/* FreeRTOS V8.2.0 - Copyright (C) 2015 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. 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. Full license text is available on the following link: http://www.freertos.org/a00114.html *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that is more than just the market leader, it * * is the industry's de facto standard. * * * * Help yourself get started quickly while simultaneously helping * * to support the FreeRTOS project by purchasing a FreeRTOS * * tutorial book, reference manual, or both: * * http://www.FreeRTOS.org/Documentation * * * *************************************************************************** http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading the FAQ page "My application does not run, what could be wrong?". Have you defined configASSERT()? http://www.FreeRTOS.org/support - In return for receiving this top quality embedded software for free we request you assist our global community by participating in the support forum. http://www.FreeRTOS.org/training - Investing in training allows your team to be as productive as possible as early as possible. Now you can receive FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers Ltd, and the world's leading authority on the world's leading RTOS. http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, including FreeRTOS+Trace - an indispensable productivity tool, a DOS compatible FAT file system, and our tiny thread aware UDP/IP stack. http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate. Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and commercial middleware. 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. 1 tab == 4 spaces! */ /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0. ***Note*** This example uses queues to send each character into an interrupt service routine and out of an interrupt service routine individually. This is done to demonstrate queues being used in an interrupt, and to deliberately load the system to test the FreeRTOS port. It is *NOT* meant to be an example of an efficient implementation. An efficient implementation should use FIFO's or DMA if available, and only use FreeRTOS API functions when enough has been received to warrant a task being unblocked to process the data. */ /* Scheduler includes. */ #include "FreeRTOS.h" #include "queue.h" #include "semphr.h" #include "comtest2.h" /* Library includes. */ #include "stm32l152_eval.h" /* Demo application includes. */ #include "serial.h" /*-----------------------------------------------------------*/ /* Misc defines. */ #define serINVALID_QUEUE ( ( QueueHandle_t ) 0 ) #define serNO_BLOCK ( ( TickType_t ) 0 ) /*-----------------------------------------------------------*/ /* The queue used to hold received characters. */ static QueueHandle_t xRxedChars; static QueueHandle_t xCharsForTx; /*-----------------------------------------------------------*/ /* * See the serial2.h header file. */ xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) { USART_InitTypeDef USART_InitStructure; xComPortHandle xReturn; NVIC_InitTypeDef NVIC_InitStructure; /* Create the queues used to hold Rx/Tx characters. */ xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); /* If the queues were created correctly then setup the serial port hardware. */ if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) ) { USART_InitStructure.USART_BaudRate = ulWantedBaud; USART_InitStructure.USART_WordLength = USART_WordLength_8b; USART_InitStructure.USART_StopBits = USART_StopBits_1; USART_InitStructure.USART_Parity = USART_Parity_No; USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; /* The Eval board COM2 is being used, which in reality is the STM32 USART3. */ STM_EVAL_COMInit( COM2, &USART_InitStructure ); NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; /* Not used as 4 bits are used for the pre-emption priority. */; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init( &NVIC_InitStructure ); USART_ITConfig( USART3, USART_IT_RXNE, ENABLE ); } else { xReturn = ( xComPortHandle ) 0; } /* This demo file only supports a single port but we have to return something to comply with the standard demo header file. */ return xReturn; } /*-----------------------------------------------------------*/ signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime ) { /* The port handle is not required as this driver only supports one port. */ ( void ) pxPort; /* Get the next character from the buffer. Return false if no characters are available, or arrive before xBlockTime expires. */ if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) ) { return pdTRUE; } else { return pdFALSE; } } /*-----------------------------------------------------------*/ void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength ) { signed char *pxNext; /* A couple of parameters that this port does not use. */ ( void ) usStringLength; ( void ) pxPort; /* NOTE: This implementation does not handle the queue being full as no block time is used! */ /* The port handle is not required as this driver only supports UART1. */ ( void ) pxPort; /* Send each character in the string, one at a time. */ pxNext = ( signed char * ) pcString; while( *pxNext ) { xSerialPutChar( pxPort, *pxNext, serNO_BLOCK ); pxNext++; } } /*-----------------------------------------------------------*/ signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime ) { signed portBASE_TYPE xReturn; if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) == pdPASS ) { xReturn = pdPASS; USART_ITConfig( USART3, USART_IT_TXE, ENABLE ); } else { xReturn = pdFAIL; } return xReturn; } /*-----------------------------------------------------------*/ void vSerialClose( xComPortHandle xPort ) { /* Not supported as not required by the demo application. */ } /*-----------------------------------------------------------*/ void USART3_IRQHandler( void ) { portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; char cChar; if( USART_GetITStatus( USART3, USART_IT_TXE ) == SET ) { /* The interrupt was caused by the TX register 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 USART now. */ USART_SendData( USART3, cChar ); } else { USART_ITConfig( USART3, USART_IT_TXE, DISABLE ); } } if( USART_GetITStatus( USART3, USART_IT_RXNE ) == SET ) { /* A character has been received on the USART, send it to the Rx handler task. */ cChar = USART_ReceiveData( USART3 ); xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken ); } /* If sending or receiving from a queue has caused a task to unblock, and the unblocked task has a priority equal to or higher than the currently running task (the task this ISR interrupted), then xHigherPriorityTaskWoken will have automatically been set to pdTRUE within the queue send or receive function. portEND_SWITCHING_ISR() will then ensure that this ISR returns directly to the higher priority unblocked task. */ portEND_SWITCHING_ISR( xHigherPriorityTaskWoken ); }