/* | |
* 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 uart1. | |
*/ | |
/* Standard includes. */ | |
#include <stdlib.h> | |
/* Kernel includes. */ | |
#include "FreeRTOS.h" | |
#include "queue.h" | |
#include "task.h" | |
/* Demo application includes. */ | |
#include <machine/uart.h> | |
#include <machine/ic.h> | |
#include "serial.h" | |
/*-----------------------------------------------------------*/ | |
#define comBLOCK_RETRY_TIME 10 | |
/*-----------------------------------------------------------*/ | |
/* The interrupt handlers are naked functions that call C handlers. The C | |
handlers are marked as noinline to ensure they work correctly when the | |
optimiser is on. */ | |
void interrupt5_handler( void ) __attribute__((naked)); | |
static void prvTxHandler( void ) __attribute__((noinline)); | |
void interrupt6_handler( void ) __attribute__((naked)); | |
static void prvRxHandler( void ) __attribute__((noinline)); | |
/*-----------------------------------------------------------*/ | |
/* Queues used to hold received characters, and characters waiting to be | |
transmitted. */ | |
static QueueHandle_t xRxedChars; | |
static QueueHandle_t xCharsForTx; | |
/*-----------------------------------------------------------*/ | |
xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) | |
{ | |
/* Create the queues used to hold Rx and Tx characters. */ | |
xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); | |
xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); | |
if( ( xRxedChars ) && ( xCharsForTx ) ) | |
{ | |
/* Set up interrupts */ | |
/* tx interrupt will be enabled when we need to send something */ | |
uart1->tx_mask = 0; | |
uart1->rx_mask = 1; | |
irq[IRQ_UART1_TX].ien = 1; | |
irq[IRQ_UART1_RX].ien = 1; | |
} | |
return ( xComPortHandle ) 0; | |
} | |
/*-----------------------------------------------------------*/ | |
signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime ) | |
{ | |
/* The port handle is not required as this driver only supports uart1. */ | |
(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 pdTRUE; | |
} | |
else | |
{ | |
return pdFALSE; | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength ) | |
{ | |
int i; | |
signed char *pChNext; | |
/* Send each character in the string, one at a time. */ | |
pChNext = ( signed char * )pcString; | |
for( i = 0; i < usStringLength; i++ ) | |
{ | |
/* Block until character has been transmitted. */ | |
while( xSerialPutChar( pxPort, *pChNext, comBLOCK_RETRY_TIME ) != pdTRUE ); pChNext++; | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime ) | |
{ | |
( void ) pxPort; | |
/* 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. */ | |
uart1->tx_mask = 1; | |
return pdPASS; | |
} | |
/*-----------------------------------------------------------*/ | |
void vSerialClose( xComPortHandle xPort ) | |
{ | |
/* Not supported as not required by the demo application. */ | |
( void ) xPort; | |
} | |
/*-----------------------------------------------------------*/ | |
/* UART Tx interrupt handler. */ | |
void interrupt5_handler( void ) | |
{ | |
/* This is a naked function. */ | |
portSAVE_CONTEXT(); | |
prvTxHandler(); | |
portRESTORE_CONTEXT(); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvTxHandler( void ) | |
{ | |
signed char cChar; | |
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; | |
/* The interrupt was caused by the transmit fifo having space for at least one | |
character. Are there any more characters to transmit? */ | |
if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE ) | |
{ | |
/* A character was retrieved from the queue so can be sent to the uart now. */ | |
uart1->tx_data = cChar; | |
} | |
else | |
{ | |
/* Queue empty, nothing to send so turn off the Tx interrupt. */ | |
uart1->tx_mask = 0; | |
} | |
/* If an event caused a task to unblock then we call "Yield from ISR" to | |
ensure that the unblocked task is the task that executes when the interrupt | |
completes if the unblocked task has a priority higher than the interrupted | |
task. */ | |
portYIELD_FROM_ISR( xHigherPriorityTaskWoken ); | |
} | |
/*-----------------------------------------------------------*/ | |
/* UART Rx interrupt. */ | |
void interrupt6_handler( void ) | |
{ | |
portSAVE_CONTEXT(); | |
prvRxHandler(); | |
portRESTORE_CONTEXT(); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvRxHandler( void ) | |
{ | |
signed char cChar; | |
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; | |
/* The interrupt was caused by the receiver getting data. */ | |
cChar = uart1->rx_data; | |
xQueueSendFromISR(xRxedChars, &cChar, &xHigherPriorityTaskWoken ); | |
/* If an event caused a task to unblock then we call "Yield from ISR" to | |
ensure that the unblocked task is the task that executes when the interrupt | |
completes if the unblocked task has a priority higher than the interrupted | |
task. */ | |
portYIELD_FROM_ISR( xHigherPriorityTaskWoken ); | |
} | |
/*-----------------------------------------------------------*/ | |