SIM card related Projects » SIMtrace

/*

	FreeRTOS.org V4.2.1 - Copyright (C) 2003-2007 Richard Barry.

	This file is part of the FreeRTOS.org distribution.

	FreeRTOS.org is free software; you can redistribute it and/or modify

	it under the terms of the GNU General Public License as published by

	the Free Software Foundation; either version 2 of the License, or

	(at your option) any later version.

	FreeRTOS.org 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.org; if not, write to the Free Software

	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

	A special exception to the GPL can be applied should you wish to distribute

	a combined work that includes FreeRTOS.org, without being obliged to provide

	the source code for any proprietary components.  See the licensing section

	of http://www.FreeRTOS.org for full details of how and when the exception

	can be applied.

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

	See http://www.FreeRTOS.org for documentation, latest information, license

	and contact details.  Please ensure to read the configuration and relevant

	port sections of the online documentation.

	Also see http://www.SafeRTOS.com for an IEC 61508 compliant version along

	with commercial development and support options.

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

*/

/*

	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 portCHAR * pucData,

				unsigned portSHORT usRequestedLength,

				unsigned portLONG ulLengthLeftToSend,

				portLONG 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 portCHAR ucUSBConfig = (unsigned portCHAR) 0;

static unsigned portLONG ulReceivedAddress = (unsigned portLONG) 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;

static const unsigned portCHAR pxLineCoding[] =

  { 0x00, 0xC2, 0x01, 0x00, 0x00, 0x00, 0x08 };

/* Status variables. */

static unsigned portCHAR ucControlState;

static unsigned int uiCurrentBank;

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

void

vUSBCDCTask (void *pvParameters)

{

  xISRStatus *pxMessage;

  unsigned portLONG ulStatus;

  unsigned portLONG ulRxBytes;

  unsigned portCHAR ucByte;

  portBASE_TYPE i;

  (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))

	    {

		      /* No data buffered to transmit. */

		      break;

		    }

		  for(i=0; i<chunk[0]; i++) {

			  AT91C_BASE_UDP->UDP_FDR[usbEND_POINT_2] = chunk[1+i];

			  xByte++;

		  }

	      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 (portCHAR cByte)

	vUSBSendByte_blocking(cByte, usbNO_BLOCK);

}

void

vUSBSendByte_blocking (portCHAR cByte, portTickType xTicksToWait)

	chunk[0] = 1;

	chunk[1] = cByte;

#define MIN(a,b) ((a)>(b)?(b):(a))

void

	unsigned char chunk[CHUNK_SIZE];

	while(length > 0) {

		int next_size = MIN(length, CHUNK_SIZE-1);

		chunk[0] = next_size;

		memcpy(chunk+1, buffer+offset, next_size);

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

		offset += next_size;

	}

vUSBSendBuffer (unsigned char *buffer, portBASE_TYPE offset, portBASE_TYPE length)

{

	vUSBSendBuffer_blocking(buffer, offset, length, usbNO_BLOCK);

}

portLONG

vUSBRecvByte (portCHAR *cByte, portLONG size, portTickType xTicksToWait)

{

    portLONG res;

    if(size<=0 || !cByte || !xRxCDC)

        return 0;

    res=0;

    while(size-- && xQueueReceive(xRxCDC, cByte++, xTicksToWait))

        res++;

    return res;

}

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

static void

prvSendZLP (void)

{

  unsigned portLONG 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 portLONG 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 portLONG 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 portLONG) 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 portLONG) (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 portLONG 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 portLONG 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 portLONG) 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 portCHAR 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 portCHAR 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 portCHAR *) &pxDeviceDescriptor,

			  pxRequest->usLength, sizeof (pxDeviceDescriptor),

			  pdTRUE);

      break;

    case usbDESCRIPTOR_TYPE_CONFIGURATION:

      prvSendControlData ((unsigned portCHAR *) &(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 portCHAR *)

			      &pxLanguageStringDescriptor,

			      pxRequest->usLength,

			      sizeof (pxLanguageStringDescriptor), pdTRUE);

	  break;

	case usbMANUFACTURER_STRING:

	  prvSendControlData ((unsigned portCHAR *)

			      &pxManufacturerStringDescriptor,

			      pxRequest->usLength,

			      sizeof (pxManufacturerStringDescriptor),

			      pdTRUE);

	  break;

	case usbPRODUCT_STRING:

	  prvSendControlData ((unsigned portCHAR *)

			      &pxProductStringDescriptor, pxRequest->usLength,

			      sizeof (pxProductStringDescriptor), pdTRUE);

	  break;

	default:

	  prvSendStall ();

	  break;

	}

      break;

    default:

      prvSendStall ();

      break;

    }

}

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

static void

prvHandleStandardDeviceRequest (xUSB_REQUEST * pxRequest)

{

  unsigned portSHORT usStatus = 0;

  switch (pxRequest->ucRequest)

    {

    case usbGET_STATUS_REQUEST:

      /* Just send two byte dummy status. */

      prvSendControlData ((unsigned portCHAR *) &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 portCHAR *) &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 portLONG) pxRequest->usValue;

      break;

    case usbSET_CONFIGURATION_REQUEST:

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

      ucUSBConfig = (unsigned portCHAR) (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 portCHAR *) &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 portSHORT) 0xff00) >> 8)

    {

    default:

      prvSendStall ();

      break;

    }

}

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

static void

prvHandleStandardInterfaceRequest (xUSB_REQUEST * pxRequest)

{

  unsigned portSHORT usStatus = 0;

  switch (pxRequest->ucRequest)

    {

    case usbGET_STATUS_REQUEST:

      /* Send dummy 2 bytes. */

      prvSendControlData ((unsigned portCHAR *) &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;