| /* | |
| FreeRTOS V7.4.0 - Copyright (C) 2013 Real Time Engineers Ltd. | |
| FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT | |
| http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. | |
| *************************************************************************** | |
| * * | |
| * FreeRTOS tutorial books are available in pdf and paperback. * | |
| * Complete, revised, and edited pdf reference manuals are also * | |
| * available. * | |
| * * | |
| * Purchasing FreeRTOS documentation will not only help you, by * | |
| * ensuring you get running as quickly as possible and with an * | |
| * in-depth knowledge of how to use FreeRTOS, it will also help * | |
| * the FreeRTOS project to continue with its mission of providing * | |
| * professional grade, cross platform, de facto standard solutions * | |
| * for microcontrollers - completely free of charge! * | |
| * * | |
| * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * | |
| * * | |
| * Thank you for using FreeRTOS, and thank you for your support! * | |
| * * | |
| *************************************************************************** | |
| This file is part of the FreeRTOS distribution. | |
| FreeRTOS is free software; you can redistribute it and/or modify it under | |
| the terms of the GNU General Public License (version 2) as published by the | |
| Free Software Foundation AND MODIFIED BY the FreeRTOS exception. | |
| >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to | |
| distribute a combined work that includes FreeRTOS without being obliged to | |
| provide the source code for proprietary components outside of the FreeRTOS | |
| kernel. | |
| FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY | |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
| FOR A PARTICULAR PURPOSE. See the GNU General Public License for more | |
| details. You should have received a copy of the GNU General Public License | |
| and the FreeRTOS license exception along with FreeRTOS; if not itcan be | |
| viewed here: http://www.freertos.org/a00114.html and also obtained by | |
| writing to Real Time Engineers Ltd., contact details for whom are available | |
| on the FreeRTOS WEB site. | |
| 1 tab == 4 spaces! | |
| *************************************************************************** | |
| * * | |
| * Having a problem? Start by reading the FAQ "My application does * | |
| * not run, what could be wrong?" * | |
| * * | |
| * http://www.FreeRTOS.org/FAQHelp.html * | |
| * * | |
| *************************************************************************** | |
| http://www.FreeRTOS.org - Documentation, books, training, latest versions, | |
| license and Real Time Engineers Ltd. contact details. | |
| http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, | |
| including FreeRTOS+Trace - an indispensable productivity tool, and our new | |
| fully thread aware and reentrant UDP/IP stack. | |
| http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High | |
| Integrity Systems, who sell the code with commercial support, | |
| indemnification and middleware, under the OpenRTOS brand. | |
| http://www.SafeRTOS.com - High Integrity Systems also provide a safety | |
| engineered and independently SIL3 certified version for use in safety and | |
| mission critical applications that require provable dependability. | |
| */ | |
| /* | |
| BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR USART0. | |
| This file contains all the serial port components that must be compiled | |
| to ARM mode. The components that can be compiled to either ARM or THUMB | |
| mode are contained in serial.c. | |
| */ | |
| /* Standard includes. */ | |
| #include <stdlib.h> | |
| /* Scheduler includes. */ | |
| #include "FreeRTOS.h" | |
| #include "queue.h" | |
| #include "task.h" | |
| /* Demo application includes. */ | |
| #include "serial.h" | |
| #include "AT91R40008.h" | |
| #include "usart.h" | |
| /*-----------------------------------------------------------*/ | |
| /* Constant to access the AIC. */ | |
| #define serCLEAR_AIC_INTERRUPT ( ( unsigned long ) 0 ) | |
| /* Constants to determine the ISR source. */ | |
| #define serSOURCE_THRE ( ( unsigned char ) 0x02 ) | |
| #define serSOURCE_RX_TIMEOUT ( ( unsigned char ) 0x0c ) | |
| #define serSOURCE_ERROR ( ( unsigned char ) 0x06 ) | |
| #define serSOURCE_RX ( ( unsigned char ) 0x04 ) | |
| #define serINTERRUPT_SOURCE_MASK ( ( unsigned long ) (US_RXRDY | US_TXRDY | US_RXBRK | US_OVRE | US_FRAME | US_PARE) ) | |
| /* Queues used to hold received characters, and characters waiting to be | |
| transmitted. */ | |
| static xQueueHandle xRxedChars; | |
| static xQueueHandle xCharsForTx; | |
| /*-----------------------------------------------------------*/ | |
| /* UART0 interrupt service routine. This can cause a context switch so MUST | |
| be declared "naked". */ | |
| void vUART_ISR_Wrapper( void ) __attribute__ ((naked)); | |
| /* The ISR function that actually performs the work. This must be separate | |
| from the wrapper to ensure the correct stack frame is set up. */ | |
| void vUART_ISR_Handler( void ) __attribute__ ((noinline)); | |
| /*-----------------------------------------------------------*/ | |
| void vSerialISRCreateQueues( unsigned portBASE_TYPE uxQueueLength, xQueueHandle *pxRxedChars, xQueueHandle *pxCharsForTx ) | |
| { | |
| /* Create the queues used to hold Rx and Tx characters. */ | |
| xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); | |
| xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); | |
| /* Pass back a reference to the queues so the serial API file can | |
| post/receive characters. */ | |
| *pxRxedChars = xRxedChars; | |
| *pxCharsForTx = xCharsForTx; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vUART_ISR_Wrapper( void ) | |
| { | |
| /* Save the context of the interrupted task. */ | |
| portSAVE_CONTEXT(); | |
| /* Call the handler. This must be a separate function to ensure the | |
| stack frame is correctly set up. */ | |
| __asm volatile( "bl vUART_ISR_Handler" ); | |
| /* Restore the context of whichever task will run next. */ | |
| portRESTORE_CONTEXT(); | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vUART_ISR_Handler( void ) | |
| { | |
| /* Now we can declare the local variables. These must be static. */ | |
| signed char cChar; | |
| portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; | |
| unsigned long ulStatus; | |
| /* What caused the interrupt? */ | |
| ulStatus = AT91C_BASE_US0->US_CSR & AT91C_BASE_US0->US_IMR; | |
| if (ulStatus & US_TXRDY) | |
| { | |
| /* The interrupt was caused by the THR becoming empty. Are there any | |
| more characters to transmit? */ | |
| if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE ) | |
| { | |
| /* A character was retrieved from the queue so can be sent to the | |
| THR now. */ | |
| AT91C_BASE_US0->US_THR = cChar; | |
| } | |
| else | |
| { | |
| /* Queue empty, nothing to send so turn off the Tx interrupt. */ | |
| AT91C_BASE_US0->US_IDR = US_TXRDY; | |
| } | |
| } | |
| if (ulStatus & US_RXRDY) | |
| { | |
| /* The interrupt was caused by the receiver getting data. */ | |
| cChar = AT91C_BASE_US0->US_RHR; | |
| xQueueSendFromISR(xRxedChars, &cChar, &xHigherPriorityTaskWoken); | |
| } | |
| /* Acknowledge the interrupt at AIC level... */ | |
| AT91C_BASE_AIC->AIC_EOICR = serCLEAR_AIC_INTERRUPT; | |
| /* If an event caused a task to unblock then we call "Yield from ISR" to | |
| ensure that the unblocked task is the task that executes when the interrupt | |
| completes if the unblocked task has a priority higher than the interrupted | |
| task. */ | |
| if( xHigherPriorityTaskWoken ) | |
| { | |
| portYIELD_FROM_ISR(); | |
| } | |
| } | |
| /*-----------------------------------------------------------*/ | |