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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.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
/*-----------------------------------------------------------
* Normally, a demo application would define ParTest (parallel port test)
* functions to write to an LED. In this case, four '*' symbols that are
* output to the debug printf() port are used to simulate LED outputs.
*-----------------------------------------------------------*/
/* Standard includes. */
#include <stdio.h>
#include <string.h>
/* Library includes. */
#include "lpc43xx_i2c.h"
/* Kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
/* Standard demo include. */
#include "partest.h"
/* The number of LED outputs. */
#define partstMAX_LEDS 4
/* Commands written to the PCA9502. */
#define partstIO_WRITE_COMMAND ( ( unsigned char ) ( 0x0BU << 3U ) )
#define partstIO_DIR_COMMAND ( ( unsigned char ) ( 0x0AU << 3U ) )
#define partstSLAVE_ADDRESS ( ( unsigned char ) ( 0x9AU >> 1U ) )
/* Just defines the length of the queue used to pass toggle commands to the I2C
gatekeeper task. */
#define partstLED_COMMAND_QUEUE_LENGTH ( 6 )
/*-----------------------------------------------------------*/
/*
* The LEDs are connected to an I2C port expander. Therefore, writing to an
* LED takes longer than might be expected if the LED was connected directly
* to a GPIO pin. As several tasks, and a timer, toggle LEDs, it is convenient
* to use a gatekeeper task to ensure access is both mutually exclusive and
* serialised. Tasks other than this gatekeeper task must not access the I2C
* port directly.
*/
static void prvI2CGateKeeperTask( void *pvParameters );
/* The queue used to communicate toggle commands with the I2C gatekeeper
task. */
static QueueHandle_t xI2CCommandQueue = NULL;
/*-----------------------------------------------------------*/
void vParTestInitialise( void )
{
unsigned char ucBuffer[ 2 ];
I2C_M_SETUP_Type xI2CMessage;
/* The LEDs are on an I2C IO expander. Initialise the I2C interface. */
I2C_Init( LPC_I2C0, 300000 );
I2C_Cmd( LPC_I2C0, ENABLE );
/* GPIO0-GPIO2 to output. */
ucBuffer[ 0 ] = partstIO_DIR_COMMAND;
ucBuffer[ 1 ] = 0x0f;
xI2CMessage.sl_addr7bit = partstSLAVE_ADDRESS;
xI2CMessage.tx_data = ucBuffer ;
xI2CMessage.tx_length = sizeof( ucBuffer );
xI2CMessage.rx_data = NULL;
xI2CMessage.rx_length = 0;
xI2CMessage.retransmissions_max = 3;
I2C_MasterTransferData( LPC_I2C0, &xI2CMessage, I2C_TRANSFER_POLLING );
/* Create the mutex used to guard access to the I2C bus. */
xI2CCommandQueue = xQueueCreate( partstLED_COMMAND_QUEUE_LENGTH, sizeof( unsigned char ) );
configASSERT( xI2CCommandQueue );
/* Create the I2C gatekeeper task itself. */
xTaskCreate( prvI2CGateKeeperTask, "I2C", configMINIMAL_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, NULL );
}
/*-----------------------------------------------------------*/
void vParTestToggleLED( unsigned long ulLED )
{
unsigned char ucLED = ( unsigned char ) ulLED;
/* Only the gatekeeper task will actually access the I2C port, so send the
toggle request to the gatekeeper task. A block time of zero is used as
this function is called by a software timer callback. */
xQueueSend( xI2CCommandQueue, &ucLED, 0UL );
}
/*-----------------------------------------------------------*/
static void prvI2CGateKeeperTask( void *pvParameters )
{
unsigned char ucBuffer[ 2 ], ucLED;
static unsigned char ucLEDState = 0xffU;
static I2C_M_SETUP_Type xI2CMessage; /* Static so it is not on the stack as this is called from task code. */
/* Just to remove compiler warnings. */
( void ) pvParameters;
for( ;; )
{
/* Wait for the next command. */
xQueueReceive( xI2CCommandQueue, &ucLED, portMAX_DELAY );
/* Only this task is allowed to touch the I2C port, so there is no need
for additional mutual exclusion. */
if( ucLED < partstMAX_LEDS )
{
/* Which bit is being manipulated? */
ucLED = 0x01 << ucLED;
/* Is the bit currently set or clear? */
if( ( ucLEDState & ucLED ) == 0U )
{
ucLEDState |= ucLED;
}
else
{
ucLEDState &= ~ucLED;
}
ucBuffer[ 0 ] = partstIO_WRITE_COMMAND;
ucBuffer[ 1 ] = ucLEDState;
xI2CMessage.sl_addr7bit = partstSLAVE_ADDRESS;
xI2CMessage.tx_data = ucBuffer ;
xI2CMessage.tx_length = sizeof( ucBuffer );
xI2CMessage.rx_data = NULL;
xI2CMessage.rx_length = 0;
xI2CMessage.retransmissions_max = 3;
I2C_MasterTransferData( LPC_I2C0, &xI2CMessage, I2C_TRANSFER_POLLING );
}
}
}
/*-----------------------------------------------------------*/
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