Danger-alarm/SOFTWARE-FreeRTOS/Common/Minimal/comtest.c
2024-06-03 16:27:41 +08:00

266 lines
10 KiB
C

/*
* FreeRTOS V202212.00
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/*
* This version of comtest. c is for use on systems that have limited stack
* space and no display facilities. The complete version can be found in
* the Demo/Common/Full directory.
*
* Creates two tasks that operate on an interrupt driven serial port. A
* loopback connector should be used so that everything that is transmitted is
* also received. The serial port does not use any flow control. On a
* standard 9way 'D' connector pins two and three should be connected together.
*
* The first task posts a sequence of characters to the Tx queue, toggling an
* LED on each successful post. At the end of the sequence it sleeps for a
* pseudo-random period before resending the same sequence.
*
* The UART Tx end interrupt is enabled whenever data is available in the Tx
* queue. The Tx end ISR removes a single character from the Tx queue and
* passes it to the UART for transmission.
*
* The second task blocks on the Rx queue waiting for a character to become
* available. When the UART Rx end interrupt receives a character it places
* it in the Rx queue, waking the second task. The second task checks that the
* characters removed from the Rx queue form the same sequence as those posted
* to the Tx queue, and toggles an LED for each correct character.
*
* The receiving task is spawned with a higher priority than the transmitting
* task. The receiver will therefore wake every time a character is
* transmitted so neither the Tx or Rx queue should ever hold more than a few
* characters.
*
*/
/* Scheduler include files. */
#include <stdlib.h>
#include "FreeRTOS.h"
#include "task.h"
/* Demo program include files. */
#include "serial.h"
#include "comtest.h"
#include "partest.h"
#define comSTACK_SIZE configMINIMAL_STACK_SIZE
#define comTX_LED_OFFSET ( 0 )
#define comRX_LED_OFFSET ( 1 )
#define comTOTAL_PERMISSIBLE_ERRORS ( 2 )
/* The Tx task will transmit the sequence of characters at a pseudo random
* interval. This is the maximum and minimum block time between sends. */
#define comTX_MAX_BLOCK_TIME ( ( TickType_t ) 0x96 )
#define comTX_MIN_BLOCK_TIME ( ( TickType_t ) 0x32 )
#define comOFFSET_TIME ( ( TickType_t ) 3 )
/* We should find that each character can be queued for Tx immediately and we
* don't have to block to send. */
#define comNO_BLOCK ( ( TickType_t ) 0 )
/* The Rx task will block on the Rx queue for a long period. */
#define comRX_BLOCK_TIME ( ( TickType_t ) 0xffff )
/* The sequence transmitted is from comFIRST_BYTE to and including comLAST_BYTE. */
#define comFIRST_BYTE ( 'A' )
#define comLAST_BYTE ( 'X' )
#define comBUFFER_LEN ( ( UBaseType_t ) ( comLAST_BYTE - comFIRST_BYTE ) + ( UBaseType_t ) 1 )
#define comINITIAL_RX_COUNT_VALUE ( 0 )
/* Handle to the com port used by both tasks. */
static xComPortHandle xPort = NULL;
/* The transmit task as described at the top of the file. */
static portTASK_FUNCTION_PROTO( vComTxTask, pvParameters );
/* The receive task as described at the top of the file. */
static portTASK_FUNCTION_PROTO( vComRxTask, pvParameters );
/* The LED that should be toggled by the Rx and Tx tasks. The Rx task will
* toggle LED ( uxBaseLED + comRX_LED_OFFSET). The Tx task will toggle LED
* ( uxBaseLED + comTX_LED_OFFSET ). */
static UBaseType_t uxBaseLED = 0;
/* Check variable used to ensure no error have occurred. The Rx task will
* increment this variable after every successfully received sequence. If at any
* time the sequence is incorrect the the variable will stop being incremented. */
static volatile UBaseType_t uxRxLoops = comINITIAL_RX_COUNT_VALUE;
/*-----------------------------------------------------------*/
void vAltStartComTestTasks( UBaseType_t uxPriority,
uint32_t ulBaudRate,
UBaseType_t uxLED )
{
/* Initialise the com port then spawn the Rx and Tx tasks. */
uxBaseLED = uxLED;
xSerialPortInitMinimal( ulBaudRate, comBUFFER_LEN );
/* The Tx task is spawned with a lower priority than the Rx task. */
xTaskCreate( vComTxTask, "COMTx", comSTACK_SIZE, NULL, uxPriority - 1, ( TaskHandle_t * ) NULL );
