/* | |
* FreeRTOS Kernel V10.3.0 | |
* 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. | |
* | |
* http://www.FreeRTOS.org | |
* http://aws.amazon.com/freertos | |
* | |
* 1 tab == 4 spaces! | |
*/ | |
/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER for port 1. | |
Note that this driver is written to test the RTOS port and is not intended | |
to represent an optimised solution. */ | |
/* Processor Expert generated includes. */ | |
#include "com0.h" | |
/* Scheduler include files. */ | |
#include "FreeRTOS.h" | |
#include "queue.h" | |
#include "task.h" | |
/* Demo application include files. */ | |
#include "serial.h" | |
/* The queues used to communicate between the task code and the interrupt | |
service routines. */ | |
static QueueHandle_t xRxedChars; | |
static QueueHandle_t xCharsForTx; | |
/* Interrupt identification bits. */ | |
#define serOVERRUN_INTERRUPT ( 0x08 ) | |
#define serRX_INTERRUPT ( 0x20 ) | |
#define serTX_INTERRUPT ( 0x80 ) | |
/*-----------------------------------------------------------*/ | |
/* | |
* Initialise port for interrupt driven communications. | |
*/ | |
xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) | |
{ | |
/* Hardware setup is performed by the Processor Expert generated code. | |
This function just creates the queues used to communicate between the | |
interrupt code and the task code - then sets the required baud rate. */ | |
xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); | |
xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); | |
COM0_SetBaudRateMode( ( char ) ulWantedBaud ); | |
return NULL; | |
} | |
/*-----------------------------------------------------------*/ | |
signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime ) | |
{ | |
/* Get the next character from the buffer queue. 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 ) | |
{ | |
/* Place the character in the queue of characters to be transmitted. */ | |
if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS ) | |
{ | |
return pdFAIL; | |
} | |
/* Turn on the Tx interrupt so the ISR will remove the character from the | |
queue and send it. This does not need to be in a critical section as | |
if the interrupt has already removed the character the next interrupt | |
will simply turn off the Tx interrupt again. */ | |
SCI0CR2_SCTIE = 1;; | |
return pdPASS; | |
} | |
/*-----------------------------------------------------------*/ | |
void vSerialClose( xComPortHandle xPort ) | |
{ | |
/* Not supported. */ | |
( void ) xPort; | |
} | |
/*-----------------------------------------------------------*/ | |
/* | |
* Interrupt service routine for the serial port. Must be in non-banked | |
* memory. | |
*/ | |
#pragma CODE_SEG __NEAR_SEG NON_BANKED | |
__interrupt void vCOM0_ISR( void ) | |
{ | |
volatile unsigned char ucByte, ucStatus; | |
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; | |
/* What caused the interrupt? */ | |
ucStatus = SCI0SR1; | |
if( ucStatus & serOVERRUN_INTERRUPT ) | |
{ | |
/* The interrupt was caused by an overrun. Clear the error by reading | |
the data register. */ | |
ucByte = SCI0DRL; | |
} | |
if( ucStatus & serRX_INTERRUPT ) | |
{ | |
/* The interrupt was caused by a character being received. | |
Read the received byte. */ | |
ucByte = SCI0DRL; | |
/* Post the character onto the queue of received characters - noting | |
whether or not this wakes a task. */ | |
xQueueSendFromISR( xRxedChars, ( void * ) &ucByte, &xHigherPriorityTaskWoken ); | |
} | |
if( ( ucStatus & serTX_INTERRUPT ) && ( SCI0CR2_SCTIE ) ) | |
{ | |
/* The interrupt was caused by a character being transmitted. */ | |
if( xQueueReceiveFromISR( xCharsForTx, ( void * ) &ucByte, &xHigherPriorityTaskWoken ) == pdTRUE ) | |
{ | |
/* Clear the SCRF bit. */ | |
SCI0DRL = ucByte; | |
} | |
else | |
{ | |
/* Disable transmit interrupt */ | |
SCI0CR2_SCTIE = 0; | |
} | |
} | |
if( xHigherPriorityTaskWoken ) | |
{ | |
portYIELD(); | |
} | |
} | |
#pragma CODE_SEG DEFAULT | |