );
\r
97 /* Configure the UART. */
\r
98 UART_OnOffConfig( UART0, ENABLE );
\r
99 UART_FifoConfig( UART0, DISABLE );
\r
100 UART_FifoReset( UART0, UART_RxFIFO );
\r
101 UART_FifoReset( UART0, UART_TxFIFO );
\r
102 UART_LoopBackConfig(UART0, DISABLE );
\r
103 UART_Config( UART0, ulWantedBaud, UART_NO_PARITY, UART_1_StopBits, UARTM_8D );
\r
104 UART_RxConfig( UART0, ENABLE );
\r
106 /* Configure the IEC for the UART interrupts. */
\r
107 EIC_IRQChannelPriorityConfig( UART0_IRQChannel, 1 );
\r
108 EIC_IRQChannelConfig( UART0_IRQChannel, ENABLE );
\r
109 EIC_IRQConfig( ENABLE );
\r
110 UART_ItConfig( UART0, UART_RxBufFull, ENABLE );
\r
112 portEXIT_CRITICAL();
\r
116 xReturn = ( xComPortHandle ) 0;
\r
119 /* This demo file only supports a single port but we have to return
\r
120 something to comply with the standard demo header file. */
\r
123 /*-----------------------------------------------------------*/
\r
125 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
\r
127 /* The port handle is not required as this driver only supports one port. */
\r
130 /* Get the next character from the buffer. Return false if no characters
\r
131 are available, or arrive before xBlockTime expires. */
\r
132 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
141 /*-----------------------------------------------------------*/
\r
143 void vSerialPutString( xComPortHandle pxPort, const signed portCHAR * const pcString, unsigned portSHORT usStringLength )
\r
145 signed portCHAR *pxNext;
\r
147 /* A couple of parameters that this port does not use. */
\r
148 ( void ) usStringLength;
\r
151 /* NOTE: This implementation does not handle the queue being full as no
\r
152 block time is used! */
\r
154 /* The port handle is not required as this driver only supports UART0. */
\r
157 /* Send each character in the string, one at a time. */
\r
158 pxNext = ( signed portCHAR * ) pcString;
\r
161 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
165 /*-----------------------------------------------------------*/
\r
167 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
\r
169 /* Place the character in the queue of characters to be transmitted. */
\r
170 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
175 /* Turn on the Tx interrupt so the ISR will remove the character from the
\r
176 queue and send it. This does not need to be in a critical section as
\r
177 if the interrupt has already removed the character the next interrupt
\r
178 will simply turn off the Tx interrupt again. */
\r
183 /*-----------------------------------------------------------*/
\r
185 void vSerialClose( xComPortHandle xPort )
\r
187 /* Not supported as not required by the demo application. */
\r
189 /*-----------------------------------------------------------*/
\r
191 /* Serial port ISR. This can cause a context switch so is not defined as a
\r
192 standard ISR using the __irq keyword. Instead a wrapper function is defined
\r
193 within serialISR.s79 which in turn calls this function. See the port
\r
194 documentation on the FreeRTOS.org website for more information. */
\r
195 __arm void vSerialISR( void )
\r
197 unsigned portSHORT usStatus;
\r
198 signed portCHAR cChar;
\r
199 portBASE_TYPE xTaskWokenByTx = pdFALSE, xTaskWokenByPost = pdFALSE;
\r
201 /* What caused the interrupt? */
\r
202 usStatus = UART_FlagStatus( UART0 );
\r
204 if( usStatus & UART_TxHalfEmpty )
\r
206 /* The interrupt was caused by the THR becoming empty. Are there any
\r
207 more characters to transmit? */
\r
208 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWokenByTx ) == pdTRUE )
\r
210 /* A character was retrieved from the queue so can be sent to the
\r
212 UART0->TxBUFR = cChar;
\r
216 /* Queue empty, nothing to send so turn off the Tx interrupt. */
\r
217 serINTERRUPT_OFF();
\r
221 if( usStatus & UART_RxBufFull )
\r
223 /* The interrupt was caused by a character being received. Grab the
\r
224 character from the RHR and place it in the queue of received
\r
226 cChar = UART0->RxBUFR;
\r
227 xTaskWokenByPost = xQueueSendFromISR( xRxedChars, &cChar, xTaskWokenByPost );
\r
230 /* If a task was woken by either a character being received or a character
\r
231 being transmitted then we may need to switch to another task. */
\r
232 portEND_SWITCHING_ISR( ( xTaskWokenByPost || xTaskWokenByTx ) );
\r
234 /* End the interrupt in the EIC. */
\r