| /* | |
| FreeRTOS V8.1.1 - Copyright (C) 2014 Real Time Engineers Ltd. | |
| All rights reserved | |
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| *************************************************************************** | |
| * * | |
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| *************************************************************************** | |
| This file is part of the FreeRTOS distribution. | |
| FreeRTOS is free software; you can redistribute it and/or modify it under | |
| the terms of the GNU General Public License (version 2) as published by the | |
| Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception. | |
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| >>! outside of the FreeRTOS kernel. !<< | |
| FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY | |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
| FOR A PARTICULAR PURPOSE. Full license text is available from the following | |
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| 1 tab == 4 spaces! | |
| *************************************************************************** | |
| * * | |
| * Having a problem? Start by reading the FAQ "My application does * | |
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| *************************************************************************** | |
| http://www.FreeRTOS.org - Documentation, books, training, latest versions, | |
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| mission critical applications that require provable dependability. | |
| 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 ); | |
| } | |
| } | |
| } | |
| /*-----------------------------------------------------------*/ | |