/* FreeRTOS V8.2.3 - 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. */ /* Standard includes. */ #include /* Scheduler includes. */ #include "FreeRTOS.h" #include "queue.h" /* Demo application includes. */ #include "serial.h" /* Atmel library includes. */ #include #include #include /*-----------------------------------------------------------*/ /* Location of the COM0 registers. */ #define serCOM0 ( ( AT91PS_USART ) AT91C_BASE_US0 ) /* Interrupt control macros. */ #define serINTERRUPT_LEVEL ( 5 ) #define vInterruptOn() serCOM0->US_IER = ( AT91C_US_TXRDY | AT91C_US_RXRDY ) #define vInterruptOff() serCOM0->US_IDR = AT91C_US_TXRDY /* Misc constants. */ #define serINVALID_QUEUE ( ( QueueHandle_t ) 0 ) #define serHANDLE ( ( xComPortHandle ) 1 ) #define serNO_BLOCK ( ( TickType_t ) 0 ) #define serNO_TIMEGUARD ( ( unsigned long ) 0 ) #define serNO_PERIPHERAL_B_SETUP ( ( unsigned long ) 0 ) /* Queues used to hold received characters, and characters waiting to be transmitted. */ static QueueHandle_t xRxedChars; static QueueHandle_t xCharsForTx; /*-----------------------------------------------------------*/ /* The interrupt service routine. */ __arm void vSerialISR( void ); /*-----------------------------------------------------------*/ /* * See the serial2.h header file. */ xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) { xComPortHandle xReturn = serHANDLE; /* 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 ) ); /* If the queues were created correctly then setup the serial port hardware. */ if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) ) { PMC_EnablePeripheral( AT91C_ID_US0 ); portENTER_CRITICAL(); { USART_Configure( serCOM0, ( AT91C_US_CHRL_8_BITS | AT91C_US_PAR_NONE ), ulWantedBaud, configCPU_CLOCK_HZ ); /* Enable Rx and Tx. */ USART_SetTransmitterEnabled( serCOM0, pdTRUE ); USART_SetReceiverEnabled( serCOM0, pdTRUE ); /* Enable the Rx interrupts. The Tx interrupts are not enabled until there are characters to be transmitted. */ serCOM0->US_IER = AT91C_US_RXRDY; /* Enable the interrupts in the AIC. */ AIC_ConfigureIT( AT91C_ID_US0, AT91C_AIC_PRIOR_LOWEST, ( void (*)( void ) ) vSerialISR ); AIC_EnableIT( AT91C_ID_US0 ); } portEXIT_CRITICAL(); } 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 UART0. */ ( 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 ) { /* Just to remove compiler warning. */ ( void ) pxPort; /* Place the character in the queue of characters to be transmitted. */ if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS ) { return pdFAIL; } /* Turn on the Tx interrupt so the ISR will remove the character from the queue and send it. This does not need to be in a critical section as if the interrupt has already removed the character the next interrupt will simply turn off the Tx interrupt again. */ vInterruptOn(); return pdPASS; } /*-----------------------------------------------------------*/ void vSerialClose( xComPortHandle xPort ) { /* Not supported as not required by the demo application. */ ( void ) xPort; } /*-----------------------------------------------------------*/ /* Serial port ISR. This can cause a context switch so is not defined as a standard ISR using the __irq keyword. Instead a wrapper function is defined within serialISR.s79 which in turn calls this function. See the port documentation on the FreeRTOS.org website for more information. */ __arm void vSerialISR( void ) { unsigned long ulStatus; signed char cChar; portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; /* What caused the interrupt? */ ulStatus = serCOM0->US_CSR &= serCOM0->US_IMR; if( ulStatus & AT91C_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. */ serCOM0->US_THR = cChar; } else { /* Queue empty, nothing to send so turn off the Tx interrupt. */ vInterruptOff(); } } if( ulStatus & AT91C_US_RXRDY ) { /* The interrupt was caused by a character being received. Grab the character from the RHR and place it in the queue or received characters. */ cChar = serCOM0->US_RHR; xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken ); } /* If a task was woken by either a character being received or a character being transmitted then we may need to switch to another task. */ portEND_SWITCHING_ISR( xHigherPriorityTaskWoken ); /* End the interrupt in the AIC. */ AT91C_BASE_AIC->AIC_EOICR = 0; }