mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-05-22 04:59:03 -04:00
208 lines
7 KiB
C
208 lines
7 KiB
C
/*
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* FreeRTOS Kernel V10.2.1
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* Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* http://www.FreeRTOS.org
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* http://aws.amazon.com/freertos
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*
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* 1 tab == 4 spaces!
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*/
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/* Basic interrupt driven serial port driver for uart1.
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*/
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/* Standard includes. */
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#include <stdlib.h>
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/* Kernel includes. */
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#include "FreeRTOS.h"
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#include "queue.h"
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#include "task.h"
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/* Demo application includes. */
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#include <machine/uart.h>
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#include <machine/ic.h>
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#include "serial.h"
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/*-----------------------------------------------------------*/
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#define comBLOCK_RETRY_TIME 10
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/*-----------------------------------------------------------*/
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/* The interrupt handlers are naked functions that call C handlers. The C
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handlers are marked as noinline to ensure they work correctly when the
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optimiser is on. */
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void interrupt5_handler( void ) __attribute__((naked));
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static void prvTxHandler( void ) __attribute__((noinline));
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void interrupt6_handler( void ) __attribute__((naked));
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static void prvRxHandler( void ) __attribute__((noinline));
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/*-----------------------------------------------------------*/
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/* Queues used to hold received characters, and characters waiting to be
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transmitted. */
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static QueueHandle_t xRxedChars;
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static QueueHandle_t xCharsForTx;
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/*-----------------------------------------------------------*/
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xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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{
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/* Create the queues used to hold Rx and Tx characters. */
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xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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if( ( xRxedChars ) && ( xCharsForTx ) )
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{
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/* Set up interrupts */
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/* tx interrupt will be enabled when we need to send something */
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uart1->tx_mask = 0;
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uart1->rx_mask = 1;
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irq[IRQ_UART1_TX].ien = 1;
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irq[IRQ_UART1_RX].ien = 1;
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}
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return ( xComPortHandle ) 0;
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
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{
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/* The port handle is not required as this driver only supports uart1. */
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(void) pxPort;
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/* Get the next character from the buffer. Return false if no characters
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are available, or arrive before xBlockTime expires. */
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if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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{
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return pdTRUE;
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}
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else
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{
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return pdFALSE;
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}
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}
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/*-----------------------------------------------------------*/
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void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
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{
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int i;
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signed char *pChNext;
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/* Send each character in the string, one at a time. */
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pChNext = ( signed char * )pcString;
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for( i = 0; i < usStringLength; i++ )
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{
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/* Block until character has been transmitted. */
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while( xSerialPutChar( pxPort, *pChNext, comBLOCK_RETRY_TIME ) != pdTRUE ); pChNext++;
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}
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
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{
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( void ) pxPort;
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/* Place the character in the queue of characters to be transmitted. */
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if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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{
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return pdFAIL;
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}
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/* Turn on the Tx interrupt so the ISR will remove the character from the
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queue and send it. This does not need to be in a critical section as
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if the interrupt has already removed the character the next interrupt
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will simply turn off the Tx interrupt again. */
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uart1->tx_mask = 1;
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return pdPASS;
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}
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/*-----------------------------------------------------------*/
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void vSerialClose( xComPortHandle xPort )
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{
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/* Not supported as not required by the demo application. */
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( void ) xPort;
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}
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/*-----------------------------------------------------------*/
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/* UART Tx interrupt handler. */
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void interrupt5_handler( void )
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{
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/* This is a naked function. */
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portSAVE_CONTEXT();
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prvTxHandler();
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portRESTORE_CONTEXT();
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}
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/*-----------------------------------------------------------*/
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static void prvTxHandler( void )
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{
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signed char cChar;
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portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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/* The interrupt was caused by the transmit fifo having space for at least one
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character. Are there any more characters to transmit? */
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if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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{
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/* A character was retrieved from the queue so can be sent to the uart now. */
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uart1->tx_data = cChar;
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}
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else
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{
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/* Queue empty, nothing to send so turn off the Tx interrupt. */
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uart1->tx_mask = 0;
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}
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/* If an event caused a task to unblock then we call "Yield from ISR" to
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ensure that the unblocked task is the task that executes when the interrupt
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completes if the unblocked task has a priority higher than the interrupted
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task. */
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portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
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}
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/*-----------------------------------------------------------*/
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/* UART Rx interrupt. */
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void interrupt6_handler( void )
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{
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portSAVE_CONTEXT();
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prvRxHandler();
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portRESTORE_CONTEXT();
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}
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/*-----------------------------------------------------------*/
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static void prvRxHandler( void )
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{
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signed char cChar;
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portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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/* The interrupt was caused by the receiver getting data. */
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cChar = uart1->rx_data;
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xQueueSendFromISR(xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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/* If an event caused a task to unblock then we call "Yield from ISR" to
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ensure that the unblocked task is the task that executes when the interrupt
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completes if the unblocked task has a priority higher than the interrupted
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task. */
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portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
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}
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/*-----------------------------------------------------------*/
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