UsbCtrlTransfer

Description

Executes synchronous Control Transfer with a specific endpoint.

Syntax

ulrc = UsbCtrlTransfer(Handle,ucEndpoint,ucAltSetting,ucRequestType,ucRequest,usValue,usIndex,pusLength,pucData,ulTimeout)

Parameters

Handle

the Device Handle received from the previous UsbOpen.

ucEndpoint

the Endpoint Number appropriate for the control transfer.

ucAltSetting

the Alternate Setting of the interface having this endpoint.

ucRequestType

the characteristics of the Standard Device Request.

ucRequest

the specific request code of the Standard Device Request.

usValue

the request dependent value of the Standard Device Request.

usIndex

the request dependent index of the Standard Device Request.

ulTimeout

the timeout to wait for completion in milliseconds.

For device-to-host data transfer:

pusLength

the address of the variable to specify/receive the number of bytes.

pucData

the address of the buffer to receive the data bytes transferred.

For host-to-device data transfer:

pusLength

the address of the variable to specify/receive the number of bytes.

pucData

the address of the buffer with the data bytes to be transferred.

Return Code

0x0000 - NO_ERROR

Errors

0x0006 - ERROR_INVALID_HANDLE
0x0008 - ERROR_NOT_ENOUGH_MEMORY
0x0057 - ERROR_INVALID_PARAMETER
0x005F - ERROR_INTERRUPT
0x0122 - ERROR_TOO_MANY_HANDLES
0x0280 - ERROR_TIMEOUT
0x1B58 - USB_NOT_INIT
0x4000 - USB_IORB_REQUEST
0x80XX - USB_IORB_FAILED

Example Code

//Code Snippet - UsbCtrlTransfer
{
  APIRET ulrc;
  PUCHAR pucReport;
  PUSHORT pusLength;
  UCHAR ucAltSetting = 0;
  UCHAR ucEndPoint = 0;
  UCHAR ucReport[4096];
  UCHAR ucRequestType;
  UCHAR ucRequest;
  ULONG ulTimeout = 8000;
  USHORT usIndex;
  USHORT usLength;
  USHORT usValue;

  //device-to-host
  pucReport = &ucReport[0]; pusLength = &usLength;
  ucRequestType = 0xA1; ucRequest = 0x01; //get interface class report
  usIndex = 0x0000; usValue = 0x0300; usLength = 8; //hid feature report
  ulrc = UsbCtrlTransfer(Handle,ucEndPoint,ucAltSetting,ucRequestType,ucRequest,usValue,usIndex,pusLength,pucReport,ulTimeout);
  printf("\nUsbCtrlTransfer - ulrc: 0x%04X (%hu)",ulrc,ulrc);
  if (!ulrc) //success
  {
    int i; printf(" - hid feature report:\n");
    for (i=0;i<usLength;i++) printf("%02X",ucReport[i]);
  }

  //host-to-device
  pucReport = &ucReport[0]; pusLength = &usLength;
  ucRequestType = 0x21; ucRequest = 0x09; //set interface class report
  usIndex = 0x0000; usValue = 0x0300; usLength = 8; //hid feature report
  ulrc = UsbCtrlTransfer(Handle,ucEndPoint,ucAltSetting,ucRequestType,ucRequest,usValue,usIndex,pusLength,pucReport,ulTimeout);
  printf("\nUsbCtrlTransfer - ulrc: 0x%04X (%hu)",ulrc,ulrc);
  if (!ulrc) //success
  {
    int i; printf(" - hid feature report:\n");
    for (i=0;i<usLength;i++) printf("%02X",ucReport[i]);
  }
}