Demo/ARM9_STR91X_IAR/serial/serial.c

/*
	FreeRTOS V5.4.2 - Copyright (C) 2009 Real Time Engineers Ltd.

	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.
	**NOTE** The exception to the GPL is included to allow you to distribute a
	combined work that includes FreeRTOS without being obliged to provide the 
	source code for proprietary components outside of the FreeRTOS kernel.  
	Alternative commercial license and support terms are also available upon 
	request.  See the licensing section of http://www.FreeRTOS.org for full 
	license details.

	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.  See the GNU General Public License for
	more details.

	You should have received a copy of the GNU General Public License along
	with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
	Temple Place, Suite 330, Boston, MA  02111-1307  USA.


	***************************************************************************
	*                                                                         *
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	* See http://www.FreeRTOS.org/Documentation for details                   *
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	***************************************************************************

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	Please ensure to read the configuration and relevant port sections of the
	online documentation.

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*/

/*
	BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART1.
*/

/* Library includes. */
#include "91x_lib.h"

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "queue.h"
#include "semphr.h"

/* Demo application includes. */
#include "serial.h"
/*-----------------------------------------------------------*/

/* Misc defines. */
#define serINVALID_QUEUE				( ( xQueueHandle ) 0 )
#define serNO_BLOCK						( ( portTickType ) 0 )
#define serTX_BLOCK_TIME				( 40 / portTICK_RATE_MS )

/* Interrupt and status bit definitions. */
#define mainTXRIS 0x20	
#define mainRXRIS 0x50
#define serTX_FIFO_FULL 0x20
#define serCLEAR_ALL_INTERRUPTS 0x3ff
/*-----------------------------------------------------------*/

/* The queue used to hold received characters. */
static xQueueHandle xRxedChars;

/* The semaphore used to wake a task waiting for space to become available
in the FIFO. */
static xSemaphoreHandle xTxFIFOSemaphore;

/*-----------------------------------------------------------*/

/* UART interrupt handler. */
void UART1_IRQHandler( void );

/* The interrupt service routine - called from the assembly entry point. */
__arm void UART1_IRQHandler( void );

/*-----------------------------------------------------------*/

/* Flag to indicate whether or not a task is blocked waiting for space on
the FIFO. */
static portLONG lTaskWaiting = pdFALSE;

/*
 * See the serial2.h header file.
 */
xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
xComPortHandle xReturn;
UART_InitTypeDef xUART1_Init;
GPIO_InitTypeDef GPIO_InitStructure;
	
	/* Create the queues used to hold Rx characters. */
	xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
	
	/* Create the semaphore used to wake a task waiting for space to become
	available in the FIFO. */
	vSemaphoreCreateBinary( xTxFIFOSemaphore );

	/* If the queue/semaphore was created correctly then setup the serial port
	hardware. */
	if( ( xRxedChars != serINVALID_QUEUE ) && ( xTxFIFOSemaphore != serINVALID_QUEUE ) )
	{
		/* Pre take the semaphore so a task will block if it tries to access
		it. */
		xSemaphoreTake( xTxFIFOSemaphore, 0 );
		
		/* Configure the UART. */
		xUART1_Init.UART_WordLength = UART_WordLength_8D;
		xUART1_Init.UART_StopBits = UART_StopBits_1;
		xUART1_Init.UART_Parity = UART_Parity_No;
		xUART1_Init.UART_BaudRate = ulWantedBaud;
		xUART1_Init.UART_HardwareFlowControl = UART_HardwareFlowControl_None;
		xUART1_Init.UART_Mode = UART_Mode_Tx_Rx;
		xUART1_Init.UART_FIFO = UART_FIFO_Enable;

		/* Enable the UART1 Clock */
		SCU_APBPeriphClockConfig( __UART1, ENABLE );
		
		/* Enable the GPIO3 Clock */
		SCU_APBPeriphClockConfig( __GPIO3, ENABLE );
		
		/* Configure UART1_Rx pin GPIO3.2 */
		GPIO_InitStructure.GPIO_Direction = GPIO_PinInput;
		GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
		GPIO_InitStructure.GPIO_Type = GPIO_Type_PushPull ;
		GPIO_InitStructure.GPIO_IPConnected = GPIO_IPConnected_Enable;
		GPIO_InitStructure.GPIO_Alternate = GPIO_InputAlt1 ;
		GPIO_Init( GPIO3, &GPIO_InitStructure );
		
