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/*

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

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

    *                                                                         *

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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.

    ***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

    License and the FreeRTOS license exception along with FreeRTOS; if not it

    can be viewed here: http://www.freertos.org/a00114.html and also obtained

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

    FreeRTOS WEB site.

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    http://www.FreeRTOS.org - Documentation, latest information, license and

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*/

/*

        USB Communications Device Class driver.

        Implements task vUSBCDCTask and provides an Abstract Control Model serial

        interface.  Control is through endpoint 0, device-to-host notification is

        provided by interrupt-in endpoint 3, and raw data is transferred through

        bulk endpoints 1 and 2.

        - developed from original FreeRTOS HID example by Scott Miller

        - modified to support 3.2 GCC by najay

*/

/* Standard includes. */

#include <string.h>

#include <stdio.h>

/* Demo board includes. */

#include "Board.h"

/* Scheduler includes. */

#include "FreeRTOS.h"

#include "task.h"

#include "queue.h"

/* Demo app includes. */

#include "USB-CDC.h"

#include "descriptors.h"

#define usbNO_BLOCK ( ( portTickType ) 0 )

/* Reset all endpoints */

static void prvResetEndPoints( void );

/* Clear pull up resistor to detach device from host */

static void vDetachUSBInterface( void );

/* Set up interface and initialize variables */

static void vInitUSBInterface( void );

/* Handle control endpoint events. */

static void prvProcessEndPoint0Interrupt( xISRStatus *pxMessage );

/* Handle standard device requests. */

static void prvHandleStandardDeviceRequest( xUSB_REQUEST *pxRequest );

/* Handle standard interface requests. */

static void prvHandleStandardInterfaceRequest( xUSB_REQUEST *pxRequest );

/* Handle endpoint requests. */

static void prvHandleStandardEndPointRequest( xUSB_REQUEST *pxRequest );

/* Handle class interface requests. */

static void prvHandleClassInterfaceRequest( xUSB_REQUEST *pxRequest );

/* Prepare control data transfer.  prvSendNextSegment starts transfer. */

static void prvSendControlData( unsigned char *pucData, unsigned short usRequestedLength, unsigned long ulLengthLeftToSend, long lSendingDescriptor );

/* Send next segment of data for the control transfer */

static void prvSendNextSegment( void );

/* Send stall - used to respond to unsupported requests */

static void prvSendStall( void );

/* Send a zero-length (null) packet */

static void prvSendZLP( void );

/* Handle requests for standard interface descriptors */

static void prvGetStandardInterfaceDescriptor( xUSB_REQUEST *pxRequest );

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

/* File scope static variables */

static unsigned char ucUSBConfig = ( unsigned char ) 0;

static unsigned long ulReceivedAddress = ( unsigned long ) 0;

static eDRIVER_STATE eDriverState = eNOTHING;

/* Incoming and outgoing control data structures */

static xCONTROL_MESSAGE pxControlTx;

static xCONTROL_MESSAGE pxControlRx;

/* Queue holding pointers to pending messages */

xQueueHandle xUSBInterruptQueue;

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

transmitted.  Rx queue must be larger than FIFO size. */

static xQueueHandle xRxCDC;

static xQueueHandle xTxCDC;

/* Line coding - 115,200 baud, N-8-1 */

static const unsigned char pxLineCoding[] = { 0x00, 0xC2, 0x01, 0x00, 0x00, 0x00, 0x08 };

/* Status variables. */

static unsigned char ucControlState;

static unsigned int uiCurrentBank;

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

void vUSBCDCTask( void *pvParameters )

{

xISRStatus *pxMessage;

unsigned long ulStatus;

unsigned long ulRxBytes;

unsigned char ucByte;

portBASE_TYPE xByte;

        ( void ) pvParameters;

        /* Disconnect USB device from hub.  For debugging - causes host to register reset */

        portENTER_CRITICAL();

                 vDetachUSBInterface();

        portEXIT_CRITICAL();

        vTaskDelay( portTICK_RATE_MS * 60 );

