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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [AVR_ATMega323_IAR/] [serial/] [serial.c] - Blame information for rev 664

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1 589 jeremybenn
/*
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    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
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    ***************************************************************************
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    *                                                                         *
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    * If you are:                                                             *
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    *                                                                         *
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    *    + New to FreeRTOS,                                                   *
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    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
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    *    + Looking for basic training,                                        *
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    *    + Wanting to improve your FreeRTOS skills and productivity           *
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    *                                                                         *
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    * then take a look at the FreeRTOS books - available as PDF or paperback  *
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    *                                                                         *
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    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
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    *                  http://www.FreeRTOS.org/Documentation                  *
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    *                                                                         *
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    * A pdf reference manual is also available.  Both are usually delivered   *
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    * to your inbox within 20 minutes to two hours when purchased between 8am *
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    * and 8pm GMT (although please allow up to 24 hours in case of            *
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    * exceptional circumstances).  Thank you for your support!                *
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    *                                                                         *
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    ***************************************************************************
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    This file is part of the FreeRTOS distribution.
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    FreeRTOS is free software; you can redistribute it and/or modify it under
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    the terms of the GNU General Public License (version 2) as published by the
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    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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    ***NOTE*** The exception to the GPL is included to allow you to distribute
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    a combined work that includes FreeRTOS without being obliged to provide the
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    source code for proprietary components outside of the FreeRTOS kernel.
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    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
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    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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    more details. You should have received a copy of the GNU General Public
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    License and the FreeRTOS license exception along with FreeRTOS; if not it
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    can be viewed here: http://www.freertos.org/a00114.html and also obtained
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    by writing to Richard Barry, contact details for whom are available on the
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    FreeRTOS WEB site.
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    1 tab == 4 spaces!
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    http://www.FreeRTOS.org - Documentation, latest information, license and
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    contact details.
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    http://www.SafeRTOS.com - A version that is certified for use in safety
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    critical systems.
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    http://www.OpenRTOS.com - Commercial support, development, porting,
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    licensing and training services.
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*/
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/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR IAR AVR PORT. */
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#include <stdlib.h>
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#include "FreeRTOS.h"
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#include "queue.h"
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#include "task.h"
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#include "serial.h"
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#define serBAUD_DIV_CONSTANT                    ( ( unsigned long ) 16 )
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/* Constants for writing to UCSRB. */
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#define serRX_INT_ENABLE                                ( ( unsigned char ) 0x80 )
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#define serRX_ENABLE                                    ( ( unsigned char ) 0x10 )
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#define serTX_ENABLE                                    ( ( unsigned char ) 0x08 )
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#define serTX_INT_ENABLE                                ( ( unsigned char ) 0x20 )
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/* Constants for writing to UCSRC. */
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#define serUCSRC_SELECT                                 ( ( unsigned char ) 0x80 )
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#define serEIGHT_DATA_BITS                              ( ( unsigned char ) 0x06 )
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static xQueueHandle xRxedChars;
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static xQueueHandle xCharsForTx;
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#define vInterruptOn()                                                                          \
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{                                                                                                                       \
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        unsigned char ucByte;                                                           \
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                                                                                                                        \
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        ucByte = UCSRB;                                                                                 \
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        ucByte |= serTX_INT_ENABLE;                                                             \
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        outb( UCSRB, ucByte );                                                                  \
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}
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/*-----------------------------------------------------------*/
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#define vInterruptOff()                                                                         \
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{                                                                                                                       \
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        unsigned char ucByte;                                                           \
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                                                                                                                        \
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        ucByte = UCSRB;                                                                                 \
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        ucByte &= ~serTX_INT_ENABLE;                                                    \
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        outb( UCSRB, ucByte );                                                                  \
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}
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/*-----------------------------------------------------------*/
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xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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{
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unsigned long ulBaudRateCounter;
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unsigned char ucByte;
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        portENTER_CRITICAL();
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        {
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                /* Create the queues used by the com test task. */
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                xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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                xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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                /* Calculate the baud rate register value from the equation in the
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                data sheet. */
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                ulBaudRateCounter = ( configCPU_CLOCK_HZ / ( serBAUD_DIV_CONSTANT * ulWantedBaud ) ) - ( unsigned long ) 1;
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                /* Set the baud rate. */
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                ucByte = ( unsigned char ) ( ulBaudRateCounter & ( unsigned long ) 0xff );
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                outb( UBRRL, ucByte );
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                ulBaudRateCounter >>= ( unsigned long ) 8;
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                ucByte = ( unsigned char ) ( ulBaudRateCounter & ( unsigned long ) 0xff );
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                outb( UBRRH, ucByte );
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                /* Enable the Rx interrupt.  The Tx interrupt will get enabled
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                later. Also enable the Rx and Tx. */
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                outb( UCSRB, serRX_INT_ENABLE | serRX_ENABLE | serTX_ENABLE );
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                /* Set the data bits to 8. */
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                outb( UCSRC, serUCSRC_SELECT | serEIGHT_DATA_BITS );
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        }
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        portEXIT_CRITICAL();
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        /* Unlike other ports, this serial code does not allow for more than one
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        com port.  We therefore don't return a pointer to a port structure and can
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        instead just return NULL. */
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        return NULL;
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
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{
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        /* Get the next character from the buffer.  Return false if no characters
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        are available, or arrive before xBlockTime expires. */
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        if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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        {
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                return pdTRUE;
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        }
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        else
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        {
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                return pdFALSE;
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        }
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
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{
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        /* Return false if after the block time there is no room on the Tx queue. */
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        if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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        {
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                return pdFAIL;
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        }
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        vInterruptOn();
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        return pdPASS;
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}
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/*-----------------------------------------------------------*/
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void vSerialClose( xComPortHandle xPort )
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{
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unsigned char ucByte;
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        /* Turn off the interrupts.  We may also want to delete the queues and/or
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        re-install the original ISR. */
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        portENTER_CRITICAL();
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        {
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                vInterruptOff();
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                ucByte = UCSRB;
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                ucByte &= ~serRX_INT_ENABLE;
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                outb( UCSRB, ucByte );
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        }
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        portEXIT_CRITICAL();
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}
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/*-----------------------------------------------------------*/
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__interrupt void SIG_UART_RECV( void )
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{
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signed char ucChar, xHigherPriorityTaskWoken = pdFALSE;
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        /* Get the character and post it on the queue of Rxed characters.
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        If the post causes a task to wake force a context switch as the woken task
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        may have a higher priority than the task we have interrupted. */
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        ucChar = UDR;
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        xQueueSendFromISR( xRxedChars, &ucChar, &xHigherPriorityTaskWoken );
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        if( xHigherPriorityTaskWoken != pdFALSE )
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        {
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                taskYIELD();
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        }
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}
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/*-----------------------------------------------------------*/
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__interrupt void SIG_UART_DATA( void )
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{
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signed char cChar, cTaskWoken = pdFALSE;
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        if( xQueueReceiveFromISR( xCharsForTx, &cChar, &cTaskWoken ) == pdTRUE )
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        {
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                /* Send the next character queued for Tx. */
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                outb( UDR, cChar );
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        }
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        else
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        {
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                /* Queue empty, nothing to send. */
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                vInterruptOff();
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        }
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}
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