blob: eda5bf914e9c868da74d1032baf4af7a70b396e9 [file] [log] [blame]
/*
FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd.
All rights reserved
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
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 from the following
link: http://www.freertos.org/a00114.html
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***************************************************************************
* *
* 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, a DOS
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Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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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.
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*/
/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR DEMO PURPOSES */
#include <stdlib.h>
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"
#include "serial.h"
/* Constants required to setup the serial control register. */
#define ser8_BIT_MODE ( ( unsigned char ) 0x40 )
#define serRX_ENABLE ( ( unsigned char ) 0x10 )
/* Constants to setup the timer used to generate the baud rate. */
#define serCLOCK_DIV_48 ( ( unsigned char ) 0x03 )
#define serUSE_PRESCALED_CLOCK ( ( unsigned char ) 0x10 )
#define ser8BIT_WITH_RELOAD ( ( unsigned char ) 0x20 )
#define serSMOD ( ( unsigned char ) 0x10 )
static QueueHandle_t xRxedChars;
static QueueHandle_t xCharsForTx;
data static unsigned portBASE_TYPE uxTxEmpty;
/*-----------------------------------------------------------*/
xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
unsigned long ulReloadValue;
const portFLOAT fBaudConst = ( portFLOAT ) configCPU_CLOCK_HZ * ( portFLOAT ) 2.0;
unsigned char ucOriginalSFRPage;
portENTER_CRITICAL();
{
ucOriginalSFRPage = SFRPAGE;
SFRPAGE = 0;
uxTxEmpty = pdTRUE;
/* Create the queues used by the com test task. */
xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) );
xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) );
/* Calculate the baud rate to use timer 1. */
ulReloadValue = ( unsigned long ) ( ( ( portFLOAT ) 256 - ( fBaudConst / ( portFLOAT ) ( 32 * ulWantedBaud ) ) ) + ( portFLOAT ) 0.5 );
/* Set timer one for desired mode of operation. */
TMOD &= 0x08;
TMOD |= ser8BIT_WITH_RELOAD;
SSTA0 |= serSMOD;
/* Set the reload and start values for the time. */
TL1 = ( unsigned char ) ulReloadValue;
TH1 = ( unsigned char ) ulReloadValue;
/* Setup the control register for standard n, 8, 1 - variable baud rate. */
SCON = ser8_BIT_MODE | serRX_ENABLE;
/* Enable the serial port interrupts */
ES = 1;
/* Start the timer. */
TR1 = 1;
SFRPAGE = ucOriginalSFRPage;
}
portEXIT_CRITICAL();
/* Unlike some ports, this serial code does not allow for more than one
com port. We therefore don't return a pointer to a port structure and can
instead just return NULL. */
return NULL;
}
/*-----------------------------------------------------------*/
void vSerialISR( void ) interrupt 4
{
char cChar;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
/* 8051 port interrupt routines MUST be placed within a critical section
if taskYIELD() is used within the ISR! */
portENTER_CRITICAL();
{
if( RI )
{
/* Get the character and post it on the queue of Rxed characters.
If the post causes a task to wake force a context switch if the woken task
has a higher priority than the task we have interrupted. */
cChar = SBUF;
RI = 0;
xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
}
if( TI )
{
if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == ( portBASE_TYPE ) pdTRUE )
{
/* Send the next character queued for Tx. */
SBUF = cChar;
}
else
{
/* Queue empty, nothing to send. */
uxTxEmpty = pdTRUE;
}
TI = 0;
}
if( xHigherPriorityTaskWoken )
{
portYIELD();
}
}
portEXIT_CRITICAL();
}
/*-----------------------------------------------------------*/
portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
{
/* There is only one port supported. */
( 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 ( portBASE_TYPE ) pdTRUE;
}
else
{
return ( portBASE_TYPE ) pdFALSE;
}
}
/*-----------------------------------------------------------*/
portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
{
portBASE_TYPE xReturn;
/* There is only one port supported. */
( void ) pxPort;
portENTER_CRITICAL();
{
if( uxTxEmpty == pdTRUE )
{
SBUF = cOutChar;
uxTxEmpty = pdFALSE;
xReturn = ( portBASE_TYPE ) pdTRUE;
}
else
{
xReturn = xQueueSend( xCharsForTx, &cOutChar, xBlockTime );
if( xReturn == ( portBASE_TYPE ) pdFALSE )
{
xReturn = ( portBASE_TYPE ) pdTRUE;
}
}
}
portEXIT_CRITICAL();
return xReturn;
}
/*-----------------------------------------------------------*/
void vSerialClose( xComPortHandle xPort )
{
/* Not implemented in this port. */
( void ) xPort;
}
/*-----------------------------------------------------------*/