        /* Init USB interface */

        portENTER_CRITICAL();

                vInitUSBInterface();

        portEXIT_CRITICAL();

        /* Main task loop.  Process incoming endpoint 0 interrupts, handle data transfers. */

        for( ;; )

        {

                /* Look for data coming from the ISR. */

                if( xQueueReceive( xUSBInterruptQueue, &pxMessage, usbSHORTEST_DELAY ) )

                {

                        if( pxMessage->ulISR & AT91C_UDP_EPINT0 )

                        {

                                /* All endpoint 0 interrupts are handled here. */

                                prvProcessEndPoint0Interrupt( pxMessage );

                        }

                        if( pxMessage->ulISR & AT91C_UDP_ENDBUSRES )

                        {

                                /* End of bus reset - reset the endpoints and de-configure. */

                                prvResetEndPoints();

                        }

                }

                /* See if we're ready to send and receive data. */

                if( eDriverState == eREADY_TO_SEND && ucControlState )

                {

                        if( ( !(AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_2 ] & AT91C_UDP_TXPKTRDY) ) && uxQueueMessagesWaiting( xTxCDC ) )

                        {

                                for( xByte = 0; xByte < 64; xByte++ )

                                {

                                        if( !xQueueReceive( xTxCDC, &ucByte, 0 ) )

                                        {

                                                /* No data buffered to transmit. */

                                                break;

                                        }

                                        /* Got a byte to transmit. */

                                        AT91C_BASE_UDP->UDP_FDR[ usbEND_POINT_2 ] = ucByte;

                                }

                                AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_2 ] |= AT91C_UDP_TXPKTRDY;

                        }

                        /* Check for incoming data (host-to-device) on endpoint 1. */

                        while( AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ] & (AT91C_UDP_RX_DATA_BK0 | AT91C_UDP_RX_DATA_BK1) )

                        {

                                ulRxBytes = (AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ] >> 16) & usbRX_COUNT_MASK;

                                /* Only process FIFO if there's room to store it in the queue */

                                if( ulRxBytes < ( USB_CDC_QUEUE_SIZE - uxQueueMessagesWaiting( xRxCDC ) ) )

                                {

                                        while( ulRxBytes-- )

                                        {

                                                ucByte = AT91C_BASE_UDP->UDP_FDR[ usbEND_POINT_1 ];

                                                xQueueSend( xRxCDC, &ucByte, 0 );

                                        }

                                        /* Release the FIFO */

                                        portENTER_CRITICAL();

                                        {

                                                ulStatus = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ];

                                                usbCSR_CLEAR_BIT( &ulStatus, uiCurrentBank );

                                                AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ] = ulStatus;

                                        }

                                        portEXIT_CRITICAL();

                                        /* Re-enable endpoint 1's interrupts */

                                        AT91C_BASE_UDP->UDP_IER = AT91C_UDP_EPINT1;

                                        /* Update the current bank in use */

                                        if( uiCurrentBank == AT91C_UDP_RX_DATA_BK0 )

                                        {

                                                uiCurrentBank = AT91C_UDP_RX_DATA_BK1;

                                        }

                                        else

                                        {

                                                uiCurrentBank = AT91C_UDP_RX_DATA_BK0;

                                        }

                                }

                                else

                                {

                                        break;

                                }

                        }

                }

        }

}

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

void vUSBSendByte( char cByte )

{

        /* Queue the byte to be sent.  The USB task will send it. */

        xQueueSend( xTxCDC, &cByte, usbNO_BLOCK );

}

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

static void prvSendZLP( void )

{

unsigned long ulStatus;

        /* Wait until the FIFO is free - even though we are not going to use it.