xTaskCreate( vComRxTask, "COMRx", comSTACK_SIZE, NULL, uxPriority, ( TaskHandle_t * ) NULL );
}
/*-----------------------------------------------------------*/
static portTASK_FUNCTION( vComTxTask, pvParameters )
{
char cByteToSend;
TickType_t xTimeToWait;
/* Just to stop compiler warnings. */
( void ) pvParameters;
for( ; ; )
{
/* Simply transmit a sequence of characters from comFIRST_BYTE to
* comLAST_BYTE. */
for( cByteToSend = comFIRST_BYTE; cByteToSend <= comLAST_BYTE; cByteToSend++ )
{
if( xSerialPutChar( xPort, cByteToSend, comNO_BLOCK ) == pdPASS )
{
vParTestToggleLED( uxBaseLED + comTX_LED_OFFSET );
}
}
/* Turn the LED off while we are not doing anything. */
vParTestSetLED( uxBaseLED + comTX_LED_OFFSET, pdFALSE );
/* We have posted all the characters in the string - wait before
* re-sending. Wait a pseudo-random time as this will provide a better
* test. */
xTimeToWait = xTaskGetTickCount() + comOFFSET_TIME;
/* Make sure we don't wait too long... */
xTimeToWait %= comTX_MAX_BLOCK_TIME;
/* ...but we do want to wait. */
if( xTimeToWait < comTX_MIN_BLOCK_TIME )
{
xTimeToWait = comTX_MIN_BLOCK_TIME;
}
vTaskDelay( xTimeToWait );
}
} /*lint !e715 !e818 pvParameters is required for a task function even if it is not referenced. */
/*-----------------------------------------------------------*/
static portTASK_FUNCTION( vComRxTask, pvParameters )
{
signed char cExpectedByte, cByteRxed;
BaseType_t xResyncRequired = pdFALSE, xErrorOccurred = pdFALSE;
/* Just to stop compiler warnings. */
( void ) pvParameters;
for( ; ; )
{
/* We expect to receive the characters from comFIRST_BYTE to
* comLAST_BYTE in an incrementing order. Loop to receive each byte. */
for( cExpectedByte = comFIRST_BYTE; cExpectedByte <= comLAST_BYTE; cExpectedByte++ )
{
/* Block on the queue that contains received bytes until a byte is
* available. */
if( xSerialGetChar( xPort, &cByteRxed, comRX_BLOCK_TIME ) )
{
/* Was this the byte we were expecting? If so, toggle the LED,
* otherwise we are out on sync and should break out of the loop
* until the expected character sequence is about to restart. */
if( cByteRxed == cExpectedByte )
{
vParTestToggleLED( uxBaseLED + comRX_LED_OFFSET );
}
else
{
xResyncRequired = pdTRUE;
break; /*lint !e960 Non-switch break allowed. */
}
}
}
/* Turn the LED off while we are not doing anything. */
vParTestSetLED( uxBaseLED + comRX_LED_OFFSET, pdFALSE );
/* Did we break out of the loop because the characters were received in
* an unexpected order? If so wait here until the character sequence is
* about to restart. */
if( xResyncRequired == pdTRUE )
{
while( cByteRxed != comLAST_BYTE )
{
/* Block until the next char is available. */
xSerialGetChar( xPort, &cByteRxed, comRX_BLOCK_TIME );
}
/* Note that an error occurred which caused us to have to resync.
* We use this to stop incrementing the loop counter so
* sAreComTestTasksStillRunning() will return false - indicating an
* error. */
xErrorOccurred++;
/* We have now resynced with the Tx task and can continue. */
xResyncRequired = pdFALSE;
}
else
{
if( xErrorOccurred < comTOTAL_PERMISSIBLE_ERRORS )
{
/* Increment the count of successful loops. As error
* occurring (i.e. an unexpected character being received) will
* prevent this counter being incremented for the rest of the
* execution. Don't worry about mutual exclusion on this
* variable - it doesn't really matter as we just want it
* to change. */
uxRxLoops++;
}
}
}
} /*lint !e715 !e818 pvParameters is required for a task function even if it is not referenced. */
/*-----------------------------------------------------------*/
BaseType_t xAreComTestTasksStillRunning( void )
{
BaseType_t xReturn;
/* If the count of successful reception loops has not changed than at
* some time an error occurred (i.e. a character was received out of sequence)
* and we will return false. */
if( uxRxLoops == comINITIAL_RX_COUNT_VALUE )
{
xReturn = pdFALSE;
}
else
{
xReturn = pdTRUE;
}
/* Reset the count of successful Rx loops. When this function is called
* again we expect this to have been incremented. */
uxRxLoops = comINITIAL_RX_COUNT_VALUE;
return xReturn;
}