2 FreeRTOS V8.0.0:rc1 - Copyright (C) 2014 Real Time Engineers Ltd.
\r
5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
7 ***************************************************************************
\r
9 * FreeRTOS provides completely free yet professionally developed, *
\r
10 * robust, strictly quality controlled, supported, and cross *
\r
11 * platform software that has become a de facto standard. *
\r
13 * Help yourself get started quickly and support the FreeRTOS *
\r
14 * project by purchasing a FreeRTOS tutorial book, reference *
\r
15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
\r
19 ***************************************************************************
\r
21 This file is part of the FreeRTOS distribution.
\r
23 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
24 the terms of the GNU General Public License (version 2) as published by the
\r
25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
\r
27 >>! NOTE: The modification to the GPL is included to allow you to distribute
\r
28 >>! a combined work that includes FreeRTOS without being obliged to provide
\r
29 >>! the source code for proprietary components outside of the FreeRTOS
\r
32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
\r
33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
\r
34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
\r
35 link: http://www.freertos.org/a00114.html
\r
39 ***************************************************************************
\r
41 * Having a problem? Start by reading the FAQ "My application does *
\r
42 * not run, what could be wrong?" *
\r
44 * http://www.FreeRTOS.org/FAQHelp.html *
\r
46 ***************************************************************************
\r
48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
\r
49 license and Real Time Engineers Ltd. contact details.
\r
51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
\r
53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
\r
55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
\r
56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
\r
57 licenses offer ticketed support, indemnification and middleware.
\r
59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
\r
60 engineered and independently SIL3 certified version for use in safety and
\r
61 mission critical applications that require provable dependability.
\r
67 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
70 /* Standard includes. */
\r
73 /* Scheduler includes. */
\r
74 #include "FreeRTOS.h"
\r
77 /* Demo application includes. */
\r
80 /* Atmel library includes. */
\r
81 #include <usart/usart.h>
\r
82 #include <aic/aic.h>
\r
83 #include <pmc/pmc.h>
\r
85 /*-----------------------------------------------------------*/
\r
87 /* Location of the COM0 registers. */
\r
88 #define serCOM0 ( ( AT91PS_USART ) AT91C_BASE_US0 )
\r
90 /* Interrupt control macros. */
\r
91 #define serINTERRUPT_LEVEL ( 5 )
\r
92 #define vInterruptOn() serCOM0->US_IER = ( AT91C_US_TXRDY | AT91C_US_RXRDY )
\r
93 #define vInterruptOff() serCOM0->US_IDR = AT91C_US_TXRDY
\r
95 /* Misc constants. */
\r
96 #define serINVALID_QUEUE ( ( QueueHandle_t ) 0 )
\r
97 #define serHANDLE ( ( xComPortHandle ) 1 )
\r
98 #define serNO_BLOCK ( ( TickType_t ) 0 )
\r
99 #define serNO_TIMEGUARD ( ( unsigned long ) 0 )
\r
100 #define serNO_PERIPHERAL_B_SETUP ( ( unsigned long ) 0 )
\r
103 /* Queues used to hold received characters, and characters waiting to be
\r
105 static QueueHandle_t xRxedChars;
\r
106 static QueueHandle_t xCharsForTx;
\r
108 /*-----------------------------------------------------------*/
\r
110 /* The interrupt service routine. */
\r
111 __arm void vSerialISR( void );
\r
113 /*-----------------------------------------------------------*/
\r
116 * See the serial2.h header file.