        THERE IS NO TIMEOUT HERE! */

        while( AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] & AT91C_UDP_TXPKTRDY )

        {

                vTaskDelay( usbSHORTEST_DELAY );

        }

        portENTER_CRITICAL();

        {

                /* Cancel any further pending data */

                pxControlTx.ulTotalDataLength = pxControlTx.ulNextCharIndex;

                /* Set the TXPKTRDY bit to cause a transmission with no data. */

                ulStatus = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ];

                usbCSR_SET_BIT( &ulStatus, AT91C_UDP_TXPKTRDY );

                AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] = ulStatus;

        }

        portEXIT_CRITICAL();

}

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

static void prvSendStall( void )

{

        unsigned long ulStatus;

        portENTER_CRITICAL();

        {

                /* Force a stall by simply setting the FORCESTALL bit in the CSR. */

                ulStatus = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ];

                usbCSR_SET_BIT( &ulStatus, AT91C_UDP_FORCESTALL );

                AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] = ulStatus;

        }

        portEXIT_CRITICAL();

}

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

static void prvResetEndPoints( void )

{

unsigned long ulTemp;

        eDriverState = eJUST_RESET;

        ucControlState = 0;

        /* Reset all the end points. */

        AT91C_BASE_UDP->UDP_RSTEP  = usbEND_POINT_RESET_MASK;

        AT91C_BASE_UDP->UDP_RSTEP  = ( unsigned long ) 0x00;

        /* Enable data to be sent and received. */

        AT91C_BASE_UDP->UDP_FADDR = AT91C_UDP_FEN;

        /* Repair the configuration end point. */

        portENTER_CRITICAL();

        {

                ulTemp = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ];

                usbCSR_SET_BIT( &ulTemp, ( ( unsigned long ) ( AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_CTRL ) ) );

                AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] = ulTemp;

                AT91C_BASE_UDP->UDP_IER = AT91C_UDP_EPINT0;

        }

        portEXIT_CRITICAL();

        uiCurrentBank = AT91C_UDP_RX_DATA_BK0;

}

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

static void prvProcessEndPoint0Interrupt( xISRStatus *pxMessage )

{

static xUSB_REQUEST xRequest;

unsigned long ulRxBytes;

        /* Get number of bytes received, if any */

        ulRxBytes = pxMessage->ulCSR0 >> 16;

        ulRxBytes &= usbRX_COUNT_MASK;

        if( pxMessage->ulCSR0 & AT91C_UDP_TXCOMP )

        {

                /* We received a TX complete interrupt.  What we do depends on

                what we sent to get this interrupt. */

                if( eDriverState == eJUST_GOT_CONFIG )

                {

                        /* We sent an acknowledgement of a SET_CONFIG request.  We

                        are now at the end of the enumeration.

                        TODO: Config 0 sets unconfigured state, should enter Address state.

                        Request for unsupported config should stall. */

                        AT91C_BASE_UDP->UDP_GLBSTATE = AT91C_UDP_CONFG;

                        /* Set up endpoints */

                        portENTER_CRITICAL();

                        {

                                unsigned long ulTemp;

                                /* Set endpoint 1 to bulk-out */

                                ulTemp = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ];

                                usbCSR_SET_BIT( &ulTemp, AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT );

                                AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ] = ulTemp;

                                AT91C_BASE_UDP->UDP_IER = AT91C_UDP_EPINT1;

                                /* Set endpoint 2 to bulk-in */

                                ulTemp = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_2 ];

                                usbCSR_SET_BIT( &ulTemp, AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN );

                                AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_2 ] = ulTemp;

                                AT91C_BASE_UDP->UDP_IER = AT91C_UDP_EPINT2;

                                        /* Set endpoint 3 to interrupt-in, enable it, and enable interrupts */

                                ulTemp = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_3 ];

                                usbCSR_SET_BIT( &ulTemp, AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_INT_IN );

                                AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_3 ] = ulTemp;

                                /*AT91F_UDP_EnableIt( AT91C_BASE_UDP, AT91C_UDP_EPINT3 );                                */

                        }

                        portEXIT_CRITICAL();

                        eDriverState = eREADY_TO_SEND;

                }

                else if( eDriverState == eJUST_GOT_ADDRESS )

                {

                        /* We sent an acknowledgement of a SET_ADDRESS request.  Move

                        to the addressed state. */

                        if( ulReceivedAddress != ( unsigned long ) 0 )

                        {

                                AT91C_BASE_UDP->UDP_GLBSTATE = AT91C_UDP_FADDEN;