		/* Configure UART1_Tx pin GPIO3.3 */
		GPIO_InitStructure.GPIO_Direction = GPIO_PinOutput;
		GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
		GPIO_InitStructure.GPIO_Type = GPIO_Type_PushPull ;
		GPIO_InitStructure.GPIO_IPConnected = GPIO_IPConnected_Enable;
		GPIO_InitStructure.GPIO_Alternate = GPIO_OutputAlt2 ;
		GPIO_Init( GPIO3, &GPIO_InitStructure );
		
		
		portENTER_CRITICAL();
		{		
			/* Configure the UART itself. */
			UART_DeInit( UART1 );		
			UART_Init( UART1, &xUART1_Init );
			UART_ITConfig( UART1, UART_IT_Receive | UART_IT_Transmit, ENABLE );
			UART1->ICR = serCLEAR_ALL_INTERRUPTS;
			UART_LoopBackConfig( UART1, DISABLE );
			UART_IrDACmd( IrDA1, DISABLE );

			/* Configure the VIC for the UART interrupts. */			
			VIC_Config( UART1_ITLine, VIC_IRQ, 9 );
			VIC_ITCmd( UART1_ITLine, ENABLE );

			UART_Cmd( UART1, ENABLE );			
			lTaskWaiting = pdFALSE;
		}
		portEXIT_CRITICAL();
	}
	else
	{
		xReturn = ( xComPortHandle ) 0;
	}

	/* This demo file only supports a single port but we have to return
	something to comply with the standard demo header file. */
	return xReturn;
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
{
	/* The port handle is not required as this driver only supports one port. */
	( 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 portCHAR * const pcString, unsigned portSHORT usStringLength )
{
signed portCHAR *pxNext;

	/* A couple of parameters that this port does not use. */
	( void ) usStringLength;
	( void ) pxPort;

	/* NOTE: This implementation does not handle the queue being full as no
	block time is used! */

	/* The port handle is not required as this driver only supports UART1. */
	( void ) pxPort;

	/* Send each character in the string, one at a time. */
	pxNext = ( signed portCHAR * ) pcString;
	while( *pxNext )
	{
		xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
		pxNext++;
	}
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
{
portBASE_TYPE xReturn;

	portENTER_CRITICAL();
	{
		/* Can we write to the FIFO? */
		if( UART1->FR & serTX_FIFO_FULL )
		{
			/* Wait for the interrupt letting us know there is space on the
			FIFO.  It is ok to block in a critical section, interrupts will be
			enabled	for other tasks once we force a switch. */
			lTaskWaiting = pdTRUE;
			
			/* Just to be a bit different this driver uses a semaphore to
			block the sending task when the FIFO is full.  The standard COMTest
			task assumes a queue of adequate length exists so does not use
			a block time.  For this demo the block time is therefore hard
			coded. */
			xReturn = xSemaphoreTake( xTxFIFOSemaphore, serTX_BLOCK_TIME );
			if( xReturn )
			{
				UART1->DR = cOutChar;
			}
		}
		else
		{
			UART1->DR = cOutChar;
			xReturn = pdPASS;
		}
	}
	portEXIT_CRITICAL();

	return xReturn;
}
/*-----------------------------------------------------------*/

void vSerialClose( xComPortHandle xPort )
{
	/* Not supported as not required by the demo application. */
}
/*-----------------------------------------------------------*/

void UART1_IRQHandler( void )
{
signed portCHAR cChar;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

	while( UART1->RIS &	mainRXRIS )
	{
		/* The interrupt was caused by a character being received.  Grab the
		character from the DR and place it in the queue of received
		characters. */
		cChar = UART1->DR;
		xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
	}	
	
	if( UART1->RIS & mainTXRIS )
	{
		if( lTaskWaiting == pdTRUE )
		{
			/* This interrupt was caused by space becoming available on the Tx
			FIFO, wake any task that is waiting to post (if any). */
			xSemaphoreGiveFromISR( xTxFIFOSemaphore, &xHigherPriorityTaskWoken );
			lTaskWaiting = pdFALSE;
		}
		
		UART1->ICR = mainTXRIS;
	}

	/* If a task was woken by either a character being received or a character
	being transmitted then we may need to switch to another task. */
	portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
}