Subversion Repositories openrisc_2011-10-31

/*

    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.

    ***************************************************************************

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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.

    ***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.

    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

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    by writing to Richard Barry, contact details for whom are available on the

    FreeRTOS WEB site.

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*/

/*

        BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.

*/

/* Library includes. */

#include "75x_uart.h"

#include "75x_gpio.h"

#include "75x_eic.h"

#include "75x_mrcc.h"

/* Scheduler includes. */

#include "FreeRTOS.h"

#include "queue.h"

/* Demo application includes. */

#include "serial.h"

#define serINVALID_QUEUE                                ( ( xQueueHandle ) 0 )

#define serNO_BLOCK                                             ( ( portTickType ) 0 )

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

/* Queues used to hold received characters, and characters waiting to be

transmitted. */

static xQueueHandle xRxedChars;

static xQueueHandle xCharsForTx;

static volatile portBASE_TYPE xQueueEmpty = pdTRUE;

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

/* The interrupt service routine - called from the assembly entry point. */

__arm void vSerialISR( void );

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

/*

 * See the serial2.h header file.

 */

xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )

{

xComPortHandle xReturn;

UART_InitTypeDef UART_InitStructure;

GPIO_InitTypeDef GPIO_InitStructure;

EIC_IRQInitTypeDef  EIC_IRQInitStructure;

        /* 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 the queues were created correctly then setup the serial port

        hardware. */

        if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )

        {

                portENTER_CRITICAL();

                {

                        /* Enable the UART0 Clock. */

                        MRCC_PeripheralClockConfig( MRCC_Peripheral_UART0, ENABLE );

                        /* Configure the UART0_Tx as alternate function */

                        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

                        GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_11;

                        GPIO_Init(GPIO0, &GPIO_InitStructure);

                        /* Configure the UART0_Rx as input floating */

                        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

                        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;

                        GPIO_Init(GPIO0, &GPIO_InitStructure);

                        /* Configure UART0. */

                        UART_InitStructure.UART_WordLength = UART_WordLength_8D;

                        UART_InitStructure.UART_StopBits = UART_StopBits_1;

                        UART_InitStructure.UART_Parity = UART_Parity_No;

                        UART_InitStructure.UART_BaudRate = ulWantedBaud;

                        UART_InitStructure.UART_HardwareFlowControl = UART_HardwareFlowControl_None;

                        UART_InitStructure.UART_Mode = UART_Mode_Tx_Rx;

                        UART_InitStructure.UART_TxFIFOLevel = UART_FIFOLevel_1_2; /* FIFO size 16 bytes, FIFO level 8 bytes */

                        UART_InitStructure.UART_RxFIFOLevel = UART_FIFOLevel_1_2; /* FIFO size 16 bytes, FIFO level 8 bytes */

                        UART_Init(UART0, &UART_InitStructure);

                        /* Enable the UART0 */

                        UART_Cmd(UART0, ENABLE);

                        /* Configure the IEC for the UART interrupts. */

                        EIC_IRQInitStructure.EIC_IRQChannelCmd = ENABLE;

                        EIC_IRQInitStructure.EIC_IRQChannel = UART0_IRQChannel;

                        EIC_IRQInitStructure.EIC_IRQChannelPriority = 1;

                        EIC_IRQInit(&EIC_IRQInitStructure);

                        xQueueEmpty = pdTRUE;

                        UART_ITConfig( UART0, UART_IT_Transmit | UART_IT_Receive, ENABLE );

                }

                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 char *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 char * const pcString, unsigned short usStringLength )

{

signed char *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 UART0. */

        ( void ) pxPort;

        /* Send each character in the string, one at a time. */

        pxNext = ( signed char * ) pcString;

        while( *pxNext )

        {

                xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );

                pxNext++;

        }

}

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

signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )

{

portBASE_TYPE xReturn;

        /* Place the character in the queue of characters to be transmitted. */

        portENTER_CRITICAL();

        {

                if( xQueueEmpty == pdTRUE )

                {

                        UART0->DR = cOutChar;

                        xReturn = pdPASS;

                }

                else

                {

                        if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )

                        {

                                xReturn = pdFAIL;

                        }

                        else

                        {

                                xReturn = pdPASS;

                        }

                }

                xQueueEmpty = pdFALSE;

        }

        portEXIT_CRITICAL();

        return xReturn;

}

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

void vSerialClose( xComPortHandle xPort )

{

        /* Not supported as not required by the demo application. */

}

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

__arm void vSerialISR( void )

{

signed char cChar;

portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

        do

        {

                if( UART0->MIS & UART_IT_Transmit )

                {

                        /* The interrupt was caused by the THR becoming empty.  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

                                THR now. */

                                UART0->DR = cChar;

                        }

                        else

                        {

                                xQueueEmpty = pdTRUE;

                        }

                        UART_ClearITPendingBit( UART0, UART_IT_Transmit );

                }

                if( UART0->MIS & UART_IT_Receive )

                {

                        /* The interrupt was caused by a character being received.  Grab the

                        character from the RHR and place it in the queue of received

                        characters. */

                        cChar = UART0->DR;

                        xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );

                        UART_ClearITPendingBit( UART0, UART_IT_Receive );

                }

        } while( UART0->MIS );

        /* 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 );

}