                        }

                        else

                        {

                                AT91C_BASE_UDP->UDP_GLBSTATE = 0;

                        }

                        AT91C_BASE_UDP->UDP_FADDR = ( AT91C_UDP_FEN | ulReceivedAddress );

                        eDriverState = eNOTHING;

                }

                else

                {

                        /* The TXCOMP was not for any special type of transmission.  See

                        if there is any more data to send. */

                        prvSendNextSegment();

                }

        }

        if( pxMessage->ulCSR0 & AT91C_UDP_RX_DATA_BK0 )

        {

                /* Received a control data packet.  May be a 0-length ACK or a data stage. */

                unsigned char ucBytesToGet;

                /* Got data.  Cancel any outgoing data. */

                pxControlTx.ulNextCharIndex = pxControlTx.ulTotalDataLength;

                 /* Determine how many bytes we need to receive. */

                ucBytesToGet = pxControlRx.ulTotalDataLength - pxControlRx.ulNextCharIndex;

                if( ucBytesToGet > ulRxBytes )

                {

                        ucBytesToGet = ulRxBytes;

                }

                /* If we're not expecting any data, it's an ack - just quit now. */

                if( !ucBytesToGet )

                {

                         return;

                }

                /* Get the required data and update the index. */

                memcpy( pxControlRx.ucBuffer, pxMessage->ucFifoData, ucBytesToGet );

                pxControlRx.ulNextCharIndex += ucBytesToGet;

        }

        if( pxMessage->ulCSR0 & AT91C_UDP_RXSETUP )

        {

                /* Received a SETUP packet.  May be followed by data packets. */

                if( ulRxBytes >= usbEXPECTED_NUMBER_OF_BYTES )

                {

                        /* Create an xUSB_REQUEST variable from the raw bytes array. */

                        xRequest.ucReqType = pxMessage->ucFifoData[ usbREQUEST_TYPE_INDEX ];

                        xRequest.ucRequest = pxMessage->ucFifoData[ usbREQUEST_INDEX ];

                        xRequest.usValue = pxMessage->ucFifoData[ usbVALUE_HIGH_BYTE ];

                        xRequest.usValue <<= 8;

                        xRequest.usValue |= pxMessage->ucFifoData[ usbVALUE_LOW_BYTE ];

                        xRequest.usIndex = pxMessage->ucFifoData[ usbINDEX_HIGH_BYTE ];

                        xRequest.usIndex <<= 8;

                        xRequest.usIndex |= pxMessage->ucFifoData[ usbINDEX_LOW_BYTE ];

                        xRequest.usLength = pxMessage->ucFifoData[ usbLENGTH_HIGH_BYTE ];

                        xRequest.usLength <<= 8;

                        xRequest.usLength |= pxMessage->ucFifoData[ usbLENGTH_LOW_BYTE ];

                        pxControlRx.ulNextCharIndex = 0;

                        if( ! (xRequest.ucReqType & 0x80) ) /* Host-to-Device transfer, may need to get data first */

                        {

                                if( xRequest.usLength > usbMAX_CONTROL_MESSAGE_SIZE )

                                {

                                        /* Too big!  No space for control data, stall and abort. */

                                        prvSendStall();

                                        return;

                                }

                                pxControlRx.ulTotalDataLength = xRequest.usLength;

                        }

                        else

                        {

                                /* We're sending the data, don't wait for any. */

                                pxControlRx.ulTotalDataLength = 0;

                        }

                }

        }

        /* See if we've got a pending request and all its associated data ready */

        if( ( pxMessage->ulCSR0 & ( AT91C_UDP_RX_DATA_BK0 | AT91C_UDP_RXSETUP ) )

                && ( pxControlRx.ulNextCharIndex >= pxControlRx.ulTotalDataLength ) )

        {

                unsigned char ucRequest;

                /* Manipulate the ucRequestType and the ucRequest parameters to

                generate a zero based request selection.  This is just done to

                break up the requests into subsections for clarity.  The

                alternative would be to have more huge switch statement that would

                be difficult to optimise. */

                ucRequest = ( ( xRequest.ucReqType & 0x60 ) >> 3 );

                ucRequest |= ( xRequest.ucReqType & 0x03 );

                switch( ucRequest )

