--- /dev/null
+/*\r
+ FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry.\r
+\r
+ This file is part of the FreeRTOS.org distribution.\r
+\r
+ FreeRTOS.org is free software; you can redistribute it and/or modify\r
+ it under the terms of the GNU General Public License as published by\r
+ the Free Software Foundation; either version 2 of the License, or\r
+ (at your option) any later version.\r
+\r
+ FreeRTOS.org is distributed in the hope that it will be useful,\r
+ but WITHOUT ANY WARRANTY; without even the implied warranty of\r
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\r
+ GNU General Public License for more details.\r
+\r
+ You should have received a copy of the GNU General Public License\r
+ along with FreeRTOS.org; if not, write to the Free Software\r
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA\r
+\r
+ A special exception to the GPL can be applied should you wish to distribute\r
+ a combined work that includes FreeRTOS.org, without being obliged to provide\r
+ the source code for any proprietary components. See the licensing section\r
+ of http://www.FreeRTOS.org for full details of how and when the exception\r
+ can be applied.\r
+\r
+ ***************************************************************************\r
+ ***************************************************************************\r
+ * *\r
+ * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *\r
+ * *\r
+ * This is a concise, step by step, 'hands on' guide that describes both *\r
+ * general multitasking concepts and FreeRTOS specifics. It presents and *\r
+ * explains numerous examples that are written using the FreeRTOS API. *\r
+ * Full source code for all the examples is provided in an accompanying *\r
+ * .zip file. *\r
+ * *\r
+ ***************************************************************************\r
+ ***************************************************************************\r
+\r
+ Please ensure to read the configuration and relevant port sections of the\r
+ online documentation.\r
+\r
+ http://www.FreeRTOS.org - Documentation, latest information, license and\r
+ contact details.\r
+\r
+ http://www.SafeRTOS.com - A version that is certified for use in safety\r
+ critical systems.\r
+\r
+ http://www.OpenRTOS.com - Commercial support, development, porting,\r
+ licensing and training services.\r
+*/\r
+\r
+/*\r
+ BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.\r
+*/\r
+\r
+/* Standard includes. */\r
+#include <stdlib.h>\r
+\r
+/* Scheduler includes. */\r
+#include "FreeRTOS.h"\r
+#include "queue.h"\r
+\r
+/* Demo application includes. */\r
+#include "serial.h"\r
+\r
+/* Atmel library includes. */\r
+#include <usart/usart.h>\r
+#include <aic/aic.h>\r
+#include <pmc/pmc.h>\r
+\r
+/*-----------------------------------------------------------*/\r
+\r
+/* Location of the COM0 registers. */\r
+#define serCOM0 ( ( AT91PS_USART ) AT91C_BASE_US0 )\r
+\r
+/* Interrupt control macros. */\r
+#define serINTERRUPT_LEVEL ( 5 )\r
+#define vInterruptOn() serCOM0->US_IER = ( AT91C_US_TXRDY | AT91C_US_RXRDY )\r
+#define vInterruptOff() serCOM0->US_IDR = AT91C_US_TXRDY\r
+\r
+/* Misc constants. */\r
+#define serINVALID_QUEUE ( ( xQueueHandle ) 0 )\r
+#define serHANDLE ( ( xComPortHandle ) 1 )\r
+#define serNO_BLOCK ( ( portTickType ) 0 )\r
+#define serNO_TIMEGUARD ( ( unsigned portLONG ) 0 )\r
+#define serNO_PERIPHERAL_B_SETUP ( ( unsigned portLONG ) 0 )\r
+\r
+\r
+/* Queues used to hold received characters, and characters waiting to be\r
+transmitted. */\r
+static xQueueHandle xRxedChars;\r
+static xQueueHandle xCharsForTx;\r
+\r
+/*-----------------------------------------------------------*/\r
+\r
+/* The interrupt service routine. */\r
+__arm void vSerialISR( void );\r
+\r
+/*-----------------------------------------------------------*/\r
+\r
+/*\r
+ * See the serial2.h header file.\r
+ */\r
+xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )\r
+{\r
+xComPortHandle xReturn = serHANDLE;\r
+\r
+ /* Create the queues used to hold Rx and Tx characters. */\r
+ xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );\r
+ xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );\r
+\r
+ /* If the queues were created correctly then setup the serial port\r
+ hardware. */\r
+ if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )\r
+ {\r
+ PMC_EnablePeripheral( AT91C_ID_US0 ); \r
+ portENTER_CRITICAL();\r
+ {\r
+ USART_Configure( serCOM0, ( AT91C_US_CHRL_8_BITS | AT91C_US_PAR_NONE ), ulWantedBaud, configCPU_CLOCK_HZ );\r