\r
118 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
120 xComPortHandle xReturn = serHANDLE;
\r
122 /* Create the queues used to hold Rx and Tx characters. */
\r
123 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
124 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
126 /* If the queues were created correctly then setup the serial port
\r
128 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
130 PMC_EnablePeripheral( AT91C_ID_US0 );
\r
131 portENTER_CRITICAL();
\r
133 USART_Configure( serCOM0, ( AT91C_US_CHRL_8_BITS | AT91C_US_PAR_NONE ), ulWantedBaud, configCPU_CLOCK_HZ );
\r
135 /* Enable Rx and Tx. */
\r
136 USART_SetTransmitterEnabled( serCOM0, pdTRUE );
\r
137 USART_SetReceiverEnabled( serCOM0, pdTRUE );
\r
139 /* Enable the Rx interrupts. The Tx interrupts are not enabled
\r
140 until there are characters to be transmitted. */
\r
141 serCOM0->US_IER = AT91C_US_RXRDY;
\r
143 /* Enable the interrupts in the AIC. */
\r
144 AIC_ConfigureIT( AT91C_ID_US0, AT91C_AIC_PRIOR_LOWEST, ( void (*)( void ) ) vSerialISR );
\r
145 AIC_EnableIT( AT91C_ID_US0 );
\r
147 portEXIT_CRITICAL();
\r
151 xReturn = ( xComPortHandle ) 0;
\r
154 /* This demo file only supports a single port but we have to return
\r
155 something to comply with the standard demo header file. */
\r
158 /*-----------------------------------------------------------*/
\r
160 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
\r
162 /* The port handle is not required as this driver only supports one port. */
\r
165 /* Get the next character from the buffer. Return false if no characters
\r
166 are available, or arrive before xBlockTime expires. */
\r
167 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
176 /*-----------------------------------------------------------*/
\r
178 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
\r
180 signed char *pxNext;
\r
182 /* A couple of parameters that this port does not use. */
\r
183 ( void ) usStringLength;
\r
186 /* NOTE: This implementation does not handle the queue being full as no
\r
187 block time is used! */
\r
189 /* The port handle is not required as this driver only supports UART0. */
\r
192 /* Send each character in the string, one at a time. */
\r
193 pxNext = ( signed char * ) pcString;
\r
196 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
200 /*-----------------------------------------------------------*/
\r
202 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
\r
204 /* Just to remove compiler warning. */
\r
207 /* Place the character in the queue of characters to be transmitted. */
\r
208 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
213 /* Turn on the Tx interrupt so the ISR will remove the character from the
\r
214 queue and send it. This does not need to be in a critical section as
\r
215 if the interrupt has already removed the character the next interrupt
\r
216 will simply turn off the Tx interrupt again. */
\r
221 /*-----------------------------------------------------------*/
\r
223 void vSerialClose( xComPortHandle xPort )
\r
225 /* Not supported as not required by the demo application. */
\r
228 /*-----------------------------------------------------------*/
\r
230 /* Serial port ISR. This can cause a context switch so is not defined as a
\r
231 standard ISR using the __irq keyword. Instead a wrapper function is defined
\r
232 within serialISR.s79 which in turn calls this function. See the port
\r
233 documentation on the FreeRTOS.org website for more information. */
\r
234 __arm void vSerialISR( void )
\r
236 unsigned long ulStatus;
\r
238 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
240 /* What caused the interrupt? */
\r
241 ulStatus = serCOM0->US_CSR &= serCOM0->US_IMR;
\r
243 if( ulStatus & AT91C_US_TXRDY )
\r
245 /* The interrupt was caused by the THR becoming empty. Are there any
\r
246 more characters to transmit? */
\r
247 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
249 /* A character was retrieved from the queue so can be sent to the
\r
251 serCOM0->US_THR = cChar;
\r
255 /* Queue empty, nothing to send so turn off the Tx interrupt. */
\r
260 if( ulStatus & AT91C_US_RXRDY )
\r
262 /* The interrupt was caused by a character being received. Grab the
\r
263 character from the RHR and place it in the queue or received
\r
265 cChar = serCOM0->US_RHR;
\r
266 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
269 /* If a task was woken by either a character being received or a character
\r
270 being transmitted then we may need to switch to another task. */
\r
271 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r
273 /* End the interrupt in the AIC. */
\r
274 AT91C_BASE_AIC->AIC_EOICR = 0;
\r