You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
304 lines
9.6 KiB
C
304 lines
9.6 KiB
C
/*
|
|
FreeRTOS V6.0.0 - Copyright (C) 2009 Real Time Engineers Ltd.
|
|
|
|
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 exception 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.
|
|
Alternative commercial license and support terms are also available upon
|
|
request. See the licensing section of http://www.FreeRTOS.org for full
|
|
license details.
|
|
|
|
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. See the GNU General Public License for
|
|
more details.
|
|
|
|
You should have received a copy of the GNU General Public License along
|
|
with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
|
|
Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
|
|
|
|
|
***************************************************************************
|
|
* *
|
|
* The FreeRTOS eBook and reference manual are available to purchase for a *
|
|
* small fee. Help yourself get started quickly while also helping the *
|
|
* FreeRTOS project! See http://www.FreeRTOS.org/Documentation for details *
|
|
* *
|
|
***************************************************************************
|
|
|
|
1 tab == 4 spaces!
|
|
|
|
Please ensure to read the configuration and relevant port sections of the
|
|
online documentation.
|
|
|
|
http://www.FreeRTOS.org - Documentation, latest information, license and
|
|
contact details.
|
|
|
|
http://www.SafeRTOS.com - A version that is certified for use in safety
|
|
critical systems.
|
|
|
|
http://www.OpenRTOS.com - Commercial support, development, porting,
|
|
licensing and training services.
|
|
*/
|
|
|
|
|
|
/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER.
|
|
*
|
|
* This file only supports UART 1
|
|
*/
|
|
|
|
/* Standard includes. */
|
|
#include <stdlib.h>
|
|
|
|
/* Scheduler includes. */
|
|
#include "FreeRTOS.h"
|
|
#include "queue.h"
|
|
#include "task.h"
|
|
|
|
/* Demo application includes. */
|
|
#include "serial.h"
|
|
|
|
/* Constants required to setup the hardware. */
|
|
#define serTX_AND_RX ( ( unsigned char ) 0x03 )
|
|
|
|
/* Misc. constants. */
|
|
#define serNO_BLOCK ( ( portTickType ) 0 )
|
|
|
|
/* Enable the UART Tx interrupt. */
|
|
#define vInterruptOn() IFG2 |= UTXIFG1
|
|
|
|
/* The queue used to hold received characters. */
|
|
static xQueueHandle xRxedChars;
|
|
|
|
/* The queue used to hold characters waiting transmission. */
|
|
static xQueueHandle xCharsForTx;
|
|
|
|
static volatile short sTHREEmpty;
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
|
|
{
|
|
unsigned long ulBaudRateCount;
|
|
|
|
/* Initialise the hardware. */
|
|
|
|
/* Generate the baud rate constants for the wanted baud rate. */
|
|
ulBaudRateCount = configCPU_CLOCK_HZ / ulWantedBaud;
|
|
|
|
portENTER_CRITICAL();
|
|
{
|
|
/* Create the queues used by the com test task. */
|
|
xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
|
|
xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
|
|
|
|
/* Reset UART. */
|
|
UCTL1 |= SWRST;
|
|
|
|
/* Set pin function. */
|
|
P4SEL |= serTX_AND_RX;
|
|
|
|
/* All other bits remain at zero for n, 8, 1 interrupt driven operation.