+\r
+ /* Enable Rx and Tx. */\r
+ USART_SetTransmitterEnabled( serCOM0, pdTRUE );\r
+ USART_SetReceiverEnabled( serCOM0, pdTRUE );\r
+\r
+ /* Enable the Rx interrupts. The Tx interrupts are not enabled\r
+ until there are characters to be transmitted. */\r
+ serCOM0->US_IER = AT91C_US_RXRDY;\r
+\r
+ /* Enable the interrupts in the AIC. */\r
+ AIC_ConfigureIT( AT91C_ID_US0, AT91C_AIC_PRIOR_LOWEST, ( void (*)( void ) ) vSerialISR );\r
+ AIC_EnableIT( AT91C_ID_US0 );\r
+ }\r
+ portEXIT_CRITICAL();\r
+ }\r
+ else\r
+ {\r
+ xReturn = ( xComPortHandle ) 0;\r
+ }\r
+\r
+ /* This demo file only supports a single port but we have to return\r
+ something to comply with the standard demo header file. */\r
+ return xReturn;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )\r
+{\r
+ /* The port handle is not required as this driver only supports one port. */\r
+ ( void ) pxPort;\r
+\r
+ /* Get the next character from the buffer. Return false if no characters\r
+ are available, or arrive before xBlockTime expires. */\r
+ if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )\r
+ {\r
+ return pdTRUE;\r
+ }\r
+ else\r
+ {\r
+ return pdFALSE;\r
+ }\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+void vSerialPutString( xComPortHandle pxPort, const signed portCHAR * const pcString, unsigned portSHORT usStringLength )\r
+{\r
+signed portCHAR *pxNext;\r
+\r
+ /* A couple of parameters that this port does not use. */\r
+ ( void ) usStringLength;\r
+ ( void ) pxPort;\r
+\r
+ /* NOTE: This implementation does not handle the queue being full as no\r
+ block time is used! */\r
+\r
+ /* The port handle is not required as this driver only supports UART0. */\r
+ ( void ) pxPort;\r
+\r
+ /* Send each character in the string, one at a time. */\r
+ pxNext = ( signed portCHAR * ) pcString;\r
+ while( *pxNext )\r
+ {\r
+ xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );\r
+ pxNext++;\r
+ }\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )\r
+{\r
+ /* Just to remove compiler warning. */\r
+ ( void ) pxPort;\r
+ \r
+ /* Place the character in the queue of characters to be transmitted. */\r
+ if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )\r
+ {\r
+ return pdFAIL;\r
+ }\r
+\r
+ /* Turn on the Tx interrupt so the ISR will remove the character from the\r
+ queue and send it. This does not need to be in a critical section as\r
+ if the interrupt has already removed the character the next interrupt\r
+ will simply turn off the Tx interrupt again. */\r
+ vInterruptOn();\r
+\r
+ return pdPASS;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+void vSerialClose( xComPortHandle xPort )\r
+{\r
+ /* Not supported as not required by the demo application. */\r
+ ( void ) xPort;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+/* Serial port ISR. This can cause a context switch so is not defined as a\r
+standard ISR using the __irq keyword. Instead a wrapper function is defined\r
+within serialISR.s79 which in turn calls this function. See the port\r
+documentation on the FreeRTOS.org website for more information. */\r
+__arm void vSerialISR( void )\r
+{\r
+unsigned portLONG ulStatus;\r
+signed portCHAR cChar;\r
+portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;\r
+\r
+ /* What caused the interrupt? */\r
+ ulStatus = serCOM0->US_CSR &= serCOM0->US_IMR;\r
+\r
+ if( ulStatus & AT91C_US_TXRDY )\r
+ {\r
+ /* The interrupt was caused by the THR becoming empty. Are there any\r
+ more characters to transmit? */\r
+ if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )\r
+ {\r
+ /* A character was retrieved from the queue so can be sent to the\r
+ THR now. */\r
+ serCOM0->US_THR = cChar;\r
+ }\r
+ else\r
+ {\r
+ /* Queue empty, nothing to send so turn off the Tx interrupt. */\r
+ vInterruptOff();\r
+ } \r
+ }\r
+\r
+ if( ulStatus & AT91C_US_RXRDY )\r
+ {\r
+ /* The interrupt was caused by a character being received. Grab the\r
+ character from the RHR and place it in the queue or received\r
+ characters. */\r
+ cChar = serCOM0->US_RHR;\r
+ xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );\r
+ }\r
+\r
+ /* If a task was woken by either a character being received or a character\r
+ being transmitted then we may need to switch to another task. */\r
+ portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );\r
+\r
+ /* End the interrupt in the AIC. */\r
+ AT91C_BASE_AIC->AIC_EOICR = 0;\r
+}\r
+\r
+\r
+\r
+\r
+ \r
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