                {

                        case usbSTANDARD_DEVICE_REQUEST:

                                /* Standard Device request */

                                prvHandleStandardDeviceRequest( &xRequest );

                                break;

                        case usbSTANDARD_INTERFACE_REQUEST:

                                /* Standard Interface request */

                                prvHandleStandardInterfaceRequest( &xRequest );

                                break;

                        case usbSTANDARD_END_POINT_REQUEST:

                                /* Standard Endpoint request */

                                prvHandleStandardEndPointRequest( &xRequest );

                                break;

                        case usbCLASS_INTERFACE_REQUEST:

                                /* Class Interface request */

                                prvHandleClassInterfaceRequest( &xRequest );

                                break;

                        default:        /* This is not something we want to respond to. */

                                prvSendStall();

                }

        }

}

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

static void prvGetStandardDeviceDescriptor( xUSB_REQUEST *pxRequest )

{

        /* The type is in the high byte.  Return whatever has been requested. */

        switch( ( pxRequest->usValue & 0xff00 ) >> 8 )

        {

                case usbDESCRIPTOR_TYPE_DEVICE:

                        prvSendControlData( ( unsigned char * ) &pxDeviceDescriptor, pxRequest->usLength, sizeof( pxDeviceDescriptor ), pdTRUE );

                        break;

                case usbDESCRIPTOR_TYPE_CONFIGURATION:

                        prvSendControlData( ( unsigned char * ) &( pxConfigDescriptor ), pxRequest->usLength, sizeof( pxConfigDescriptor ), pdTRUE );

                        break;

                case usbDESCRIPTOR_TYPE_STRING:

                        /* The index to the string descriptor is the lower byte. */

                        switch( pxRequest->usValue & 0xff )

                        {

                                case usbLANGUAGE_STRING:

                                        prvSendControlData( ( unsigned char * ) &pxLanguageStringDescriptor, pxRequest->usLength, sizeof(pxLanguageStringDescriptor), pdTRUE );

                                        break;

                                case usbMANUFACTURER_STRING:

                                        prvSendControlData( ( unsigned char * ) &pxManufacturerStringDescriptor, pxRequest->usLength, sizeof( pxManufacturerStringDescriptor ), pdTRUE );

                                        break;

                                case usbPRODUCT_STRING:

                                        prvSendControlData( ( unsigned char * ) &pxProductStringDescriptor, pxRequest->usLength, sizeof( pxProductStringDescriptor ), pdTRUE );

                                        break;

                                case usbCONFIGURATION_STRING:

                                        prvSendControlData( ( unsigned char * ) &pxConfigurationStringDescriptor, pxRequest->usLength, sizeof( pxConfigurationStringDescriptor ), pdTRUE );

                                        break;

                                case usbINTERFACE_STRING:

                                        prvSendControlData( ( unsigned char * ) &pxInterfaceStringDescriptor, pxRequest->usLength, sizeof( pxInterfaceStringDescriptor ), pdTRUE );

                                        break;

                                default:

                                        prvSendStall();

                                        break;

                        }

                        break;

                default:

                        prvSendStall();

                        break;

        }

}

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

static void prvHandleStandardDeviceRequest( xUSB_REQUEST *pxRequest )

{

unsigned short usStatus = 0;

        switch( pxRequest->ucRequest )

        {

                case usbGET_STATUS_REQUEST:

                        /* Just send two byte dummy status. */

                        prvSendControlData( ( unsigned char * ) &usStatus, sizeof( usStatus ), sizeof( usStatus ), pdFALSE );

                        break;

                case usbGET_DESCRIPTOR_REQUEST:

                        /* Send device descriptor */

                        prvGetStandardDeviceDescriptor( pxRequest );

                        break;

                case usbGET_CONFIGURATION_REQUEST:

                        /* Send selected device configuration */

                        prvSendControlData( ( unsigned char * ) &ucUSBConfig, sizeof( ucUSBConfig ), sizeof( ucUSBConfig ), pdFALSE );