|
|
LOOPBACK MODE!*/
|
|
U1CTL |= CHAR + LISTEN;
|
|
U1TCTL |= SSEL1;
|
|
|
|
/* Setup baud rate low byte. */
|
|
U1BR0 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff );
|
|
|
|
/* Setup baud rate high byte. */
|
|
ulBaudRateCount >>= 8UL;
|
|
U1BR1 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff );
|
|
|
|
/* Enable ports. */
|
|
ME2 |= UTXE1 + URXE1;
|
|
|
|
/* Set. */
|
|
UCTL1 &= ~SWRST;
|
|
|
|
/* Nothing in the buffer yet. */
|
|
sTHREEmpty = pdTRUE;
|
|
|
|
/* Enable interrupts. */
|
|
IE2 |= URXIE1 + UTXIE1;
|
|
}
|
|
portEXIT_CRITICAL();
|
|
|
|
/* Unlike other 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;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
|
|
{
|
|
/* 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;
|
|
}
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
|
|
{
|
|
signed portBASE_TYPE xReturn;
|
|
|
|
/* Transmit a character. */
|
|
|
|
portENTER_CRITICAL();
|
|
{
|
|
if( sTHREEmpty == pdTRUE )
|
|
{
|
|
/* If sTHREEmpty is true then the UART Tx ISR has indicated that
|
|
there are no characters queued to be transmitted - so we can
|
|
write the character directly to the shift Tx register. */
|
|
sTHREEmpty = pdFALSE;
|
|
U1TXBUF = cOutChar;
|
|
xReturn = pdPASS;
|
|
}
|
|
else
|
|
{
|
|
/* sTHREEmpty is false, so there are still characters waiting to be
|
|
transmitted. We have to queue this character so it gets
|
|
transmitted in turn. */
|
|
|
|
/* Return false if after the block time there is no room on the Tx
|
|
queue. It is ok to block inside a critical section as each task
|
|
maintains it's own critical section status. */
|
|
xReturn = xQueueSend( xCharsForTx, &cOutChar, xBlockTime );
|
|
|
|
/* Depending on queue sizing and task prioritisation: While we
|
|
were blocked waiting to post on the queue interrupts were not
|
|
disabled. It is possible that the serial ISR has emptied the
|
|
Tx queue, in which case we need to start the Tx off again
|
|
writing directly to the Tx register. */
|
|
if( ( sTHREEmpty == pdTRUE ) && ( xReturn == pdPASS ) )
|
|
{
|
|
/* Get back the character we just posted. */
|
|
xQueueReceive( xCharsForTx, &cOutChar, serNO_BLOCK );
|
|
sTHREEmpty = pdFALSE;
|
|
U1TXBUF = cOutChar;
|
|
}
|
|
}
|
|
}
|
|
portEXIT_CRITICAL();
|
|
|
|
return pdPASS;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if configINTERRUPT_EXAMPLE_METHOD == 1
|
|
|
|
/*
|
|
* UART RX interrupt service routine.
|
|
*/
|
|
void vRxISR( void ) __interrupt[ UART1RX_VECTOR ]
|
|
{
|
|
signed char cChar;
|
|
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
|
|
|
|
/* Get the character from the UART and post it on the queue of Rxed
|
|
characters. */
|
|
cChar = U1RXBUF;
|
|
|
|
xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
|
|
|
|
if( xHigherPriorityTaskWoken )
|
|
{
|
|
/*If the post causes a task to wake force a context switch
|
|
as the woken task may have a higher priority than the task we have
|
|
interrupted. */
|
|
taskYIELD();
|
|
}
|
|
|
|
/* Make sure any low power mode bits are clear before leaving the ISR. */
|
|
__bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
|
|
* UART Tx interrupt service routine.
|
|
*/
|
|
void vTxISR( void ) __interrupt[ UART1TX_VECTOR ]
|
|
{
|
|
signed char cChar;
|
|
portBASE_TYPE xTaskWoken = pdFALSE;
|
|
|
|
/* The previous character has been transmitted. See if there are any
|
|
further characters waiting transmission. */
|
|
|
|
if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
|
|
{
|
|
/* There was another character queued - transmit it now. */
|
|
U1TXBUF = cChar;
|
|
}
|
|
else
|
|
{
|
|
/* There were no other characters to transmit. */
|
|
sTHREEmpty = pdTRUE;
|
|
}
|
|
|
|
/* Make sure any low power mode bits are clear before leaving the ISR. */
|
|
__bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#elif configINTERRUPT_EXAMPLE_METHOD == 2
|
|
|
|
/* This is a standard C function as an assembly file wrapper is used as an
|
|
interrupt entry point. */
|
|
void vRxISR( void )
|
|
{
|
|
signed char cChar;
|
|
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
|
|
|
|
/* Get the character from the UART and post it on the queue of Rxed
|
|
characters. */
|
|
cChar = U1RXBUF;
|
|
|
|
xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
|
|
|
|
/*If the post causes a task to wake force a context switch
|
|
as the woken task may have a higher priority than the task we have
|
|
interrupted. */
|
|
portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/* This is a standard C function as an assembly file wrapper is used as an
|
|
interrupt entry point. */
|
|
void vTxISR( void )
|
|
{
|
|
signed char cChar;
|
|
portBASE_TYPE xTaskWoken = pdFALSE;
|
|
|
|
/* The previous character has been transmitted. See if there are any
|
|
further characters waiting transmission. */
|
|
|
|
if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
|
|
{
|
|
/* There was another character queued - transmit it now. */
|
|
U1TXBUF = cChar;
|
|
}
|
|
else
|
|
{
|
|
/* There were no other characters to transmit. */
|
|
sTHREEmpty = pdTRUE;
|
|
}
|
|
}
|
|
|
|
#endif /* configINTERRUPT_EXAMPLE_METHOD */
|
|
/*-----------------------------------------------------------*/
|