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/*
* FreeRTOS V202107.00
* 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
*
*/
/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR IAR AVR PORT. */
#include <stdlib.h>
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"
#include "serial.h"
#include <avr/interrupt.h>
#define USART_BAUD_RATE(BAUD_RATE) ((float)(configCPU_CLOCK_HZ * 64 / (16 * (float)BAUD_RATE)) + 0.5)
static QueueHandle_t xRxedChars;
static QueueHandle_t xCharsForTx;
#define vInterruptOn() USART3.CTRLA |= (1 << USART_DREIE_bp)
#define vInterruptOff() USART3.CTRLA &= ~(1 << USART_DREIE_bp)
xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
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 ) );
USART3.BAUD = (uint16_t)USART_BAUD_RATE(ulWantedBaud); /* set baud rate register */
USART3.CTRLA = 1 << USART_LBME_bp /* Loop-back Mode Enable: enabled */
| USART_RS485_OFF_gc /* RS485 Mode disabled */
| 1 << USART_RXCIE_bp; /* Receive Complete Interrupt Enable: enabled */
USART3.CTRLB = 1 << USART_RXEN_bp /* Receiver enable: enabled */
| USART_RXMODE_NORMAL_gc /* Normal mode */
| 1 << USART_TXEN_bp; /* Transmitter Enable: enabled */
}
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, TickType_t 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, TickType_t xBlockTime )
{
/* Return false if after the block time there is no room on the Tx queue. */
if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
{
return pdFAIL;
}
vInterruptOn();
return pdPASS;
}
/*-----------------------------------------------------------*/
void vSerialClose( xComPortHandle xPort )
{
/* Turn off the interrupts. We may also want to delete the queues and/or
re-install the original ISR. */
portENTER_CRITICAL();
{
vInterruptOff();
USART3.CTRLB &= ~(1 << USART_RXEN_bp);
}
portEXIT_CRITICAL();
}
/*-----------------------------------------------------------*/
ISR(USART3_RXC_vect)
{
signed char ucChar, xHigherPriorityTaskWoken = pdFALSE;
/* Get the character and post it on the queue of Rxed characters.
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. */
ucChar = USART3.RXDATAL;
xQueueSendFromISR( xRxedChars, &ucChar, &xHigherPriorityTaskWoken );
if( xHigherPriorityTaskWoken != pdFALSE )
{
portYIELD_FROM_ISR();
}
}
ISR(USART3_DRE_vect)
{
signed char cChar, cTaskWoken = pdFALSE;
if( xQueueReceiveFromISR( xCharsForTx, &cChar, &cTaskWoken ) == pdTRUE )
{
/* Send the next character queued for Tx. */
USART3.TXDATAL = cChar;
}
else
{
/* Queue empty, nothing to send. */
vInterruptOff();
}
}
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