                        break;

                case usbSET_FEATURE_REQUEST:

                        prvSendZLP();

                        break;

                case usbSET_ADDRESS_REQUEST:

                        /* Get assigned address and send ack, but don't implement new address until we get a TXCOMP */

                        prvSendZLP();

                        eDriverState = eJUST_GOT_ADDRESS;

                        ulReceivedAddress = ( unsigned long ) pxRequest->usValue;

                        break;

                case usbSET_CONFIGURATION_REQUEST:

                        /* Ack SET_CONFIGURATION request, but don't implement until TXCOMP */

                        ucUSBConfig = ( unsigned char ) ( pxRequest->usValue & 0xff );

                        eDriverState = eJUST_GOT_CONFIG;

                        prvSendZLP();

                        break;

                default:

                        /* Any unsupported request results in a STALL response. */

                        prvSendStall();

                        break;

        }

}

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

static void prvHandleClassInterfaceRequest( xUSB_REQUEST *pxRequest )

{

        switch( pxRequest->ucRequest )

        {

                case usbSEND_ENCAPSULATED_COMMAND:

                        prvSendStall();

                        break;

                case usbGET_ENCAPSULATED_RESPONSE:

                        prvSendStall();

                        break;

                case usbSET_LINE_CODING:

                        /* Set line coding - baud rate, data bits, parity, stop bits */

                        prvSendZLP();

                        memcpy( ( void * ) pxLineCoding, pxControlRx.ucBuffer, sizeof( pxLineCoding ) );

                        break;

                case usbGET_LINE_CODING:

                        /* Get line coding */

                        prvSendControlData( (unsigned char *) &pxLineCoding, pxRequest->usLength, sizeof( pxLineCoding ), pdFALSE );

                        break;

                case usbSET_CONTROL_LINE_STATE:

                        /* D0: 1=DTR, 0=No DTR,  D1: 1=Activate Carrier, 0=Deactivate carrier (RTS, half-duplex) */

                        prvSendZLP();

                        ucControlState = pxRequest->usValue;

                        break;

                default:

                        prvSendStall();

                        break;

        }

}

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

static void prvGetStandardInterfaceDescriptor( xUSB_REQUEST *pxRequest )

{

        switch( ( pxRequest->usValue & ( unsigned short ) 0xff00 ) >> 8 )

        {

                default:

                        prvSendStall();

                        break;

        }

}

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

static void prvHandleStandardInterfaceRequest( xUSB_REQUEST *pxRequest )

{

unsigned short usStatus = 0;

        switch( pxRequest->ucRequest )

        {

                case usbGET_STATUS_REQUEST:

                        /* Send dummy 2 bytes. */

                        prvSendControlData( ( unsigned char * ) &usStatus, sizeof( usStatus ), sizeof( usStatus ), pdFALSE );

                        break;

                case usbGET_DESCRIPTOR_REQUEST:

                        prvGetStandardInterfaceDescriptor( pxRequest );

                        break;

                /* This minimal implementation does not respond to these. */

                case usbGET_INTERFACE_REQUEST:

                case usbSET_FEATURE_REQUEST:

                case usbSET_INTERFACE_REQUEST:

                default:

                        prvSendStall();

                        break;

        }

}

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

static void prvHandleStandardEndPointRequest( xUSB_REQUEST *pxRequest )

{

        switch( pxRequest->ucRequest )

        {

                /* This minimal implementation does not expect to respond to these. */

                case usbGET_STATUS_REQUEST:

                case usbCLEAR_FEATURE_REQUEST:

                case usbSET_FEATURE_REQUEST:

                default:

                        prvSendStall();

                        break;

        }

}

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

static void vDetachUSBInterface( void)

{

        /* Setup the PIO for the USB pull up resistor. */

        AT91C_BASE_PIOA->PIO_PER = AT91C_PIO_PA16;

        AT91C_BASE_PIOA->PIO_OER = AT91C_PIO_PA16;

        /* Disable pull up */

        AT91C_BASE_PIOA->PIO_SODR = AT91C_PIO_PA16;